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Severe intestinal mucositis (IM) increases the risk of bloodstream infections (BSI) and inflammatory toxicity during acute lymphoblastic leukaemia (ALL) induction treatment. However, the implications of IM in subsequent ALL therapy phases after achieving remission remain unknown. This study investigated the relationship between IM (measured by plasma citrulline and the chemokine CCL20) and the development of BSI and systemic inflammation (reflected by C‐reactive protein, CRP) in children with ALL during high‐dose methotrexate (HDMTX) treatment, an important part of ALL consolidation therapy. The study compared patients treated according to the NOPHO ALL 2008 protocol (n = 52) and the ALLTogether1 protocol (n = 42), both with identical HDMTX procedures but different scheduling. One week post‐HDMTX, citrulline dropped to median levels of 14.5 and 16.9 μM for patients treated according to the NOPHO ALL 2008 and ALLTogether1 protocols, respectively (p = 0.11). In a protocol and neutrophil count‐adjusted analysis, hypocitrullinaemia (<10 μmol/L) was associated with increased odds of BSI within 3 weeks from HDMTX (OR = 26.2, p = 0.0074). Patients treated according to the NOPHO ALL 2008 protocol exhibited increased mucosal‐ and systemic inflammation post‐HDMTX compared to patients treated according to ALLTogether1, with increased CCL20 (14.6 vs. 3.7 pg/mL, p < 0.0001) and CRP levels (10.0 vs. 1.0 mg/L, p < 0.0001). Both citrulline and CCL20 correlated with CRP for these patients (rs = −0.44, p = 0.0016 and rs = 0.35, p = 0.016, respectively). These results suggest that hypocitrullinaemia following HDMTX increases the risk of BSI, confirming previous observations from more intensive treatments. Moreover, these data indicate that the patients' vulnerability to mucositis and inflammatory toxicity after chemotherapy varies with treatment protocol. [ABSTRACT FROM AUTHOR]

Summary: This Good Practice Paper provides recommendations for the baseline investigation, risk stratification and use of prophylactic interventions for patients with large B‐cell lymphoma at risk of central nervous system relapse. Recent evidence which has questioned the role of high‐dose methotrexate in this clinical scenario is discussed in detail. [ABSTRACT FROM AUTHOR]

Background: High-dose methotrexate (HDMTX) chemotherapy is associated with a significant risk of acute kidney injury (AKI). Acetazolamide is thought to increase methotrexate solubility via urinary alkalinisation, potentially reducing the risk of crystalline nephropathy. A tertiary hospital has included acetazolamide in its HDMTX protocols, although data on the risks and benefits are limited. This study evaluated the role of acetazolamide in managing patients receiving HDMTX and identified risk factors for AKI. Methods: The retrospective cohort pilot study included consecutive hospital patients who received HDMTX (≥500 mg/m2). Data collected from digital medical records included demographics, comorbidities, methotrexate dosages and serum concentrations, and pathology results. The development of AKI was defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Relationships between variables and AKI were initially assessed using Mann–Whitney U-tests and chi-square tests, and significant variables were further analysed using logistic regression to identify independent predictors of AKI. Results: Among 66 HDMTX treatment cycles in 31 patients, AKI occurred in 0/7 cycles with acetazolamide versus 14/59 cycles without (p = 0.33). Increasing age, the presence of hypertension, and concurrent use of beta-lactam antibiotics were associated with the development of AKI. Age was identified as the strongest independent risk factor for AKI (odds ratio 1.12, p = 0.034). Conclusions: Optimising management protocols, especially for older patients, is essential to reduce AKI risk during HDMTX therapy. While acetazolamide did not appear to reduce the risk of AKI, this pilot study was limited by a small sample size. Large randomised controlled trials are needed to assess efficacy and patient outcomes. [ABSTRACT FROM AUTHOR]

Bruton's tyrosine kinase inhibitors (BTKi) exhibit superior efficacy in relapsed/refractory primary central nervous system lymphoma (PCNSL), but few studies have evaluated patients with newly diagnosed PCNSL, and even fewer studies have evaluated differences in efficacy between treatment with BTKi and traditional chemotherapy. This study retrospectively analyzed the clinical characteristics of 86 patients with PCNSL and identified predictors of poor prognosis for overall survival (OS). After excluding patients who only received palliative care, 82 patients were evaluated for efficacy and survival. According to the induction regimen, patients were divided into the traditional chemotherapy, BTKi combination therapy, and radiotherapy groups; the objective response rates (ORR) of the three groups were 71.4%, 96.2%, and 71.4% (P = 0.037), respectively. Both median progression-free survival and median duration of remission showed statistically significant differences (P = 0.019 and P = 0.030, respectively). The median OS of the BTKi-containing therapy group was also longer than that of the traditional chemotherapy group (not reached versus 47.8 (32.5–63.1) months, P = 0.038).Seventy-one patients who achieved an ORR were further analyzed, and achieved an ORR after four cycles of treatment and maintenance therapy had prolonged OS (P = 0.003 and P = 0.043, respectively). In conclusion, survival, and prognosis of patients with newly diagnosed PCNSL are influenced by the treatment regimen, with the BTKi-containing regimen showing great potential. [ABSTRACT FROM AUTHOR]

Purpose: Osteosarcoma is a rare tumor with an incidence of 4.4 cases per million per year in adolescent. High-dose methotrexate (HD-MTX) is the standard first-line chemotherapeutic agent for osteosarcoma. However, its efficacy can vary significantly among individuals due to wide pharmacokinetic variability. Despite this, only a few population pharmacokinetics (popPK) models based on Chinese patients with osteosarcoma have been reported. Thus, this study aimed to develop a HD-MTX popPK model and an individual model-based dose optimizer for osteosarcoma therapy. Method: A total of 680 MTX serum concentrations from 57 patients with osteosarcoma were measured at the end of MTX infusion and 10 h, 24 h, 48 h, and 72 h after the start of infusion. Using the first-order conditional estimation method with NONMEM, a popPK model was estimated. Goodness-of-fit plots, visual predictive checks, and bootstrap analysis were generated to evaluate the final model. A dose optimizer tool was developed based on the validated models using R Shiny. Additionally, clinical data from 12 patients with newly diagnosed osteosarcoma were collected and used as the validation set to preliminarily verify the predictive ability of the popPK model and the dose optimizer tool. Results: Body surface area (BSA) was the most significant covariate for compartment distribution. Creatinine clearance (CrCL) and co-administration of NSAIDs were introduced as predictors for central compartmental and peripheral compartmental clearance, respectively. Co-administration of NSAIDs was associated with significantly higher MTX concentrations at 72 h (p = 0.019). The dose optimizer tool exhibited a high consistency in predicting MTX AUC compared to the actual AUC (r = 0.821, p < 0.001) in the validation set. Conclusion: The dose optimizer tool could be used to estimate individual PK parameters, and optimize personalized MTX therapy in particular patients. [ABSTRACT FROM AUTHOR]

Background: Oral mucositis affects about 20% of children undergoing high‐dose methotrexate (HDMTX) for acute lymphoblastic leukemia (ALL), despite existing management strategies. Personalized HDMTX dosing, adjusted by pharmacokinetics and leukemia risk, has reduced mucositis incidence, but variations still occur with similar 24‐h methotrexate levels. Methods: This retrospective study investigated risk factors for oral mucositis under individualized methotrexate protocols. Data from patients with ≥ Grade 2 oral mucositis (CTCAE v4.0) were analyzed from the St. Jude Children's Research Hospital total 16 trial. A 1:1 case–control matching method considered age, sex, risk classification, immunophenotype, and methotrexate course. McNemar's, Bowker's symmetry, and Wilcoxon signed‐rank tests were used for statistical analyses. Risk factors for recurrent mucositis were identified in a case‐only analysis. Results: The study found significant associations between methotrexate‐induced mucositis and new‐onset skin rashes (p = 0.0027), fever (p = 0.0016), neutropenic fever (p = 0.0008), lower absolute neutrophil count (p < 0.0001), acute kidney injury (AKI) (p = 0.0164), delayed methotrexate clearance (p = 0.0133), and higher 42‐h methotrexate levels (p = 0.0179). In the standard/high‐risk group, mercaptopurine dose was also linked to mucositis (p = 0.0495). Multivariable analysis showed that skin rashes (OR 6.5, p = 0.0016), fever (OR 2.8, p = 0.009), and neutropenia (OR 2.3, p = 0.0106) were independent risk factors for mucositis. Female sex (OR 7.12, p = 0.015) and AKI (OR 3.819, p = 0.037) were associated with recurrent mucositis. Conclusions: Fever, skin rashes, AKI, delayed methotrexate clearance, and higher 42‐h methotrexate levels were key risk factors for HDMTX‐induced oral mucositis. Skin rashes, fever, and neutropenia were independent predictors, while female sex and AKI were linked to recurrent mucositis. [ABSTRACT FROM AUTHOR]

Introduction: High‐dose methotrexate (HDMTX) use can be limited by the development of acute kidney injury (AKI). Early AKI detection is paramount to prevent further renal injury and irreversible toxicities. This study sought to determine whether early elimination patterns of MTX would be useful as a biomarker of AKI in HDMTX treatment. Methods: This retrospective cohort study included two sites that collected ≥2 MTX levels within 16 h from completion of MTX infusion. Early levels were tagged and MTX elimination half‐life (t½) were calculated from combinations of two of three different early time periods. Receiver operating characteristic (ROC) curves were synthesized for each elimination t½ (biomarker) with respect to AKI and delayed methotrexate elimination (DME); the biomarker with the highest area under the ROC curve (AUC) was tested in a multiple variable logistic regression model. Results: Data from 169 patients who received a total of 556 courses of HDMTX were analyzed. ROC analysis revealed MTX elimination t½ calculated from the second and third time periods had the highest AUC for AKI at 0.62 (interquartile range [IQR] 0.56–0.69) and DME at 0.86 (IQR 0.73–1.00). After adjusting for age, sex, dose (mg/m2), infusion duration, HDMTX course, and baseline estimated glomerular filtration rate, it remained significant for AKI with an OR of 1.29 and 95% confidence interval of 1.03–1.65. Conclusion: Early MTX elimination t½ measured within 16 h of infusion completion was significantly associated with the development of AKI and serves as an early clearance biomarker that may identify patients who benefit from increased hydration, augmented leucovorin rescue, and glucarpidase administration. [ABSTRACT FROM AUTHOR]

Variations in pharmacokinetic responses to high-dose methotrexate are essential for the prognosis and management of toxicity in the treatment of pediatric acute lymphoblastic leukemia (ALL) patients. This systematic review aimed to identify and evaluate genetic polymorphisms that are significantly associated with the pharmacokinetic parameters of methotrexate during the consolidation phase of pediatric ALL treatment. Using the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines, we systematically reviewed the literature from 2013 to 2023. The databases used were PubMed and Scopus. The outcomes of interest are the study design, patient characteristics, sample size, chemotherapy protocol utilized, pharmacokinetic parameters identified, and genetic polymorphisms implicated. We included 31 articles in the qualitative synthesis and found that the SLCO1B1, ABCB1, ABCC2, and MTHFR genes appear to play significant roles in MTX metabolism and clearance. Among these, variations in SLCO1B1 have the most significant and consistent impact on methotrexate clearance. These implicated variants may contribute to the precision and tailoring of HD-MTX treatment in pediatric ALL patients. [ABSTRACT FROM AUTHOR]

Primary central nervous system lymphoma (PCNSL) is a type of non-Hodgkin lymphoma that involves the brain, spinal cord, and eyes. It is a rare, aggressive tumor that can affect immunocompetent or immunocompromised patients. Immunodeficiency states are a risk factor for developing PCNSL. The gold standard method to confirm the diagnosis is a stereotactic brain biopsy. Given the rarity and acuity of the disease, management recommendations are based on a few prospective trials and retrospective studies. It is a chemosensitive malignancy; however, half of the respondents will relapse with a dismal prognosis. The adoption of high-dose methotrexate, rituximab, and consolidation strategies has significantly improved outcomes. The prognosis has improved over the past decade, but it remains dismal for the elderly. Targeted therapies and immunotherapies may have promising results. This review article summarizes the clinical presentation, evaluation, and management of patients with PCNSL and shed some light on the future advances in this disease. [ABSTRACT FROM AUTHOR]

AbstractCardiotoxicity is a well-established adverse effect of several drugs across multiple therapeutic indications. It is particularly prevalent following anticancer therapy. In order to evaluate the changes in cellular metabolism associated with methotrexate cardiotoxicity, we treated Wistar rats with a single high dose of methotrexate (HDMTX), and after five days, the animals were sacrificed. We then analyzed the cardiotoxicity parameters in serum like Cardiac enzymes(CK-MB, Troponin T, ALP), Inflammatory markers (TNF-α and IL-6), oxidative stress markers (NO, NOX-2), histopathology and cardiac tissue with the goal of identifying a metabolic signature of cardiotoxicity using discovery-based metabolomics. The biochemical parameters for cardiac enzymes, oxidative stress and inflammatory markers showed a significant increase in all three categories in rats treated with HDMTX. These findings were mirrored in the histopathological analysis confirming cardiotoxicity due to HDMTX. The results showed a total of 95 metabolites that were found to be significantly (p < 0.05) modulated: either up- or downregulated in the HDMTX-treated group when compared with the control group. Using integrated pathway analysis we found these metabolites were associated with many important cardiac tissue metabolic pathways, such as the malate aspartate shuttle, taurine and hypotaurine metabolism, betaine metabolism, spermidine biosynthesis, and homocysteine degradation. Among them, L-arginine, homocysteine, and betaine were significantly upregulated, suggesting their possible association with cardiac tissue injury. Overall, we provided evidence for using untargeted metabolomics to identify novel metabolites associated with HDMTX cardiac toxicity. [ABSTRACT FROM AUTHOR]

Background. A significant advancement in the treatment of high-grade aggressive non-Hodgkin’s lymphomas and acute lymphoblastic leukemia is the inclusion of high-dose (1000–5000 mg/m2) methotrexate in the treatment protocol. This approach has significantly increased the long-term survival rate, but it has been associated with toxicity, requiring supportive care. Factors that predict toxicity were identified, including genes involved in the metabolism (MTHFR) or transport (SLCO1B1) of methotrexate. The analysis of methotrexate metabolism has identified additional genes responsible for the elimination of this drug, allowing for more effective prevention and treatment of methotrexate-associated toxicity.Aim. To study the genetic polymorphisms of enzymes involved in the methotrexate metabolism and associated toxicity in the treatment of pediatric acute lymphoblastic leukemia and non-Hodgkin’s lymphomas.Materials and methods. Data were analyzed in specialized medical databases such as Pubmed, Scopus, Web of Science, Frontiers, and Google Scholar from 2001 to 2024.Results. The main predictors of high-dose methotrexate-associated toxicity are gene polymorphisms in MTHFR, SLCO1B1, ARID5B.Conclusion. Despite the contradictory data presented in the literature, it is important to consider the detection of polymorphisms during high-dose methotrexate treatment in order to administer timely supportive care and prevent significant toxicity.

Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin lymphoma (NHL) manifesting in the brain, spinal cord, cerebrospinal fluid and/or eyes, in the absence of systemic manifestations. With an increasing incidence and a 30% 5-year overall survival if promptly treated, timely diagnosis and subsequent treatment is paramount. The typical MRI appearance for PCNSL is a solitary or multiple T2-hypointense, homogeneous gadolinium-enhancing lesion with restricted diffusion. Dexamethasone treatment might compromise and delay the diagnosis. Hallmark of treatment is induction with intravenous high-dose methotrexate consisting polychemotherapy followed by consolidation treatment. Consolidation treatment consists of either whole brain radiotherapy (WBRT) or autologous stem cell transplantation (ASCT). Given the (cognitive) side effects of WBRT, ASCT is increasingly being used as the first choice of treatment. [ABSTRACT FROM AUTHOR]

High-dose methotrexate (HDMTX) is used to treat a broad spectrum of cancers. Methotrexate (MTX) monitoring and adequate supportive care are critical for safe drug administration; however, MTX level timing is not always possible in low- and middle-income countries. The aim of this study was to evaluate HDMTX supportive care capacity and MTX monitoring practices in Latin America (LATAM) to identify gaps and opportunities for improvement. A multicenter survey was conducted among LATAM pediatric oncologists. Twenty healthcare providers from 20 institutions answered the online questionnaire. HDMTX was used to treat acute lymphoblastic leukemia (ALL; 100%), non-Hodgkin lymphoma (84.2%), diffuse large B-cell lymphoma (47.4%), osteosarcoma (78.9%), and medulloblastoma (31.6%). Delays in starting HDMTX infusion were related to bed shortages (47.4%) and MTX shortages (21.1%). MTX monitoring was performed at an in-hospital laboratory in 52%, at an external/nearby laboratory in 31.6%, and was not available in 10.5%. Median interval between sampling and obtaining MTX levels was ≤ 2 h in 45% and ≥ 6 h in 30%, related to laboratory location. Sites without access to MTX monitoring reduced the MTX dose for patients with high-risk ALL or did not include MTX in the treatment of patients with osteosarcoma. Respondents reported that implementation of point-of-care testing of MTX levels is feasible. In LATAM, highly variable supportive care capacity may affect the safe administration of MTX doses. Improving accessibility of MTX monitoring and the speed of obtaining results should be prioritized to allow delivery of full doses of MTX required by the current protocols. [ABSTRACT FROM AUTHOR]

Abstract Background Primary breast diffuse large B‐cell lymphoma (PB‐DLBCL) is a rare subtype of extranodal DLBCL, and the standard treatment remains controversial. In this study, we aimed to define the optimal treatment management in the rituximab era. Methods A total of 5089 newly diagnosed DLBCL patients treated with rituximab‐containing immunochemotherapy between 2008 and 2019 from the Chinese Southwest Oncology Group‐affiliated institutes were identified, of whom 135 diagnosed with PB‐DLBCL were eligible for this analysis. Results PB‐DLBCL accounted for 2.7% of all DLBCLs. With a median follow‐up of 4.2 years, the 5‐year overall survival and progression‐free survival rates were 84.8% and 71.6%, respectively. Breast and central nervous system (CNS) relapses were the main cause of treatment failure. We observed that consolidative breast radiotherapy (RT) significantly decreased breast relapse risk (5‐year risk, 2.9% vs. 20.1%, p = 0.007). The CNS relapse risk was lower for patients who received high‐dose methotrexate (HD‐MTX) than for patients who did not (5‐year risk, 0% vs. 15.2%, p = 0.015). We further screened the genetic mutation profile of 20 patients from two institutes, and found that MYD88 (25%) and CD79B mutations (25%) frequently occur in PB‐DLBCL. In addition, four patients with MYD88 and/or CD79B mutations experienced CNS relapse, while three patients with MYD88 and/or CD79B mutations who received HD‐MTX did not experience CNS relapse. Conclusion Collectively, our results indicate combined modality therapy including rituximab‐containing immunochemotherapy and consolidative breast RT is a promising approach for PB‐DLBCL, while HD‐MTX is useful for preventing CNS relapse.

BACKGROUND: High-dose methotrexate (HD-MTX), defined as doses ≥1000 mg/m², requires extensive monitoring and employment of supportive care strategies to prevent adverse events. Leucovorin is an integral component of supportive care management, and dose escalations are indicated in the setting of delayed MTX clearance. In 2017, our institution implemented a pharmacist-driven monitoring protocol to manage patients receiving HD-MTX therapy. OBJECTIVE: To evaluate the impact of a pharmacist-driven HD-MTX monitoring protocol on improving the management of delayed MTX elimination and preventing MTX-associated adverse events. METHODS: A single-center, retrospective chart review was conducted on adults (aged ≥18 years) hospitalized to receive HD-MTX therapy. Patients who received HD-MTX before protocol implementation were compared with those who received HD-MTX after protocol implementation. The primary outcome was the appropriateness of leucovorin dose adjustments, defined by adherence to the institution-specific HD-MTX monitoring guidelines. Secondary outcomes included MTX concentrations at 24, 48, and 72 hours, time to MTX clearance, evidence of delayed MTX clearance, median urine pH, length of stay, drug-drug interactions, and the incidence of adverse events. RESULTS: A total of 141 encounters were assessed: 82 in the standard protocol and 59 in the pharmacist-run protocol. A higher rate of appropriate leucovorin dose adjustments was observed in the pharmacist-run protocol group compared with the standard protocol group (61.9% vs 90.9%; P=.034). In addition, a higher incidence of delayed MTX clearance was observed in the pharmacist-run protocol group (19.5% vs 30.5%; P<.001). CONCLUSION: Implementation of a pharmacist-driven HD-MTX monitoring program was associated with an improvement in appropriate leucovorin dose escalations. Although a higher incidence of delayed MTX clearance and select adverse events occurred the pharmacist-run protocol, confounders may have contributed to this finding. Further studies are needed to confirm the impact of a pharmacist-driven HD-MTX monitoring protocol on clinical outcomes. [ABSTRACT FROM AUTHOR]

The efficacy of high-dose methotrexate (HD-MTX) for central nervous system (CNS) relapse prophylaxis in patients with high-risk diffuse large B-cell lymphoma (DLBCL) is controversial. We compared the prophylactic effects of HD-MTX and intrathecal methotrexate (IT-MTX) on CNS relapse in high-risk DLBCL, in a multicenter retrospective study. A total of 132 patients with DLBCL at high risk of CNS relapse who received frontline chemotherapy and IT-MTX from 2003 to 2013 (n = 34) or HD-MTX from 2014 to 2020 (n = 98) were included. After a median follow-up of 52 months (range: 9–174), 11 patients had isolated CNS relapse: six (6.1%) in the HD-MTX group and five (14.7%) in the IT-MTX group. The median time until CNS relapse was 38 months (range: 11–122), and the cumulative incidence of CNS relapse at 3 years was 3.9% in the HD-MTX group and 6.1% in the IT-MTX group (P = 0.93). Similar results were obtained after adjusting for background factors using propensity score-matched analysis (4.5% HD-MTX vs. 7.6% IT-MTX, P = 0.84). The CNS relapse rate in HD-MTX-treated patients was equivalent to that in IT-MTX patients, demonstrating that HD-MTX was not superior to IT-MTX in preventing CNS relapse. [ABSTRACT FROM AUTHOR]

Primary central nervous system lymphoma (PCNSL) is a rare disease with an incidence of 0.4/per 100,000 person‐years. As there is a limited number of prospective randomized trials in PCNSL, large retrospective studies on this rare disease may yield information that might prove useful for the future design of randomized clinical trials. We retrospectively analyzed the data of 222 newly diagnosed PCNSL patients treated in five referral centers in Israel between 2001 and 2020. During this period, combination therapy became the treatment of choice, rituximab has been added to the induction therapy, and consolidation with irradiation was largely laid off and was mostly replaced by high‐dose chemotherapy with or without autologous stem cell transplantation (HDC‐ASCT). Patients older than 60 comprised 67.5% of the study population. First‐line treatment included high‐dose methotrexate (HD‐MTX) in 94% of patients with a median MTX dose of 3.5 g/m2 (range 1.14–6 g/m2) and a median cycle number of 5 (range 1–16). Rituximab was given to 136 patients (61%) and consolidation treatment to 124 patients (58%). Patients treated after 2012 received significantly more treatment with HD‐MTX and rituximab, more consolidation treatments, and autologous stem cell transplantation. The overall response rate was 85% and the complete response (CR)/unconfirmed CR rate was 62.1%. After a median follow‐up of 24 months, the median progression‐free survival (PFS) and overall survival (OS) were 21.9 and 43.5 months respectively with a significant improvement since 2012 (PFS: 12.5 vs. 34.2 p = 0.006 and OS: 19.9 vs. 77.3 p = 0.0003). A multivariate analysis found that the most important factors related to OS were obtaining a CR followed by rituximab treatment and Eastern Cooperative Oncology Group performance status. The observed improvement in outcomes may be due to multiple components such as an intention to treat all patients regardless of age with HD‐MTX‐based combination chemotherapy, treatment in dedicated centers, and more aggressive consolidation with the introduction of HDC‐ASCT. [ABSTRACT FROM AUTHOR]

Background: Primary breast diffuse large B‐cell lymphoma (PB‐DLBCL) is a rare subtype of extranodal DLBCL, and the standard treatment remains controversial. In this study, we aimed to define the optimal treatment management in the rituximab era. Methods: A total of 5089 newly diagnosed DLBCL patients treated with rituximab‐containing immunochemotherapy between 2008 and 2019 from the Chinese Southwest Oncology Group‐affiliated institutes were identified, of whom 135 diagnosed with PB‐DLBCL were eligible for this analysis. Results: PB‐DLBCL accounted for 2.7% of all DLBCLs. With a median follow‐up of 4.2 years, the 5‐year overall survival and progression‐free survival rates were 84.8% and 71.6%, respectively. Breast and central nervous system (CNS) relapses were the main cause of treatment failure. We observed that consolidative breast radiotherapy (RT) significantly decreased breast relapse risk (5‐year risk, 2.9% vs. 20.1%, p = 0.007). The CNS relapse risk was lower for patients who received high‐dose methotrexate (HD‐MTX) than for patients who did not (5‐year risk, 0% vs. 15.2%, p = 0.015). We further screened the genetic mutation profile of 20 patients from two institutes, and found that MYD88 (25%) and CD79B mutations (25%) frequently occur in PB‐DLBCL. In addition, four patients with MYD88 and/or CD79B mutations experienced CNS relapse, while three patients with MYD88 and/or CD79B mutations who received HD‐MTX did not experience CNS relapse. Conclusion: Collectively, our results indicate combined modality therapy including rituximab‐containing immunochemotherapy and consolidative breast RT is a promising approach for PB‐DLBCL, while HD‐MTX is useful for preventing CNS relapse. [ABSTRACT FROM AUTHOR]

Abstract Background Taiwanese patients frequently experience severe hepatotoxicity associated with high‐dose methotrexate (HD‐MTX) treatment, which interferes with subsequent treatment. Drug–drug interactions occur when MTX is used in combination with proton pump inhibitors (PPIs), trimethoprim‐sulfamethoxazole (TMP‐SMX), or non‐steroidal anti‐inflammatory drugs (NSAIDs). In East Asia, real‐world analyses on the effects of co‐medication and other potential risk factors on the clinical course of HD‐MTX‐mediated acute hepatotoxicity in patients with osteogenic sarcoma (OGS) are limited. Methods This cohort study included patients with newly diagnosed OGS who were treated with HD‐MTX between 2009 and 2017 at Taipei Veterans General Hospital. We collected data on the clinical course of HD‐MTX‐mediated acute hepatotoxicity, co‐medications, and other potential risk factors, and analyzed the effects of these factors on the clinical course of HD‐MTX‐mediated acute hepatotoxicity. Results Almost all patients with OGS treated with HD‐MTX developed acute hepatotoxicity with elevated alanine aminotransferase (ALT) levels. Most patients with Grade 3–4 ALT elevation failed to recover to Grade 2 within 7 days. Women and children are high‐risk subgroups for HD‐MTX‐mediated elevation of ALT levels. Age is a factor that contributes to the pharmacokinetic differences of HD‐MTX. However, the concurrent use of PPIs, TMP‐SMX, or NSAIDs did not affect the elimination of MTX when administered with adequate supportive therapy. Conclusions Co‐administration of PPIs, TMP‐SMX, or NSAIDs may have limited effects on acute hepatotoxicity in well‐monitored and adequately pre‐medicated patients with OGS undergoing chemotherapy with HD‐MTX. Clinicians should pay particular attention to ALT levels when prescribing HD‐MTX to children and women.

Background: Pediatric patients with Philadelphia chromosome positive (Ph+) or ABL-class fusion positive acute lymphoblastic leukemia (ALL) are currently treated with the tyrosine kinase inhibitor (TKI) imatinib added to a chemotherapy backbone that also contains several courses of high-dose methotrexate (HDMTX). A limited number of case studies suggested delayed MTX clearance in patients concomitantly using HDMTX and imatinib. Methods: MTX clearance and serum creatinine in 24 newly diagnosed Ph+/ABL-class fusion positive pediatric ALL patients treated with imatinib (imatinib group) were compared with 281 randomly selected age-matched Ph-negative pediatric ALL patients treated without TKI (control group), receiving in total 61 and 897 HDMTX courses, respectively. Results: Mild to severe delayed MTX clearance (MTX level at T48 hours>0.4 µM) was more frequently found in the imatinib group than in the control group in all courses (55.7% vs 41.1% p = 0.036). After the first HDMTX course, 12.5% (n = 3) of the imatinib group presented with a severe delayed MTX clearance (T48 > 5 µM) versus 2.3% in the control group (p = 0.039). In two (8.3%) of these patients in the imatinib group, this was accompanied by increased creatinine, therefore meeting the criteria for Delayed MTX Elimination (DME). In the control group 12/281 (4.3%) patients presented with DME. Glucarpidase was administered in 2 (8.3%) vs 4 (1.4%) patients in the imatinib group and control group, respectively. Conclusion: Imatinib increased the risk of delayed MTX clearance in newly diagnosed pediatric Ph+ chromosome or ABL-class fusion positive ALL patients. We therefore recommend stringent supportive care measures and for patients with severe delayed MTX clearance resulting in severe toxicities temporary discontinuation of imatinib or a lower dose of MTX during the next HDMTX courses.

Relapse of the central nervous system (CNS) is a rare but fatal complication in diffuse large B-cell lymphoma (DLBCL). The purpose of this study is to learn how to identify high-risk patients and take effective preventive measures. We retrospectively analyzed 1,290 adult patients with DLBCL at Peking University Cancer Hospital and Shanxi Bethune Hospital between 2010 and 2020. There were 55 patients with CNS relapse who had a median follow-up of 5 years. The risk of CNS relapse was 1.58% in the low-risk group, 5.66% in the moderate-risk group, and 11.67% in the high-risk group based on CNS International Prognostic Index (CNS-IPI). We found that CNS-IPI and testicular involvement were risk factors for CNS relapse, with OR 1.913 (95% CI: 1.036∼3.531; P = 0.038) versus. OR 3.526 (95% CI: 1.335∼9.313; P = 0.011), respectively. Intrathecal MTX and/or cytarabine prophylaxis was used in 166 patients (13.94%), intravenous (IV) high-dose methotrexate (HD-MTX) prophylaxis in 8 patients (0.67%), and intrathecal plus intravenous prophylaxis in 15 patients (1.26%). There was no significant difference in CNS relapse risk between IT, HD-MTX, and no prophylaxis recipients (12.7% vs. 0% vs. 23.6%, respectively, P = 0.170). The risk of CNS relapse was similar whether or not patients accepted prophylaxis (5-year risk 4.1% vs. 2.2%, P = 0.140). Central nervous system (CNS) relapse is associated with high risk CNS-IPI and testicular involvement. Therefore, it is necessary to pursue novel prophylactic strategies for CNS relapse. [ABSTRACT FROM AUTHOR]

Abstract Background Treatment of relapsed or refractory primary CNS lymphoma (r/r PCNSL) is difficult, particularly in patients not eligible for high dose chemotherapy with autologous stem cell transplantation (HDC-ASCT). No standard treatment has been defined for these patients yet. Methods We retrospectively analyzed survival, prognostic factors, hospitalization time and Karnofsky performance score (KPS) before and after treatment in 54 r/r PCNSL patients with isolated cerebral relapse or progression (n = 23 refractory, n = 31 relapsed) not eligible for HDC-ASCT, who received heterogenous salvage treatments. Results Treatments were temozolomide (+ rituximab) (n = 21), high dose methotrexate (HD-MTX)-based therapy (n = 11), whole brain radiotherapy (WBRT)/focal radiotherapy (n = 11), other systemic treatments (n = 2) and best supportive care (BSC, n = 9). Median progression free survival (PFS) and overall survival (OS) were 2.6 months (95% CI 1.0–4.2 months) and 4.8 months (95% CI 3.3–6.3 months), respectively. Eight patients survived for ≥ 3 years (13.1%, n = 3 received temozolomide, n = 3 WBRT, n = 2 HD-MTX-based treatment). Application of any salvage treatment (vs. BSC), younger age at relapse and asymptomatic (vs. symptomatic) relapse were positive prognostic factors. No significant differences in OS were found for the different salvage treatments. Median hospitalization time for treatment was 15/13 days for temozolomide (+ rituximab)/radiotherapy compared to 55 days for HD-MTX-based therapy. Median KPS in assessable patients (n = 41) was 60 (range 30–100) before treatment and 50 (range 20–90) after treatment. In patients with response to treatment (n = 16) KPS improved from 60 (range 40–90) before treatment to 70 (range 50–90) after treatment, while patients with PD (n = 25) deteriorated from 60 (range 30–100) to 40 (range 20–70). Conclusion Survival for this cohort of r/r PCNSL patients with isolated cerebral relapse or progression was poor. Considering long hospital stays associated with HD-MTX-based chemotherapy and neurotoxicity associated with WBRT, temozolomide might be worth considering with a chance of prolonged survival and avoidance of long hospitalization. Novel therapeutic agents are urgently needed to improve survival in r/r PCNSL patients.

Purpose: To assess the risk factors associated with high-dose methotrexate (HDMTX) (≥ 1 g/m2) treatment-induced acute kidney injury (AKI). Methods: Patients who received HDMTX from July 2014 to August 2019 in one medical center were enrolled. The patients' demographic, laboratory, and medication data were collected and compared between groups with or without AKI. Risk factors of HDMTX-induced AKI were explored using univariate and multivariate logistic regression analyses. Additionally, we searched and summarized previous studies to identify key correlates of AKI in a narrative review. Results: We enrolled 59 patients who had received 200 HDMTX courses. The incidence of HDMTX-induced nephrotoxicity was 9.5%. Multivariate logistic regression revealed that male sex (odds ratio [OR], 4.20; P =.037), and angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) (OR, 5.18; P =.016) were significantly associated with AKI. Diuretics with urinary acidification, such as loop diuretics, were also a key factor in AKI (OR, 4.91; P =.018). Furthermore, a forest plot identified 21 predictors from nine additional cohort studies showing correlations with the development of AKI. Conclusion: Male sex, ACEIs/ARBs, and diuretics with urinary acidification are associated with AKI. Furthermore, laboratory data should be monitored to assess AKI risk before HDMTX therapy, especially in elderly patients with obesity, diabetes, or acute lymphoblastic leukemia. [ABSTRACT FROM AUTHOR]

Introduction: High-dose methotrexate (HDMTX) is administered for the treatment of some cancers. HDMTX is usually safe but may crystallize in renal tubules causing acute kidney injury (AKI). Consequently, MTX elimination is delayed, resulting in a severe and life-threatening condition. No studies have been published about the impact of MTX toxicity in Spain. This study aims to estimate the incidence and management of MTX delayed elimination and toxicity. Methods: A two-round Delphi study was performed to reach consensus between 10 medical experts on haemato-oncology and paediatric oncology with experience in the management of HDMTX treated patients from leading Spanish hospitals. An online questionnaire was developed based on national and international guidelines and previous evidence regarding HDMTX-related toxicity. Consensus was established at 80% agreement. Median and interquartile ranges were calculated, and incidence data were extrapolated to the Spanish general population. Results: Out of 1.475 patients estimated to receive HDMTX treatment annually in Spain, 27.5% present MTX delayed elimination and 11.6% develop HDMTX-induced AKI (35.4% with severe systemic toxicities (>grade 3) and 18.8% develop chronic renal disease). Mortality is estimated in 4.2%. Immuno-enzymatic assay is used in most of the hospitals (90%) for MTX serum level monitoring. All experts use increased supportive care and high leucovorin as first-line treatment. Available treatments in experts' hospitals in case toxicity persists are haemodialysis (90% of hospitals), glucarpidase (60%) and hemofiltration (50%). Most prevalent non-renal systemic toxicities are haematologic and mucositis (21–40% of patients). Patients with HDMTX-induced AKI require from intensive care (5% of patients), more than 3 sessions and 4 days of dialysis, and about 8.5 days of hospitalization (non-ICU patients) and 12 days in case of patients requiring ICU. Conclusions: These results are the first evidence regarding HDMTX-induced AKI in Spain. Incidence and mortality results are in line with previous studies. Clinical management is based on preventive measures and the treatment depend on the availability in the hospital. The need for effective, safe and rapid treatment for the reduction of MTX toxic levels and the improvement of monitoring methods were noted by experts as urgent needs. Further observational studies to validate these results would be needed. [ABSTRACT FROM AUTHOR]

Background: Taiwanese patients frequently experience severe hepatotoxicity associated with high‐dose methotrexate (HD‐MTX) treatment, which interferes with subsequent treatment. Drug–drug interactions occur when MTX is used in combination with proton pump inhibitors (PPIs), trimethoprim‐sulfamethoxazole (TMP‐SMX), or non‐steroidal anti‐inflammatory drugs (NSAIDs). In East Asia, real‐world analyses on the effects of co‐medication and other potential risk factors on the clinical course of HD‐MTX‐mediated acute hepatotoxicity in patients with osteogenic sarcoma (OGS) are limited. Methods: This cohort study included patients with newly diagnosed OGS who were treated with HD‐MTX between 2009 and 2017 at Taipei Veterans General Hospital. We collected data on the clinical course of HD‐MTX‐mediated acute hepatotoxicity, co‐medications, and other potential risk factors, and analyzed the effects of these factors on the clinical course of HD‐MTX‐mediated acute hepatotoxicity. Results: Almost all patients with OGS treated with HD‐MTX developed acute hepatotoxicity with elevated alanine aminotransferase (ALT) levels. Most patients with Grade 3–4 ALT elevation failed to recover to Grade 2 within 7 days. Women and children are high‐risk subgroups for HD‐MTX‐mediated elevation of ALT levels. Age is a factor that contributes to the pharmacokinetic differences of HD‐MTX. However, the concurrent use of PPIs, TMP‐SMX, or NSAIDs did not affect the elimination of MTX when administered with adequate supportive therapy. Conclusions: Co‐administration of PPIs, TMP‐SMX, or NSAIDs may have limited effects on acute hepatotoxicity in well‐monitored and adequately pre‐medicated patients with OGS undergoing chemotherapy with HD‐MTX. Clinicians should pay particular attention to ALT levels when prescribing HD‐MTX to children and women. [ABSTRACT FROM AUTHOR]

Jun Wang,1 Yue-Tao Zhao,2,3 Meng-Jiao Sun,1 Feng Chen,3 Hong-Li Guo3 1Department of Hematology and Oncology, Children’s Hospital of Nanjing Medical University, Nanjing, 210008, People’s Republic of China; 2School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, People’s Republic of China; 3Pharmaceutical Sciences Research Center, Department of Pharmacy, Children’s Hospital of Nanjing Medical University, Nanjing, 210008, People’s Republic of ChinaCorrespondence: Hong-Li Guo, Children’s Hospital of Nanjing Medical University, 72 Guangzhou Road, Nanjing, 210008, People’s Republic of China, Email guomomohl@163.comAbstract: High-dose methotrexate (HDMTX) is a pivotal component of the chemotherapeutic regimens of osteosarcoma. However, the use of HDMTX is limited by an increased risk of dose-dependent toxicity. It is thought that the plasma levels and therapy-related toxicity of MTX could be associated with single nucleotide polymorphisms (SNPs) within MTX metabolism pathway genes. Here, we report a case of a paediatric osteosarcoma girl with delayed MTX excretion who was successfully managed using supportive measures and continuous veno-venous haemodiafiltration. We further identified the cause that could account for delayed elimination by genotyping analysis. The results showed that variations have been found in SLCO1B1, SLC19A1, ABCB1 and MTHFR, all those were reported to have a strong association with delayed elimination of MTX in clinical studies. After comprehensive consideration of genotype and clinical phenotype, the second course of HDMTX was administered to this patient at a half reduced dose. We also performed a literature review to summarize the pharmacogenetic factors that influence HDMTX pharmacokinetics or MTX-related adverse effects in osteosarcoma patients. It is suggested that the potential risk of delayed MTX elimination is worthy of clinical attention, and the implementation of genotyping should be considered to ensure therapeutic safety.Graphical Abstract: Keywords: high-dose methotrexate, osteosarcoma, delayed excretion, single nucleotide polymorphisms

Purpose: High-dose methotrexate (HD-MTX)-based chemotherapy regimen is the first-line option for primary central nervous system lymphoma (PCNSL). This prospective cohort study aimed to evaluate the efficacy and adverse effects of HD-MTX plus idarubicin (IDA) in patients with newly diagnosed immunocompetent PCNSL. Methods: We recruited newly diagnosed PCNSL patients from January 2017 to August 2020. Patients were assigned into two groups: HD-MTX monotherapy and HD-MTX plus IDA (HD-MTX/IDA). In the HD-MTX monotherapy group, patients were treated with MTX 8 g/m2 alone on day 1, while the HD-MTX/IDA group received MTX 8 g/m2 on day 1 and IDA 10 mg/m2 on day 2. Treatments were repeated every 3 weeks for 8 cycles except for progression and/or unacceptable toxicity. Results: We recruited 61 PCNSL patients, including 36 in the HD-MTX and 25 in the HD-MTX/IDA group. The CR rate was 68% in the HD-MTX/IDA group and 72.22% of patients in the HD-MTX monotherapy group (p = 0.7221), while the overall response rate was 72% vs. 77.78% (p = 0.6063). Median PFS in HD-MTX/IDA group and HD-MTX monotherapy group were 15.6 months and 18.5 months, respectively (p = 0.6374). Median OS was not reached in both groups. There were no significant differences in adverse effects between the two groups. Conclusions: The combination of IDA with HD-MTX showed no obvious therapeutic advantage over HD-MTX monotherapy in newly diagnosed patients with PCNSL. HD-MTX dose of 8 g/m2 monotherapy can still provide better therapeutic benefits in patients with acceptable adverse effects. Future studies could explore HD-MTX in combination with other chemotherapeutic agents in the first-line treatment of PCNSL. [ABSTRACT FROM AUTHOR]

Purpose: Hydration before starting high-dose methotrexate (HD-MTX) ensures good renal perfusion and alkaline urinary pH. The duration of pre-hydration is not uniform across protocols. We compared 6-h versus 12-h of pre-hydration for HD-MTX therapy in childhood acute lymphoblastic leukaemia (ALL) at our centre where serial MTX level monitoring is not feasible. Methods: This randomised cross-over study consecutively enrolled children < 12 years with ALL receiving HD-MTX. Children with pre-existing renal disease or those exposed to nephrotoxic drugs were excluded. Two groups receiving 6-h versus 12-h pre-hydration on alternate basis in same patient (each exposed to four cycles of 2–5 g/m2 of HD-MTX) were compared for HD-MTX induced nephrotoxicity (primary outcome) and other HD-MTX toxicities (HMT) as per common terminology criteria for adverse events (CTCAE-4.0). HD-MTX was administered over 24 h as per BFM-protocol-2009. Solitary MTX levels at 36-h (MTX36) were outsourced and leucovorin (LV) was started at 36 h at 15 mg/m2/dose for 6–8 doses 6-hourly depending on MTX36. Hydration fluid was dextrose normal saline with sodium-bicarbonate and administered till last LV dose. Results: Total 136 HD-MTX cycles in 34 patients (age range 5–144 months) were evaluated. Nephrotoxicity [2/68 (2.9%) in 6-h versus 1/68 (1.5%) in 12-h] and HMT incidence was comparable in two pre-hydration groups. Median MTX36 levels were not affected by duration of hydration irrespective of administered dose of HD-MTX. Median serum creatinine at baseline, post-pre-hydration and at 36-h post start of HD-MTX were comparable. Conclusion: Reduction of pre-hydration duration does not affect HD-MTX induced nephrotoxicity and MTX36 levels in children < 12 years. [ABSTRACT FROM AUTHOR]

Simple Summary: High-dose methotrexate (HDMTX) is the backbone of induction therapy for primary central nervous system lymphoma (PCNSL). There are numerous different protocols to treat PCNSL that incorporate a wide range of HDMTX doses and various combinations with other chemotherapeutic agents. This systematic review was conducted to summarize the various treatment regimens for PCNSL and determine outcomes among the different doses of HDMTX and combination regimens. The findings are intended to provide guidance on the optimal dose and regimen of HDMTX for the treatment of PCNSL. Primary central nervous system lymphoma (PCNSL) is a highly aggressive non-Hodgkin lymphoma that is confined within the CNS. Due to its ability to cross the blood–brain barrier, high-dose methotrexate (HDMTX) is the backbone for induction chemotherapy. This systematic review was conducted to observe outcomes among different HDMTX doses (low, <3 g/m2; intermediate, 3–4.9 g/m2; high, ≥5 g/m2) and regimens used in the treatment of PCNSL. A PubMed search resulted in 26 articles reporting clinical trials using HDMTX for PCNSL, from which 35 treatment cohorts were identified for analysis. The median dose of HDMTX used for induction was 3.5 g/m2 (interquartile range IQR, 3–3.5); the intermediate dose was most frequently used in the studies examined (24 cohorts, 69%). Five cohorts used HDMTX monotherapy, 19 cohorts used HDMTX + polychemotherapy, and 11 cohorts used HDMTX + rituximab ± polychemotherapy. Pooled overall response rate (ORR) estimates for low, intermediate, and high dose HDMTX cohorts were 71%, 76%, and 76%, respectively. Pooled 2-year progression-free survival (PFS) estimates for low, intermediate, and high HDMTX dose cohorts were 50%, 51%, and 55%, respectively. Regimens that included rituximab showed a tendency to have higher ORR and 2-year PFS than those that did not include rituximab. These findings indicate that current protocols utilizing 3–4 g/m2 of HDMTX in combination with rituximab provide therapeutic efficacy in PCNSL. [ABSTRACT FROM AUTHOR]

Objectives: Methotrexate (MTX) is a key therapeutic agent for leukemias. When given in high doses, leucovorin rescue is added to reduce its toxicity. It has been postulated that low albumin levels are associated with delayed clearance and increased toxicity of MTX. Hence, this prospective cohort study was proposed to evaluate the correlation between serum albumin level and HDMTX toxicity in acute lymphocytic leukemia (ALL) patients and to compare the MTX toxicity in hypo and normoalbuminemic patients. Methods: Forty-six ALL patients of either gender aged 2–40 years receiving HDMTX for 1st time were included in the study. The serum albumin levels were measured before chemotherapy before each cycle. The patients received 24-h infusion of HDMTX on days 8, 22, 36, and 50 (four cycles). The serum concentration of MTX was measured after first cycle only. The patients were followed for toxicities that were graded according to CTCAE-V4.0. Results: There was a negligible correlation between cumulative albumin levels of all four cycles and cumulative toxic events. The median toxic events were 19 (16–23). The Spearmen correlation coefficient ρ was 0.055 (P = 0.460). No association was found between albumin level and MTX toxicity in cycle wise analysis also. In each cycle, there was no significant difference in the toxicities between the hypo and normoalbuminemic patients. Only vomiting showed significant (P < 0.05) inverse correlation with albumin levels. Hypoalbuminemic patients showed significantly (P < 0.01) higher grade of nausea compared to normoalbuminemia. Conclusion: There was negligible correlation between albumin levels and MTX toxicity despite delayed clearance supporting the safety of MTX in mildly hypoabuminemic patients. [ABSTRACT FROM AUTHOR]

Introduction: Methotrexate is administered through different routes to treat childhood acute lymphoblastic leukemia. Toxicities of low, intermediate, or high doses of methotrexate have been described in the literature. Methotrexate-induced or related pneumonitis is a rare complication that leads, in most cases, to discontinuing this drug. Case report: We report a case of a 17-year-old female patient with newly diagnosed B-acute lymphoblastic leukemia who received a high-dose methotrexate on an induction course. Eight days after methotrexate infusion, she developed fever, dyspnea, hypoxemia, and dry cough. Chest computed tomography showed mosaic attenuation of lung parenchyma and bilateral interstitial infiltrate in favor of hypersensitivity pneumonitis with no evidence of bacterial or fungal infections. Management and outcome: Methotrexate-related pneumonitis was diagnosed and corticosteroids were prescribed. Improvement of the symptomatology was noted within four days. Given the importance of methotrexate in the treatment of acute lymphoblastic leukemia, intrathecal methotrexate was administered without incident and high-dose methotrexate was re-introduced successfully two and a half months after the pneumonitis episode while using corticosteroids. According to Naranjo's algorithm, the reaction to the drug was found to be probable with a score of 6. Discussion: Methotrexate is the backbone of acute lymphoblastic leukemia treatment, but numerous adverse reactions have been published of which methotrexate pneumonitis can be fatal in some cases. In this case, we concluded that this drug can be successfully reintroduced after methotrexate-related pneumonitis. [ABSTRACT FROM AUTHOR]

Given the rarity of primary central nervous system lymphoma (PCNSL), evaluations of different high-dose methotrexate-(HD-MTX)-based treatment regimens is sparse. This retrospective, multicenter study evaluates clinical characteristics and outcomes (progression-free, overall and disease-specific survival) after five HD-MTX-based polychemotherapeutic regimens and two consolidation therapies. 346 patients with histologically confirmed PCNSL, treated with ≥ 1 cycle HD-MTX-based strategies (≥3g/m2/cycle) were included. The regimens included MATRIX (HD-MTX, HD-AraC, thiotepa, and rituximab), (R)MBVP±HD-AraC (HD-MTX, teniposide/etoposide, carmustine, prednisolone, ± HD-AraC, ± rituximab), (R)MP (HD-MTX, procarbazine, ± rituximab), and a combination of HD-MTX and HD-AraC. The overall response rate after induction was 69 %, 28 % complete remission and progressive disease was observed in 100 (29 %) patients. 126 (36 %) patients received consolidation, including high-dose-BCNU-thiotepa with autologous stem cell transplantation (HD-BCNU-TT/ASCT, n = 59 (17 %)) or whole brain radiotherapy (WBRT, n = 67 (19 %)). Clinical characteristics associated with adverse mortality risk by multivariable prognostication contained age > 60 years (HR 1.61, p = 0.011), elevated LDH (HR 1.75, p = 0.004) and WHO status ≥ 2 (HR 1.56, p = 0.010). Independently, induction regimens containing HD-AraC demonstrated survival benefit compared to induction regimens without HD-AraC (HR 0.59, p = 0.002). Without preference for HD-BCNU-TT/ASCT or WBRT, a favorable effect of consolidation (HR 0.44 and HR 0.42, p < 0.001) was confirmed, also with consolidation as time-dependent variable. Competing risk analysis showed similar low incidence of lymphoma-unrelated deaths in consolidated and unconsolidated patients. This study confirms that age, elevated LDH and WHO status increase the mortality risk. HD-AraC containing treatment regimens and consolidation with HD-BCU-TT/ASCT or WBRT were associated with superior survival, including a favorable low incidence of lymphoma-unrelated deaths. [Display omitted] • In PCNSL, age, elevated LDH and WHO are associated with increased mortality risk. • HD-AraC containing treatment regimens were associated with improved survival. • A favorable effect of consolidation with HD-BCNU-TT/ASCT or WBRT was confirmed. • Lymphoma-unrelated deaths similar between consolidated and unconsolidated patients. [ABSTRACT FROM AUTHOR]

Jing Wang,1 Muhamad Alhaj Moustafa,2 Justin J Kuhlman,1 Karan Seegobin,2 Liuyan Jiang,3 Vivek Gupta,4 Han W Tun2 1Department of Internal Medicine, Mayo Clinic Florida, Jacksonville, FL, 32224, USA; 2Division of Hematology and Medical Oncology, Mayo Clinic Florida, Jacksonville, FL, 32224, USA; 3Department of Pathology and Laboratory Medicine, Mayo Clinic Florida, Jacksonville, FL, 32224, USA; 4Department of Radiology, Mayo Clinic Florida, Jacksonville, FL, 32224, USACorrespondence: Han W Tun, Mayo Clinic Florida Division of Hematology/Oncology, 4500 San Pablo Road S, Jacksonville, FL, 32224, USA, Tel +1 904-953-2000, Email tun.han@mayo.eduAbstract: Intravascular large B cell lymphoma (IVL) is a rare subtype of diffuse large B cell lymphoma confined to small blood vessels with a predilection for CNS involvement. The prognosis of IVL with CNS involvement (CNS-IVL) is extremely poor. The optimal treatment for CNS-IVL is not well defined. Thus, we report three patients with CNS-IVL successfully treated with a CNS-centric approach consisting of high-dose methotrexate (HDMTX) and high-dose Ara-C (HiDAC) based CNS-directed chemoimmunotherapy (CIT) alternating with anthracycline-based CIT. Our rationale for intensifying the CNS-directed therapy is the presence of intracerebral bleeding in two of our patients which would result in extravasation of lymphoma cells into the cerebral parenchyma with the development of CNS lymphoma. All three patients have achieved excellent therapeutic outcomes. Two patients with intracerebral bleeding have been in complete remission (CR) for about 11 years and 4 years. One patient was successfully induced into CR about 10 months ago and currently is in CR. This unique therapeutic approach should be further explored for CNS-IVL.Keywords: intravascular lymphoma, CNS involvement, CNS-directed chemoimmunotherapy, anthracycline-based chemoimmunotherapy, high-dose methotrexate, high-dose Ara-C

Abstract Background High-dose methotrexate (HD-MTX) is used in the treatment of different childhood cancers, including leukemia, the most common cancer type and is commonly defined as an intravenous dose of at least 1 g/m2 body surface area per application. A systematic review on late effects on different organs due to HD-MTX is lacking. Method We conducted a systematic literature search in PubMed, including studies published in English or German between 1985 and 2020. The population of each study had to consist of at least 75% childhood cancer survivors (CCSs) who had completed the cancer treatment at least twelve months before late effects were assessed and who had received HD-MTX. The literature search was not restricted to specific cancer diagnosis or organ systems at risk for late effects. We excluded case reports, case series, commentaries, editorial letters, poster abstracts, narrative reviews and studies only reporting prevalence of late effects. We followed PRISMA guidelines, assessed the quality of the eligible studies according to GRADE criteria and registered the protocol on PROSPERO (ID: CRD42020212262). Results We included 15 out of 1731 identified studies. Most studies included CCSs diagnosed with acute lymphoblastic leukemia (n = 12). The included studies investigated late effects of HD-MTX on central nervous system (n = 10), renal (n = 2) and bone health (n = 3). Nine studies showed adverse outcomes in neuropsychological testing in exposed compared to non-exposed CCSs, healthy controls or reference values. No study revealed lower bone density or worse renal function in exposed CCSs. As a limitation, the overall quality of the studies per organ system was low to very low, mainly due to selection bias, missing adjustment for important confounders and low precision. Conclusions CCSs treated with HD-MTX might benefit from neuropsychological testing, to intervene early in case of abnormal results. Methodological shortcomings and heterogeneity of the tests used made it impossible to determine the most appropriate test. Based on the few studies on renal function and bone health, regular screening for dysfunction seems not to be justified. Only screening for neurocognitive late effects is warranted in CCSs treated with HD-MTX.

Background: Treatment of relapsed or refractory primary CNS lymphoma (r/r PCNSL) is difficult, particularly in patients not eligible for high dose chemotherapy with autologous stem cell transplantation (HDC-ASCT). No standard treatment has been defined for these patients yet. Methods: We retrospectively analyzed survival, prognostic factors, hospitalization time and Karnofsky performance score (KPS) before and after treatment in 54 r/r PCNSL patients with isolated cerebral relapse or progression (n = 23 refractory, n = 31 relapsed) not eligible for HDC-ASCT, who received heterogenous salvage treatments. Results: Treatments were temozolomide (+ rituximab) (n = 21), high dose methotrexate (HD-MTX)-based therapy (n = 11), whole brain radiotherapy (WBRT)/focal radiotherapy (n = 11), other systemic treatments (n = 2) and best supportive care (BSC, n = 9). Median progression free survival (PFS) and overall survival (OS) were 2.6 months (95% CI 1.0–4.2 months) and 4.8 months (95% CI 3.3–6.3 months), respectively. Eight patients survived for ≥ 3 years (13.1%, n = 3 received temozolomide, n = 3 WBRT, n = 2 HD-MTX-based treatment). Application of any salvage treatment (vs. BSC), younger age at relapse and asymptomatic (vs. symptomatic) relapse were positive prognostic factors. No significant differences in OS were found for the different salvage treatments. Median hospitalization time for treatment was 15/13 days for temozolomide (+ rituximab)/radiotherapy compared to 55 days for HD-MTX-based therapy. Median KPS in assessable patients (n = 41) was 60 (range 30–100) before treatment and 50 (range 20–90) after treatment. In patients with response to treatment (n = 16) KPS improved from 60 (range 40–90) before treatment to 70 (range 50–90) after treatment, while patients with PD (n = 25) deteriorated from 60 (range 30–100) to 40 (range 20–70). Conclusion: Survival for this cohort of r/r PCNSL patients with isolated cerebral relapse or progression was poor. Considering long hospital stays associated with HD-MTX-based chemotherapy and neurotoxicity associated with WBRT, temozolomide might be worth considering with a chance of prolonged survival and avoidance of long hospitalization. Novel therapeutic agents are urgently needed to improve survival in r/r PCNSL patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: High-dose methotrexate (HDMTX) is the backbone of many pediatric and adult oncology treatment protocols. It requires appropriate monitoring and supportive care because delayed elimination of MTX can lead to serious toxicities. No reviews specifically addressing nursing management regarding standard treatment protocols and delayed MTX elimination exist. OBJECTIVES: This article provides an overview of HDMTX treatment and nursing considerations, including toxicities, components of supportive care management, and strategies to manage administration and delayed elimination of MTX. METHODS: A review of published literature and guidelines was performed to evaluate nursing considerations for patients receiving HDMTX. FINDINGS: Using existing and novel tools, nurses can closely monitor patients and provide supportive care to mitigate HDMTX toxicity. Early identification of delayed MTX elimination and subsequent treatment with glucarpidase, if appropriate, has been associated with shorter length of hospital stay and decreased incidence of grade 4 toxicities and mortality. [ABSTRACT FROM AUTHOR]

Aims: High‐dose methotrexate (HDMTX) is an essential part of the treatment of several adult and paediatric malignancies. Despite meticulous supportive care during HDMTX administration, severe toxicities, including acute kidney injury (AKI), may occur contributing to patient morbidity. Population pharmacokinetics provide a powerful tool to predict time to clear HDMTX and adjust subsequent doses. We sought to develop and validate pharmacokinetic models for HDMTX in adults with diverse malignancies and to relate systemic exposure with the occurrence of severe toxicity. Methods: Anonymized, de‐identified data were provided from 101 US oncology practices that participate in the Guardian Research Network, a non‐profit clinical research consortium. Modelled variables included clinical, laboratory, demographic and pharmacological data. Population pharmacokinetic analysis was performed by means of nonlinear mixed effects modelling using MonolixSuite. Results: A total of 693 HDMTX courses from 243 adults were analysed, of which 62 courses (8.8%) were associated with stage 2/3 acute kidney injury (43 stage 2, 19 stage 3). A three‐compartment model adequately fitted the data. Time‐dependent serum creatinine, baseline serum albumin and allometrically scaled bodyweight were clinically significant covariates related to methotrexate clearance. External evaluation confirmed a satisfactory predictive performance of the model in adults receiving HDMTX. Dose‐normalized methotrexate concentration at 24 and 48 hours correlated with AKI incidence. Conclusion: We developed a population pharmacometric model that considers weight, albumin and time‐dependent creatinine that can be used to guide supportive care in adult patients with delayed HDMTX elimination. [ABSTRACT FROM AUTHOR]

Purpose: Methotrexate is an antifolate agent used in treatment of several malignancies. Many toxicities accompany methotrexate that are minimized with urine alkalinization. Parenteral sodium bicarbonate is the historical standard alkalinizing agent, but use has been limited by intermittent shortages. However, intravenous sodium acetate may be considered as a chemically equivalent alternative. The primary objective of this study is to determine the efficacy of sodium acetate versus sodium bicarbonate for urine alkalinization for high-dose methotrexate (HDMTX). Methods: This is a retrospective cohort study including adults admitted to Barnes-Jewish Hospital to receive HDMTX for lymphoma, breast cancer with leptomeningial spread, or osteosarcoma. Patients must have received intravenous sodium acetate or sodium bicarbonate alkalinization. Results: Of 192 HDMTX encounters, 154 (sodium bicarbonate, n = 86; sodium acetate, n = 68) were evaluated for efficacy and safety. Safety outcomes were not significantly different between groups except for higher peak methotrexate level in the bicarbonate group (2.9 mcmol/L vs. 1.7 mcmol/L, p = 0.023), and increased incidence of grade 3–4 ALT in the sodium bicarbonate group (23.5% vs. 9%, p = 0.02). Time from alkalinizer initiation to pH ≥7 was significantly shorter with sodium bicarbonate (4 vs. 5.15 h, p = 0.021). Nonetheless, outcomes such as length of stay (4.4 vs. 4 days respectively, p = 0.037) and time to methotrexate clearance (3.6 vs. 3.2 days respectively, p = 0.023) reveal that inpatient time was shorter with sodium acetate overall. Conclusion: This retrospective analysis suggests that sodium acetate has similar efficacy and safety to sodium bicarbonate for alkalinization and may be considered as an alternative in future shortage situations. [ABSTRACT FROM AUTHOR]

To evaluate the efficacy of high-dose methotrexate (HD-MTX, ≥1 g/m2) for the prevention of central nervous system (CNS) recurrence in patients with intravascular large B-cell lymphoma (IVLBCL), we reviewed 51 patients with pathologically diagnosed untreated IVLBCL. In total, there were five cases of CNS relapse (9.8%), and the 12-month CNS relapse rate was 9.2%. No statistical difference in CNS relapse rate (p = 0.86) was observed between patients with and without HD-MTX (n = 20 and 31, respectively). Furthermore, the composite endpoint defined as either CNS and/or neurolymphomatosis relapse was not significant in terms of the administration of HD-MTX (p = 0.25). No significant predictor of CNS relapse was found. In conclusion, patients with IVLBCL are at high risk of CNS recurrence; however, HD-MTX administration may not be effective for CNS recurrence prophylaxis. The administration of HD-MTX for patients with untreated IVLBCL may not be effective for preventing CNS relapse. [ABSTRACT FROM AUTHOR]

What is Known and Objective: Methotrexate (MTX) is an antimetabolic antitumor drug with high individual differences and may lead to severe toxicities in a considerable number of patients. This study aimed to explore the factors influencing major adverse events in patients with primary central nervous system lymphoma treated with high‐dose MTX (HD‐MTX), which could be useful in clinical practice. Methods: Fifty‐four patients who received 175 courses of MTX at 3–8 g/m2 between January 2015 and December 2016 were enrolled in this study. We assessed the association between clinical characteristics, MTX pharmacokinetics, MTX delayed elimination, and adverse events, including hepatotoxicity, acute kidney injury (AKI), and myelosuppression. Results and Discussion: A total of 124 adverse events occurred after MTX infusion. Using independent sample t‐tests, we found that patients with myelosuppression had higher MTX area under the concentration‐time curve up to 48 h after infusion (AUC0‐48h) (p = 0.001) and MTX peak concentration (Cmax) (p = 0.002). MTX concentrations at 48 and 72 h were higher in patients with AKI than in those without (p = 0.034 and p = 0.041, respectively). Using chi‐square tests, we found that AKI was correlated with MTX elimination at either 48 h or 72 h (22.1% vs. 8.2%, p = 0.010). By multivariate logistic regression model, our results showed that baseline level of ALT and WBC had a significant effect on hepatotoxicity (OR = 1.079, 95% CI 1.044–1.116, p = 6.9 × 10−6; OR = 0.808, 95% CI 0.711–0.917, p = 0.001, respectively). Patient's age, eGFR before MTX infusion, and co‐administration of vindesine had a significant effect on AKI (OR = 0.960, 95% CI 0.935–0.986, p = 0.003; OR = 1.009, 95% CI 1.001–1.017, p = 0.034; OR = 5.463, 95% CI 1.793–16.646, p = 0.003, respectively). LDH and Co‐administration of vindesine had a significant effect on myelosuppression (OR = 0.985, 95% CI 0.972–0.998, p = 0.025; OR = 3.070, 95% CI 1.032–9.133, p = 0.044). What is New and Conclusion: Our study demonstrated that co‐administration of VDS, eGFR before MTX infusion, and the baseline index of laboratory examinations including ALT, WBC, LDH may be useful biomarkers for predicting MTX‐induced toxicities. [ABSTRACT FROM AUTHOR]

Although >10% of primary CNS lymphoma (PCNSL) patients are ≥80 years, data on this population are limited. We analyzed 19 consecutive octogenarians with PCNSL treated with high-dose methotrexate (HD-MTX)-based chemotherapy at our institution concerning outcome, prognostic factors and living conditions at six-month follow-up for 11 patients alive and in remission. Seven patients received intracerebroventricular (ICV) treatment additional to systemic therapy. Median follow-up was 27.3 months. Median overall survival was 16.3 months. Positive prognosticators of survival were application of ICV treatment (p = 0.033) and female gender (p = 0.015). All 11 patients alive and in remission at 6-month follow-up were living at home with a median Karnofsky performance score of 60 (range 50–90) and a median instrumental activities of daily living score of 3 (range 1–8). HD-MTX-based polychemotherapy including ICV treatment was feasible in this population, patients in remission needed moderate support in everyday live. [ABSTRACT FROM AUTHOR]

Opinion statement: Improvements in systemic therapy in the treatment of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) have improved patient outcomes and reduced the incidence of CNS relapse. However, management of patients with CNS disease remains challenging, and relapses in the CNS can be difficult to salvage. In addition to treatment with CNS-penetrant systemic therapy (high-dose methotrexate and cytarabine), intrathecal prophylaxis is indicated in all patients with ALL, however is not uniformly administered in patients with AML without high-risk features. There is a limited role for radiation treatment in CNS prophylaxis; however, radiation should be considered for consolidative treatment in patients with CNS disease, or as an option for palliation of symptoms. Re-examining the role of established treatment paradigms and investigating the role of radiation as bridging therapy in the era of cellular therapy, particularly in chemotherapy refractory patients, is warranted. [ABSTRACT FROM AUTHOR]

Osteosarcoma (OGS) is the most common primary bone tumor in children and adolescents which requires a multidisciplinary approach to management. Although chemotherapy and surgery can cure more than half of localized OGS cases, the unique challenges faced by resource-limited countries like India make this outcome difficult to achieve. Various questions in the management of OGS including role of high-dose methotrexate (HDMTX) in neoadjuvant setting, triplet vs doublet chemotherapy, intensification of chemotherapy based on response in setting of doublet, and indigenous prosthesis in setting of limb salvage need to be defined. Similarly, in the metastatic and recurrent setting, questions regarding intent of treatment, indications of chemotherapy, timing of surgery, and role of targeted therapies need clarification. Lack of randomized trials from India makes definite conclusions difficult, but an attempt can be made to define the best approach in the Indian scenario from available evidence. Hence, a critical review of literature from India and the West was done to define possible management approaches and highlight the lacuna for future research. [ABSTRACT FROM AUTHOR]

Background: Hydration and urine alkalinization are the mainstays for the prevention of methotrexate-induced nephrotoxicity. Current oncology protocols recommend pediatric patients who are administered high-dose methotrexate (HDMTX) to be aggressively hydrated with an alkaline solution, which may lead to overhydration. This pilot study sought to determine whether reduced posthydration results in a shorter time to methotrexate elimination without increasing adverse effects., Methods: A prospective randomized controlled crossover study design of pediatric patients with acute lymphoblastic leukemia was performed. Patients were randomized to begin with standard or reduced volume intravenous fluids. Over the course of four cycles of HDMTX, patients alternated between the standard rate of 125 mL/m 2 /h and a reduced volume rate of 62.5 mL/m 2 /h. The primary endpoint was the time from the start of HDMTX to a serum methotrexate concentration less than 0.1 µmol/L., Results: Data from 37 HDMTX courses were analyzed in 10 patients aged 1-17 years. The median time to methotrexate elimination was similar between the standard and reduced hydration regimens at 71.7 h (60.8-115.6 h) versus 72.9 h (59.9-132 h, p value = 0.6539). There was no difference in the change from baseline to maximum creatinine (10% vs. 18.9%, p value = 0.6566), maximum weight gain (0.7 kg vs. 0.4 kg, p value = 0.0967), or rates of severe mucositis between hydration regimens., Conclusion: Reduced posthydration appeared to be safe and provided similar time to HDMTX elimination. A multicenter study is indicated to confirm the use of reduced hydration to optimize supportive care in pediatric patients administered HDMTX., Trial Registration: NCT03964259., (© 2025 Wiley Periodicals LLC.)

Ectopic pregnancy is a severe complication of early pregnancy that can lead to significant morbidity and mortality. Methotrexate is a standard non-surgical treatment for ectopic pregnancy, especially in cases where beta-human chorionic gonadotropin (β-HCG) levels are low. However, its effectiveness decreases as β-HCG levels rise. We present a case of a 38-year-old nulliparous woman with a high-β-HCG level ectopic pregnancy, who was managed successfully with methotrexate despite initial concerns about potential treatment failure. This case underscores the importance of patient-centered care, thorough counseling, and a multidisciplinary approach in managing complex ectopic pregnancies, particularly when standard guidelines may not fully apply. The patient was closely monitored and achieved a successful outcome without the need for surgery., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Petroulakis et al.)

Background: Thiotepa-based autologous stem cell transplantation (ASCT) improves survival in primary central nervous system lymphoma (PCNSL), but > 30% of patients are unable to undergo ASCT following commonly used intensive induction regimens., Methods: This retrospective population-based study included consecutive patients ≥ 18 years old with PCNSL who were intended for ASCT in Alberta, Canada between 2011 and 2022. A reduced-intensity induction protocol was further abbreviated in 2018 to decrease toxicity and expediate ASCT by incorporating rituximab, procarbazine, and only 2 doses of high-dose methotrexate and 1 cycle of high-dose cytarabine before consolidation with thiotepa-busulfan conditioning. Progression-free survival (PFS) and overall survival (OS) were determined using the Kaplan-Meier method., Results: Among 71 patients with median age 58 years (range 26-72), ASCT was completed in 56 (79%), with the transplantation rate among patients > 60 years old increasing by 30% following the abbreviation of induction therapy. With median follow-up time 3.9 years, 4-year PFS and OS were 69% (95% CI 56%-79%) and 80% (95% CI 67%-88%) for all patients and 75% (95% CI 57%-86%) and 85% (95% CI 68%-93%) for ASCT recipients, respectively. There was 1 death due to treatment-related mortality during induction and none after ASCT, including among 17 transplanted patients > 60 years old., Conclusion: An abbreviated induction regimen followed by thiotepa-busulfan-based ASCT achieves high transplantation rates with low risks of relapse and treatment-related mortality, thereby providing an effective treatment strategy for PCNSL., Competing Interests: Disclosure The authors have stated that they have no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Methotrexate (MTX) is a folic acid antagonist, the mechanism of action is to inhibit DNA synthesis, repair and cell proliferation by decreasing the activities of several folate-dependent enzymes. It is widely used as a chemotherapy drug for children and adults with malignant tumors. High-dose methotrexate (HD-MTX) is an effective treatment for extramedullary infiltration and systemic consolidation in children with acute lymphoblastic leukemia (ALL). However, significant toxicity results in most patients treated with HD-MTX, which limits its use. HD-MTX-induced toxicity is heterogeneous, and this heterogeneity may be related to gene polymorphisms in related enzymes of the MTX intracellular metabolic pathway. To gain a deeper understanding of the differences in toxicity induced by HD-MTX in individuals, the present review examines the correlation between HD-MTX-induced toxicity and the gene polymorphisms of related enzymes in the MTX metabolic pathway in ALL. In this review, we conclude that only the association of SLCO1B1 and ARID5B gene polymorphisms with plasma levels of MTX and MTX-related toxicity is clearly described. These results suggest that SLCO1B1 and ARID5B gene polymorphisms should be evaluated before HD-MTX treatment. In addition, considering factors such as age and race, the other exact predictor of MTX induced toxicity in ALL needs to be further determined. [ABSTRACT FROM AUTHOR]

Background: Primary central nervous system lymphomas (PCNSLs) are sensitive to chemotherapy. The standard treatment is high-dose methotrexate (MTX)-based chemotherapy. There are no reports of successful treatment of acute uric acid nephropathy with rasburicase after MTX administration in PCNSLs. Case presentation: A 54-year-old man with a history of gout presented with a change in character and cognitive dysfunction. MRI showed a large enhancing mass spanning the bilateral frontal lobes and the right temporal lobe. After endoscopic biopsy, an MTX, procarbazine, and vincristine (MPV) regimen was initiated for the treatment of the PCNSL. After the initiation of chemotherapy, the patient experienced a gout attack, and blood examination revealed acute renal failure (ARF) and hyperuricemia. The considered causes of ARF included MTX toxicity and acute uric acid nephropathy. As the dramatic effect of MTX was observed, treatment was continued despite ARF, most probably due to acute hyperuricemia due to tumor lysis, which was treated in parallel. After an improvement in renal function, MTX was resumed, and rasburicase was initiated to control hyperuricemia. A complete response was obtained after induction chemotherapy. Hyperuricemia was controlled with rasburicase, and renal function was preserved. Conclusions: Acute uric acid nephropathy should be considered when ARF occurs after the initiation of MTX in PCNSLs, especially in newly diagnosed PCNSL patients with large tumors or hyperuricemia. [ABSTRACT FROM AUTHOR]