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Background: The predictive value of programmed death-ligand 1 (PD-L1) expression in nasopharyngeal cancer (NPC) patients receiving immune checkpoint inhibitors (ICIs) remains controversial. This study aimed to evaluate the optimal threshold of PD-L1 expression in predicting the efficacy of ICIs in patients with recurrent or metastatic (R/M) NPC. Methods: A meta-analysis was performed by retrieving relevant literature from PubMed, EMBASE, and Cochrane Library databases. Data on the pooled risk ratio (RR), mean overall survival (OS), progression-free survival (PFS), overall response rate (ORR) with 95% confidence interval, and 1%, 10%, and 25% PD-L1 expression cutoff points were obtained to examine the role of PD-L1 as a biomarker in R/M NPC patients receiving immunotherapy. Results: In total, 1,312 patients from 14 studies were included. An improvement in PFS was observed in both patients with PD-L1 ≥ 1% (RR = 0.76, 95% CI 0.62-0.92, P = 0.005) and those with PD-L1 < 1% (RR = 0.68, 95% CI: 0.35-1.32, P = 0.26) who received first-line treatment with immunotherapy, with no significant difference between these subgroups. The pooled ORR was significantly higher in patients with PD-L1 ≥ 1% (ORR = 0.37) than in those with PD-L1 < 1% (ORR = 0.22) (P < 0.01) undergoing subsequent-line treatment. However, when we used the PD-L1 cutoff values of 10% and 25%, there was no significant difference between the positive (PD-L1 expression ≥ the cutoff value) and negative (PD-L1 expression < the cutoff value) subgroups. PD-L1 ≥ 1% also tended to be associated with better PFS and OS. Conclusions: Our meta-analysis suggested that first-line immunotherapy could significantly improve PFS in R/M NPC patients, regardless of the PD-L1 expression levels. Positive PD-L1 expression (≥ 1%) might be a potential predictive biomarker for a better overall response to immunotherapy in R/M NPC patients in subsequent-line setting. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024495841 PROSPERO, identifier CRD42024495841. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is a malignant tumor characterized by the malignant transformation of nasopharyngeal epithelial cells. It is highly sensitive to radiation therapy, making radiotherapy the primary treatment modality. However, 60-80% of patients are initially diagnosed with locally advanced NPC (LA-NPC), where radiotherapy alone often fails to achieve desirable outcomes. Therefore, combining radiotherapy with chemotherapy has emerged as an effective strategy to optimize treatment for LA-NPC patients. Among the various chemotherapy regimens, concurrent chemoradiotherapy (CCRT) using platinum-based drugs has been established as the most commonly utilized approach for LA-NPC patients. The extensive utilization of platinum drugs in clinical settings underscores their therapeutic potential and emphasizes ongoing efforts in the development of novel platinum-based complexes for anticancer therapy. The aim of this review is to elucidate the remarkable advances made in the field of platinum-based therapies for nasopharyngeal carcinoma, emphasizing their transformative impact on patient prognosis. [ABSTRACT FROM AUTHOR]

Background: We conducted this study to evaluate if a reduced cumulative dose of induction and concurrent cisplatin conferred similar favorable outcomes when compared to trial NPC-0501. Methods: Newly diagnosed nasopharyngeal carcinoma (NPC) with stage III-IVA were prospectively recruited from January 2015 to September 2019. Induction chemotherapy (IC) consisted of cisplatin 80mg/m2 on day 1 and capecitabine 1000mg/m2 twice daily from day 1 to 14 every 3 weeks for 3 cycles followed by concurrent chemoradiotherapy (CCRT) with 2 cycles of cisplatin 100mg/m2 given every 3 weeks. Tumor response was evaluated according to RECIST v1.1. Acute and late adverse events (AEs) were graded with CTCAE v4.0 and Late Radiation Morbidity Scoring of the RTOG, respectively. Results: 135 patients were recruited. At 16 weeks after CCRT, all 130 patients who completed the entire course of radiotherapy (RT) had a complete response upon final assessment. With a median follow-up of 36.2 months, 22 treatment failures and 8 deaths were observed. The 3-year progression-free survival, overall survival, locoregional recurrence-free survival, and distant recurrence-free survival were 83.7%, 94.1%, 94.1%, and 85.9%, respectively. Our survival data outcomes were similar to those reported in the cisplatin and capecitabine (PX) induction arm of the 0501 trial. 103 patients (76.3%) reported acute grade 3-4 AEs. Two patients (1.5%) had late grade 3-4 complications, numerically fewer than those reported in the NPC-0501 trial. Conclusions: Induction PX and concurrent cisplatin with a reduced cumulative cisplatin dose yield survival outcomes comparable to those reported in the NPC-0501 trial with excellent tolerability. Therefore, a reduced cumulative dose of cisplatin is a promising treatment scheme for nasopharyngeal carcinoma. [ABSTRACT FROM AUTHOR]

Nasopharyngeal cancer (NPC) is one of the most difficult cancers in the head and neck region due to the complex geometry of the tumour and the surrounding critical organs. High-dose radical radiotherapy with or without concurrent platinum-based chemotherapy is the primary treatment modality. Around 10%–15% of NPC patients have their diagnosis at age after 70. The management of NPC in elderly patients is particularly challenging as they encompass a broad range of patient phenotypes and are often prone to treatment-related toxicities. Chronologic age alone is insufficient to decide on the management plan. Comprehensive geriatric assessment with evaluation on patients' functional status, mental condition, estimated life expectancy, comorbidities, risks and benefits of the treatment, patients' preference, and family support is essential. In addition, little data from randomized controlled trials are available to guide treatment decisions in elderly patients with NPC. In deciding which treatment strategy would be suitable for an individual elderly patient, we reviewed the literature and reviewed the analysis of primary studies, reviews, and guidelines on management of NPC. This review also summarises the current evidence for NPC management in elderly adults from early to late stage of disease. [ABSTRACT FROM AUTHOR]

Objective: Anti-EGFR Targeted agents were found to be capable of modulating the antitumor immunity in head and neck cancer and become more and more frequently used in the treatment of nasopharyngeal carcinoma(NPC). We aimed to explore whether adding concurrent chemotherapy influences the survival outcome of patients with stage II-IVb NPC treated with concurrent anti-EGFR agents and intensity-modulated radiation therapy (IMRT) and explore other prognostic factors for the patients. Materials and Methods: A total of 656 stage II-IVb NPC patients treated with concurrent anti-EGFR agents plus IMRT between January 2011 and November 2015 were enrolled. Firstly, from these patients, a well-balanced cohort of 302 patients who received concurrent chemotherapy was created by matching potential prognostic factors. Furthermore, for all 656 stage II-IVb NPC patients, univariate and multivariate analyses of overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRRFS) and distant metastasis-free survival (DMFS) were conducted to identify prognostic factors and to confirm the findings from the matching cohort. Results: Compared with concurrent anti-EGFR agents alone, combining concurrent cisplatin and anti-EGFR agents significantly improved the OS (5-year 94.7% versus 84.3%, P=0.012) and PFS (5-year 82.0% versus 71.7%, P=0.039) of NPC patients with more severe hematologic toxicity and mucositis. The independent prognostic factors identified by multivariate analysis of OS and PFS included concurrent chemotherapy, epstein-barr virus(EBV) status and clinical stage. Patients treated without induction chemotherapy (IC) may achieve more benefits from the addition of concurrent chemotherapy to concurrent anti-EGFR agents. Conclusions: For stage II-IVb NPC patients treated with concurrent anti-EGFR agents, the addition of concurrent chemotherapy can significantly improve the survival outcome. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy and safety of induction chemotherapy (IC) combined with concurrent chemoradiotherapy (CCRT) versus CCRT combined with adjuvant chemotherapy (AC) in patients with stage II–IVA nasopharyngeal carcinoma (NPC), we conducted a retrospective study and a meta-analysis combining the results of our studies. Patients and Methods: We used the propensity score matching (PSM) to balance variables. A total of 168 patients were chosen by one-to-two PSM, including 101 patients with IC + CCRT and 67 cases with CCRT + AC. We used the Kaplan–Meier curve to compare survival outcomes and also used Cox regression analysis to determine independent prognostic factors. For meta-analysis, we determined the related studies by searching the PubMed database. We used STATA v12 software to perform meta-analysis of the extracted data and calculate pooled hazard ratios, 95% confidence intervals of survival outcomes, and risk ratios for the toxicities. Results: In this retrospective study, there was no significant difference in 5-year overall survival (76.9% vs. 79.0%, P = 0.966), progression-free survival (71.3% vs. 68.5%, P = 0.332), distant metastasis-free survival (80.5% vs. 74.2%, P = 0.140), and locoregional relapse-free survival (91.5% vs. 91.8%, P = 0.894) among patients with NPC with IC + CCRT versus CCRT + AC after PSM. For meta-analysis, six articles (including our study) reporting 1,052 cases of IC + CCRT and 883 cases of CCRT + AC were included in the meta-analysis. There was no difference of OS (pooled HR = 0.90, 95% CI: 0.63–1.29, P = 0.561), PFS (pooled HR = 1.07, 95% CI: 0.87–1.33, P = 0.633), DMFS (pooled HR= 0.98, 95% CI: 0.76-1.25, P =0.861), and LRRFS (pooled HR = 1.06, 95% CI: 0.76–1.48, P = 0.724). Conclusion: The efficacy of IC + CCRT and CCRT + AC was comparable in patients with stage II–IVA NPC. In terms of compliance and acute adverse reactions, IC + CCRT may be a potential therapeutic strategy. [ABSTRACT FROM AUTHOR]

Objective: To compare the dosimetric parameters of different radiotherapy plans [helical tomotherapy (HT), volume-modulated arc therapy (VMAT), and fixed-field intensity-modulated radiation therapy (FF-IMRT)] for locally advanced nasopharyngeal carcinoma (NPC). Methods: A total of 15 patients with locally advanced NPC were chosen for this retrospective analysis and replanned for HT, VMAT, and FF-IMRT. The prescribed planning target volume (PTV) dose for the primary tumor and metastatic lymph nodes was 70 Gy (2.12 Gy/fraction, delivered over 33 fractions). The prescribed PTV dose for the high-risk subclinical region was 59.4 Gy (1.8 Gy/fraction, delivered over 33 fractions). The dosimetric parameters of the PTV and organs at risk (OARs) and the efficiency of radiation delivery were assessed and compared using the paired-samples t-test. Results: Compared with VMAT and FF-IMRT plans, HT plans significantly improved the mean conformity index (CI) and homogeneity index (HI). The HT plans reduced the maximum doses delivered to OARs, such as the brainstem, spinal cord, and optic nerves, and significantly reduced the volume delivered to the high-dose region, especially when examining the V 30 value of the parotid glands. However, VMAT reduced the treatment time and improved the efficiency of radiation delivery compared with HT. Conclusions: For locally advanced NPC, the results showed that HT and VMAT possessed better target homogeneity and conformity, reducing the dose delivered to OARs compared with conventional FF-IMRT, with HT achieving the best effect. Among the techniques studied, VMAT had the shortest radiation delivery time. The results of this study can provide guidance for the selection of appropriate radiation technologies used to treat patients with locally advanced NPC who are undergoing concurrent chemoradiotherapy. [ABSTRACT FROM AUTHOR]

Background: Oxaliplatin (OXA), a third-generation platinum derivative, has become one of the main chemotherapeutic drugs for colorectal cancer and other cancers, but reports of adverse reactions are also increasing with the extensive application of OXA. In this study, post-marketing surveillance was carried out to investigate the safety profile of OXA in a real-world setting in Chinese cancer patients to provide a reference for the rational application of OXA. Methods: All patients with cancer who received OXA-based chemotherapy in 10 tertiary hospitals in Hubei Province, China, between May 2016 and November 2016 were enrolled. A central registration method was used to document patients' demographics, clinical use, and any incidence of adverse reactions to OXA. All adverse drug reactions (ADRs) were collected and analyzed to assess causality, severity, treatment, and outcome. Results: In total, 3687 patients were enrolled in this study. Approximately 64.6% of the patients were male, and 68.8% were aged 50-70 years, with a mean age of 55.3 years. The proportions of patients diagnosed with colorectal and gastric cancers were 59.3% and 31.6%, respectively. In this study, the overall incidence of ADRs and serious ADRs was 42.7% and 1.3%, respectively. The most common ADRs were gastrointestinal disorders (25.7%), blood disorders (21.1%), and peripheral nervous system disorders (8.0%). The serious ADRs identified were hypersensitivity reactions, thrombocytopenia, abnormal hepatic function, and leukopenia/neutropenia. The median onset of gastrointestinal toxicity, myelosuppression, peripheral neurotoxicity, and abnormal hepatic function was 1 d, 5 d, 1 d, and 14 d, respectively. The majority (84.7%) of hypersensitivity reactions were mild to moderate, and the median time to onset of these reactions was within the first 20 min of OXA infusion. Almost 88.0% of patients who experienced ADRs recovered or improved with treatment. Conclusion: Our data suggest that OXA-induced ADRs are very common in Chinese patients with cancer; however, more attention should be paid to hypersensitivity reactions caused by OXA. This study provides a valuable reference regarding the safe application of OXA in a real-world setting. [ABSTRACT FROM AUTHOR]

Purpose: Radiotherapy is the most important primary treatment for patients with nasopharyngeal carcinoma. Generally, the treatment duration of radiotherapy takes six or six and half weeks with 30 to 33 fractions. The current study was conducted to evaluate the association between prognosis and the duration of radiotherapy in nasopharyngeal carcinoma patients. Methods: Patients with primary nasopharyngeal carcinoma who were treated with intensity-modulated radiotherapy and concurrent cisplatin-based chemotherapy, with or without induction chemotherapy between January, 2008 and December, 2013 at a single institution were retrospectively reviewed. Results: In total, 1292 patients were included. At a median follow-up of 71.0 months (range 2.0–126.0 months), locoregional recurrence, distant failure and death were observed in 8.8%, 12.2% and 15.6% of all patients, respectively. Estimated 5-year locoregional relapse–free survival, distant metastasis–free survival, progression-free survival and overall survival in patients with radiation ≤ 7 weeks versus patients with radiation >7 weeks were: 93.2% versus 87.0% (P < 0.001), 89.4% versus 84.4% (P = 0.016), 79.8% versus 70.6% (P < 0.001) and 87.2% versus 78.4% (P < 0.001), respectively. Conclusions: Prolonged duration of radiotherapy with a significantly higher risk of distant metastasis and death in nasopharyngeal carcinoma patients. Understanding this point, healthcare providers should make efforts to avoid prolonged duration of radiotherapy to minimize the risk of treatment failure. [ABSTRACT FROM AUTHOR]

Background: The efficiency of concurrent chemotherapy (CC) remains controversial for stage II–IVa nasopharyngeal carcinoma (NPC) patients treated with induction chemotherapy (IC) followed by intensity-modulated radiotherapy (IMRT). Therefore, we aimed to propose a nomogram to identify patients who would benefit from CC. Methods: A total of 434 NPC patients (stage II–IVa) treated with IC followed by IMRT between January 2010 and December 2015 were included. There were 808 dosimetric parameters extracted by the in-house script for each patient. A dosimetric signature was developed with the least absolute shrinkage and selection operator algorithm. A nomogram was built by incorporating clinical factors and dosimetric signature using Cox regression to predict recurrence-free survival (RFS). The C-index was used to evaluate the performance of the nomogram. The patients were stratified into low- and high-risk recurrence according to the optimal cutoff of risk score. Results: The nomogram incorporating age, TNM stage, and dosimetric signature yielded a C-index of 0.719 (95% confidence interval, 0.658–0.78). In the low-risk group, CC was associated with a 9.4% increase of 5-year locoregional RFS and an 8.8% increase of 5-year overall survival (OS), whereas it was not significantly associated with an improvement of locoregional RFS (LRFS) and OS in the high-risk group. However, in the high-risk group, patients could benefit from adjuvant chemotherapy (AC) by improving 33.6% of the 5-year LRFS. Conclusions: The nomogram performed an individualized risk quantification of RFS in patients with stage II–IVa NPC treated with IC followed by IMRT. Patients with low risk could benefit from CC, whereas patients with high risk may require additional AC. [ABSTRACT FROM AUTHOR]

Background: The prognostic value of epidermal growth factor receptor (EGFR)/phosphorylated EGFR (p-EGFR) expression in nasopharyngeal carcinoma remains controversial. A meta-analysis was performed to investigate prognostic significance of EGFR/p-EGFR expression in patients with nasopharyngeal carcinoma. Methods: Literatures published before November 2020 were systematically searched in relevant databases, including PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and Wan fang databases. STATA 13 statistical software was used to analyze the pooled hazard ratio (HR) and 95% confidence interval (CI). Heterogeneity of the studies was examined by I2. Sensitivity and subgroup analysis were performed to explore sources of heterogeneity. The potential publication bias was assessed using both Egger's and Begg's tests. Results: A total of 20 literatures with 1545 patients were included for the meta-analysis. The meta-analysis results suggested that high expression of EGFR was significantly associated with poor overall survival (OS) (HR = 1.70, 95% CI: 1.24–3.15, P = 0.001) and disease-free survival (DFS) (HR = 2.58, 95% CI: 1.87–3.56, P = 0.000). However, it was not significantly associated with progression-free survival (PFS) (HR = 1.85, 95% CI: 0.90–3.82, P = 0.09) and distant metastasis-free survival (DMFS) (HR = 1.39, 95% CI: 0.73–2.67, P = 0.319). The subgroup analysis indicated that patients with EGFR high expression in studies of higher TNM stage (III–IV) ratio had significantly poor OS (HR = 2.27, 95% CI: 1.09–4.73, P = 0.03), but heterogeneity existed in studies (I2 = 95.1%, P = 0.000). Sensitivity analyses revealed that EGFR expression did not significantly affect OS by an individual study solely, indicating there was inherent heterogeneity in OS cohorts. There was no significant heterogeneity among eight studies in the DFS cohorts (I2 = 0%, P = 0.606). There was significant heterogeneity between EGFR expression and DMFS (I2 = 82.8%, P = 0.000). Sub-group analysis in differentiated carcinoma demonstrated a smaller heterogeneity (I2 = 33.2%). In addition, p-EGFR high expression had no significant correlation with OS (HR = 1.00, 95% CI: 0.88–1.14, P = 0.982) and DMFS (HR = 1.21, 95% CI: 0.96–1.52, P = 0.112). The heterogeneity among p-EGFR and OS studies was small (I2 = 21%, P = 0.26). There was no significant heterogeneity in the DMFS cohorts (I2 = 0%, P = 0.497). Conclusion: EGFR high-expression was significantly associated with poor OS and DFS, which may serve as a prognostic predictor for nasopharyngeal cancer. Systematic Review Registration: [ https://www.crd.york.ac.uk/PROSPERO ], identifier [number CRD42021258457]. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors of the head and neck, and it originates from the mucous epithelium of the nasopharynx. Because it is "hidden", the symptoms of NPC can easily be missed, and more than 70% of patients present with locally advanced disease at diagnosis. Concurrent radiation therapy with chemotherapy can significantly improve regional control of NPC. At present, distant metastasis is the main cause of treatment failure. At the end of the 20th century, clinical trial No. IG0099 in the United States confirmed the effectiveness of adjuvant chemotherapy (AC) for the first time. However, in the past 20 years, various clinical trials and meta-analyses conducted globally have yielded contradictory results regarding the effect of AC on locally advanced NPC. AC has changed from category 1 to the current category 2A in the National Comprehensive Cancer Network (NCCN) guidelines, and it remains controversial whether AC can significantly improve the survival of NPC patients. Here, we comprehensively analyzed the role of AC in locally advanced NPC by comparing some treatment methods. We conclude the role of AC in treating locally advanced NPC, based on the studies presented, remains undefined but is associated with increased toxicity. [ABSTRACT FROM AUTHOR]

Cerebral radiation necrosis (CRN) is one of the most prominent sequelae following radiation therapy for nasopharyngeal carcinoma (NPC), which might have devastating effects on patients' quality of life (QOL). Advances in histopathology and neuro-radiology have shed light on the management of CRN more comprehensively, yet effective therapeutic interventions are still lacking. CRN was once regarded as progressive and irreversible, however, in the past 20 years, with the application of intensity-modulated radiation therapy (IMRT), both the incidence and severity of CRN have declined. In addition, newly developed medical agents including bevacizumab-a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), nerve growth factor (NGF), monosialotetrahexosylganglioside (GM1), etc., have shown great potency in successfully reversing radiation-induced CRN. As temporal lobes are most frequently compromised in NPC patients, this review will summarize the state-of-the-art progress regarding the incidence, pathophysiology, prevention, treatment, and prognosis of temporal lobe necrosis (TLN) after IMRT in NPC. [ABSTRACT FROM AUTHOR]

Background and Aims: Malnutrition is a concern in patients with nasopharyngeal carcinoma (NPC) during chemoradiotherapy (CRT)/radiotherapy (RT), which is considered to be related with radiation–induced oral mucositis (ROM). The study aimed to evaluate the nutritional status of NPC patients during RT and investigate its association with ROM. Methods: A prospective study was conducted in NPC patients. Patients were divided into three subgroups (mild, moderate, and severe groups) based on the duration of severe ROM (≥ grade 3). Body weight, body mass index (BMI), albumin, prealbumin, NRS2002, and ROM grade were assessed on a weekly basis before and during CRT/RT. The statistical analysis was performed in the overall group and between three subgroups. Results: A total of 176 patients were included. In the overall group, body weight and BMI kept decreasing since week 1 of RT, and NRS2002 score and ROM grade increased (p < 0.001). NRS2002 score and prealbumin levels were significantly different between each subgroup (p ≤ 0.046). Significant differences were observed in the proportion of patients receiving enteral nutrition, duration of parenteral nutrition, and total calories provided by nutritional support among three subgroups (p = 0.045–0.001). Conclusions: Malnutrition occurred early in NPC patients and worsened continuously during RT. ROM was strongly associated with nutritional status. Nutritional support should be provided at the start of RT, especially in patients at high-risk of severe ROM. [ABSTRACT FROM AUTHOR]

Background: Patients with metastatic nasopharyngeal carcinoma (NPC) have heterogeneous survival outcomes. This study aimed to establish an effective prognostic nomogram for patients with NPC with distant metastases using easily determined factors. Methods: The nomogram was based on a retrospective study of 103 patients with metastatic NPC at the First Affiliated Hospital of Xiamen University during January 2009–March 2016. Nomogram performance was evaluated using a concordance index (C-index) and assessed using calibration plot. Bootstraps with 1,000 resamples were applied to these analyses. Results: In univariate and multivariate Cox proportional hazards model analyses, chemotherapy, metastatic liver involvement, number of tumor metastases, N stage and derived neutrophil–lymphocyte ratio correlated with overall survival (OS). The recurrence probability calibration curve indicated good agreement between nomogram-based predictions and actual observations. For OS predictions, the nomogram had a C-index of 0.824 (95% confidence interval, 0.74–0.91). The stratification by nomogram score of patients into different subgroups showed significant distinction. Conclusion: This novel nomogram comprises factors that are easily determined at most hospitals and can predict survival in patients with distant metastases of NPC. This model can precisely estimate the survival of individual patients and identify subgroups of patients requiring specific therapeutic strategies. [ABSTRACT FROM AUTHOR]

Trastuzumab is established as standard care for patients with HER2-positive breast cancer both in the adjuvant and metastatic setting. However, approximately 50% of the patients do not respond to the trastuzumab therapy, and therefore new predictive biomarkers are highly warranted. MicroRNAs (miRs) constitute a new group of biomarkers and their cellular expression can be determined in tumor samples by in situ hybridization (ISH) analysis. miR-21 is highly prevalent and up-regulated in breast cancer and has been linked to drug resistance in clinical and in vitro settings. To determine expression patterns of miR-21 in high-grade breast cancers, we examined miR-21 expression in 22 HER2-positive tumors and 15 HER2-negative high-grade tumors by ISH. The histological examination indicated that patient samples could be divided into 3 major expression patterns: miR-21 predominantly in tumor stroma, predominantly in cancer cells or in both stromal and cancer cells. There was no obvious difference between the HER2-positive and HER2-negative tumors in terms of the miR-21 expression patterns and intensities. To explore the possibility that miR-21 expression levels and/or cellular localization could predict resistance to adjuvant trastuzumab in HER2-positive breast cancer patients, we analyzed additional 16 HER2-positive tumors from patients that were treated with trastuzumab in the adjuvant setting. Eight of the 16 patients showed clinical recurrence and were considered resistant. Examination of the miR-21 expression patterns and intensities revealed no association between the miR-21 scores in the cancer cell population (p=0.69) or the stromal cells population (p=0.13) and recurrent disease after adjuvant trastuzumab. Thus, our findings show that elevated miR-21 expression does not predict resistance to adjuvant trastuzumab. [ABSTRACT FROM AUTHOR]