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There are no standard treatments to prevent or hasten the recovery from severe conditioning-regimen–induced thrombocytopenia occurring after autologous hematopoietic cell transplantation (auto-HCT). We conducted an open-label, single-arm pilot study of romiplostim, a thrombopoietin receptor agonist, to enhance platelet recovery in patients with multiple myeloma or lymphoma undergoing auto-HCT. All patients were treated weekly with romiplostim starting day +1 after auto-HCT until the platelet count was >50 × 109/L without transfusion. Compared with contemporary retrospective data from romiplostim-naïve patients (N = 853), romiplostim-treated patients (N = 59) had a similar median number of days of grade 4 thrombocytopenia or days requiring transfusions, time to platelet engraftment, and number of platelets transfusions during the auto-HCT. However, romiplostim-treated patients had enhanced platelet recovery to normal values beginning at approximately day +15. In matched cohort multivariable analyses, romiplostim treatment was associated with higher platelet counts by an average of 40 × 109/L (95% confidence interval (CI) (14, 67), P = .003) and 118 × 109/L (95% CI [84, 152], P

Cancer-associated thrombosis, with the incidence rising over the years, is associated with significant morbidity and mortality in patients with cancer. Recent advances in the treatment of cancer-associated venous thromboembolism (VTE) include the introduction of direct oral anticoagulants (DOACs), which provide a more convenient and effective option than low-molecular-weight heparin (LMWH). Nonetheless, important unmet needs remain including an increased risk of bleeding in certain patient subgroups such as those with gastroesophageal cancer, concerns about drug-drug interactions, and management of patients with severe renal impairment. Although DOACs are more convenient than LMWH, persistence can decline over time. Factor XI inhibitors have potential safety advantages over DOACs because factor XI appears to be essential for thrombosis but not hemostasis. In phase II trials, some factor XI inhibitors were superior to enoxaparin for the prevention of VTE after knee replacement surgery without increasing the risk of bleeding. Ongoing trials are assessing the efficacy and safety of factor XI inhibitors for the treatment of cancer-associated VTE. ispartof: ONCOLOGIST vol:28 issue:7 ispartof: location:England status: Published online

Background: Cancer patients with venous thromboembolic (VTE) disease are complex, and many factors must be considered when initiating anticoagulation management. Clinical decision support systems can aid in decision-making by utilizing guidelines at the point of care. Objectives: The purpose of our project was to develop, implement, and evaluate an electronic clinical decision tool (CDT) utilizing evidence-based guidelines to aid in decision-making for adult oncologic patients who present with new VTE to symptom care clinics. Methods: We compared a pre-intervention group of patients who were prescribed anticoagulation (n = 98) with two post-intervention groups: CDT applied (n = 96) and not applied (n = 46). Outcomes included whether the CDT anticoagulation recommendations were followed and if the tool was perceived to be helpful or improve confidence in initiating management for new VTE by the SCC advanced practitioners and physicians. Results: There was no significant difference between the pre- and post-intervention groups in how many of the CDT anticoagulation recommendations were followed (68.8% pre-intervention, 60.8% post-intervention tool applied, and 63.5% post-intervention tool not applied; χ2 [2, N = 161] = .921, p = .631). However, the tool was found to be helpful and improved confidence of the providers in initiating management for new VTE (pre median = 3, interquartile range [IQR] = 2, 3.5; post median = 3, IQR 3, 4; p = .033). Conclusion: This CDT provided evidence-based anticoagulation recommendations for cancer-associated VTE and enhanced familiarity with the standard of care. Further development of the CDT will be required to account for situations that resulted in deviation from the recommendations.

Objective The objective of this study was to examine the pathophysiology of ischemic stroke with cancer. Methods We conducted a prospective cross-sectional study from 2016 to 2020 at 2 hospitals. We enrolled 3 groups of 50 adult participants each. The main group included patients with active solid tumor cancer and acute ischemic stroke. The control groups included patients with acute ischemic stroke only or active cancer only. The patients with stroke-only and patients with cancer-only were matched to the patients with cancer-plus-stroke by age, sex, and cancer type, if applicable. The outcomes were prespecified hematological biomarkers and transcranial Doppler microemboli detection. Hematological biomarkers included markers of coagulation (D-dimer and thrombin-antithrombin), platelet function (P-selectin), and endothelial integrity (thrombomodulin, soluble intercellular adhesion molecule-1 [sICAM-1], and soluble vascular cell adhesion molecule-1 [sVCAM-1]). Hematological biomarkers were compared between groups using the Kruskal-Wallis and Wilcoxon Rank-Sum tests. In multivariable linear regression models, we adjusted for race, number of stroke risk factors, smoking, stroke severity, and antithrombotic use. Transcranial Doppler microemboli presence was compared between groups using chi-square tests. Results Levels of all study biomarkers were different between groups. In univariate between-group comparisons, patients with cancer-plus-stroke had higher levels of D-dimer, sICAM-1, sVCAM-1, and thrombomodulin than both control groups; higher levels of thrombin-antithrombin than patients with cancer-only; and higher levels of P-selectin than patients with stroke-only. Findings were similar in multivariable analyses. Transcranial Doppler microemboli were detected in 32% of patients with cancer-plus-stroke, 16% of patients with stroke-only, and 6% of patients with cancer-only (p = 0.005). Interpretation Patients with cancer-related stroke have higher markers of coagulation, platelet, and endothelial dysfunction, and more circulating microemboli, than matched controls. ANN NEUROL 2021;90:159-169.

Thrombocytopenia results from a variety of conditions, including radiation, chemotherapy, autoimmune disease, bone marrow disorders, pathologic conditions associated with surgical procedures, hematopoietic stem cell transplant (HSCT), and hematologic disorders associated with severe aplastic anemia. Immune thrombocytopenia (ITP) is caused by immune reactions that accelerate destruction and reduce production of platelets. Thrombopoietin (TPO) is a critical component of platelet production pathways, and TPO receptor agonists (TPO-RAs) are important for the management of ITP by increasing platelet production and reducing the need for other treatments. Romiplostim is a TPO-RA approved for use in patients with ITP in the United States, European Union, Australia, and several countries in Africa and Asia, as well as for use in patients with refractory aplastic anemia in Japan and Korea. Romiplostim binds to and activates the TPO receptor on megakaryocyte precursors, thus promoting cell proliferation and viability, resulting in increased platelet production. Through this mechanism, romiplostim reduces the need for other treatments and decreases bleeding events in patients with thrombocytopenia. In addition to its efficacy in ITP, studies have shown that romiplostim is effective in improving platelet counts in various settings, thereby highlighting the versatility of romiplostim. The efficacy of romiplostim in such disorders is currently under investigation. Here, we review the structure, mechanism, pharmacokinetics, and pharmacodynamics of romiplostim. We also summarize the clinical evidence supporting its use in ITP and other disorders that involve thrombocytopenia, including chemotherapy-induced thrombocytopenia, aplastic anemia, acute radiation syndrome, perisurgical thrombocytopenia, post-HSCT thrombocytopenia, and liver disease.

Malignancy is a significant risk factor for venous thromboembolism (VTE). It is estimated that up to 20% of patients with cancer may develop VTE at some time in their cancer journey. Cancer-associated VTE can lead to hospitalizations, morbidity, delayed cancer treatment, and mortality. The optimal prevention and management of cancer-associated thrombosis (CAT) is of utmost importance. Direct oral anticoagulants have been recommended as first-line therapy for VTE treatment in the general population and their efficacy has recently been demonstrated in the cancer population, leading to increased use. However, patients with cancer have unique challenges and comorbidities that can lead to increased risks and concerns with anticoagulation. Herein we will discuss commonly encountered challenges in patients with CAT, review available literature, and provide practice suggestions. Implications for Practice This article aims to specifically address cancer-associated thrombosis issues for which there is limited or absent evidence to guide best practice, for circumstances that pose unique challenges for clinicians, and for directions when the literature is conflicting. It reviews pertinent data for each selected topic and provides guidance for patient management based on the best available evidence and experiences from the panel.

Chemotherapy-induced thrombocytopenia (CIT) is a known hematologic complication of oncology treatment. This single-institution study examines the degree with which CIT impacts specific pediatric solid tumor cohorts reflected by platelet transfusion burden and treatment modifications.Data regarding clinically relevant CIT were obtained via a retrospective chart review of pediatric solid tumor patients treated at Memorial Sloan Kettering Cancer Center from 2013 to 2020. Patients were stratified based on histologic diagnoses as well as chemotherapy regimen. CIT impact was assessed through platelet transfusion means, chemotherapy dose reductions, and treatment delays.A total of 150 patients were included with mean age 10.3 [0.2-21.0]. Patients receiving therapy for high-risk neuroblastoma and localized Ewing sarcoma, both of which included high-dose cyclophosphamide and doxorubicin, required the most platelet transfusions over the treatment course, with a mean of 13 and 9, respectively. Reduced relative dose intensity (RDI), due in part to CIT, was greatest for the patients receiving therapy for high-risk and intermediate-risk rhabdomyosarcoma. Fifty-six percent of high-risk patients experienced a reduced RDI during the final two cycles of treatment and 69% of intermediate-risk patients experienced one during the final four cycles of treatment.The impact of CIT varied by the administered chemotherapy regimens and dose intensity of chemotherapy agents. This study demonstrated that CIT causes both marked platelet transfusion burden as well as treatment reduction and delay within certain solid tumor cohorts. This can lend to future studies aimed at reducing the burden of CIT and targeting the most at-risk populations.

Since the development of the Khorana score to predict risk of cancer-associated venous thromboembolism (VTE), many modified and de novo risk prediction models (RPMs) have been proposed. Comparison of the prognostic performance across models requires comprehensive reporting and standardized methods for model development, validation and evaluation. To improve the standardization of RPM reporting, the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) tool was published in 2015. To better understand the quality of reporting and development of RPMs for cancer-associated VTE, we performed a literature search of published RPMs and assessed each model using the TRIPOD checklist. Our results yielded 29 RPMs for which 30 items were evaluated. There was a non-significant (p = 0.15) improvement in reporting of the 30 items in the post-TRIPOD era (81%) versus the pre-TRIPOD era (75%). Of seven items (title, sample size, missing data handling, baseline demographics, methods and results for model performance, and supplemental resources) with the lowest reporting in the pre-TRIPOD era (70%), there was an average improvement of 22% in the post-TRIPOD era. Only two of the 22 studies published in the post-TRIPOD era acknowledged compliance with TRIPOD. Informed by the results of this assessment, the Scientific and Standardization Committee (SSC) Subcommittee on HemostasisMalignancy of the International Society on Thrombosis and Hemostasis (ISTH) advocates for standardization of four key elements of RPMs for cancer-associated VTE: (1) inclusion of the TRIPOD checklist, (2) clear definition of the derivation population, with justification of sample size, (3) clear definition of predictors, and (4) external validation prior to implementation.

Cancer‐associated venous thromboembolism (VTE) is a frequent, potentially life‐threatening event that complicates cancer management. Anticoagulants are the cornerstone of therapy for the treatment and prevention of cancer‐associated thrombosis (CAT); factor Xa–inhibiting direct oral anticoagulants (DOACs; apixaban, edoxaban, and rivaroxaban), which have long been recommended for the treatment of VTE in patients without cancer, have been investigated in this setting. The first randomized comparisons of DOACs against low‐molecular‐weight heparin for the treatment of CAT indicated that DOACs are efficacious in this setting, with findings reflected in recent updates to published guidance on CAT treatment. However, the higher risk of bleeding events (particularly in the gastrointestinal tract) with DOACs highlights the need for appropriate patient selection. Further insights will be gained from additional studies that are ongoing or awaiting publication. The efficacy and safety of DOAC thromboprophylaxis in ambulatory patients with cancer at a high risk of VTE have also been assessed in placebo‐controlled randomized controlled trials of apixaban and rivaroxaban. Both studies showed efficacy benefits with DOACs, but both studies also showed a nonsignificant increase in major bleeding events while on treatment. This review summarizes the evidence base for rivaroxaban use in CAT, the patient profile potentially most suited to DOAC use, and ongoing controversies under investigation. We also describe ongoing studies from the CALLISTO (Cancer Associated thrombosis—expLoring soLutions for patients through Treatment and Prevention with RivarOxaban) program, which comprises several randomized clinical trials and real‐world evidence studies, including investigator‐initiated research.

Introduction In the CASSINI study, rivaroxaban thromboprophylaxis significantly reduced primary venous thromboembolism (VTE) endpoints during the intervention period, but several thromboembolic events designated as secondary efficacy endpoints were not included in the primary analysis. This study was aimed to evaluate the full impact of rivaroxaban thromboprophylaxis on all prespecified thromboembolic endpoints occurring on study. Methods CASSINI was a double-blind, randomized, placebo-controlled study in adult ambulatory patients with cancer at risk for VTE (Khorana score ≥2). Patients were screened at baseline for deep-vein thrombosis (DVT) and randomized if none was found. The primary efficacy endpoint was a composite of lower extremity proximal DVT, symptomatic upper extremity, or lower extremity distal DVT, any pulmonary embolism, and VTE-related death. This analysis evaluated all prespecified thromboembolic endpoints occurring on study to determine the full benefit of rivaroxaban prophylaxis. All endpoints were independently adjudicated. Results Total thromboembolic events occurred in fewer patients randomized to rivaroxaban during the full study period (29/420 [6.9%] and 49/421 [11.6%] patients in rivaroxaban and placebo groups, respectively [hazard ratio (HR) = 0.57; 95% confidence interval (CI): 0.36–0.90; p = 0.01]; number needed to treat [NNT] = 21). Similarly, fewer patients randomized to rivaroxaban experienced thromboembolism during the intervention period (13/420 [3.1%] patients) versus placebo (38/421 [9.0%] patients; HR = 0.33; 95% CI: 0.18–0.62; p < 0.001; NNT = 17). Conclusion Our findings confirm the substantial benefit of rivaroxaban thromboprophylaxis when considering all prespecified thromboembolic events, even after excluding baseline screen-detected DVT. The low NNT, coupled with prior data demonstrating a high number needed to harm, should assist clinicians in determining the risk/benefit of thromboprophylaxis in high-risk patients with cancer.

Chemotherapy-induced thrombocytopenia (CIT) is common during treatment with antineoplastic therapies and may adversely impact chemotherapy dose intensity. There is no approved therapy for CIT. In our recent phase II randomized study, romiplostim led to correction of platelet counts in 85% of treated patients and allowed resumption of chemotherapy, with low rates of recurrent CIT in the first two cycles or 8 weeks of chemotherapy. However, there is a lack of long-term data on the efficacy and safety of romiplostim in CIT.To analyze efficacy and safety of romiplostim in the patients in the phase 2 study, who received romiplostim for ≥1 year.Twenty-one patients remained on romiplostim for ≥1 year. We analyzed the effect of romiplostim on platelet counts, absolute neutrophil counts, and hemoglobin, as well as impact on ongoing chemotherapy. We also tracked venous or arterial thrombotic events.During the study period, romiplostim was effective in preventing reduction of chemotherapy dose intensity due to CIT. Fourteen of the 20 (70%) analyzable patients experienced no episode of CIT, 4 subjects experienced a single chemotherapy dose delay due CIT, and 2 patients required a chemotherapy dose reduction. Platelet counts were preserved throughout the duration of the extension analysis. One patient experienced a proximal deep vein thrombosis, and one patient experienced multiple tumor-related ischemic events.Long-term use of romiplostim for treatment of CIT was effective and safe, with no evidence of resistance or increased risk of thrombosis.

Background Prophylactic anticoagulation with rivaroxaban significantly reduced the risk of cancer-associated thrombosis during the intervention period in the CASSINI trial. Direct oral anticoagulants may increase the risk of gastrointestinal (GI) tract bleeding in patients with an in situ GI tract cancer or lesion. Objective This post hoc analysis characterized the efficacy and safety of rivaroxaban in patients with and without gastric/gastroesophageal junction (G/GEJ) tumors. Methods Primary and secondary efficacy end points and adjudicated bleeding events, including bleeding sites, were analyzed for the intent-to-treat population by cancer type (G/GEJ vs non-G/GEJ) for the 180-day observation period. Results In patients with G/GEJ tumors, the rates for the primary efficacy end point were 3.4% for rivaroxaban versus 6.9% for placebo (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.11-1.80). In patients with non-G/GEJ tumors, the rivaroxaban group had a lower risk of the primary end point (6.6% vs 9.3%; HR, 0.70; 95% CI, 0.40-1.21). Rates of major bleeding in patients with G/GEJ tumors were 4.6% (4/88) versus 1.2% (1/85) for rivaroxaban and placebo; rates in patients with non-G/GEJ tumors were 1.3% (4/317) versus 0.9% (3/319), respectively. Conclusions Excluding patients with G/GEJ tumors resulted in a definable population of cancer patients who achieved an improved benefit-risk balance from rivaroxaban prophylaxis.

Background Low‐molecular‐weight heparin has been the preferred treatment of cancer‐associated thrombosis (CAT); however, emerging data support the use of direct oral anticoagulants (DOACs). Objectives The Memorial Sloan Kettering Cancer Center Clinical Pathway has served as the institutional guideline for the use of rivaroxaban to treat CAT since 2014. Key elements are to recommend against use of a DOAC in patients with active gastrointestinal (GI) or genitourinary tract lesions, and a prespecified dose reduction in the elderly (75+ years old). We present our institutional experience for treatment of CAT. Methods From January 2014 through September 2016, 1072 patients began rivaroxaban treatment for CAT; 91.9% had a solid tumor, 8.1% had hematologic malignancies, and 75% of patients with solid tumors had metastatic disease. All patients with CAT treated with rivaroxaban were included in this analysis, regardless of adherence to the Clinical Pathway. Results The 6‐month cumulative incidence of recurrent venous thromboembolism and major bleeding were 4.2% (95% confidence interval [CI], 2.7%‐5.7%) and 2.2% (95% CI, 1.1%‐3.2%), respectively. The incidence of clinically relevant non–major bleeding leading to discontinuation of rivaroxaban for at least 7 days was 5.5% (95% CI, 3.7%‐7.1%), and 73.3% of major bleeds occurred in the GI tract. The 6‐month cumulative mortality rate was 22.2% (95% CI, 19.4%‐24.9%). The elderly had similar rates of recurrent thrombosis and bleeding as those aged under 75 years. Conclusion Our institutional experience suggests that in appropriately selected patients, rivaroxaban may be used for treatment of CAT with promising safety and efficacy.

Background Currently, there are no approved options to prevent or treat chemotherapy-induced thrombocytopenia (CIT). We performed a systematic literature review and meta-analysis on use of thrombopoietic agents for CIT. Patients and methods We searched Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PubMed, EMBASE, ClinicalTrials.gov, and health technology assessments from January 1995 to March 2021 for studies evaluating thrombopoietic agents for CIT, including recombinant human thrombopoietin (rhTPO), megakaryocyte growth and development factor (MGDF), romiplostim, and eltrombopag. Random effects meta-analyses were conducted for efficacy and safety endpoints. Results We screened 1503 titles/abstracts, assessed 138 articles, and abstracted data from 39 publications (14 recombinant human thrombopoietin, 7 megakaryocyte growth and development factor, 9 romiplostim, 8 eltrombopag, and 1 romiplostim/eltrombopag). Random effects meta-analyses of data from multiple studies comparing thrombopoietic agents versus control (comparator, placebo, or no treatment) showed that thrombopoietic agents did not significantly improve chemotherapy dose delays and/or reductions (21.1% vs 40.4%, P = 0.364), grade 3/4 thrombocytopenia (39.3% vs 34.8%; P = 0.789), platelet transfusions (16.7% vs 31.7%, P = 0.111), grade ≥ 2 bleeding (6.7% vs 16.5%; P = 0.250), or thrombosis (7.6% vs 12.5%; P = 0.131). However, among individual studies comparing thrombopoietic agents with placebo or no treatment, thrombopoietic agents positively improved outcomes in some studies, including significantly increasing mean peak platelet counts (186 x 109/L with rhTPO vs 122 x 109/L with no treatment; P < 0.05) in one study and significantly increasing platelet count at nadir (56 x 109/L with rhTPO vs 28 x 109/L with not treatment; P < 0.05) in another study. Safety findings included thrombosis (n = 23 studies) and bleeding (n = 11), with no evidence of increased thrombosis risk with thrombopoietic agents. Conclusion Our analyses generate the hypothesis that thrombopoietic agents may benefit patients with CIT. Further studies with well-characterized bleeding and platelet thresholds are warranted to explore the possible benefits of thrombopoietic agents for CIT.

Introduction: Chemotherapy-induced thrombocytop enia (CIT) is a common complication of cancer treatment causing chemotherapy delays, dose reductions, and treatment discontinuation, negatively impacting treatment outcomes and putting patients at risk for bleeding complications. There is no FDA-approved agent available to manage CIT.Areas covered: This article covers the diagnosis, definitions, and clinical challenges of CIT, and then focuses on the therapeutics developed to manage CIT. The first-generation thrombopoietic agents (oprelvekin and recombinant human thrombopoietins) are reviewed for critical background and context, followed by a detailed discussion of the data for the thrombopoietin receptor agonists (TPO-RAs) to manage CIT. Efficacy of TPO-RAs in treatment and prevention of CIT, as well as safety concerns such as the risk of thromboembolic complications, are reviewed in detail. For this review, a PubMed/MEDLINE literature search was undertaken for relevant articles published from 1995-2021.Expert opinion: After over two decades of drug development for CIT, multiple clinical trials and observational studies have found TPO-RAs, in particular romiplostim, to be safe and effective agents to manage patients with CIT, although no agent is yet FDA-approved for this indication. Active management of CIT with TPO-RAs is likely to improve oncologic outcomes, although additional data are needed. Phase 3 trials are ongoing.

Purpose To determine the incidence of venous thromboembolism (VTE) and define clinical risk factors associated with the development of new-onset VTE in patients receiving neoadjuvant chemotherapy (NACT) for ovarian cancer (OC). Methods An institutional ovarian cancer database was used to identify all OC patients receiving NACT from 04/2015–09/2018. VTE events were recorded and included clinically diagnosed deep venous thrombosis (DVT) and/or pulmonary embolism (PE). The incidence of VTE events was categorized according to treatment phases (P): P0) First visit/prior to induction of NACT; P1) during NACT before interval debulking surgery (IDS); P2) intraoperative through day 28 post-IDS; P3) during adjuvant chemotherapy. Results A total of 290 patients were identified during the study period. Seventy-five (25.9%) developed a VTE at some point from time of presentation through the peri-operative period. Forty (13.8%) presented with VTE prior to initiation of NACT. An additional 27 (11.6%) developed a VTE during NACT (P1); 6 (3.9%) during the intraoperative and 28-day post-operative period (P2); and 2 (1.3%) during the adjuvant period (P3). The overall VTE rate was 25.9% (n = 75). FIGO stage IV disease was the only factor associated with increased risk for a new-onset VTE [Odds Ratio (OR): 3.9 (95% Confidence Interval [CI] = 1.2–13.6; p = 0.03]. Conclusions Patients receiving NACT for advanced OC are at extremely high risk for developing thromboembolic events, either at initial presentation or during induction of NACT, a treatment phase that is traditionally without use of prophylactic anticoagulation. Since Khorana scoring is not predictive in this population, clinicians might need to consider increased screening or use of prophylactic anticoagulation in patients receiving NACT for OC, particularly in advanced metastatic disease.

Objectives To estimate the risk of thrombocytopenia in various cancers and chemotherapy regimens. Methods Structured patient‐level data from the Flatiron Health Electronic Health Record database were used to identify adult patients who received chemotherapy for a solid tumor or hematologic malignancy from 2012 to 2017. Three‐month cumulative incidence of thrombocytopenia was assessed based on platelet counts, overall and by grade of thrombocytopenia. Co‐occurrence of anemia, neutropenia, and leukopenia was evaluated. Results Of 15,521 patients with solid tumors, 13% had thrombocytopenia within 3 months (platelet count

Chemotherapy-induced thrombocytopenia (CIT) contributes to treatment dose delay and/or modification, often resulting in poorer survival and disease progression. We explored the incidence and clinical consequences of CIT among metastatic colorectal cancer (mCRC) patients.Data from two prospective randomized phase 3 trials of mCRC patients receiving either first-line FOLFOX4 (fluorouracil, leucovorin, oxaliplatin) or second-line FOLFIRI (fluorouracil, leucovorin, irinotecan) were analyzed. Thrombocytopenia was defined by platelet count 100 × 10Among 1078 mCRC patients in the FOLFOX4 study, cumulative incidence of CIT based on platelet count was 37% (grade 3, 2%; grade 4, 1%) during an average 8 months' follow-up. Neutropenia or anemia were absent in 44% of CIT episodes; 62% of CIT AEs led to chemotherapy dose delay, change, and/or discontinuation. Among 1067 mCRC patients in the FOLFIRI study, cumulative incidence of CIT based on platelet count was 4% (grade 3, 1%; grade 4, 0) during an average 4 months' follow-up. Neutropenia or anemia were absent in 22% of CIT episodes; 32% of CIT AEs led to chemotherapy dose delay, change, and/or discontinuation. With both regimens, transfusions and hospitalizations after CIT AEs were rare (3%).CIT was common among mCRC patients receiving the FOLFOX4 regimen. The most frequent consequence of CIT was a delay in chemotherapy, highlighting the unmet need in CIT management.

Cancer-associated venous thromboembolism (CAT) is a well-described complication of cancer and a leading cause of death in cancer patients. The purpose of this study was to assess potential associations of molecular signatures with CAT, including tumor-specific mutations and the presence of clonal hematopoiesis. We analyzed deep-coverage targeted DNA-sequencing data of >14,000 solid tumor samples using the MSK-IMPACT™ platform to identify somatic alterations associated with VTE. Endpoint was defined as the first instance of cancer-associated pulmonary embolism and/or proximal/distal lower extremity deep vein thrombosis. Cause-specific Cox proportional hazards regression was used, adjusting for pertinent clinical covariates. Of 11,695 evaluable individuals, 72% had metastatic disease at time of IMPACT. Tumor-specific mutations in KRAS (HR=1.34 [1.09-1.64]; adjusted p=0.08), STK11 (HR=2.12 [1.55-2.89]; adjusted pKEAP1 (HR=1.84 [1.21-2.79]; adjusted p=0.07), CTNNB1 (HR=1.73 [1.15-2.60]; adjusted p=0.09), CDKN2B (HR= 1.45 [1.13-1.85], adjusted p=0.07) and MET (HR=1.83 [1.15-2.92]; adjusted p=0.09) were associated with a significantly increased risk of CAT independent of tumor type. Mutations in SETD2 were associated with a decreased risk of CAT (HR=0.35 [0.16-0.79], adjusted p=0.09). The presence of clonal hematopoiesis was not associated with an increased VTE rate. This is the first large-scale analysis to elucidate tumor-specific genomic events associated with CAT. Somatic tumor mutations of STK11, KRAS, CTNNB1, KEAP1, CDKN2B and MET were associated with an increased risk of VTE in solid tumor patients. Further analysis is needed to validate these findings and identify additional molecular signatures unique to individual tumor types.Key PointsTumor mutations in STK11, KRAS, CTNNB1, KEAP1, CDKN2B, MET and SETD2 modulate the risk of cancer-associated thrombosis.The presence of clonal hematopoiesis does not affect the risk of cancer-associated thrombosis.

Acute promyelocytic leukemia (APL) is associated with a profound coagulopathy. Based on retrospective assessments, several potential risk factors for hemorrhagic morbidity and mortality have emerged. Several studies have shown elevated white blood cell (WBC) count at presentation to be a robust predictor of bleeding events. Other clinical and laboratory parameters have been evaluated with variable association with hemorrhagic morbidity or mortality. These include ECOG performance status, age, morphological subtype, platelet count, peripheral blood blast count, ethnicity, body mass index, prothrombin time, activated partial thromboplastin time, lactate dehydrogenase, d-dimers, creatinine and fibrinogen levels. Unfortunately, most of those assessments were based on a small patient sample and the results have been at times contradictory in terms of which parameters are independent predictors. More recently, two large retrospective studies have reported on the issue. They included data from several international trials of chemotherapy for APL, one on adults and the other focused on the pediatric population. Importantly, both analyses found that WBC count at presentation is the main predictor of early hemorrhagic death and early thrombo-hemorrhagic death, respectively. Much remains to be done if the rate of induction mortality in APL is going to be reduced significantly. One approach would be to incorporate the known risk factors for early hemorrhagic death into a risk stratification system and devise personalized transfusion interventions to meet an individual patient's risk, which could be evaluated in future randomized trials.

Background: Chemotherapy induced thrombocytopenia (CIT) is common, adversely impacts chemotherapy relative dose intensity, and may adversely impact cancer control. There is no approved therapy for CIT. In our recent phase II study of solid tumor patients with CIT (Soff et al, J. Clin. Onc., 2019), romiplostim lead to correction of platelet counts in 85% of participants within 3 weeks. While on romiplostim maintenance, only 6.8% of participants experienced chemotherapy dose reduction or delay as a result of recurrent CIT within a minimum of two cycles of chemotherapy or 8 weeks. However, there is a lack of long-term data on the efficacy and safety of romiplostim in CIT. Objectives: This is an extension analysis of the phase II study for patients receiving romiplostim maintenance for 12 months or longer. Patients/Methods: In the phase II study, 44 patients successfully met the primary endpoint of correction of their platelet count within 3 weeks and resumed chemotherapy with romiplostim maintenance. 21 patients (48%) remained on romiplostim for 12 months or longer. Data were collected from one month prior to initiation of romiplostim to one month after the last dose of drug. Data extracted included complete blood count, chemotherapy doses and dates, romiplostim doses and dates, body weight, cancer diagnosis, age, gender, date of death and thrombotic events. Efficacy was demonstrated by persistent maintenance of platelet counts during long-term chemotherapy and avoidance of episodes of reduced chemotherapy dose intensity. Safety was assessed by two methods: tracking the rates of venous or arterial thrombosis; as well as development of marrow fibrosis and/or secondary hematologic malignancy. The mean romiplostim doses and lab values are calculated by month of study participation. Results: All participants had metastatic disease. Breast (N=6) and colorectal (N=6) were the most common cancers. No participant discontinued romiplostim therapy due to an adverse event or futility. One patient received romiplostim at our institution, but chemotherapy at an outside hospital; details of his chemotherapy were not available for this analysis. 14 of the 20 (70%) of the analyzable participants experienced no episode of CIT; 4 subjects experienced a single chemotherapy dose delay due CIT. No patient experienced multiple delays in chemotherapy due to CIT. Two patients required a chemotherapy dose reduction. The mean monthly platelet counts remained controlled throughout the period of analysis. (Figure 1A). The mean romiplostim doses were in the range of 3-5 mcg/kg through 35 months. There were insufficient participants beyond month 36 to allow meaningful interpretation of platelet counts or mean romiplostim doses. There was no evidence of adverse impact on absolute neutrophil count or hemoglobin levels (Figure 1B). No patient developed leukoerythroblastic changes indicative of marrow fibrosis, and no cases of secondary hematologic malignancy were identified. Two participants experienced thrombosis. One individual experienced a deep vein thrombosis. A second participant with an established history of congenital thrombophilia, experienced multiple tumor associated infarctions. The thrombotic events did not lead to discontinuation of participation in the trial for either participant. Of the 44 patients in the phase 2 study who resumed chemotherapy, 21 were alive at 12 months (48%) and 12 were alive at 24 months (27%). Conclusions: In this long-term analysis, romiplostim was effective and safe in the treatment of CIT with no evidence of drug resistance, marrow fibrosis, or secondary hematologic malignancy. The rates of thrombosis were no higher than expected for this patient demographic. There are some limitations to our analysis which includes our inability to accurately capture non-parenteral chemotherapy (oral or investigational agents) which were excluded from our analysis. We are unable to assess an impact on overall survival or cancer progression. However, the fact that half the participants were alive at 12 months and a quarter at 24 months is a reassuring signal. The analysis also is limited to the patients who were eligible for the initial phase 2 trial and corrected their platelet count within 3 weeks. Within these limitations, the extension study provides reassurance for long-term efficacy and safety of romiplostim treatment for CIT. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Romiplostim is approved to increase platelet counts in ITP and pre-surgery. We are describing the results of a clinical trial.

Venous thromboembolism (VTE) is a frequent complication of cancer associated with morbidity, mortality, increased hospitalizations and higher health care costs. Cancer patients at increased risk for VTE can be identified using a validated risk assessment score, and the incidence of VTE can be reduced in high-risk settings using anticoagulation. Rivaroxaban is a potent, oral, direct, factor Xa inhibitor approved for the prevention and treatment of thromboembolic events, including VTE. CASSINI is a double-blind, randomized, parallel-group, multicentre study comparing rivaroxaban with placebo in adult ambulatory patients with various cancers who are initiating systemic cancer therapy and are at high risk of VTE (Khorana score ≥ 2). Patients with primary brain tumours or those at risk for bleeding are excluded. Approximately 700 patients will be randomized 1:1 to rivaroxaban 10 mg daily or placebo for up to 6 months if there is no evidence of VTE from compression ultrasonography (CU) during screening or from routine care imaging within 30 days prior to randomization. Mandatory CU will also be performed at weeks 8 and 16 (±7 days), and at study end (±3 days). The primary efficacy hypothesis is that anticoagulation with rivaroxaban reduces the composite of objectively confirmed symptomatic or asymptomatic, lower-extremity, proximal deep-vein thrombosis (DVT); symptomatic, upper-extremity DVT; symptomatic or incidental pulmonary embolism; and VTE-related death compared with placebo. The primary safety objective is to assess major bleeding events (Clinical trial information: NCT02555878).

Introduction: The Khorana Score (KS) is a validated tool to assess the risk of thrombosis in cancer patients, prior to initiation of chemotherapy. The AVERT and CASSINI studies evaluated prophylactic anticoagulation with apixaban or rivaroxaban for patients with KS of 2 or higher. Both studies demonstrated that while patients were taking prophylactic anticoagulant, the Hazard Ratio of cancer associated thrombosis was approximately 0.4. The NCCN and other societies are now recommending oral anticoagulant prophylaxis should be considered for up to 6 months, for patients with an intermediate or high-risk score of ≥2. Methods: We have developed a medical record tool, that identifies all MSKCC patients prior to initiation of a new chemotherapy regimen, captures the KS parameters, and generates the KS. Once fully implemented, it is anticipated that this tool and appropriate use of prophylactic anticoagulation, will reduce the burden of cancer associated thrombosis. To accurately document a potential reduction in rates of cancer associated thrombosis, we need to establish current baseline rates of cancer associated thrombosis via a contemporary verification of the KS, reflecting potential changes in oncology in the 12 years since the score was first published. We applied our KS capture tool to a 2-year period (10/17/2017 to 11/29/2019). 13,992 patients were identified with a new chemotherapy order, of whom 13,176 were found to have cancer and had complete parameters for the KS. We tracked all patients for 6 months, to identify possible episodes of Venous Thromboembolism (VTE). VTE episodes were identified by capturing the impressions of all contrast imaging studies, Doppler ultrasounds, and V/Q scans, combined with keyword and phrase computer identification, and manual review. To identify possible VTE events that occurred at an outside emergency department or hospital, we also queried new prescriptions for therapeutic doses of anticoagulants and ICD10 codes. In this analysis we focus on deep vein thrombosis (DVT) and pulmonary embolism (PE). Results: The 6-month rate of VTE (DVT or PE) was 6.4%. The VTE rate was 4.1% in the KS 0 cohort, and >18% for patients with a score of 4 or greater. We assessed the contribution of each parameter of the KS, in univariate analysis. Of the cancers assigned 2 points in the KS, pancreatic cancer had the highest VTE rate of 13.7%, but gastric/esophageal cancer did not have an increased rate. Of the cancers assigned 1 point, germ cell/testis, gynecologic, and lung cancer, also had increased risk of VTE, but bladder and non-Hodgkin lymphoma did not. Renal/urothelial cancers and cholangiocarcinoma/biliary tract cancers were also associated with high rates of VTE, although were not assigned points using the KS. Elevated BMI (≥35 kg/m2) was a weak risk factor. However, baseline anemia (11,000/mcL) and thrombocytosis (≥350,000/mcL) were all strong predictors of VTE rate. Conclusions: The purpose of this QA project was to provide contemporary data on baseline cancer associated thrombosis rates, anticipating implementation of a program of targeted primary thrombosis prophylaxis. It remains clear that the KS provides a valuable risk assessment tool, stratifying 6-month VTE risk from 4.1% to >18%. Cancer type is typically the parameter that gets the first consideration. And most of the cancers with 1 or 2 points did predict increased risk. We don't have an explanation as to why, gastric/esophageal cancers and non-Hodgkin lymphoma were not associated with increased risk, but this finding may reflect the stage of their treatment at which patients begin care at MSKCC. Renal/urothelial, and cholangiocarcinoma/biliary tract cancers are associated with a high risk of VTE, and one may choose to include them for consideration of prophylactic anticoagulation. The relative contribution of pre-chemotherapy blood counts has been questioned in the past, but in this cohort, they clearly contributed to appropriate risk assessment. These data will serve as baseline for future assessment of thrombosis risk reduction upon implementation of a program of targeted prophylactic anticoagulation. Table Disclosures Khorana: Leap: Research Funding; BMS: Honoraria, Research Funding; Merck: Research Funding; Array: Other: Research funding (to institution); Janssen: Honoraria; Bayer: Honoraria; Pfizer: Honoraria; Sanofi: Honoraria; Medscape: Honoraria; Leo Pharma: Honoraria; Seattle Genetics: Honoraria; Pharmacyte: Honoraria; Pharmacyclics: Honoraria. Mantha:MJH Associates: Honoraria; Physicians Education Resource: Honoraria. Soff:Amgen: Research Funding; Amgen: Honoraria; Janssen Scientific Affairs: Honoraria; Dova Pharmaceuticals: Honoraria; Bristol-Myers Squibb, Pfizer: Honoraria; Janssen Scientific Affairs: Research Funding; Dova Pharmaceuticals: Research Funding.

International audience; Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer. These patients are at a high risk of VTE recurrence and bleeding during anticoagulant therapy. The International Initiative on Thrombosis and Cancer is an independent academic working group aimed at establishing a global consensus for the treatment and prophylaxis of VTE in patients with cancer. The International Initiative on Thrombosis and Cancer last updated its evidence-based clinical practice guidelines in 2016 with a free, web-based mobile phone application, which was subsequently endorsed by the International Society on Thrombosis and Haemostasis. The 2019 International Initiative on Thrombosis and Cancer clinical practice guidelines, which are based on a systematic review of the literature published up to December, 2018, are presented along with a Grading of Recommendations Assessment Development and Evaluation scale methods, with the support of the French National Cancer Institute. These guidelines were reviewed by an expanded international advisory committee and endorsed by the International Society on Thrombosis and Haemostasis. Results from head-to-head clinical trials that compared direct oral anticoagulant with low-molecular-weight heparin are also summarised, along with new evidence for the treatment and prophylaxis of VTE in patients with cancer.

PURPOSE Chemotherapy-induced thrombocytopenia (CIT) leads to delay or reduction in cancer treatment. There is no approved treatment. METHODS We conducted a phase II randomized trial of romiplostim versus untreated observation in patients with solid tumors with CIT. Before enrollment, patients had platelets less than 100,000/μL for at least 4 weeks, despite delay or dose reduction of chemotherapy. Patients received weekly titrated romiplostim with a target platelet count of 100,000/μL or more, or were monitored with usual care. The primary end point was correction of platelet count within 3 weeks. Twenty-three patients were treated in a randomization phase, and an additional 37 patients were treated in a single-arm, romiplostim phase. Resumption of chemotherapy without recurrent CIT was a secondary end point. RESULTS The mean platelet count at enrollment was 62,000/μL. In the randomization phase, 14 of 15 romiplostim-treated patients (93%) experienced correction of their platelet count within 3 weeks, compared with one of eight control patients (12.5%; P < .001). Including all romiplostim-treated patients (N = 52), the mean platelet count at 2 weeks of treatment was 141,000/μL. The mean platelet count in the eight observation patients at 3 weeks was 57,000/μL. Forty-four patients who achieved platelet correction with romiplostim resumed chemotherapy with weekly romiplostim. Only three patients (6.8%) experienced recurrent reduction or delay of chemotherapy because of isolated CIT. CONCLUSION This prospective trial evaluated treatment of CIT with romiplostim. Romiplostim is effective in correcting CIT, and maintenance allows for resumption of chemotherapy without recurrence of CIT in most patients.

Ambulatory patients receiving systemic cancer therapy are at varying risk for venous thromboembolism. However, the benefit of thromboprophylaxis in these patients is uncertain.In this double-blind, randomized trial involving high-risk ambulatory patients with cancer (Khorana score of ≥2, on a scale from 0 to 6, with higher scores indicating a higher risk of venous thromboembolism), we randomly assigned patients without deep-vein thrombosis at screening to receive rivaroxaban (at a dose of 10 mg) or placebo daily for up to 180 days, with screening every 8 weeks. The primary efficacy end point was a composite of objectively confirmed proximal deep-vein thrombosis in a lower limb, pulmonary embolism, symptomatic deep-vein thrombosis in an upper limb or distal deep-vein thrombosis in a lower limb, and death from venous thromboembolism and was assessed up to day 180. In a prespecified supportive analysis involving the same population, the same end point was assessed during the intervention period (first receipt of trial agent to last dose plus 2 days). The primary safety end point was major bleeding.Of 1080 enrolled patients, 49 (4.5%) had thrombosis at screening and did not undergo randomization. Of the 841 patients who underwent randomization, the primary end point occurred in 25 of 420 patients (6.0%) in the rivaroxaban group and in 37 of 421 (8.8%) in the placebo group (hazard ratio, 0.66; 95% confidence interval [CI], 0.40 to 1.09; P = 0.10) in the period up to day 180. In the prespecified intervention-period analysis, the primary end point occurred in 11 patients (2.6%) in the rivaroxaban group and in 27 (6.4%) in the placebo group (hazard ratio, 0.40; 95% CI, 0.20 to 0.80). Major bleeding occurred in 8 of 405 patients (2.0%) in the rivaroxaban group and in 4 of 404 (1.0%) in the placebo group (hazard ratio, 1.96; 95% CI, 0.59 to 6.49).In high-risk ambulatory patients with cancer, treatment with rivaroxaban did not result in a significantly lower incidence of venous thromboembolism or death due to venous thromboembolism in the 180-day trial period. During the intervention period, rivaroxaban led to a substantially lower incidence of such events, with a low incidence of major bleeding. (Funded by Janssen and others; CASSINI ClinicalTrials.gov number, NCT02555878.).

The management of cancer-associated thrombosis (CAT) is complex, and treatment strategies have been evolving over the past 15 years. It is well recognized that oral vitamin K antagonists are difficult to use in cancer patients, with higher rates of treatment failure and bleeding complications than in non-cancer patients. Low-molecular-weight-heparin (LMWH) became the widely accepted standard of care for treatment of cancer-associated thrombosis, following the CLOT study comparing dalteparin with warfarin in 2003. LMWH remains widely used for the treatment of CAT. However, in the past two years, several studies have served to validate direct oral anticoagulants as a safe and effective alternative to LMWH. Two randomized clinical trials comparing edoxaban and rivaroxaban with dalteparin, and several retrospective studies have shown the efficacy of edoxaban and rivaroxaban for the treatment of CAT. However, there is an evidence of increased bleeding with the DOACs, particularly gastrointestinal or urinary tract bleeding in patients with lesions within the gastrointestinal or urinary tracts. This chapter discusses the ongoing development of optimal treatment strategies for cancer-associated thrombosis.

Chemotherapy-induced thrombocytopenia (CIT) is a frequent complication of cancer therapy, leading to increased risk of bleeding, when the thrombocytopenia is severe (

"The frequent concurrence of phlegmasia alba dolens with an appreciable cancerous tumor, led me to the inquiry whether a relationship of cause and effect did not exist between the two, and whether the phlegmasia was not the consequence of the cancerous cachexia." (translated from the original French). This famous quote, delivered in a lecture by Armand Trousseau in 1865, is widely recognized as the initial and insightful understanding of the relationship of thrombosis and cancer.Although the association of thrombosis with cancer has been recognized for over 150 years, only recently has there been meaningful advances in our understanding of the relationship. Contemporary translational research tools have greatly enhanced our understanding the unique aspects of the pathophysiology of the relationship; how cancer cells exploit multiple aspects of the coagulation system for primary and metastatic growth leading, leading to an increased thrombotic risk. Further, there has been a growing appreciation of the complexity of the treatment of cancer-associated thrombosis. The superiority of low molecular weight heparin over warfarin, published in 2003, represented the first important divergence from the approach to management of thrombosis in the non-cancer population. With the introduction of the new generation of anticoagulants, the direct oral anticoagulants, there has been continued evolution of management guidelines.This text presents a much needed and comprehensive update of the field of thrombosis and hemostasis in cancer. We are fortunate to have so many leading authorities contribute their expertise and insight into this work. In the following chapters, the reader will find insight and guidance that will enhance scholarship, as well as patient care.

Low-molecular weight heparin (LMWH) has been the standard of care for treatment of venous thromboembolism (VTE) in patients with cancer. Rivaroxaban was approved in 2012 for the treatment of pulmonary embolism (PE) and deep vein thrombosis (DVT), but no prior studies have been reported specifically evaluating the efficacy and safety of rivaroxaban for cancer-associated thrombosis (CAT). Under a Quality Assessment Initiative (QAI), we established a Clinical Pathway to guide rivaroxaban use for CAT and now report a validation analysis of our first 200 patients. A 200 patient cohort with CAT (PE or symptomatic, proximal DVT), whose full course of anticoagulation was with rivaroxaban, were accrued. In competing risk analysis, primary endpoints at 6 months included new or recurrent PE or symptomatic proximal lower extremity DVT, major bleeding, clinically-relevant non-major bleeding leading to discontinuation of rivaroxaban, or death. In competing risk analysis, the 6 months cumulative incidence of new or recurrent VTE was 4.4 % (95 % CI = 1.4–7.4 %), major bleeding was 2.2 % (95 % CI = 0−4.2 %) and all-cause mortality 17.6 % (95 % CI = 11.7–23.0 %). In this cohort of 200 patients with active cancer and CAT the rates of new or recurrent VTE and major bleeding were comparable to the cancer subgroup analysis from the EINSTEIN studies. The results of our Clinical Pathway provide guidance on Rivaroxaban use for treatment of CAT, and suggest that safety and efficacy is preserved, compared with past-published experience with LMWH. Electronic supplementary material The online version of this article (doi:10.1007/s11239-016-1429-1) contains supplementary material, which is available to authorized users.

We prospectively evaluated the safety and efficacy of adding preoperative chemoprophylaxis to our institution's operative venous thromboembolism (VTE) prophylaxis policy as part of a physician-led quality improvement initiative.Patients undergoing major cancer surgery between August 2013 and January 2014 were screened according to service-specific eligibility criteria and targeted to receive preoperative VTE chemoprophylaxis. Bleeding, transfusion, and VTE rates were compared with rates of historical controls who had not received preoperative chemoprophylaxis.The 2,058 eligible patients who underwent operation between August 2013 and January 2014 (post-intervention) were compared with a cohort of 4,960 patients operated on between January 2012 and June 2013, who did not receive preoperative VTE chemoprophylaxis (pre-intervention). In total, 71% of patients in the post-intervention group were screened for eligibility; 82% received preoperative anticoagulation. When compared with the pre-intervention group, the post-intervention group had significantly lower transfusion rates (pre- vs post-intervention, 17% vs 14%; difference 3.5%, 95% CI 1.7% to 5%, p = 0.0003) without significant difference in major bleeding (difference 0.3%, 95% CI -0.1% to 0.7%, p = 0.2). Rates of deep venous thrombosis (1.3% vs 0.2%; difference 1.1%, 95% CI 0.7% to 1.4%, p0.0001) and pulmonary embolus (1.0% vs 0.4%; difference 0.6%, 95% CI 0.2% to 1%, p = 0.017) were significantly lower in the post-intervention group.In patients undergoing major cancer surgery, institution of a single dose of preoperative chemoprophylaxis, as part of a physician-led quality improvement initiative, did not increase bleeding or blood transfusions and was associated with a significant decrease in VTE rates.

Background: Several clinical prediction scores have been designed to assess the risk of cancer-associated thrombosis (CAT). The most commonly used in current clinical practice is the Khorana score, however it is applicable only to patients prior to initiation of chemotherapy. We now apply machine learning with clinical, demographic, and genomics parameters to predict CAT events. Methods: The random survival forest (RSF) ensemble learning method was selected to illustrate a machine approach to CAT prediction. The cohort consisted of 14,223 individuals with a solid tumor malignancy and MSK IMPACT somatic genomic data collected during the years 2014 to 2016. CAT was defined as the diagnosis of lower extremity deep vein thrombosis (proximal or distal) or pulmonary embolism, incidental or symptomatic. Covariates considered for inclusion in the model consisted of tumor type, metastatic status, age, exposure to cytotoxic chemotherapy in the month before cohort entry, time elapsed since cancer diagnosis, time elapsed since tumor sampling, normalized mean blood cell counts (white cell count, hemoglobin, platelet count) in the prior 3 months, normalized mean prothrombin time (PT) and activated partial thromboplastin time (aPTT) in the prior 3 months, body mass index (BMI), and presence or absence of a somatic genetic alteration for oncogenes/tumor suppressor genes with an alteration frequency ≥ 1.5% (n = 56). The primary endpoint consisted of time to CAT episode. The C-index for models including different covariates was derived from the test holdout sample using repeated 10-fold cross-validation. The C-index, measuring the relative agreement between the RSF predicted risk and the CAT times of patients, has values between 0.5 and 1.0 with the latter indicating perfect agreement. Results: 12,040 patients were included in the final analysis. There were 855 CAT events during the observation period. The most common tumor types were lung (17%), breast (15%) and colorectal cancer (9%). Blood cell count data and coagulation parameters were missing for 8% and 51% of patients respectively. Using cross-validation, the baseline model with cancer type and metastatic status had a C-index of 0.62 (95% CI = 0.61-0.64), which increased to 0.65 (95% CI = 0.63-0.66) with the addition of chemotherapy, age, time from tissue sampling, time from cancer diagnosis and BMI. Further adding genetic data increased the C-index to 0.68 (95% CI = 0.66-0.69). Replacing genetic data in this model with cell counts and coagulation parameters resulted in a C-index of 0.69 (95% CI = 0.68-0.70). The model with all available covariates had a C-index of 0.70 (95% CI = 0.69-0.71). The cumulative incidence of CAT at 6 months for 5 categories of predicted risk using the model with all available covariates is plotted in Figure A. Scaled Ishwaran-Kogalur Variable Importance (VIMP) values, presented in Figure B, indicate that cancer type and prior chemotherapy are the two top factors for model performance. Conclusions: Machine learning is a promising approach in the search of more accurate and generalizable models for prediction of CAT. In the application described here, the use of random survival forests performed well without information about future chemotherapy administration. Additional work is needed to identify the optimal algorithm and covariates, including better delineation of which cancer genomic information should be retained. Future models will have to be validated independently before being used for patient care. Disclosures Mantha: Physicians Education Resource: Honoraria; MJH Associates: Honoraria. Bolton:GRAIL: Research Funding. Soff:Bristol-Myers Squibb, Pfizer: Honoraria; Dova Pharmaceuticals: Honoraria; Janssen Scientific Affairs: Honoraria; Amgen: Research Funding; Janssen Scientific Affairs: Research Funding; Amgen: Honoraria; Dova Pharmaceuticals: Research Funding.

e13537 Background: Patients with cancer have an increased risk of arterial thromboembolic events (ATE). Clinical characteristics such as medical comorbidities, cancer type, cancer stage and a history of smoking are established risk factors for ATE, but scant data exist about the effect of cancer-specific genomic alterations. We aimed to determine whether individual tumor mutations influence ATE risk. Methods: We performed a retrospective cohort study using tumor mutational data from adults with solid cancers who had MSK-IMPACT testing at Memorial Sloan Kettering Cancer Center between 2014 and 2016. MSK-IMPACT is an FDA-authorized DNA sequencing panel targeting 341+ oncogenes and tumor suppressor genes identifying mutations, copy number alterations, and gene fusions in solid malignancies. The primary ATE outcome was defined as ischemic stroke, myocardial infarction or coronary revascularization and detected by systematic electronic health record assessments. Patients were followed up to one year from the date of tissue-matched blood control sampling to the first ATE or death. We used Cox proportional hazards regression adjusting for age, cancer type, cytotoxic chemotherapy treatment (time-dependent) and tobacco use to determine hazard ratios (HR) of individual genes for ATE risk. We adjusted for multiple comparisons using the Benjamini-Hochberg method. Results: Among 11,317 patients, mean age was 59 years (SD = 14 years) and 55% were women. The most frequent cancers were lung (16%), breast (15%), and colorectal (10%), and 73% were metastatic. During a median follow-up of 253 days, 151 patients had an ATE (1.3%). In multivariable analysis, genomic alterations in KRAS (HR, 2.11; CI, 1.41-3.16), STK11 (HR, 2.62; 95% CI, 1.49-4.59), and ROS1 (HR, 5.3; 95% CI, 1.93-14.58) were independently associated with an increased risk of ATE. Presence of clonal hematopoiesis was not found to be associated with an increased risk of ATE in this cohort (HR, 0.96; 95% CI, 0.63-1.47). Conclusions: In a large genomic tumor-profiling registry of patients with solid cancers, alterations in KRAS, STK11, and ROS1 were associated with an increased risk of ATE independent of cancer type. [Table: see text]

6073 Background: To identify the incidence of newly occurring venous thromboembolism (VTE) in patients with ovarian cancer receiving neoadjuvant chemotherapy (NACT). Methods: Using our prospectively maintained ovarian cancer database, we identified all ovarian cancer patients who received NACT at our institution from 4/15-9/18. VTE events included clinically diagnosed deep venous thrombosis (DVT) or pulmonary embolism (PE). Patients who presented with VTE prior to induction of NACT or patients on anticoagulation therapy prior to diagnosis were excluded. The incidence of newly occurring thrombotic events were categorized according to treatment phases, defined as 1) NACT prior to interval debulking surgery (IDS); 2) intraoperative and 30-day post-IDS; and 3) adjuvant chemotherapy. Results: 290 patients underwent NACT during the study period. Thirty-eight patients (13%) who presented with VTE, 12 (4%) on anticoagulation at presentation, and 4 (1.4%) seeking only a second opinion were excluded from analysis. Of the 236 evaluable patients, the overall rate of VTE during all treatment phases was 15% (35/236). In treatment phase I, 11% (27/236) of patients experienced VTE during NACT. In phase II, an additional 2.5% (6/236) developed VTE in the intraoperative and 30-day postoperative period. In phase III, an additional 0.8% (2/236) experienced a thrombotic event >30 days postoperatively. Sevety-seven percent (27/35) of VTE events occured during phase I. Conclusions: Patients receiving NACT for advanced ovarian cancer are at high risk for the development of clinically detectable thromboembolic events. The highest rate of new VTE events was seen during induction of NACT, a phase of treatment traditionally without any prophylactic anticoagulation. Further research regarding the timing of thromboprophylaxis for this patient population is warranted. [Table: see text]

Venous thromboembolism (VTE) is common in patients with cancer and increases morbidity and mortality. VTE prevention and treatment are more complex in patients with cancer. The NCCN Guidelines for Cancer-Associated Venous Thromboembolic Disease outline strategies for treatment and prevention of VTE in adult patients diagnosed with cancer or in whom cancer is clinically suspected. These NCCN Guidelines Insights explain recent changes in anticoagulants recommended for the treatment of cancer-associated VTE.

For patients with cancer who experience venous thromboembolism (VTE), low-molecular-weight heparin (LMWH) remains the standard of care in the NCCN Guidelines for VTE, but under certain conditions direct oral anticoagulants (DOACs) are acceptable alternatives. A growing body of literature suggests that DOACs may more effective than LMWHs in preventing recurrences, but they do carry some increased risk of bleeding. Most of this risk is seen in patients with gastrointestinal or urinary pathology or implanted devices. DOACs are also acceptable when the pain, cost, and inconvenience of LMWHs are expected to be obstacles to compliance. Through careful patient selection, most patients can be treated successfully with a DOAC, although for most patients with gastrointestinal or urinary pathology, LMWH remains the safer choice.

Regulatory brain cytoplasmic 200 RNA (BC200 RNA) is highly expressed in human mammary carcinoma cells. Here, we ask whether BC200 RNA becomes detectable in peripheral blood of patients with invasive breast cancer. Using quantitative reverse-transcription PCR (qRT-PCR) methodology, we observed that BC200 RNA blood levels were significantly elevated, in comparison with healthy subjects, in patients with invasive breast cancer prior to tumorectomy (p=0.001) and in patients with metastatic breast cancer (p=0.003). In patients with invasive breast cancer who had recently undergone tumorectomy, BC200 RNA blood levels were not distinguishable from levels in healthy subjects. However, normality analysis revealed a heterogeneous distribution of patients in this group, including a subgroup of individuals with high residual BC200 RNA blood levels. In blood from patients with invasive breast cancer, BC200 RNA was specifically detected in the mononuclear leukocyte fraction. The qRT-PCR approach is sensitive enough to detect as few as three BC200 RNA-expressing tumor cells. Our work establishes the potential of BC200 RNA detection in blood to serve as a molecular indicator of invasive breast malignancy.