Cancer-Associated Thrombosis: Management of a Patient With an Isolated Calf Deep Vein Thrombosis

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.Venous thromboembolism occurs frequently in patients with cancer and is the second leading cause of death, after the cancer itself. There is a well-established consensus of the need for anticoagulation in patients with a proximal deep vein thrombosis or pulmonary embolism. But with improved imaging technology and widescale use of contrast imaging for cancer staging, many incidental pulmonary emboli are detected in patients with cancer. Furthermore, many isolated distal deep vein thromboses and subsegmental pulmonary emboli are identified. There have been questions if these small or asymptomatic thromboses require anticoagulation management similar to more proximal or symptomatic thromboses. In this Oncology Grand Rounds, we will review the existing evidence for these situations. We will also review management strategies for cancer-associated thrombosis, reflecting the evolving drugs and evidence over the past 20 years.

British Royalty and Aristocracy: Their skin maladies Part II. Queen Mary II's death from hemorrhagic smallpox

In 1694, Queen Mary II (1662-1694) died at age 32 of hemorrhagic smallpox, a rare and fatal form of the viral infection. This contribution presents the clinical features of Queen Mary II's smallpox infection. It also reviews, from a modern-day perspective, the disseminated intravascular coagulopathy involved in the pathophysiology of hemorrhagic smallpox, which is characterized by thrombocytopenia, coagulation factor deficiency, and hypofibrinogenemia.

Thrombosis with thrombocytopenia syndrome: A database review of clinical trial and post-marketing experience with Ad26.COV2.S

BACKGROUND

Thrombosis with thrombocytopenia syndrome (TTS) is a very rare disorder described after vaccination with adenoviral vector-based COVID-19 vaccines. Co-occurring thrombosis with thrombocytopenia reported after vaccination can be a proxy for identification of TTS.

METHODS

Descriptive database review of all cases of co-occurring (within 42 days) thrombosis with thrombocytopenia in participants in Ad26.COV2.S clinical trials or recipients of Ad26.COV2.S in real-world clinical practice. Cases were retrieved from Janssens' clinical trial and Global Medical Safety databases.

RESULTS

There were 34 cases of co-occurring thrombosis with thrombocytopenia in Ad26.COV2.S recipients (46 per 100,000 person-years) and 15 after placebo (75 per 100,000 person-years) in clinical trials. Among Ad26.COV2.S recipients, mean age at the time of the event was 63 years (range 25-85), 82 % were male, mean time-to-onset 112 days (range 8-339) post-last Ad26.COV2.S dose, 26 events occurred post-dose-1, and 7 within a 28-day risk window post-vaccination. Diagnostic certainty was evaluated using Brighton Collaboration, US Centers for Disease Control and Prevention, and European Medicines Agency Pharmacovigilance Risk Assessment Committee case definitions. One case met the highest level of diagnostic certainty for all 3 definitions. There were 355 spontaneous reports of co-occurring thrombosis with thrombocytopenia in the Global Medical Safety database, 47 % males, 85 % within 28-days after vaccination. Twenty-seven cases met the highest level of diagnostic certainty for all definitions, 21 female, 19 with cerebral venous sinus thrombosis, age-range 18-68 years. Time-to-onset was 7-14 days post-vaccination in 20 cases. There were 8 fatalities.

CONCLUSION

TTS induced by Ad26.COV2.S is very rare. Most co-occurring thrombosis with thrombocytopenia does not constitute TTS.

Treatment of Cancer-Associated Thrombosis: Recent Advances, Unmet Needs, and Future Direction

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.

A tumor-selective adenoviral vector platform induces transient antiphospholipid antibodies, without increased risk of thrombosis, in phase 1 clinical studies

Tumor-selective viruses are a novel therapeutic approach for treating cancer. Tumor-Specific Immuno Gene Therapy (T-SIGn) vectors are tumor-selective adenoviral vectors designed to express immunomodulatory transgenes. Prolonged activated partial thromboplastin time (aPTT), associated with the presence of antiphospholipid antibodies (aPL), has been observed in patients with viral infections, and following administration of adenovirus-based medicines. aPL may be detected as lupus anticoagulant (LA), anti-cardiolipin (aCL) and/or anti-beta 2 glycoprotein antibodies (aβ2GPI). No subtype alone is definitive for development of clinical sequalae, however, patients who are 'triple positive' have a greater thrombotic risk. Additionally, isolated aCL and aβ2GPI IgM do not appear to add value in thrombotic association to aPL positivity, rather IgG subtypes must also be present to confer an increased risk. Here we report induction of prolonged aPTT and aPL in patients from eight Phase 1 studies who were treated with adenoviral vectors (n = 204). Prolonged aPTT (≥ Grade 2) was observed in 42% of patients, with a peak at 2-3 weeks post-treatment and resolution within ~ 2 months. Among patients with aPTT prolongation, LA, but not aCL IgG nor aβ2GPI IgG, was observed. The transience of the prolongation and discordance between positive LA and negative aCL/aβ2GPI IgG assays is not typical of a prothrombotic state. Among the patients with prolonged aPTT there was no evidence of an increased rate of thrombosis. These findings elucidate the relationship between viral exposure and aPL in the context of clinical trials. They suggest a framework in which hematologic changes can be monitored in patients receiving similar treatments.Clinical trial registration:NCT02028442, NCT02636036, NCT02028117, NCT03852511, NCT04053283, NCT05165433, NCT04830592, NCT05043714.

OCCULT RECURRENT BREAST CANCER MASQUERADING AS THROMBOTIC THROMBOCYTOPENIC PURPURA

GATA3 immunohistochemistry stain of the bone marrow biopsy required to diagnose recurrent metastatic breast cancer.

Chemotherapy-induced thrombocytopenia in pediatric oncology: Scope of the problem and opportunities for intervention

BACKGROUND

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.

PROCEDURE

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.

RESULTS

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.

CONCLUSIONS

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.

Standardization of risk prediction model reporting in cancer-associated thrombosis: Communication from the ISTH SSC subcommittee on hemostasis and malignancy

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 Hemostasis & Malignancy 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.

Systematic literature review and meta-analysis on use of Thrombopoietic agents for chemotherapy-induced thrombocytopenia

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.

Romiplostim for chemotherapy‐induced thrombocytopenia: Efficacy and safety of extended use

Background

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.

Objectives

To analyze efficacy and safety of romiplostim in the patients in the phase 2 study, who received romiplostim for ≥1 year.

Patients/Methods

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.

Results

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.

Conclusions

Long‐term use of romiplostim for treatment of CIT was effective and safe, with no evidence of resistance or increased risk of thrombosis.

Implementing a Clinical Decision Tool to Improve Oncologic Venous Thromboembolism Management

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.

Risk of venous thromboembolism in ovarian cancer patients receiving neoadjuvant chemotherapy

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.

Rivaroxaban thromboprophylaxis for gastric/gastroesophageal junction tumors versus other tumors: A post hoc analysis of the randomized CASSINI trial

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.

Mechanisms of Ischemic Stroke in Patients with Cancer: A Prospective Study

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.

Clinical challenges and promising therapies for chemotherapy-induced thrombocytopenia

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.

Genomic profiling identifies somatic mutations predicting thromboembolic risk in patients with solid tumors

Venous thromboembolism (VTE) associated with cancer (CAT) is a well-described complication of cancer and a leading cause of death in patients with cancer. 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 Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets platform to identify somatic alterations associated with VTE. End point 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 analysis. Tumor-specific mutations in KRAS (hazard ratio [HR], 1.34; 95% confidence interval (CI), 1.09-1.64; adjusted P = .08), STK11 (HR, 2.12; 95% CI, 1.55-2.89; adjusted P < .001), KEAP1 (HR, 1.84; 95% CI, 1.21-2.79; adjusted P = .07), CTNNB1 (HR, 1.73; 95% CI, 1.15-2.60; adjusted P = .09), CDKN2B (HR, 1.45; 95% CI, 1.13-1.85; adjusted P = .07), and MET (HR, 1.83; 95% CI, 1.15-2.92; adjusted P = .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; 95% CI, 0.16-0.79; adjusted P = .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 patients with solid tumors. Further analysis is needed to validate these findings and identify additional molecular signatures unique to individual tumor types.

The incidence of thrombocytopenia in adult patients receiving chemotherapy for solid tumors or hematologic malignancies

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 < 100 × 10⁹ /L); 4% had grade 3 (25 to < 50 × 10⁹ /L), and 2% grade 4 (<25 × 10⁹ /L) thrombocytopenia. Of 2537 patients with hematologic malignancies, 28% had any thrombocytopenia, 16% with grade 3, and 12% with grade 4. Among patients with thrombocytopenia, it occurred without another cytopenia in 18% of solid tumors and 7% of hematologic malignancies.

CONCLUSIONS

In a large, US-representative sample of patients undergoing chemotherapy in clinical practice, thrombocytopenia incidence varied across tumor and regimen types. Despite recommendations to alter chemotherapy to avoid severe thrombocytopenia, 4% of patients with solid tumors and 16% with hematologic malignancies experienced grade 3 thrombocytopenia. Prediction and prevention of thrombocytopenia may help oncologists avoid dose modifications and their adverse effects on survival.

Approach to Cancer-Associated Thrombosis: Challenging Situations and Knowledge Gaps

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.

Occurrence and Management of Thrombocytopenia in Metastatic Colorectal Cancer Patients Receiving Chemotherapy: Secondary Analysis of Data From Prospective Clinical Trials

INTRODUCTION

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.

MATERIALS AND METHODS

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 × 10⁹/L (further categorized by grade) and by recorded adverse events (AEs). Co-occurrence of anemia (hemoglobin < 12 g/dL) and neutropenia (neutrophil count < 2 × 10⁹/L) and clinical consequences of CIT were also evaluated.

RESULTS

Among 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%).

CONCLUSION

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.

Association of tumor mutations with arterial thromboembolism risk in patients with solid cancer

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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]

Risk of venous thromboembolism in patients receiving neoadjuvant chemotherapy for ovarian cancer

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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]

Assessing Full Benefit of Rivaroxaban Prophylaxis in High-Risk Ambulatory Patients with Cancer: Thromboembolic Events in the Randomized CASSINI Trial

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.

Use of Direct Oral Anticoagulants for Treating Venous Thromboembolism in Patients With Cancer

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.

Romiplostim Treatment of Chemotherapy-Induced Thrombocytopenia

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.

Rivaroxaban treatment of cancer-associated venous thromboembolism: Memorial Sloan Kettering Cancer Center institutional experience

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.

Burden of thrombocytopenia in adult cancer patients receiving chemotherapy

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Background: Thrombocytopenia is a common toxicity of chemotherapy, yet there are limited data on its occurrence in routine clinical practice. Methods: Using structured patient-level data from the Flatiron Health EHR-derived database, we assessed risk (3-month cumulative incidence) of chemotherapy-induced thrombocytopenia (CIT) in adult patients (2012-2017) based on platelet counts, overall and by each grade of CIT, cancer type, and chemotherapy regimen (Table); and the co-occurrence of other hematologic abnormalities. Results: Of 15,521 solid tumor patients who initiated chemotherapy, 13% had evidence of CIT within 3 months (platelet count <100x109/L), 4% had grade 3 (25 to <50x109/L) and 2% had grade 4 (<25x109/L) CIT. Of the solid tumors examined, incidence was highest in melanoma patients. In hematologic malignancies (N = 2,537), 3-month risk was even higher with nearly 30%, 16%, and 12% having any grade, grade 3 and 4 CIT, respectively; and the greatest risk being in multiple myeloma patients. Anthracycline-based regimens were associated with the highest risk of CIT (7% grade 3; 4% grade 4), followed by gemcitabine- and platinum-based regimens. Anemia often accompanied first evidence of CIT (49%); isolated thrombocytopenia occurred in 15%. Conclusions: This study provides a current snapshot of CIT risk in a large sample of adult patients undergoing chemotherapy in routine clinical practice, highlighting patients at highest risk for CIT and underscoring the complexity of managing cancer treatment. [Table: see text]

Rivaroxaban for Thromboprophylaxis in High-Risk Ambulatory Patients with Cancer

BACKGROUND

Ambulatory patients receiving systemic cancer therapy are at varying risk for venous thromboembolism. However, the benefit of thromboprophylaxis in these patients is uncertain.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.).

Predictive factors of fatal bleeding in acute promyelocytic leukemia

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.

The von Willebrand Factor in Myocardial Infarction and Unstable Angina: A Kinetic Study

Recent studies have demonstrated elevations of von Willebrand Factor following acute myocardial infarction (AMI). In order to determine if this parameter may serve as a marker for AMI, we tested the blood levels of vWF and Factor VIII :C in 28 patients with AMI, 9 patients with unstable angina, 7 patients with atypical chest pain, and 25 healthy volunteers. The level of ristocetin cofactor activity of vWF was between 70 and 144% in the control group. In patients with AMI, the mean level of this activity was 175% on the first day following infarction, rose to a peak of 270% on the fifth and sixth days, and was still significantly greater than normal in all patients on the 14th day. The vWF: Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. FVIII :C was not significantly changed. No significant elevation of vWF was observed in patients with unstable angina. The ristocetin cofactor activity of vWF and vWF: Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels.

Regulatory BC200 RNA in peripheral blood of patients with invasive breast cancer

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.

Rivaroxaban for Stroke Prevention in Patients With Nonvalvular Atrial Fibrillation and Active Cancer

Rivaroxaban is broadly used for the primary prevention of stroke and systemic embolism in the general population with nonvalvular atrial fibrillation (AF). However, there is little published evidence on the safety and efficacy of rivaroxaban for AF in patients with active cancer. The aim of this study was to assess the safety and efficacy of rivaroxaban in patients with active cancer and AF. The use of rivaroxaban in patients with cancer at the Memorial Sloan Kettering Cancer Center is monitored in the setting of a Quality Assessment Initiative. Patients with active cancer and AF, treated with rivaroxaban from January 1, 2014, to March 31, 2016, are included in this analysis. Clinical end points were defined a priori and assessed through text searches of medical records. A total of 163 evaluable patients were identified. After adjusting for competing risks, the estimated 1-year cumulative incidence of ischemic stroke was 1.4% (95% CI 0% to 3.4%) and major bleeding was 1.2% (95% CI 0% to 2.9%). The risk of clinically relevant nonmajor bleeding leading to discontinuation of anticoagulation at 1 year was 14.0% (95% CI 4.2% to 22.7%). The cumulative incidence of mortality was 22.6% (95% CI 12.2% to 31.7%) at 1 year, reflecting an active cancer population. One patient died after developing an acute ischemic cerebrovascular insult. In conclusion, the safety and efficacy of rivaroxaban treatment for nonvalvular AF in patients with active cancer is comparable to the results of the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) study in the general population.

Safe and effective use of rivaroxaban for treatment of cancer-associated venous thromboembolic disease: a prospective cohort study

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.

Preoperative Chemoprophylaxis is Safe in Major Oncology Operations and Effective at Preventing Venous Thromboembolism

BACKGROUND

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.

STUDY DESIGN

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.

RESULTS

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%, p < 0.0001) 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.

CONCLUSIONS

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.

Ovarian vein thrombosis after debulking surgery for ovarian cancer: epidemiology and clinical significance

OBJECTIVE

Ovarian vein thrombosis is associated with pregnancy and pelvic surgery. Postpartum ovarian vein thrombosis is associated with infection and a high morbidity rate and is treated with anticoagulant and intravenous antibiotic therapy. The natural history of such thrombotic events after debulking surgery for ovarian cancer has not been well described. Our objective was to characterize the presentation and outcomes for patients with this condition at our institution.

STUDY DESIGN

We conducted a retrospective study of patients who underwent surgical debulking for ovarian cancer at Memorial Sloan Kettering Cancer Center between the years 2001 and 2010. Patients were included if contrast computed tomography scans of both the abdomen and pelvis were performed within 12 weeks before and 12 weeks after the surgery. The images were reviewed to assess for the presence and extent of a new postoperative ovarian vein thrombosis. When available, subsequent studies were assessed for thrombus progression. Medical records were reviewed to determine whether anticoagulation was used for treatment of the thrombotic episode and to record the occurrence of any new significant venous thromboembolic event in the next year.

RESULTS

One hundred fifty-nine patients had satisfactory imaging. New ovarian vein thrombosis was a common complication of debulking surgery, as found in 41 of patients (25.8%). Only 5 women with ovarian vein thrombosis were started on anticoagulation, of which 2 individuals had an independent venous thromboembolic event as indication for treatment. Only 2 of the ovarian vein thromboses (4.9%) progressed to the inferior vena cava or left renal vein on subsequent scan. The estimated cumulative incidence of venous thromboembolism 1 year after the first postoperative scan was 17.1% for patients in the new ovarian vein thrombosis group vs 15.3% of individuals for the group without a postoperative ovarian vein thrombosis (P = .78).

CONCLUSION

Ovarian vein thrombosis is commonly encountered after debulking surgery for ovarian cancer. Anticoagulation is usually not indicated, and clinically meaningful thrombus progression rarely occurs.

Abstract W P205: Potential Hematological Biomarkers of Stroke in Cancer Patients

Introduction: Cancer patients can develop hypercoagulability, leading to stroke. The pathophysiology of cancer-mediated hypercoagulability, however, is poorly understood and biomarkers associated with stroke in cancer patients are uncertain.

Methods: We performed a pilot cross-sectional study at a tertiary-care cancer center to evaluate potential hematological biomarkers of stroke in cancer patients. From October 2013 through May 2014, we prospectively identified 15 inpatients with active systemic cancer and acute ischemic stroke and 15 inpatients with active systemic cancer and no stroke. Using collected plasma, we compared six potential biomarkers of stroke, selected in advance based on expert opinion and prior data, which included markers of coagulation (thrombin-antithrombin complex and D-dimer), platelet function (P-selectin), and endothelial activation state (sICAM-1, vICAM-1, and thrombomodulin). We used the Wilcoxon rank-sum test to compare biomarker levels between groups.

Results: Each group comprised 14 patients with solid cancer and one patient with hematological cancer. All patients in the cancer and stroke group had stage 4 disease, while only 60% of the cancer and no stroke group had stage 4 disease. Age and demographics were similar between groups. Median levels of thrombin-antithrombin complex, D-dimer, P-selectin, sICAM-1, and vICAM-1 were significantly increased in cancer patients with stroke, but thrombomodulin was not (Table). Our results were substantially unchanged in a sensitivity analysis limited to patients with only stage 4 cancer.

Conclusion: These preliminary data suggest that thrombin-antithrombin complex, D-dimer, P-selectin, sICAM-1, and vICAM-1 could serve as the focus of future prospective studies to elucidate the potential predictive, diagnostic, or etiologic role of hematological biomarkers for stroke in the cancer population.

Alternatively spliced tissue factor promotes plaque angiogenesis through the activation of hypoxia-inducible factor-1α and vascular endothelial growth factor signaling

BACKGROUND

Alternatively spliced tissue factor (asTF) is a novel isoform of full-length tissue factor, which exhibits angiogenic activity. Although asTF has been detected in human plaques, it is unknown whether its expression in atherosclerosis causes increased neovascularization and an advanced plaque phenotype.

METHODS AND RESULTS

Carotid (n=10) and coronary (n=8) specimens from patients with stable or unstable angina were classified as complicated or uncomplicated on the basis of plaque morphology. Analysis of asTF expression and cell type-specific expression revealed a strong expression and colocalization of asTF with macrophages and neovessels within complicated, but not uncomplicated, human plaques. Our results showed that the angiogenic activity of asTF is mediated via hypoxia-inducible factor-1α upregulation through integrins and activation of phosphatidylinositol-3-kinase/Akt and mitogen-activated protein kinase pathways. Hypoxia-inducible factor-1α upregulation by asTF also was associated with increased vascular endothelial growth factor expression in primary human endothelial cells, and vascular endothelial growth factor-Trap significantly reduced the angiogenic effect of asTF in vivo. Furthermore, asTF gene transfer significantly increased neointima formation and neovascularization after carotid wire injury in ApoE(-/-) mice.

CONCLUSIONS

The results of this study provide strong evidence that asTF promotes neointima formation and angiogenesis in an experimental model of accelerated atherosclerosis. Here, we demonstrate that the angiogenic effect of asTF is mediated via the activation of the hypoxia-inducible factor-1/vascular endothelial growth factor signaling. This mechanism may be relevant to neovascularization and the progression and associated complications of human atherosclerosis as suggested by the increased expression of asTF in complicated versus uncomplicated human carotid and coronary plaques.

Clinical consequences of an indeterminate CT pulmonary angiogram in cancer patients

Our aim was to evaluate clinical management and outcomes in cancer patients who had an indeterminate Computed Tomographic Pulmonary Angiogram (CTPA) for the assessment of pulmonary embolus. We reviewed 1000 CTPA studies and identified 251 limited (indeterminate) CTPA. We examined follow-up imaging and reviewed clinical management decisions and any positive diagnosis of venous thromboembolic disease (VTE) within the subsequent 90 days. 60 patients (23.9%) had a follow-up imaging study within five days. 8 had a positive study for VTE disease within 5 days. 3 patients (1.2%) were placed on anticoagulation therapy based on the limited CT result.

Pharmacologic prophylaxis, postoperative INR, and risk of venous thromboembolism after hepatectomy

INTRODUCTION

Pharmacologic prophylaxis (PP) is recommended for patients undergoing general surgical procedures with at least moderate risk of venous thromboembolism (VTE). The role of PP in patients undergoing hepatectomy is controversial, however, due to concerns regarding postoperative liver dysfunction and bleeding.

METHODS

We conducted a retrospective analysis of a prospectively maintained institutional database in order to clarify the relationship between PP, postoperative INR, and risk of VTE.

RESULTS

Postoperative VTE occurred in 55 of 2,147 patients (2.6 %) and was independently associated with advanced age, higher BMI, longer procedure time, and development of a major complication, as well as higher postoperative INR (≥1.5 versus <1.5: OR 2.50, P = 0.006). Patients undergoing more extensive liver resection with higher postoperative INR were less likely to receive PP, but receipt of PP demonstrated no relationship with either VTE incidence or hemorrhagic complications.

CONCLUSIONS

In this large single-institution study, incidence of VTE was not associated with PP but was associated with higher postoperative INR, contrary to the notion that postoperative liver dysfunction is protective against VTE. The interplay between prothrombotic and antithrombotic mechanisms in posthepatectomy patients must be more completely characterized before broad recommendations can be made regarding PP use in these patients.

A new generation of oral direct anticoagulants

After more than 50 years of thrombosis treatment and prophylaxis being based on heparin and vitamin K antagonists, a new generation of oral, direct anticoagulants is now available. The past 5 years have brought a strikingly large number of trials that evaluated these new oral anticoagulants in a range of clinical trials, particularly nonvalvular atrial fibrillation, thrombosis prophylaxis after major joint replacement surgery, treatment of venous thromboembolic events, and, most recently, acute coronary syndrome. These studies have been notably similar in design between the drugs for specific indication. This review focuses on the 3 drugs that either have recently been approved by the US Food and Drug Administration (dabigatran and rivaroxaban) or have the most mature phase III clinical data (apixaban).

Analysis of incidence and clinical outcomes in patients with thromboembolic events and invasive exocrine pancreatic cancer

BACKGROUND

Pancreatic adenocarcinoma is among the most common malignancies associated with thromboembolic events (TEs); however, reported incidence figures vary significantly and contain small patient cohorts. Pancreatic cancer-specific thrombosis studies examining the correlation between clinical variables, including thrombosis timing and the impact of thrombosis on survival, have not been reported.

METHODS

Survival analyses were performed relating to the development and timing of a TE in 1915 patients administered chemotherapy at Memorial Sloan-Kettering Cancer Center with invasive exocrine pancreatic cancer from January 1, 2000 to December 31, 2009. TE timing, relative to clinical parameters including laboratory data, erythropoietin-stimulating agent use, and body mass index (BMI), were also analyzed.

RESULTS

A thrombosis was identified in 690 (36%) patients. After adjusting for patients with pancreatic surgery and thrombosis (n = 127), developing a TE significantly increased the risk of death (hazard ratio [HR], 2.6; 95% confidence interval [CI], 2.3-2.8; P < .01). Patients with an early TE (within 1.5 months from pancreatic cancer diagnosis) had a significantly higher risk of death (HR, 2.1; 95% CI, 1.7-2.5; P < .01) compared with patients with late TE or no TE. Erythropoietin-stimulating agent use and an elevated international normalized ratio were associated with significantly shorter time to thrombosis. Low BMI was associated with significantly longer time to thrombosis.

CONCLUSIONS

TEs are common in exocrine pancreatic cancer, with coagulopathy, erythropoietin-stimulating agent use, and underweight BMI influencing thrombosis timing. TEs, particularly early ones, confer a significantly worse prognosis, suggesting a biological significance, underscoring the relevance of ongoing prophylaxis trials, and raising the question of whether early TEs should be considered a stratification factor for clinical trials.

Disseminated intravascular coagulation with excessive fibrinolysis in prostate cancer: a case series and review of the literature

OBJECTIVES

To describe the clinical characteristics, diagnostic features, prognosis, and outcome of patients with prostate cancer and disseminated intravascular coagulation with excessive fibrinolysis (DIC XFL).

METHODS

We performed a retrospective analysis of prostate cancer patients seen at a single center from March 21, 2000, to July 31, 2006, with a fibrinogen level <150 mg/dl and two of the following criteria: platelets <150 × 10(9)/l, D-dimer >0.5 μg/ml, prothrombin time and activated partial thromboplastin time exceeding normal values, hemorrhage and/or thrombosis. Patients with comorbid conditions that cause coagulopathy were excluded.

RESULTS

Forty-two patients met the inclusion criteria. Most patients had high-grade prostate cancer (26% had Gleason 7 and 45% had Gleason 8-10). Three patients developed DIC XFL following surgery and 39 patients in the setting of metastatic disease; 93% were resistant to castration, and 50% had received prior taxanes. No deep-vein thromboses were documented. Management included blood transfusion, heparin, hormones, and chemotherapy. Median survival was 4 weeks. DIC XFL reversal was seen in 20% of metastatic patients, all of whom received new chemotherapy regimens. Median survival in this group was 26 weeks.

CONCLUSIONS

DIC XFL is a rare complication of prostate cancer. Untreated, the risk of hemorrhage is high and the prognosis poor. Reversal of DIC XFL appears to correlate with response to new anticancer therapy.

Thrombophilic-type placental pathologies and skeletal growth delay following maternal administration of angiostatin4.5 in mice

During placentation, the concentration of fibrinous deposits on the surfaces of maternal vasculature plays a role in villous development and has been strongly implicated in the pathophysiology of human fetal growth restriction (FGR). Fibrinous deposits are conspicuous sites of platelet aggregation where there is local activation of the hemostatic cascade. During activation of the hemostatic cascade, a number of pro- and antiangiogenic agents may be generated at the cell surface, and an imbalance in these factors may contribute to the placental pathology characteristic of FGR. We tested the hypothesis that angiostatin(4.5) (AS(4.5)), a cleavage fragment of plasminogen liberated at the cell surface, is capable of causing FGR in mice. Increased maternal levels of AS(4.5) in vivo result in reproducible placental pathology, including an altered vascular compartment (both in decidual and labyrinthine layers) and increased apoptosis throughout the placenta. In addition, there is significant skeletal growth delay and conspicuous edema in fetuses from mothers that received AS(4.5). Maternally generated AS(4.5), therefore, can access maternal placental vasculature and have a severe effect on placental architecture and inhibit fetal development in vivo. These findings strongly support the hypothesis that maternal AS(4.5) levels can influence placental development, possibly by directly influencing trophoblast turnover in the placenta, and contribute to fetal growth delay in mice.

Maternal administration of anti-angiogenic agents, TNP-470 and Angiostatin4.5, induces fetal microphthalmia

PURPOSE

Agents specifically targeting the vasculature as a mode of therapy are finding increasing use in the clinic, primarily in the treatment of colon cancer (Avastin) and age-related macular degeneration (Lucentis). We have previously shown that maternal administration of angiogenic inhibitors (TNP-470 [O-[chloroacetyl-carbamoyl]fumagillol, initially called AGM-1470], the first angiogenic inhibitor to undergo clinical trials, and Angiostatin(4.5), currently in phase I-III clinical trials) cause fetal growth restriction and/or placental abnormalities. During a rapid growth phase of ocular development in the mouse (embryonic days 12 to 19 [E12-E19]), the placenta mediates the metabolic requirements of the fetus and consequently may impact upon the growth of the highly oxygen sensitive fetal eye.

METHODS

We injected pregnant dams (between E10.5 - E18.5) with anti-angiogenic agents, which caused either a placental insufficiency type of IUGR (intrauterine growth restriction; i.e., TNP-470) or frank placental pathology (Angiostatin(4.5) [AS(4.5)]), and assessed changes in absolute ocular dimensions, tissue types, and vascular profiles using stereological techniques.

RESULTS

The experiments showed that ocular volumes were significantly reduced in fetal mice where dams were treated with either TNP-470 or AS(4.5). Furthermore, TNP-470 specifically caused a reduction in hyaloid blood vessel length and volume, the only intraocular vascular circulation in fetal mice.

CONCLUSIONS

These experiments support the hypothesis that the angiogenic inhibitors (specifically TNP-470 and AS(4.5)) induce microphthalmia either indirectly by their known effects on placental morphology (and/or function) or directly via altering microvascular growth in the fetus. These results also warrant further investigation of a new experimental paradigm linking placental pathology-related fetal growth restriction and microphthalmia.

Differential binding of plasminogen, plasmin, and angiostatin4.5 to cell surface beta-actin: implications for cancer-mediated angiogenesis

Angiostatin4.5 (AS4.5) is the product of plasmin autoproteolysis and consists of kringles 1 to 4 and approximately 85% of kringle 5. In culture, cancer cell surface globular beta-actin mediates plasmin autoproteolysis to AS4.5. We now show that plasminogen binds to prostate cancer cells and that the binding colocalizes with surface beta-actin, but AS4.5 does not bind to the cell surface. Plasminogen and plasmin bind to immobilized beta-actin similarly, with a Kd of approximately 140 nmol/L. The binding is inhibited by epsilon-aminocaproic acid (epsilonACA), indicating the requirement for a lysine-kringle domain interaction. Using a series of peptides derived from beta-actin in competitive binding studies, we show that the domain necessary for plasminogen binding is within amino acids 55 to 69 (GDEAQSKRGILTLKY). Substitution of Lys61 or Lys68 with arginine results in the loss of the ability of the peptide to block plasminogen binding, indicating that Lys61 and Lys68 are essential for plasminogen binding. Other actin peptides, including peptides with lysine, did not inhibit the plasminogen-actin interaction. AS4.5 did not bind actin at concentrations up to 40 micromol/L. Plasminogen, plasmin, and AS4.5 all contain kringles 1 to 4; however, kringle 5 is truncated in AS4.5. Isolated kringle 5 binds to actin, suggesting intact kringle 5 is necessary for plasminogen and plasmin to bind to cell surface beta-actin, and the truncated kringle 5 in AS4.5 results in its release from beta-actin. These data may explain the mechanism by which AS4.5 is formed locally on cancer cell surfaces and yet acts on distant sites.