Purpose Venous thromboembolism (VTE) is common in cancer patients. Evidence has suggested that low molecular weight heparin (LMWH) might improve survival in patients with cancer by preventing both VTE and the progression of metastases. No trial in a single cancer type has been powered to demonstrate a clinically significant survival difference. The aim of this trial was to investigate this question in patients with lung cancer. Patients and Methods We conducted a multicenter, open-label, randomized trial to evaluate the addition of a primary prophylactic dose of LMWH for 24 weeks to standard treatment in patients with newly diagnosed lung cancer of any stage and histology. The primary outcome was 1-year survival. Secondary outcomes included metastasis-free survival, VTE-free survival, toxicity, and quality of life. Results For this trial, 2,202 patients were randomly assigned to the two treatment arms over 4 years. The trial did not reach its intended number of events for the primary analysis (2,047 deaths), and data were analyzed after 2,013 deaths after discussion with the independent data monitoring committee. There was no evidence of a difference in overall or metastasis-free survival between the two arms (hazard ratio [HR], 1.01; 95% CI, 0.93 to 1.10; P = .814; and HR, 0.99; 95% CI, 0.91 to 1.08; P = .864, respectively). There was a reduction in the risk of VTE from 9.7% to 5.5% (HR, 0.57; 95% CI, 0.42 to 0.79; P = .001) in the LMWH arm and no difference in major bleeding events but evidence of an increase in the composite of major and clinically relevant nonmajor bleeding in the LMWH arm. Conclusion LMWH did not improve overall survival in the patients with lung cancer in this trial. A significant reduction in VTE is associated with an increase in clinically relevant nonmajor bleeding. Strategies to target those at greatest risk of VTE are warranted.

Objectives: Chemotherapy increases the risk of thromboembolism in patients with cancer. Although thrombocytopenia is a known side effect of chemotherapy, reactive thrombocytosis related to chemotherapy is uncommonly reported. The present study aimed to determine the incidence of gemcitabine-related thrombocytosis and the associated risk of thromboembolism. Methods: Medical records of 250 consecutive patients with a malignant disease who received gemcitabine-based therapy were reviewed. A multivariate analysis was done to determine factors associated with thromboembolism. Results: A total of 220 eligible patients with a median age of 63 years (range 26–83) were identified. Of these 220 patients, 95% had advanced malignancy and 59% had received prior chemotherapy. A total of 69% of patients received a platinum combination. In all, 46% patients experienced thrombocytosis following chemotherapy, with a median platelet count of 632 × 10⁹/l (range 457–1,385). Twenty-three of the 220 patients experienced a vascular event within 6 weeks of treatment. Eleven patients with thrombocytosis experienced a vascular event compared with 10 patients without thrombocytosis (not significant). On multivariate analysis, leukocytosis (odds ratio 5.8, 95% confidence interval 2.1–15.8) and comorbid illnesses (odds ratio 4.1, 95% confidence interval 1.4–12.6) were correlated with thromboembolism. Conclusions: Although gemcitabine-based therapy has been associated with an increased incidence of thrombocytosis, it does not increase the risk of thromboembolism in cancer patients. Leukocytosis and comorbid illnesses do increase the risk of thromboembolism.

502 Background: Data from preclinical studies and small numbers of IBC patients inPhase I clinical trials suggest that IBC may be particularly sensitive to the anti-tumor effects of lapatinib, an inhibitor of ErbB1/ErbB2 tyrosine kinases. EGF103009 was initiated to confirm and expand these initial observations and identify a tumor profile predicting for the sensitivity of IBC to lapatinib. Methods: Patients with relapsed/refractory IBC based on clinical criteria, were assigned to Cohort A (ErbB2 overexpressors: 2/3+ IHC/FISH+) or B (ErbB1 +/ErbB2 non-overexpressors) after analysis of a fresh tumor biopsy in a central reference lab. Patients received lapatinib daily (1500mg/d). Clinical response was documented at day 56 and in the case of CR/PR, confirmed on day 84 and every 8 weeks thereafter. Target lesions were assessed according to RECIST criteria and response in skin disease documented by digital photography. Tumor expression of ErbB2, p-ErbB2, ErbB1, p-ErbB3, IGF-IR, PTEN, ER/PR, E-cadherin, β-catenin, and Rho B/C was analyzed by quantitative IHC from a fresh, pre-treatment biopsy. Results: Of 34 patients enrolled, clinical response data is available from 22 patients of which 17 had biopsies analyzed at a reference lab and assigned to Cohorts A (N=11) and B (N=6). Eight of 11 patients (72%) in Cohort A had a clinical response (CR/PR) to lapatinib documented by RECIST, skin disease, or both. There were no responders in Cohort B. All responders (i) overexpressed ErbB2 (2/3+ IHC or FISH+), (ii) increased p-ErbB2 (2/3+), (iii) co-expressed IGF-IR, and (iv) expressed activated, p-ErbB3. PTEN status did not affect response to lapatinib. Toxicity was generally grade I/II skin and G.I. with one grade III cardiotoxicity necessitating withdrawal from study. Conclusions: ErbB2 overexpression but not ErbB1 expression alone, predicts for sensitivity to lapatinib in IBC. High ErbB2, p-ErbB2 and IGF-IR co-expression predict for clinical response to lapatinib monotherapy in patients with relapsed/refractory IBC, illustrating the importance of selecting patients based on biology rather than histology alone, to maximize the clinical efficacy of ErbB kinase inhibitors in breast carcinomas. [Table: see text]

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