Venous thromboembolism in non-small cell lung cancer patients: retrospective analysis of cases treated at the Oncology Day Hospital of Novara, Italy

Venous thromboembolism (VTE) is the leading cause of mortality and morbidity in patients with cancer. The estimated risk of VTE in cancer patients is 0.5% per year and 0.04% per month. In small cell lung cancer and non-small cell lung cancer (NSCLC) the cumulative incidence is 3% per year and it seems to be associated with advanced stage and histotype. We performed a retrospective analysis on data from all NSCLC treated at the Oncology Day Hospital in Novara, Italy, northern Italy, to assess the incidence of thromboembolic events in patients undergoing systemic cancer treatments. All patients diagnosed with NSCLC who were treated at the Oncology Day Hospital in Novara from January 2008 to May 2011 have been assessed. Many variables related to VTE were analyzed: age, gender, different NSCLC histotype, Eastern Cooperative Oncology Group (ECOG) performance status, body mass index, stage of disease, treatment and chemotherapy regimen, development of a VTE event and its temporal correlation with chemotherapy, central venous catheter presence, use of erythropoietin, use of low molecular weight heparin at baseline, use of acetyl salicylic acid. A total of 355 patients were evaluated, 307 of whom were considered to be eligible for analysis. Median age was 68 years. Histology was as follows: 7% not otherwise specified, 60% adenocarcinoma, 31% squamous cell carcinoma and 2% large cell carcinoma. Thirty-six cases of deep vein thrombosis (DVT) have been reported (incidence 12%). Thirty-one DVT were recorded in patients who were candidates for or undergoing chemotherapy: 14 during treatment, 7 at the end of chemotherapy, and 10 before treatment. The incidence was significantly higher for patients treated with cisplatin (CDDP), both during chemotherapy and after chemotherapy. A correlation with disease stage was documented: 26.5% of total VTE occurred in locally advanced and metastatic stages (IIIB and IV); 18.8% in stage IIIA (N2). A significant correlation between non-squamous histology was also highlighted (P=0.015) and ECOG 0-1 (P=0.010). According to the high incidence of VTE in patients with NSCLC, especially adenocarcinoma, and the correlation highlighted in this study with ECOG performance status 0-1 and CDDP-based treatment, we believe that outpatients undergoing chemotherapy for advanced stage (IIIB-IV) lung cancer should receive thromboembolic prophylaxis at least for the duration of chemotherapy. It is, therefore, essential to propose a thrombo-prophylaxis clinical trial that recruits only lung cancer patients to evaluate the benefit of prophylaxis in this population and to assess the real risk of bleeding during antithrombotic treatment.