Incidence of vascular thromboembolism events in cancer patients receiving immunotherapy: A single institution experience

Abstract

Background: Cancer and cancer therapy, such as chemotherapy and vascular endothelial growth factor targeted therapies, have been associated with an increased incidence of vascular thromboembolic events (VTEs): deep venous thrombosis (DVT), pulmonary embolus (PE), arterial thromboembolism (ATE), cerebrovascular accident (CVA), and myocardial infarction. However, the incidence of VTEs in patients on immunotherapy has not been well characterized. The purpose of this study was to assess the incidence of VTEs in cancer patients receiving immunotherapy in our institution. Methods: We conducted a single institution retrospective cohort study, which included all cancer patients treated with anti PD-1/PD-L1 or anti CTLA-4 therapy from June 2013 to April 2019. Data regarding clinical characteristics, incidence of VTEs and survival were collected. Results: We selected 229 patients treated with immunotherapy, of whom the majority (n = 146, 63.8%) were males with a median age of 64 years (range 19 to 86 years). Lung cancer was the most frequent tumor treated with immunotherapy (n = 110, 48.0%) followed by melanoma (n = 54, 23.6%) and renal cell carcinoma (RCC) (n = 27, 11.8%). Pembrolizumab was the most commonly used single drug immunotherapy (n = 92, 40.2%) and nivolumab plus ipilimumab was the most common multidrug regimen (n = 17, 7.4%). VTEs occurred in 18 of 229 patients (7.9%). 6 patients had DVT, 7 patients had PE, 3 patients had DVT plus PE, 1 patient had ATE and 1 patient had CVA. 13 of 18 VTEs (72.2%) were symptomatic. VTEs occurred in 12 of 110 patients with lung cancer (10.9%), 5 of 54 patients with melanoma (9.2%) and 1 of 27 patients with RCC (3.7%). In the multivariable analysis, symptomatic VTEs in patients treated with immunotherapy were associated with worse OS (3.6 vs 19.1 months for symptomatic VTEs occurrence vs no occurrence respectively), with statistically significant differences (HR = 2.4 (95%IC: 1.2-4.8) p value: 0.01). Conclusions: The incidence of VTEs in cancer patients receiving immunotherapy in our sample appears to be consistent with the incidence previously reported. Symptomatic VTEs in cancer patients were associated with worsened survival. Further and prospective studies are needed to derive definitive conclusions. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.