Risk factors for cancer-associated thrombosis in advanced cancer patients with chemotherapy or palliative treatment (retrospective study).

Abstract

819 Background:Cancer-associated thrombosis (CAT) represents the second-leading cause of death in cancer patients and venous thromboembolism (VTE) occurs in about 20% of hospitalized cancer patients. CAT is important for safety cancer treatment.However, the risk factors for CAT in Japanese cancer patients have not been well studied. Methods: We retrospectively examined cases that had received chemotherapy or palliative treatment from April 2017 to February 2018 in our hospital using medical records. Results: Fifty-five cases with 37-94 years (23 males and 32 females) were examined. Primary sites of cancers were as below; pancreatic: n = 14 (25%), colorectal: n = 12 (22%), gastric: n = 7 (13%), breast: n = 4 (7%), lung: n = 3 (5%), esophageal: n = 3 (5%), head and neck: n = 3 (5%), and others: n = 9 (16%).Forty-two patients (76%) were received chemotherapy, and 12 (22%) of them were diagnosed with CAT at the beginning or during the course of chemotherapy (CAT group). The sites of CAT were as follows; lower extremity type venous thrombosis: n = 10, cerebral infarction: n = 3, pulmonary artery thromboembolism: n = 1, portal vein thrombosis: n = 1, subclavian vein thrombosis: n = 1, and others: n = 2. In 12 patients with CAT, primary sites of cancers were as below; pancreatic: n = 6 (45%), gastric cancer: n = 3 (27%), colorectal, esophageal and ovarian cancer: n = 1 (9%), and 8 patients (67%) received anticoagulant therapy, including 7 patients treated with DOACs. 3 patients (38%) discontinued anticoagulant therapy because of gastrointestinal bleeding and 2 patients (25%) had recurrence of VTE during anticoagulant therapy. Overall survival (OS) tended to be shorter in CAT groups than non-CAT group (median OS: 118 days vs 190 days; p = 0.158). Conclusions: As reported in Western countries, the incidence of CAT was about 20%, and higher in Japanese pancreatic and gastric cancer patients. As shorter overall survival in CAT group might be responsible for development of thromboembolism, thromboembolism prophylaxis for high-risk Japanese patients may be recommended. Additionally, the present study showed that recurrence rate of CAT was higher than that of previous clinical trials.