Outcomes of Thromboembolism in COVID-19 Cancer Patients Vs Non-Cancer Patients

Background COVID-19 is associated with increased risk of thromboembolic events, through endothelial damage, severe hypoxia, and cytokine storm, leading to activation of coagulation cascade. Of note, cancer-associated thrombosis (CAT) is the second most common cause of death in cancer patients. The annual incidence of thrombosis is approximately five times higher in cancer patients comparing to non-cancer population. A few studies indicated that COVID-19 cancer patients have a higher risk of developing thrombosis comparing to COVID-19 non-cancer patients. Purpose We aim to assess the differences of thromboembolism between COVID-19 cancer patients and COVID-19 non-cancer patients. Methods We retrospectively reviewed and analyzed the data of 1306 adult patients diagnosed with COVID-19, including 1268 non-cancer patients, and 38 patients diagnosed with active cancers from 2020 to 2021. Skin cancers were excluded from this study. All patients were hospitalized at our community tertiary medical center for COVID-19 treatment and received anticoagulation prophylaxis. The primary outcome in interest was the thromboembolic incidence. Results 54% of non-cancer patients were male and 55% of cancer patients were male. There was no significant difference in baseline demographics between groups. Eight (0.63%) patients in the non-cancer group developed heparin-induced thrombocytopenia (HIT). No HIT events were reported in the cancer patients’ group. Among the non-cancer group, 180 (14.20%) patients were found to have thromboembolic events including deep venous thrombosis, pulmonary embolism, and ischemic stroke; six (15.79%) patients developed thromboembolism in cancer group. There was no statistically significant difference of thromboembolic incidences between non-cancer patients and cancer patients (p=0.967). However, the cancer group experienced significant higher mortality rate (36.84%) comparing to non-cancer group (14.98%) (p < 0.001) during hospitalization. Conclusion In our retrospective study, the incidence of thromboembolism did not appear to be increased in COVID-19 patients with active cancer comparing to non-cancer patients. However, COVID-19 cancer patients experienced significantly higher mortality comparing to COVID-19 non-cancer patients. Larger randomized studies are needed to further investigate this special population.