Efficacy and safety of
anticoagulant treatment for
venous thromboembolism (VTE) may vary in patients with different
cancer sites. We evaluated the rates of VTE recurrence and major
bleeding and the relative efficacy and safety of 6-month treatment with oral
apixaban or subcutaneous
dalteparin in patients with different
cancer sites randomized in the Caravaggio study. Primary
cancer was located at gastrointestinal sites in 375 patients (32.5%), lung in 200 (17.3%), breast in 155 (13.4%), genitourinary sites in 139 (12%), gynecological sites in 119 (10.3%), and was hematological in 85 patients (7.4%). Rates of VTE recurrence were 10.9% in patients with gynecological, 8.8% with gastrointestinal, 6.5% with genitourinary, and 5.5% with
lung cancer with lower rates in the other sites of
cancer. Rates of major
bleeding were 7.2% in patients with genitourinary and 4.8% with
gastrointestinal cancer, with lower rates in patients with other sites of
cancer. The observed absolute risk difference in VTE recurrence in favor of
apixaban was 11.9% in patients with gynecological, 5.5% with lung, 3.7% with
genitourinary cancer, and 0.6% with
gastrointestinal cancer. None of the risk differences was statistically significant. The rates of major
bleeding in patients treated with
apixaban or
dalteparin was similar across patients with different
cancer sites. In conclusion, recurrences appear to be more common in patients with gastrointestinal and gynecological
cancer and major bleedings in patients with genitourinary and
gastrointestinal cancer. Oral
apixaban is a valid oral alternative to subcutaneous
dalteparin for the treatment of a large spectrum of patients with
cancer-associated VTE.