Frequency, clinical pattern and outcome of thrombosis in cancer patients in Saudi Arabia

Objectives: Thrombotic risk is increased in patients with cancer and there are important implications forthose who suffer a venous thromboembolism (VTE). We undertook this study to determine the frequency, clinicalpatterns, and outcome of VTE in Saudi patients with cancer. Methods: Cancer (solid tumors and lymphoma)patients who developed VTE from January 2004 to January 2009 were studied retrospectively. Demographicsand clinical characteristics related to thrombosis and cancer were evaluated. Results: A total of 701 patientswith cancer were seen during the study period. VTE was diagnosed in 47 (6.7%) patients (median age 52, range18-80 years). Lower limb DVT was the most common type, seen in 47% patients, followed by PE in 19%, and19% patients had both DVT & PE. Thrombosis was symptomatic in 72% patients while it was an incidentalfinding on routine workup in 28% . Cancer and VTE were diagnosed at the same time in 38% of patients, and47% patients developed VTE during the course of disease after the cancer diagnosis. The majority of VTE postcancer diagnoses occurred during the first year (median 4 months, range 1-14). Additional risk factors for VTEwere present in 22 (47%) patients and 14 (30%) of these patients were receiving chemotherapy at the time ofthrombosis. Only 5 (10.6%) patients were receiving thrombo-prophylaxis at the time of VTE diagnosis. Mostcommon types of tumors associated with thrombosis were breast cancer, non-Hodgkin’s lymphoma and lungcancer. The majority of the affected patients (79%) had advanced stage of cancer. After a median follow-up of13 (range 0.5-60) months, 38 (81%) patients had died. There was no difference in the mortality of patients withsymptomatic or asymptomatic thrombosis (82% vs 78.6%). Conclusions: Thrombotic complications can developin a significant number of patients with cancer, and almost half of the patients have additional risk factors forVTE. Thrombosis is usually associated with advanced disease and can be asymptomatic in more than a quarterof cases. Thromboprophylaxis in cancer patients is under-utilized. Community based studies are needed toaccurately define the extent of this problem and to develop effective prophylactic strategies.