Venous thromboembolism in cancer patients in Christchurch, 1995-1999

To establish the incidence of venous thromboembolism (VTE) in oncology patients, describe risk factors, and assess outcome.

The clinical records of Christchurch Hospital were searched for all patients with a history of deep venous thrombosis (DVT) and/or pulmonary embolism (PE) between January 1995 and December 1999, who were registered with the Oncology Service. Follow up closed in December 2000.

Of 7987 patients referred to the Oncology Service, 106 patients had 122 episodes of DVT and/or PE. The overall incidence rates per 1000 for VTE, PE and DVT were 13.1, 5.5 and 7.6 respectively. The recurrence rate was 226 per 1000, 50% occurring within four months. 70% of patients with VTE had one or more risk factors in addition to their malignancy: previous VTE (8%), tumour compression (7%), hospitalisation at the time of VTE diagnosis (23%), chemotherapy (25%), radiotherapy (21 %), hormonal therapy (10%), surgery (8%). 26% were smokers. 36 patients were not anticoagulated after their initial VTE because of contraindications, including brain metastasis, terminal illness or recent bleeding. 34 of these 36 patients died, 23 within three months of initial VTE, including ten of PE. The median survival time was 5.2 months for DVT and three months for PE. Survival plateaued at 22% for DVT and 16% for PE.

VTE is a relatively common problem in cancer patients. The high recurrence rate and mortality within one year emphasise the need for better understanding of the role of predisposing factors and better guidelines for prophylaxis.