IMPORTANCE OF FINDINGS ON THE INITIAL EVALUATION FOR CANCER IN PATIENTS WITH SYMPTOMATIC IDIOPATHIC DEEP VENOUS THROMBOSIS

Background: The relation between thrombosis and cancer is well documen ted, but the clinical evaluation appropriate for detecting underlying cancer in patients with deep venous thrombosis remains unknown. Object ives: To 1) determine the appropriate initial evaluation for cancer in patients with idiopathic deep venous thrombosis and 2) estimate the i ncidence of subsequently diagnosed cancer in patients who were not fou nd to have cancer when deep venous thrombosis was diagnosed. Design: R etrospective cohort study. Setting: Urban, tertiary care teaching hosp ital. Patients: 986 consecutive patients (637 women and 349 men; mean age +/- SD, 53 +/- 17 years) who had no risk factors for venous diseas e and had venous ultrasonography because idiopathic deep venous thromb osis was suspected. Measurements: Initial clinical evaluation was asse ssed by using chart review. The incidence of cancer at a median of 34 months after diagnosis of deep venous thrombosis was obtained through hospital chart review (38%), computerized record extraction (54%), mai led questionnaires (6%), telephone interviews (1%), or a death registr y (1%). Results: Deep venous thrombosis was diagnosed in 142 patients (14%); 136 of the 142 were hospitalized. Cancer was diagnosed in 16 of these 136 patients (12%) during the index hospitalization. All 16 of these patients had one or more abnormalities on at least one of the fo ur components of the clinical examination: history, physical examinati on, basic laboratory testing, or chest radiography. The probability of detecting cancer increased as the number of findings suggestive of ca ncer on the four components of the clinical evaluation increased. Canc er was diagnosed in none of the 56 patients with deep venous thrombosi s who did not have findings on the clinical evaluation. The probabilit y of cancer-free survival during follow-up (median, 34 months) was sim ilar in patients with (3 of 122 [2.5%]) and without (23 of 844 [2.7%]) deep venous thrombosis and in the age- and sex-matched U.S. populatio n. Conclusions: A clinical evaluation that includes a comprehensive me dical history, physical examination, routine laboratory testing, and c hest radiography seems to be appropriate for detecting cancer in these patients. Additional testing should be guided by any abnormalities de tected by this clinical evaluation.