DEEP VENOUS THROMBOSIS AND OCCULT MALIGNANCY - AN EPIDEMIOLOGIC-STUDY

Objective-To determine the risk of subsequent cancer in patients with deep venous thrombosis confirmed by venography. Design-Follow up of al l patients who had venography for suspected deep venous thrombosis dur ing 1984-88. Patients were traced through a cancer registry up to 1 Ja nuary 1991. Subjects-4399 patients who had phlebography in one hospita l. Setting-General hospital in Malmo, Sweden, serving a population of 230 000. Main outcome measure-Number of cancers recorded. Results-4399 patients had venography for suspected deep venous thrombosis; 604 wer e known to have a malignancy at the time of venography and were exclud ed from further analysis. 1383 had deep venous thrombosis, 150 of whom subsequently developed cancer. 182 of the 2412 patients without throm bosis developed cancer. During the first six months after venography 6 6 patients with thrombosis developed malignancy compared with 37 patie nts without thrombosis (P < 0.0001). 38 of the cancers in the deep ven ous thrombosis group were detected by history, physical examination, a nd laboratory tests. Three patients had postoperative or post-traumati c deep venous thromboses. Only two of the remaining patients would hav e benefited from early detection by extensive screening. After six mon ths the incidence of cancer was identical in patients with and without thrombosis. Conclusion-Deep venous thrombosis is associated with a si gnificantly higher frequency of malignancy during the first six months after diagnosis. Malignancies can be found with simple clinical and d iagnostic methods and extensive screening is not required.