Prognosis of cancers associated with venous thromboembolism.

Background: Little is known about the prognosis of cancer discovered during or after an episode of venous thromboembolism. Methods: We linked the Danish National Registry of Patients, the Danish Can cer Registry, and the Danish Mortality Files to obtain data on the survival of patients who received a diagnosis of cancer at the same time as or afte r an episode of venous thromboembolism. Their survival was compared with th at of patients with cancer who did not have venous thromboembolism (control patients), who were matched in terms of type of cancer, age, sex, and year of diagnosis. Results: Of 668 patients who had cancer at the time of an episode of deep v enous thromboembolism, 44.0 percent of those with data on the spread of dis ease (563 patients) had distant metastasis, as compared with 35.1 percent o f 5371 control patients with data on spread (prevalence ratio, 1.26; 95 per cent confidence interval, 1.13 to 1.40). In the group with cancer at the ti me of venous thromboembolism, the one-year survival rate was 12 percent, as compared with 36 percent in the control group (P<0.001), and the mortality ratio for the entire follow-up period was 2.20 (95 percent confidence inte rval, 2.05 to 2.40). Patients in whom cancer was diagnosed within one year after an episode of venous thromboembolism had a slightly increased risk of distant metastasis at the time of the diagnosis (prevalence ratio, 1.23 [9 5 percent confidence interval, 1.08 to 1.40]) and a relatively low rate of survival at one year (38 percent, vs. 47 percent in the control group; P<0. 001). Conclusions: Cancer diagnosed at the same time as or within one year after an episode of venous thromboembolism is associated with an advanced stage o f cancer and a poor prognosis. (N Engl J Med 2000;343:1846-50.) (C) 2000, M assachusetts Medical Society.