Effect of perioperative low-dose heparin administration on the course of colon cancer.

There is evidence that drugs that inhibit blood coagulation or platelet activity may retard or prevent the recurrence of cancer in experimental animals and in patients. The data for 230 patients who underwent surgical resection for primary adenocarcinoma of the colon (Dukes B and C) during 1973 to 1977 were studied retrospectively to determine whether low-dose heparin given for prophylaxis of thromboembolism altered the interval to or prevalence of recurrence. Perioperative low-dose subcutaneous heparin was given to 180 patients, and 50 patients received no heparin. The groups were comparable in age, sex, extent of disease, and use of adjuvant chemotherapy or radiation therapy. Disease recurred in 54 of 180 patients (30%) who received heparin and 18 of 50 patients (36%) who did not receive heparin. This difference was not significant (chi2 = 0.6551, P = 0.418). The interval from surgery to recurrence of cancer was slightly longer in the heparin group (790 days) than in the nonheparin group (638 days), but this difference was not statistically significant (P = 0.268). Life table analysis revealed a significantly lower overall mortality rate among patients who received heparin (P less than 0.05), although there was no difference between the two groups in rate of deaths from colon cancer.