Venous thrombosis during multimodal treatment of primary breast carcinoma.

In a cooperative group study of 433 breast cancer patients treated with 2 years of postmastectomy chemotherapy, 22 (5%) developed venous thromboses of various types. Two patients died. None of the patients had demonstrable tumor metastases at the time of the venous thrombosis, although seven had metastases a median of 11 months after the thromboses. Thirteen living patients have not had tumor recurrences. No patient developed thrombosis after the chemotherapy was completed. It is possible that one or more of the chemotherapeutic agents initiated the clotting problems. Thrombophlebitis is a possible problem occurring during adjuvant chemotherapy for breast cancer and requires prompt treatment.