Six cases of heterochronous gastrointestinal cancer preceded by breast cancer.

Among 432 women with primary breast cancer, six (1.4%) were diagnosed as having gastrointestinal cancer more than six months after operation for the breast cancer. This paper presents these six cases. The patients ranged from 56 to 78 years of age at the time of breast cancer surgery, and the interval after surgery until diagnosis of the second cancer ranged from 7 months to 5 years 1 month. The second cancer was gastric cancer in 3, esophageal cancer in 2, and hepatic cancer in 1. All of the 6 patients had received postoperative adjuvant chemotherapy for breast cancer. The most frequent histological type of breast cancer was solid-tubular carcinoma (3 patients). Three patients died, due to the second cancer, 4 days, 2 months, and 6 months, respectively, after diagnosis of the second cancer, and the other patients are alive 2, 3, and 4 years after diagnosis. The Japanese literature regarding multiple cancer among breast cancer patients is reviewed. It is concluded that care should be taken to examine breast cancer patients with gastrointestinal symptoms, which are likely to be dismissed as a side effect of postoperative chemotherapy.