Second cancers after prolonged adjuvant thiotepa for operable carcinoma of the breast.

From 1963--1972, women treated with radical mastectomy for early cancer of the breast were randomly assigned to treatment with thiotepa weekly for one year (N = 90) or no further therapy (N = 77). Fifteen patients subsequently developed second cancers, six in the thiotepa-treated group, and nine in the concurrent control group. These data are compared to the incidence of second primaries in the other prospective randomized trials of adjuvant chemotherapy for breast cancer. To date there is no greater incidence of second primary malignancies in breast cancer patients treated with adjuvant chemotherapy than in those who are treated with surgery alone. The long-term results of the study were reviewed. There was no difference in survival between the thiotepa-treated patients and the control group. However, of 13 negative node patients less than 55 years old who were treated with adjuvant thiotepa, 12 remain alive and free of disease.