Breast cancer followed by second malignancy.

Among 232 cases of operable breast cancer treated by the 2nd Department of Surgery, Hiroshima University School of Medicine, between 1963 and 1982, 7 cases (3. 0%) were followed by a second primary malignancy. Eighty six percent of the second primary malignancies were found in digestive systems. The incidence of a second primary malignancy was 6. 1%* (5/82) in the irradiated group and 1. 3%* (2/150) in the non-irradiated group (*P<O. 05). These results, however, cannot instantly be accepted because the second primary malignancy in 4 cases out of 5 in the irradiated group was found in the non-irradiated sites. Moreover, this was not a complete case control study. The effect of postoperative irradiation therapy on the incidence of second primary malignancy is expected to be elucidated by a prospective randomized study. Only 2 cases out of the 7 cases followed by a second primary malignancy could undergo curative operation and only one case survived for 5 years after the operation, which fact suggests the importance of early diagnosis and treatment.