SIMULTANEOUS BILATERAL BREAST CARCINOMAS - A RETROSPECTIVE REVIEW OF 149 CASES

Purpose: To evaluate clinical and biological characteristics as well a s treatment outcome in simultaneous bilateral breast carcinomas. Metho ds and Materials: Between 1981 and 1990, 149 patients were diagnosed t o have simultaneous bilateral breast carcinoma, defined as tumor arisi ng in both breasts within a maximum of a 6-month interval, in the abse nce of distant metastases. The median age was 58. Out of a total of 29 8 tumors, the clinical tumor size was T-0-T-1 in 40%, T-2 in 45%, and T-3-T-4 in 15% of tumors. The majority of patients (83%) were clinical ly node negative. Seventy-eight percent of all tumors were classified ductal invasive; 6% were invasive lobular carcinomas; in situ tumors w ere present in 9%. More than two-thirds of all tumors were well or mod erately well differentiated. Tumors were estrogen positive in 86% and progesterone positive in 69% of 62% of patients for whom this informat ion was available in both tumors. Treatment had been by bilateral mast ectomy in 43%, by exclusive irradiation in 16%, and by combined surger y and radiation in 41%. Results: Median follow-up was 68 months (11-14 1). A number of positive correlations existed between the tumors in bo th breasts more often than by chance alone: These were the presence of lobular carcinomas in both breasts (p = 0.06), the same histological grade (p = 0.002), similar ER (p = 0.03) and PR (p = 0.01) status. Fiv e-year rates for survival and disease-free interval were 86% (80-92) a nd 70% (62-78), respectively. For each patient the stage of the larges t tumor at diagnosis was defined as maximum stage. When survival figur es were compared between each maximum stage and matched stages of a gr oup of unilateral breast cancer patients treated during the same time interval in our institute, bilateral breast cancer fared not worse tha n unilateral breast tumors. Treatment related complications occurred i n eight patients (5%). Conclusion: Simultaneous bilateral breast carci nomas have similar biological, but not clinical, features more frequen tly than would be predicted by chance alone. So far, the number of pat ients is too small, and the follow-up is too short to determine whethe r or not the prognosis is equivalent to that of unilateral breast canc er patients of equal stage. Bilateral conservative treatment is feasib le with acceptable cosmetic results and toxicity by using carefully de signed radiotherapy techniques.