Experience with opposite breast biopsy in patients with operable breast cancer.

One hundred and nine patients with unilateral breast carcinoma and no palpable abnormality of the contralateral breast were evaluated by opposite breast biopsy. Our patient population yielded four noninfiltrating carcinomas, and one infiltrating carcinoma for an incidence of 4.5%. The one infiltrating cancer was suspected on a preoperative mammogram. We have discontinued the routine use of the opposite breast biopsy as a diagnostic tool in patients with unilateral breast cancer, in patients with no palpable abnormality and a normal mammogram.