Role of contralateral breast biopsy in infiltrating lobular cancer.

BACKGROUND Although infiltrating lobular carcinoma (ILC) is known to be associated with higher rates of bilaterality, contralateral breast biopsies are not routinely performed in such patients. METHODS The pathology reports of all patients with ILC admitted to Memorial Sloan-Kettering Cancer Center between 1970 and 1980 were retrospectively reviewed. The incidence of contralateral biopsies, random and directed, was determined. The findings on contralateral biopsy were evaluated with respect to age of the patient, nodal status of the ipsilateral cancer, and multicentricity of the primary lesion. RESULTS Of the 275 patients undergoing mastectomy for ILC, 130 (47%) had contralateral biopsies. Twenty-two were directed biopsies and 108 were random biopsies. On random biopsy 11 (10%) patients were found to have infiltrating carcinomas and seven (6%) were found to have intraductal cancer. Multicentric invasive disease in the ipsilateral breast was found to be predictive of a positive contralateral biopsy (p = 0.01). CONCLUSIONS Despite the current trend toward less extensive surgery for breast cancer, random contralateral breast biopsy is indicated in patients with ILC.