Lobular carcinoma in situ of the breast Detailed analysis of 99 patients with average follow-up of 24 years

Abstract
Ninety-nine patients with in situ lobular carcinoma (LCIS) of the breast, not treated by mastectomy, were identified in a review of consecutive breast biopsies performed at Memorial Hospital between 1940 and 1950. Follow-up for an average of 24 years was obtained in order to determine the frequency of subsequent breast carcinoma. Detailed analysis of important clinical and pathologic features was undertaken to identify predictive factors that would serve to distinguish between patients with the greatest and least risk for subsequent carcinoma. Thirty-nine breast carcinomas other than the original LCIS were diagnosed in 32 patients. Half of the carcinomas occurred in the same and half in the opposite breast. The hazard rate for subsequent carcinoma increased with increasing length of follow-up and increasing age. When compared with general population data, the frequency of subsequent breast carcinoma was nine times greater than expected and deaths due to breast carcinoma were 11 times more frequent than expected. None of the currently recommended choices for therapy is entirely satisfactory. Follow-up without further surgery should be considered an investigative procedure until more information is available. This recommendation should be made only if the patient and physician are prepared to accept the responsibility of lifetime surveillance. At present, we consider it prudent in most cases to recommend ipsilateral mastectomy with low axillary dissection and concurrent biopsy of the opposite breast. Contralateral mastectomy is most appropriate when carcinoma is detected in the biopsy.