L ong after prospective randomized trials demonstrated equivalent survival with breast-conserving treatment (BCT) and mastectomy for breast carcinoma patients, BCT is used less than would be expected, particularly in certain regions of the United States. 1,2 Many different reasons have been given for not using BCT, but they have never really been proven to be legitimate causes for preferring mastectomy. The list of these "bogus" excuses has included old patient age, young patient age, positive axillary lymph nodes (ALNs), high tumor grade, large breasts, small breasts, positive family history, and the coexistence of either duct carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS). In contrast to some of these factors, the concern about offering BCT to women with coexistent LCIS at least was based on a logical concern that this might predispose women to additional new primary cancers in the ipsilateral or contralateral breast, but this has not been shown to be true for women who have already had an invasive breast carcinoma. LCIS is known to be a marker for increased risk of breast carcinoma for women who have not had the disease previously. [3][4][5][6] But why should LCIS have any effect on "true" local recurrences of cancer at the site initially treated? And does LCIS increase the risk of new breast carcinomas over and above the risk already imposed by the diagnosis of invasive ductal or lobular carcinoma? A retrospective analysis of the effect of LCIS from a large BCT series published in this issue of Cancer provides data indicating that LCIS in the surrounding breast tissue removed with 978