Pathologic findings from the National Surgical Adjuvant Breast and Bowel Project: twelve-year observations concerning lobular carcinoma in situ.

Background: The current report represents a 12-year clinicopathologic update of an earlier 5-year analysis of 180 patients with lobular carcinoma in situ (LCIS) who were treated with local excision and subsequent surveillance only.

Methods: Nineteen pathologic characteristics of LCIS were assessed as potential predictors of invasive and noninvasive ipsilateral breast tumor recurrence (IBTR) and contralateral breast tumor recurrence (CBTR) as well as mortality.

Results: Overall, only 26 IBTRs (14.