Risk for subsequent breast cancer after lobular carcinoma in situ: Do clinical factors matter?

1593 Background: Increased breast cancer risk conferred by lobular carcinoma in situ (LCIS) is poorly understood. Molecular studies suggest a subset of LCIS may behave as precursors to invasive disease, yet criteria for risk stratification in the clinical management of women with LCIS are lacking. We reviewed our experience with LCIS over 25 yrs to identify clinical factors associated with a subsequent cancer diagnosis. Methods: Patients participating in surveillance following a diagnosis of LCIS were identified from institutional databases and clinical practice records (1984-2009). Those taking tamoxifen were excluded. Comparisons were made between patients who developed cancer (cases) and those without evidence of cancer after ≥ 96 months of followup (controls). Cases were further analyzed by time to cancer diagnosis, < 12 months vs. ≥ 12 months from LCIS. Results: 675 pts with LCIS w/out concurrent cancer at presentation were identified; 31 (5%) had bilateral LCIS. Average age at LCIS dx was 52 yrs (ra...