Magnetic resonance imaging with concentric shrinkage as a prognostic factor in patients with luminal breast cancer during neoadjuvant chemotherapy.

Abstract

e11587 Background: The important characteristics of breast cancer is its tumor heterogeneity and response to neoadjuvant chemotherapy (NAC). We analyzed the patterns of tumor shrinkage as a prognostic indicator after NAC for luminal breast cancer. Methods and Results. Methods: Of 854 patients who had received NAC in the single institute between January 2000 and December 2009, 265 luminal breast cancerwere retrospevively examined. Luminal breast cancer was defined as ER and/or PgR positive in more than 10% of cancer cells and HER2 negative (IHC 0, 1+ or FISH <2.0). Before and after NAC, the primary lesion was evaluated by enhanced MRI in 235 patients. Results: The median follow-up period was 51.4 months. 38 patients(16.2%) experienced recurrence after a median DFI of 49.1 months. The median age was 50 and 232 patients received anthracycline containing chemotherapy and 179 patients received taxane. 120 out of 235 patients exhibited concentric shrinkage pattern. Multivariate analysis for DFS identified Age(49>), strong ER/PgR positivity and concentric shrinkage as significantly favorable, and lymph node metastases as significantly unfavorable prognostic factors. Multivariate analysis for OS identified tumor size as significantly unfavorable prognostic factors(p=0.012). Conclusions: the tumor shrinkage pattern could be an important prognostic factor for luminal breast cancer and this suggests that a concentric shrinkage pattern of response may be infrequently associated with chemotherapy-resistant residual cancer cells.