Abstract P1-14-02: Different Outcomes in Breast Cancer (BC) Patients with CNS Metastases According to IHC Phenotype

Abstract

Abstract Background: Phenotype plays an important role in BC biology and outcome. We evaluated the characteristics and outcomes of clinical stages I-III BC patients with recurrence according to the IHC phenotype: ER or PR+/HER2-; HER2+ (regardless the ER and PR status) and triple negative (ER-/PR-/HER2-), to determine the influence of phenotype in the SNC recurrence. Methods: We reviewed 1,232 clinical stage I-III BC treated at INEN (2000-2002). Phenotypes were categorized by IHC into [ER+ and/or PR+, HER2-], [ER-, PR-, HER2-] and [HER2+ (regardless ER/PR status)]. Patients were classified in 3 risk groups (recursive partitioning analysis [RPA]; Gaspar et al. Int J Radiat Oncol Biol Phys 1997;37:745) according to 4 criteria: those with Karnofsky Performance Status (KPS) less than 70 (Class III), those with a KPS of or more, aged less than 65, with a controlled primary, no other systemic metastases (Class I), all other patients (Class II). We used Kaplan-Meier estimates for comparing CNS-free metastases survival and survival after CNS recurrence according to IHC phenotype or classes. Results: A median follow-up of 7.6 years; 416 (33.8%) patients had local, regional or distant disease dissemination, and 454 (36.9%) deaths were registered. In total, 62 (5.0%) patients developed CNS metastases (60 cases of cerebral and 2 of meningeal metastases), 36 (2.9%) of whom had developed CNS metastases as the site of first recurrence. 12 (2.1%), 31 (7.7%) and 19 (7.5%) were ER or PR+/HER2-, HER2+ and triple negative, respectively. CNS metastases free survival shown significant differences between ER or PR+/HER2-, HER2+ and Triple negative (97.3%, 89.6% y 90.5%, respectively; P<0.001). Main multivariate predictive factor was IHC phenotype (P<0.001), using [ER or PR+/HER2-] as reference, other phenotypes were expressed by hazard ratios (HR); [HER2+] (HR=3.8, 95%CI; 1.9 - 7.4), triple-negative (HR=4.0, 95%CI; 1.9-8.4). In regard to the RPA groups, 3 (4.9%) were class I, 28 (45.9%) class II and 30 (49.2%) class III. Median survival after CNS recurrence was 12.9, 6.1 and 2.8 for RPA Class I,II and III, respectively]; however there was not significant differences (p=0.085). In the multivariate analysis for OS after SNC metastases, only phenotype was significant and Triple Negative have the higher risk (HR=2.064; IC95% 0.94 — 4.531; P=0.023), Risk groups have not significant effect (P=0.088). Phenotype and outcome Conclusion: IHC phenotype is a strong risk factor for outcome; triple negative, and Class III breast cancer patients present a shorter time to CNS recurrence and survival after CNS recurrence than other IHC phenotypes and other risk groups. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-14-02.