Abstract P2-10-12: How well predict the 2011 St Gallen early breast cancer surrogate phenotypes metastatic survival?

Abstract

Abstract BACKGROUND: The five prognostic surrogate phenotypes, defined by the 2011 St Gallen consensus, predict metastatic relapse following early breast cancer treatment (Brouckaert et al Ann Oncol 2012). It is unknown to what extent these surrogate phenotypes defined on the primary tumor predict metastatic survival (MS) in a cohort of consecutive women with metachronous metastases. PATIENTS & METHODS: All 4318 patients with primary operable breast cancer, diagnosed between 01–01-2000 and 31–12-2009 and treated in our center were prospectively entered in our institutional database. We included 345 patients with a (distant) metastatic relapse during their follow-up. We observed metastatic survival as the time between the diagnosis of the relapse and death. Tumor subtype was defined according to the 2011 St Gallen recommendations in 5 groups: luminal A (ER+/HER2−, grade 1–2), luminal B1 (ER+/HER2−, grade 3), luminal B2 or luminal-HER2 (ER+/HER2+), HER2-like (ER−/HER2−) and triple-negative. We focused on the value of the primary tumor subtype as a major prognostic determinant, but also assessed age at diagnosis, tumor size, lymph node involvement, tumor subtype, PR-status, primary detection (screening vs. palpation), histology, adjuvant therapy, distant-metastasis free interval (DMFI), first-line metastatic hormonal therapy, recurrence sites (isolate or multiple) and metastasis detection (clinical vs. biochemical). RESULTS: In our cohort, we recorded a median metastatic survival (MS) of 22.3 months (95% CI: 19.7–25.6) and a 5-year survival probability of 15%. Significant differences in median MS were noted when considering the primary tumor subtype (cf. table). We observed an independent prognostic effect for multiple recurrence sites (HR = 1.78, 95% CI 1.37–2.32), first-line metastatic hormonal therapy (HR = 0.30, 95% CI 0.18–0.49), DMFI (HR = 0.92 CI 0.85–0.98) and, finally, primary tumor subtype. CONCLUSION: Our results showed that primary tumor subtype, DMFI, solitary recurrence and first-line metastatic hormonal therapy act as independent prognostic factors in metastatic breast cancer. In order to overcome the biological complexity of metastatic breast cancer, we must appreciate the primary tumor subtype in our therapeutic approach. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-12.