Management of de novo OMBC is controversial with no specific treatment guidelines available.
We reviewed 57 consecutive de novo OMBC pts defined as ≤ 5 synchronous metastatic lesions, diagnosed between 01/2000 and 12/2012 at Oscar Lambret Center. Clinicopathological (CP) characteristics and survival data were retrospectively collected. Predictors of overall survival (OS) and progression free survival (PFS) were identified by univariate analysis before being introduced into a stepwise cox regression model.
Median primary tumor size was 40mm (0-150) and 79% of the cases were invasive ductal carcinoma. Estrogen and progesterone receptors were detected in respectively 76% and 56% of the cases. HER2 overexpression was observed in 26% and 12.5% were triple negative. Median KI67 was 40% (5-80). On SBR grading, 3 (6%) cases were grade I, 31 (66%) grade II and 12 (26%) grade III. 16% pts had ≥ 4 histologically involved axillary lymph nodes. The median number of metastatic lesions was 2 (1-5). 31 pts had bone metastases. 65% pts were treated surgically for the primary tumor, 42% had neoadjuvant (NA)/adjuvant chemotherapy (CT), 45% had radiotherapy (RT) for primary BC and 58% were locally treated for their metastatic lesions, while 17 pts were treated with palliative CT only. The median follow-up period was 6.4 years (0.2–12). 2 and 5-year OS and PFS were respectively 90.8%/52.1% and 45.7%/21.4%. Significant predictors of both OS/PFS in univariate analysis were SBR grade, surgery and RT of primary BC, use of NACT and hormonotherapy. In multivariate analysis (MV) both SBR ≤ 2 at diagnosis and the administration of NA CT were identified as significant predictors for better OS (p = 0.005 and 0.006 respectively). High SBR grade independently predicted for worse PFS (p = 0.006).
This retrospective work further highlights the CP characteristics and predictors of outcome of de novo OMBC pts. Only SBR grade at diagnosis and use of NA CT were identified as significant predictors in MV analysis. A molecular analysis of this cohort is planned to complete these findings and characterize the subset of OMBC pts who could benefit from curative therapy and those for whom alternative strategies should be adopted.
Clinical trial identification
Legal entity responsible for the study
Centre Oscar Lambret
All authors have declared no conflicts of interest.