Abstract P6-06-41: Non-palpable tumor is a surrogate factor for longer disease free survival in early breast cancer: Evaluation of a 23 years-Venezuelan cohort
Authors: Contreras AC , Acosta V , Torres LG , Ferri N , López H , Marin E , Juan P , Gil ME , Pinto JA , Flores CF , Gómez HL 
Published: August 2014

INTRODUCTION:

Tumor size has long been recognized as the strongest predictor of the outcome of patients with breast cancer. While screening programs are increasing the proportion of non-palpable breast cancer cases, it is important to know its relevance in the outcome. Our purpose was to evaluate various prognostic factors, including tumor palpability, in a multivariate fashion.

METHODS:

A Kaplan-Meier survival analysis was carried out for a retrospective cohort of 758 women with early stages of invasive breast carcinomas who were treated at the Breast Unit of the CECLINES (Caracas-Venezuela), Clinica el Viñedo y Centro Medico Dr. Rafael Guerra Mendez and University of Carabobo (Valencia-Venezuela), between 1987-2010. Endpoints were 10 years disease free survival (10 yrs-DFS) and 10 years overall survival (10 yrs-OS). Using a multivariate analysis, Hazard ratios (HR) were calculated in order to identify independent prognostic factors for 10 yrs-DFS and 10 yrs-OS.

RESULTS:

The median age for the entire cohort was 55yo; 293 (38.7%) tumors were not palpable and 465 (61.3%) were palpable; 42.2% (318 cases) were in pathological stage (PS) I and 57.8% (436 cases) in PS II. Tumor size was &lt;1cm in 26% of cases; was between 1 - 3cm in 24.9% and &gt;3cm in 49.1%; 23.2% had nodal involvement. In regard to immunohistochemistry markers, 633 were evaluable for estrogen receptor (ER); 599 for progesterone receptor (PR) and 578 for HER2. In regard to the status for these markers, 76.9% were ER+; 68.4% PR+ and 28.4% HER2+. Patients more likely to have non palpable tumors were ≥45yo (p = 0.001); smaller tumors (p&lt;0.001); negative lymph nodes (p = 0.008); HER2 negative tumors (p = 0.001) and pathological stage I (p&lt;0.001). The median of follow up was 42.6 months. The 10yrs-DFS was 78.7% and the 10yrs-OS was 91%. There were significant differences in 10yrs-DFS according to tumor palpability (non-palpable 81.1% vs palpable 73.3%, p = 0.002); tumor size (&lt;1cm 81.7% vs 1-3cm 78.3% vs &gt;3cm 77.3%, p = 0.017); nodal involvement (negative 81.9% vs positive 67.2%, p = 0.054); PS (I-IIA: 89.4% vs IIB, 74.9%, p&lt;0.001); treatment with radiotherapy (yes 79% vs no 65.9%) and hormonotherapy (yes 78.9% vs no 70.1%). For 10yrs-OS, there were significant differences in palpability (palpable 78.2% vs non palpable 86.9%, p&lt;0.001); tumor size (&lt;1cm 96% vs 1-3cm 87.6% vs &gt;3cm 75.3%, p = 0.027); HER2 (positive 95.9% vs negative 87.4%, p = 0.052); PS (I-IIA: 95.4% vs IIB, 86.5%, p&lt;0.016) and radiotherapy (yes 92.7% vs no 79.1%, p = 0.001). In the multivariate analysis for 10 yrs-DFS, significant variables were: palpability (HR = 0.43 for non-palpable tumors, CI 95%: 0.242-0.781; p = 0.005) and radiotherapy (HR = 2.5 for patients that did not undergo radiotherapy, CI 95% 1.44 - 4.23). For 10 yrs-OS significant variables were HER2 (HR = 3.6 for HER2+, CI 95%: 1.18 - 10.86, p = 0.024). There was a statistical trend with palpability (HR = 0.23 for non-palpable tumors, CI 95%: 0.05-1.06; p = 0.06).

CONCLUSIONS

Women with early stage breast cancers with non-palpable tumors were less likely to present disease recurrence, independently of other factors. In the era of genomic profiling, a variable easily assessed in routine could be a surrogate factor for disease free survival.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-41.