A Retrospective Review of Association between Clinico-Pathologic Prognostic Factors and Disease Outcome in Node-Positive or High-Risk Node Negative Breast Cancer Patients Treated with Adjuvant Cyclophosphamide, Doxorubicin Followed by Paclitaxel: A Venezuelan Study.

Abstract

Abstract Background: Breast cancer is a disease with a biologic and clinical heterogeneity explained by differences in the genetic composition, which translate into variability in estrogen receptor (ER), progesterone receptors (PR), Her2–Neu receptor (HER2) expression and permit to identify subgroups that show different prognoses and that also respond differently to treatment. The goal of this study was to determine disease-free survival (DFS) in relation to clinico-pathologic features and ER/PR/HER2 subgroups, in node-positive or high-risk breast cancer patients in a Venezuelan single institution. Methods: We reviewed data between May 1999 to July 2006, from our breast tumor registry with attention to clinical and pathologic prognostic factors. All patients were treated with either mastectomy or breast conserving surgery-with axillary node assessment for stage and adjuvant chemotherapy with doxorubicin 60mg/m2 and cyclophosphamide 600mg/m2 both IV day 1 x 4 cycles, followed by paclitaxel 175mg/m2 day 1 x 4 cycles every 3 weeks or every 2 weeks. All patient received radiation therapy and adjuvant hormonal therapy when indicated. Disease-free survival (DFS) was measured from the date of biopsy to the date of relapse. DFS was estimated using the univariate Kaplan-Meier method. Twelve clinico-pathologic factors that could influence relapse were selected and analyzed using the Cox Proportional Hazards Model. All analyses were carried out using Stata (version 6.0).Results: A total of 92 breast cancer patients all received adjuvant chemotherapy and radiotherapy, 79% of the patients received hormonal therapy with either Tamoxifen or an Aromatase Inhibitor according to their menopausal status. The median follow-up is 55.42 months (range 9.5-110 months). Median age was 50 years (27-70). Local and distant failures were 3% and 11% respectively. For the overall population, the probability of DFS at 2, 5 and 9 years was respectively 93%, 83% and 83%. The results of univariate analysis showed that the mayor significant prognostic factor for influencing relapse was Estrogen receptor (HR:0.29) (p=0.06). Univariate survival analyses comparing grade of differentiation, stage of disease and number of metastasis in axillary lymph nodes with respect to Disease-free survival were performed and showed no significant difference. Patients with triple negative tumors showed an increased risk of relapse with a significant decrease in 9-year disease-free survival 38.1% (p<0.001) and patients with ER+/PR+/HER2- had the best DFS 90% (p<0.001). Conclusions: Estrogen receptor expression was the most significant biologic prognostic factors for relapse in this population. Triple negative tumors were associated with worse DFS. Different DFS in ER/PR/HER2 subgroups clearly illustrates the heterogeneity of this disease and support the importance of tailored therapy in this era. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6056.