Prognostic Role of Tumor Size Reduction >50% after Neoadjuvant Chemotherapy for Breast Cancer

Purpose: We evaluated the efficacy of neoadjuvant chemotherapy in reducing locally advanced and early breast cancers size, improving breastconserving surgery rates and its long-term outcomes. Our first aim was to test whether patients achieving a partial pathological response of good quality after neoadjuvant chemotherapy (tumor shrinkage >50% from the original clinical-instrumental size to the size evaluated by the pathologist on the surgical specimen) had better disease-free and overall survival rates than those with a tumor size reduction <50%. Patients and Methods: We analyzed 64 patients initially candidate to mastectomy, treated with neoadjuvant chemotherapy and subsequent surgery at our institution. Results: We observed tumor size reduction in 95% of the cases resulting in downstaging in 67.2% of the patients. Women with tumor size reduction >50% after NACT had better 10-years disease-free survival and overall survival rates than women with reduction <50% (p=0.002 and p<0.05, respectively). In a multivariate analysis, tumor size reduction >50% (HR=4.29, p=0.004) was an independent predictor of disease-free survival, whereas significance was not reached concerning overall survival. Treatment with neoadjuvant chemotherapy allowed to half the rate of mastectomy, as breast-conserving surgery was used in 50% of the cases. Overall, we had recurrences in 37.5% patients. We found no significant increase in local or distant recurrences after breast conserving surgery, as compared with mastectomy. Conclusions: Our data suggest that a tumor size reduction >50% after neoadjuvant chemotherapy may represent a prognostic factor for low risk of recurrence. The use of breast-conserving surgery was not associated with significantly higher risk of local relapse.