Abstract P1-14-16: Young age: predicts poor response rate after neoadjuvant chemotherapy in endocrine-responsive breast cancer

Abstract Background: Breast cancer rarely occurs in very young women(age<35years), its diagnosis and management could sometimes be difficult. Especially, the patients with positive hormone receptors have significantly lower overall and disease-free survival rates in very young age group than in the older age group. In the previous study, adjuvant tamoxifen therapy might provide less survival benefit when added to chemotherapy in very young breast cancer patients. This study was to compare the response to neoadjuvant chemotherapy for HR-positive breast cancer patients according to the age. Patients and Methods: A total of 551 consecutive patients were evaluated, received preoperative chemotherapy and referred to surgery at the Seoul National University Hospital from January 2001 to December 2010. The clinicopathologic factors and the response to neoadjuvant chemotherapy between the very young age group and the older age group were retrospectively compared. A pCR was defined as the absence of residual invasive carcinoma in the breast. Results: Among the 551 patients who received neoadjuvant chemotherapy, 297 patients revealed HR-positive. The median age of all patients was 42 (range, 24∼67)years and very young age group accounted for 17.2%(51/297). Of 297 patients, 262 (88.2%) received taxane-containing regimen pre-operatively, and there's no difference of chemotherapeutic regimen between two age groups. There were no differences noted between two age groups about clinicopathologic characteristics. The univariate and multivariate analysis of variables related to ORR(CR+PR vs SD+PD) to neoadjuvant chemotherapy showed that very young age at diagnosis was independent predictive factor for poor neoadjuvant chemotherapeutic response.(p = 0.043, OR = 0.528) And this tendency was observed more significantly in age under 30.(p = 0.001, OR = 0.147) Only thirteen patients(4.4%) achieved pCR, which is relatively lower rate, reflective poor chemotherapeutic response in HR-positive group, and there was no relations between pCR rate and the two age groups(p = 0.861) in this study. Taxane-containing regimen(p = 0.004) and Ki67 level(p = 0.005) were related to pCR statistically significantly. Breast conservation rate is not significantly different between two age groups.(age<35: age>35= 51.2% vs 41.3%, p = 0.150) Conclusions: The very young age group showed lower ORR(CR+PR) to neoadjuvant chemotherapy, although there was no significant difference in pCR rate between the two age groups in HR-positive breast cancer patients. We might have to consider and revalue the chemotherapeutic role as neoadjuvant therapy in very young age, HR-positive group, since they had lower survival rate than others. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-16.