Association of pathologic complete response following neoadjuvant chemotherapy with survival among young women with breast cancer.

Abstract

Listen

Translate article

1122 Background: Neoadjuvant chemotherapy is increasingly being used in the treatment of breast cancer, yet data on efficacy and significance of pathologic complete response (pCR) is limited among young women. We sought to determine whether timing of chemotherapy impacted disease-free (DFS) or overall survival (OS), and whether pCR is associated with improved prognosis among young women with breast cancer. Methods: We performed an IRB-approved review of women ≤40 years old who received treatment for stage I-III breast cancer during 1996-2008 at our institution. DFS and OS were determined through use of state tumor registry, death certificate data, and Social Security Master Death Index. Tumor biology was categorized as hormone receptor positive (HR+), HER-2+, or triple negative (TN) breast cancer. pCR was defined as lack of invasive cancer in the breast and axilla on final pathologic review. Cox regression analyses were conducted to evaluate the hazard ratios (HRs) of the association between chemotherapy and outcomes. Results: 370 women ≤40 years old (median age = 36.5, range: 22-40) were treated with systemic therapy for stage I-III breast cancer. 54.7% of tumors were HR+, 20.9% were HER-2+, and 24.4% were TN. After adjusting for stage, there was no difference in DFS or OS among women who received neoadjuvant versus adjuvant chemotherapy (p=0.6 and 0.5 respectively). pCR following neoadjuvant chemotherapy was higher among HER-2+ (50%) and TN (28.6%) tumors when compared to HR+ tumors (17.6%). Among women who received neoadjuvant chemotherapy, 10-year DFS and OS rates were significantly higher when pCR was achieved when compared to lack of pCR (HR=0.20, p value=0.01 and HR=0.13, p=0.05). pCR with neoadjuvant chemotherapy trended towards higher 10-year DFS and OS when compared to women who received adjuvant chemotherapy (HR=0.30, p value=0.08 and HR=0.20, p=0.1). Conclusions: pCR after neo-adjuvant chemotherapy is associated with improved disease-free and overall survival in young women with breast cancer. Pathologic complete response may be a valuable surrogate marker for survival, and aid in the evaluation of therapeutic efficacy in young breast cancer patients.