Objective: To investigate the association between pathological complete response (pCR), clinicopathological characteristics and clinical outcomes in breast cancer patients receiving neoadjuvant chemotherapy.
Methods: Medical records of 221 patients who underwent neoadjuvant chemotherapy for breast cancer between January 2006 and December 2008 were retrospectively reviewed. Their clinicopathological features, response to neoadjuvant chemotherapy, survivals and prognostic factors were then analyzed.
Results: The total pCR rate was 11.3% (25/221). The rate of pCR was 0%(0/12), 5.7%(6/106), 7.4%(2/27) and 16.9%(11/65) in the luminal A, luminal B, HER-2, and Basal-like subtypes, respectively. Statistically significant association was found between the pCR rate and the molecular substypes of breast cancer(P<0.05). The median 5-year disease free survival and the 5-year overall survival were 72 months and 79 months. The 5-year disease free survival rate and 5-year overall survival rate were 61.1% and 71.9% in all the 221 patients. The 5-year disease free survival rates of pCR and non-pCR patients were 84.0% and 58.2%, and the 5-year overall survival rates of pCR and non-pCR patients were 96.0% and 68.9%, respectively(P<0.05 for all). The multivariate survival analysis showed that clinical and pathological node stage and pCR are independent prognostic factors for the 5-year disease-free survival and 5-year total survival in patients with neoadjuvant chemotherapy (P<0.05 for both).
Conclusions: pCR is more frequently observed in HER-2 and basal-like breast cancer subtypes compared with the luminal breast cancer subtype. The status of clinical and pathological node status and pCR are independent prognostic factors in patients treated with neoadjuvant chemotherapy.