Study of Pathological Complete Response Rate with Neoadjuvant Concurrent Chemoradiation with Paclitaxel in Locally Advanced Breast Cancer

Background: Neoadjuvant concurrent chemoradiation (CTRT) is not widely practiced in breast cancers. The current study presents our experience with the use of neoadjuvant CTRT in patients with locally advanced breast cancers (LABC) treated at our center.

Methods: The study included all consecutive female patients with inoperable stage III LABC treated at Cancer Institute (W.I.A), Chennai, India, from December 2015 to September 2016. Data were collected retrospectively from the patients' case records. The impact of neoadjuvant CTRT on the pathological complete response (pCR) and survival was analyzed. Neoadjuvant chemotherapy consisted of 4 cycles of adriamycin and cyclophosphamide given either before or after 4 cycles of paclitaxel. All chemotherapy cycles were given once in 3 weeks. Concurrent radiotherapy was incorporated with 2 cycles of paclitaxel.

Results: The study included 100 patients with a median age of 49 years, among whom 9 (9%) had IIIA disease, 73 (73%) IIIB, and 18 (18%) had IIIC disease. The hormone receptor-positive disease was observed in 36 (36%) patients, triple-negative in 24 (24%), and Her2/neu positive disease in 40 (40%) patients. All patients were operable after completing the planned neoadjuvant treatments. Ninety-one out of 100 (91%) patients underwent modified radical mastectomy whereas 9 (9%) did not consent for surgery. Among the patients who underwent MRM, 34/91 (37.7%) patients had a pCR. Moreover, pCR was observed in 12/22 (54.5%) patients with triple-negative disease, 10/34 (29.4%) patients with hormone receptor-positive disease, and 12/35 (34.2%) patients with Her2/neu positive disease (P = 0.19). Most common morbidity observed was grade 3 skin reactions. The 2-year event-free survival and overall survival for the entire cohort was 73.1% and 88%, respectively.

Conclusion: Neoadjuvant CTRT is associated with a higher pCR rate than what has been reported with neoadjuvant chemotherapy alone. Further prospective studies are required to confirm our findings.