Factors predictive of outcome in patients with breast cancer refractory to neoadjuvant chemotherapy

Abstract

Purpose: The purpose of this study was to determine the clinical, pathological, and treatment factors that are predictive of local-regional recurrence and overall survival for patients with breast cancer that is refractory to neoadjuvant chemotherapy.

Patients and methods: This study analyzed the data of the 177 breast cancer patients treated on our institutional protocols who had less than a partial response to neoadjuvant chemotherapy. The initial clinical stage of disease was II in 27%, III in 69%, and IV (supraclavicular lymph node involvement) in 4%. Surgery was performed in 94% of the patients, and 77% of these patients also received adjuvant chemotherapy.

Results: After a median follow-up of 5.2 years, 106 patients experienced disease recurrence, with 98 of these having distant metastases and 45 having local-regional recurrence. The 5- and 10-year overall survivals for the entire group were 56% and 33%, respectively. The factors that were independently associated with a statistically significant poorer overall survival in a Cox regression analysis were pathologically involved lymph nodes after surgery, estrogen receptor-negative disease, and progressive disease during neoadjuvant chemotherapy. The 5-year overall survival for patients with pathologically negative lymph nodes ranged from 84% (estrogen receptor-positive disease) to 75% (estrogen re-ceptor-negative disease), compared with rates for patients with pathologically positive lymph nodes of 66% (estrogen receptor-positive disease) and 40% (estrogen receptor-negative disease). The 5-year survival of patients with progressive disease was only 19%. The 5- and 10-year local-regional recurrence rates for the 177 patients were 27% and 34%, respectively. Significant factors on Cox analysis that predicted for local-regional recurrence were four or more pathologically involved lymph nodes and estrogen receptor-negative disease. For the 105 patients treated with surgery and postoperative radiation therapy, the 10-year local-regional recurrence rates for the subgroups with 0, 1, or 2 of these factors were 12%, 25%, and 44%, respectively.

Conclusions: For patients with a poor response to neoadjuvant chemotherapy, conventional treatments achieve reasonable outcomes in those with lymph node-negative disease or estrogen receptor-positive disease. However, more active systemic and local therapies are needed for patients with estrogen receptor-negative disease and positive lymph nodes and for those with clinical evidence of progressive disease during neoadjuvant chemotherapy.