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

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.

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.

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.

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.