Retrospective analysis of neoadjuvant chemotherapy for breast cancer in Turkish patients

Neoadjuvant systemic chemotherapy is the accepted approach for women with locally advanced breast cancer. Anthracycline- and taxane-based regimens have been extensively studied in clinical trials and consequently are widely used. In this study aimed to research the complete response (pCR) rates in different regimens for neoadjuvant setting and determine associated clinical and biological factors.

This study included 63 patients diagnosed with breast carcinoma among 95 patients that had been treated with neoadjuvant chemotherapy between 2007 and 2010. TNM staging system was used for staging. The histologic response to neoadjuvant chemotherapy was characterized as a pCR when there was no evidence of residual invasive tumor in the breast or axillary lymph nodes. Biologic subclassification using estrogen receptor (ER), progesterone receptor (PR), HER2 were performed. Luminal A was defined as ER+, PR+, HER2-; Luminal B tumor was defined as ER+, PR-, HER2-; ER+, PR-, HER2+; ER-, PR+, HER2-; ER+, PR+, HER2+, HER2 like tumor ER-, PR+, HER2+; and triple negative tumor ER, PR, HER2 negative.

Patients median age was 54.14 (min-max: 30-75). Thirty-two patients (50.8%) were premenopausal and 31 (49.2%) were postmenopausal. Staging was performed postoperatively based on the pathology report and appropriated imaging modalities The TNM (tumor, lymph node, metastasis) system was used for clinical and pathological staging. Fifty-seven (90.5%) were invasive ductal carcinomas, 6 (9.5%) were other subtypes. Thirty nine (61.9%) were grade II and 24 (38.1%) were grade III. Seven (11.1%) patients were stage II and 56 (88.9) patients were stage III. The patients were classified for ER, PR receptor and HER2 positivity. Seventeen patients had complete response to chemotherapy. Forty patients (63.5%) were treated with dose dense regimen (cyclophosphamide 600 mg/m2 and doxorubicine 60 mg/m every two weeks than paclitaxel 175 mg/m2 every two weeks with filgrastim support) 40 patients (48%) were treated anthracycline and taxane containing regimens. Thirteen patients (76%) from 17 patients with pCR were treated with the dose dense regimen but without statistical significance (p=0.06). pCR was higher in HER2(-), ER(-), grade III, premenopausal patients.

pCR rate was higher in the group that treated with dose dense regimen, which should thus be the selected regimen in neoadjuvant setting. Some other factors can predict pCR in Turkish patients, like grade, menopausal status, triple negativity, percentage of ER positivity, and HER2 expression.