Background: Neoadjuvant systemic chemotherapy is the accepted approach for women with locally advancedbreast cancer. Anthracycline- and taxane-based regimens have been extensively studied in clinical trials andconsequently are widely used. In this study aimed to research the complete response (pCR) rates in differentregimens for neoadjuvant setting and determine associated clinical and biological factors.
Methods: This studyincluded 63 patients diagnosed with breast carcinoma among 95 patients that had been treated with neoadjuvantchemotherapy between 2007 and 2010. TNM staging system was used for staging. The histologic response toneoadjuvant chemotherapy was characterized as a pCR when there was no evidence of residual invasive tumorin the breast or axillary lymph nodes. Biologic subclassification using estrogen receptor (ER), progesteronereceptor (PR), HER2 were performed. Luminal A was defined as ER+, PR+, HER2-; Luminal B tumor wasdefined as ER+, PR-, HER2-; ER+, PR-, HER2+; ER-, PR+, HER2-; ER+, PR+, HER2+; HER2 like tumorER-, PR+, HER2+; and triple negative tumor ER, PR, HER2 negative.
Results: Patients median age was 54.14(min-max: 30-75). Thirty-two patients (50.8%) were premenapousal and 31 (49.2%) were postmenapousal.Staging was performed postoperatively based on the pathology report and appropriated imaging modalitiesThe 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 IIand 24 (38.1%) were grade III. Seven (11.1%) patients were stage II and 56 (88.9) patients were stage III. Thepatients were classified for ER, PR receptor and HER2 positivity. Seventeen patients had complete response tochemotherapy. Forty patients (63.5%) were treated with dose dense regimen (cyclophosphamide 600 mg/m2 anddoxorubicine 60 mg/m every two weeks than paclitaxel 175 mg/m2 every two weeks with filgrastim support) 40patients (48%) were treated anthracycline and taxane containing regimens. Thirteen patients (76%) from 17patients with pCR were treated with the dose dense regimen but without statistical significance (p=0.06). pCRwas higher in HER2(-), ER(-), grade III, premenopausal patients.
Conclusion: pCR rate was higher in the groupthat treated with dose dense regimen, which should thus be the selected regimen in neoadjuvant setting. Someother factors can predict pCR in Turkish patients, like grade, menopausal status, triple negativity, percentageof ER positivity, and HER2 expression.