Evaluation of the Effects of Letrozole in Combination with Neoadjuvant Chemotherapy on Clinical Response Rate of Breast Cancer

This randomized clinical trial was aimed to assess the efficacy of neoadjuvant letrozole in combination with standard neoadjuvant chemotherapy regimen on clinical response rate of hormone receptor positive locally advanced breast cancer.In this randomized clinical study, 42 female patients, ≥ 18 years, with clinical stage IIB-IIIC (T1-4, N0-3, M0), pathologically proven hormone receptor positive and HER2 negative, invasive ductal carcinoma of breast, were randomly assigned to receive standard neoadjuvant chemotherapy alone (control group) or letrozole 2.5 mg/d (in association with goserlin in premenopausal patients) concurrent with standard neoadjuvant chemotherapy (study group). Standard neoadjuvant chemotherapy regimen has consisted of 4 cycles of doxorubicin (60mg/m2) and cyclophodphamide (600mg/m2), followed by 4 cycles of paclitaxel (175mg/m2) every two weeks.At the beginning of the study all patients underwent thorough exmination of breast mass and axillary lymph nudes by palpation and ultrasonography. At the end of the study response rates were also evaluated by palpation and ultrasonography and subsequently patients were referred for surgury. Pathologic response rates were also evaluated on surgical specimens. All of the clinical, ultrasonographic and pathologic examinations during the trial were performed by a single specialist. Finally all the data were analysed statistically.Overall clinical response rates in breast were 95.2%, in both study and control group. Overall clinical response rates in axilla were 80.9% and 76.2% in study and control group respectively. Similarly, overall radiologic complete response rates in breast and axilla were 95.2% and 76.2% respectively in both study and control group. Totally, the comparison of overall clinical and radiologic response rates in th breast and axilla, showed no significant difference between control and study group (p>0.05).The addition of letrozol to standard neoadjuvant chemotherapy regimen was not associated with higher clinical and radiologic response rates in patients with locally advanced hormon receptor positive breast cancer.Keywords: Neoadjuvant chemotherapy, Letrozole, Locally advanced breast cancer