Relationship between tumor sensitivity to neoadjuvant chemotherapy and histologic pattern of primary tumor in unicentric infiltrating ductal breast carcinoma

Surgical specimens from 409 patients aged from 28 to 80 years (median age 52.1 ± 10.6 years) with stage T2-4N0-2M0 unicentric infiltrating ductal breast carcinoma were investigated. Out of them, there were 309 patients who received 2-4 cycles of neoadjuvant chemotherapy according to the following regimens: CmF or CmXelon (cyclophosphane, methotrexate, 5-fluorouracil or xeloda), FAC (fluorouracil, adriamycin, cyclophosphane) CAF or CAXeloda (cyclophosphane, adriamycin, fluorouracil or xeloda). The efficacy of neoadjuvant chemotherapy was assessed for 123 patients according to WHO classification using ultrasonography and mammography. The data obtained provide insight on sensitivity of different histologic tumor patterns to neoadjuvant chemotherapy. Tumors with initially large number of structural types are most likely to be less sensitive to neoadjuvant chemotherapy. Considering the results of the assessment of treatment efficacy, predominance of parenchymal components in a tumor, presence of microalveolar structures in infiltrating component and pronounced inflammatory stromal infiltration may indicate a low sensitivity to neoadjuvant chemotherapy. Decrease in the number of tumor cells expressing receptors to progesterone is likely to be an additional parameter of adverse effect of neoadjuvant chemotherapy.