Proliferating fraction during neoadjuvant chemotherapy of primary breast cancer in relation to objective local response and relapse-free survival

In women with inoperable primary breast cancer or large T2 tumors, preopera tive chemotherapy may induce tumor shrinkage, facilitate surgery and possib ly improve survival (1). However, at present there are no reliable tumor ce ll parameters to predict which patients will benefit from preoperative chem otherapy. The aims of this study were to analyze the utility of tumor cell proliferation as assessed by Ki-67 staining in fine-needle aspirates from p rimary breast carcinomas to predict initial response to neoadjuvant chemoth erapy as well as recurrence-free survival. The study comprised 51 women wit h primary breast cancer who received 3-4 courses of CEF (cyclophosphamide, epirubicin, 5-fluorouracil) as neoadjuvant chemotherapy. Tumor cells were p rocured through fine-needle aspiration biopsy prior to treatment. A second biopsy was performed before the second course of therapy in 33 women. Twent y-nine women (56%) experienced an objective local response after neoadjuvan t treatment. During a median follow-up period of 39 months, 21 women (41%) developed disease recurrence. A decrease of more than 25% in proliferating fraction after the first course of chemotherapy correlated significantly wi th a decreased risk of disease recurrence (p = 0.033) but showed no signifi cant correlation with local objective response. A multivariate analysis rev ealed that the decrease in proliferating fraction significantly (p < 0.05) added prognostic information to that of involved lymph nodes. These results suggest that changes in proliferating fraction as assessed by Ki-67 staini ng in fine-needle aspirates during preoperative chemotherapy may be of valu e in selecting postoperative adjuvant systemic treatment.