Surgical procedures after neoadjuvant chemotherapy in operable breast cancer: results of the GEPARDUO trial.

Background: Neoadjuvant chemotherapy can increase the rate of breast-conserving surgery in patients with operable breast cancer. However, uncertainty remains regarding surgical procedures and predictors for successful breast-conserving surgery.
Methods: This study was an analysis of surgical data of a representative data subset of 607 patients enrolled in the GEPARDUO study. This prospective, multicenter, phase III study randomly assigned patients with operable breast cancer (> or = 2 cm) to neoadjuvant 8-week dose-dense doxorubicin plus docetaxel or a 24-week schedule of doxorubicin plus cyclophosphamide followed by docetaxel (AC-DOC).
Results: Breast conservation was attempted in 493 (81.2%) patients, but 43 patients eventually required mastectomy, thus resulting in a breast-conserving surgery rate of 74.1%. Breast-conserving re-excision was performed in 61 patients (12.4%). Factors associated with a significantly higher breast-conserving surgery rate were a prechemotherapy tumor size < or = 40 mm, nonlobular histological characteristics, treatment with AC-DOC, clinical response, postchemotherapy tumor size < or = 20 mm, and treatment in a larger center (>10 enrolled patients). Nonlobular histological characteristics and intraoperative frozen-section analysis for margin evaluation were associated with significantly lower reoperation rates (P = .015).
Conclusions: Breast conservation after neoadjuvant chemotherapy is feasible in most patients with operable breast cancer. For surgical planning, tumor characteristics and response to neoadjuvant chemotherapy should be taken into account. Improved breast-imaging modalities are necessary to improve detection of residual disease after neoadjuvant chemotherapy, especially when breast cancer is of lobular invasive histology. Margin assessment by intraoperative frozen-section analysis is helpful to avoid reoperation. To achieve an optimal result, an interdisciplinary surgical approach is important.