Surgical practice patterns following NCCTG N0338 “Phase II trial of docetaxel and darboplatin administered every two weeks as induction therapy for stage II and stage III breast cancer.”

Abstract

623 Background: Neoadjuvant therapy plays an important role in breast cancer treatment. Unlike patients who undergo surgery followed by adjuvant therapy,there are no established guidelines for surgical management following neoadjuvant therapy. Methods: Surgical practice patterns from 50 patients in N0338 “Phase II trial of Docetaxel and Carboplatin administered every two weeks as induction therapy for Stage II and Stage III breast cancer” were reviewed. The protocol did not mandate surgical therapy leaving the decision to the treating surgeon and patient. Results: 66% of patients underwent mastectomy (M) and 33% underwent breast conservation therapy (BCT). Three (9%) had immediate reconstruction. Eight (24%) underwent contralateral prophylactic M. Residual tumor size did not always impact primary surgical therapy. In the M group 4 (12%) had no residual disease, 15 (45%) < 2cm and 14 (42%) > 2cm; whereas, in the BCT group 1 (6%) had no residual disease, 12 (70%) < 2cm and 4 (24%) > 2cm. Axillary lymph node (ALN) staging varied tremendously. Three (6%) patients presented with palpable lymphadenopathy and proceeded to complete axillary lymph node dissection (ALND) after chemotherapy (CT). Fine needle aspiration (8) or core needle biopsy (7) of the axilla was performed in 15 (30%) patients before CT; 1 was negative and went on to have sentinel lymph node biopsy (SLNB) after CT; 14 (94%) were positive with 13 (86%) going on to ALND and 1 SLNB after CT. Five (10%) underwent SLNB prior to CT. One (20%) was positive and went on to have ALND after CT; 4 (8%) were negative and had no further ALN staging. A total of 19 (39%) had SLNB after neoadjuvant therapy; 13 (68%) were positive and underwent ALND; 1 SLNB failed; 2 of 5 that were negative underwent ALND with 1 having a positive lymph node. Ten (20%) underwent ALND with no pre-operative staging with 8 being positive for ALN metastases. Conclusions: Review of study data from multiple institutions revealed no consistent criteria in selection of surgical intervention for the breast tumor or ALN staging. There remains a need for further research in this area to establish standard practice guidelines. Support from NIH, sanofi-aventis, Amgen, Breast Cancer Research Foundation. No significant financial relationships to disclose.