FAIRFAX, Va., April 7, 2016 – Wide variability exists in radiation treatment decisions following neoadjuvant chemotherapy (NAC) and surgery for breast cancer, according to a review of the American College of Surgeons Oncology Group (ACOSOG) Z1071, a prospective trial. ACOSOG is now part of the Alliance for Clinical Trials in Oncology.

A multi-center phase II trial, ACOSOG Z1071 evaluated the false negative rate of sentinel lymph node (SLN) surgery after NAC (chemotherapy delivered prior to treatment to shrink the tumor) in 701 breast cancer patients with initial node-positive disease who met all eligibility requirements and underwent SLN surgery followed by completion axillary lymph node dissection (ALND). Six hundred eighty-five (685) patients enrolled in Z1071 were eligible for the current analysis which sought to evaluate the variability of practice patterns following NAC.

The study, "Patterns of Local-Regional Management Following Neoadjuvant Chemotherapy in Breast Cancer: Results From ACOSOG Z1071 (Alliance)," was published in the March edition of International Journal of Radiation Oncology • Biology • Physics (Red Journal). Study authors focused primarily on surgical approaches, use of reconstruction after mastectomy, and use of post-mastectomy and regional nodal irradiation, nodal status and response to NAC.

After receiving chemotherapy, 401 (58.5 percent) patients remained node-positive while 284 (41.5 percent) changed to node-negative. Of 401 node-positive patients, mastectomy was performed in 148 (36.9 percent), mastectomy with immediate reconstruction in 107 (26.7 percent) and breast-conserving surgery (BCS) in 146 patients (36.4 percent). In women undergoing reconstruction, bilateral mastectomy rates were higher than in those who did not have reconstruction (66.5 percent versus 32.2 percent, respectively, P

Most patients received RT, regardless of the surgical treatment of the primary tumor following NAC. Post-mastectomy RT was more frequently omitted after reconstruction than mastectomy (23.9 percent vs 12.1 percent, respectively, P=.002) and was omitted in 19 of 107 patients (17.8 percent) with residual node-positive disease in the reconstruction group.

The use of internal mammary RT was low, between 7.8 percent and 11.2 percent, and did not differ with surgical approaches. The rate for supraclavicular RT ranged from 46.6 percent to 52.2 percent, and was omitted in 193 node-positive patients (47.3 percent). Some of the observed variations reflect ongoing unresolved controversies in the field of radiation therapy.

Association Viewpoints Homepage