Jagsi, Reshma

Purpose ACOSOG Z0011 established that axillary lymph node dissection (ALND) is unnecessary in patients with breast cancer with one to two positive sentinel lymph nodes (SLNs) who undergo lumpectomy, radiotherapy (RT), and systemic therapy. We sought to ascertain RT coverage of the regional nodes in that trial. Methods We evaluated case report forms completed 18 months after enrollment. From 2012 to 2013, we collected all available detailed RT records for central review. Results Among 605 patients with completed case report forms, 89% received whole-breast RT. Of these, 89 (15%) were recorded as also receiving treatment to the supraclavicular region. Detailed RT records were obtained for 228 patients, of whom 185 (81.1%) received tangent-only treatment. Among 142 with sufficient records to evaluate tangent height, high tangents (cranial tangent border ≤ 2 cm from humeral head) were used in 50% of patients (33 of 66) randomly assigned to ALND and 52.6% (40 of 76) randomly assigned to SLND. Of the 228 patients with records reviewed, 43 (18.9%) received directed regional nodal RT using ≥ three fields: 22 in the ALND arm and 21 in the SLND arm. Those receiving directed nodal RT had greater nodal involvement (P < .001) than those who did not. Overall, there was no significant difference between treatment arms in the use of protocol-prohibited nodal fields. Conclusion Most patients treated in Z0011 received tangential RT alone, and some received no RT at all. Some patients received directed nodal irradiation via a third field. Further research is necessary to determine the optimal RT approach in patients with low-volume axillary disease treated with SLND alone.

Abstract Purpose/Objective: The landmark ACOSOG Z0011 trial established that axillary lymph node dissection (ALND) is unnecessary in breast cancer patients with one or two positive sentinel lymph nodes (SLN) who undergo lumpectomy, radiation therapy (RT) and systemic therapy. At a median follow-up of 6.3 years there were no differences in overall survival or local-regional recurrences between patients receiving ALND or SLN biopsy alone. The protocol required whole breast RT using standard tangential fields, but the extent of RT coverage of the regional nodes in these patients has not previously been described. We sought to ascertain this information. Methods: The RT data on the ACOSOG Z0011 trial was collected from case report forms completed by enrolling providers 18 months after enrollment. The response options on the forms included breast, supraclavicular, & other. We reviewed these data and, in 2011-2013, we attempted to identify and contact all treating radiation oncology practices to request detailed radiation treatment records for central review. RT data was sent to the Quality Assurance Review Center (QARC) and reviewed by two independent radiation oncologists, blinded regarding the arm to which the patients were randomized. Results: Of the 891 patients enrolled on Z0011, 35 withdrew consent prior to surgery, leaving 856 who were analyzed in the primary report on trial outcomes.1 Among the 605 of these patients with a completed adjuvant radiation therapy form, 89% were noted to receive whole breast RT. Of these, 89 patients (15%) were recorded as also receiving treatment to the supraclavicular region. Detailed RT records were received on 228 patients: 104/389 (26.7%) and 124/404 (30.7%) on the ALND and SLND arms, respectively. Of the 228 patients, 185 patients (81.1%) received tangent-only treatment. Among these 185 patients, there was sufficient data to evaluate tangent field height in 142 (76.8%). High tangent RT fields (with cranial tangent border within 2 cm of the humeral head) were used in 52.6% (40/76) patients randomized to the ALND arm and 50% (33/66) patients randomized to the SLND arm. Of the 228 patients with records reviewed, 43 (18.9%) received directed regional nodal RT using ≥3 fields: 22 in the ALND and 21 in the SLND arm. Those receiving directed nodal RT tended to have greater nodal involvement (p&lt;0.001). Conclusions: Most patients treated on the Z0011 trial received tangential field RT alone, and some received no radiotherapy at all. Some patients received directed nodal irradiation via a third field. In a subgroup for whom detailed RT records were available, the highest rates of directed nodal irradiation were among those with multiple nodes involved. As survival rates and local-regional recurrences were similar in the study arms, no conclusions can be drawn from this analysis on whether this additional radiation treatment was necessary or beneficial. 1JAMA 2011; 305 (6): 569-575. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-19.