Background: We assess complication rates in node negative breast cancer patients treated with breast radiotherapy (RT) only after sentinel lymph node dissection (SLND) or axillary lymph node dissection (ALND).
Materials and Methods: Between 1995 and 2001, 226 women with AJCC stage I-II breast cancer were treated with lumpectomy, either SLND or SLND+ALND, and had available toxicities in follow-up: 111/136 (82%) and 115/129 (89%) in SLND and ALND groups, respectively. RT targeted the breast to median dose of 48.2 Gy (range, 46.0 to 50.4 Gy) without axillary RT. Chi-square tests compared complication rates of 2 groups for axillary web syndrome (AWS), seroma, wound infection, decreased range of motion of the ipsilateral shoulder, paresthesia, and lymphedema.
Results: Median follow-up was 9.9 years (range, 8.3-15.3 y). Median number of nodes assessed was 2 (range, 1-5) in SLND and 18 (range, 7-36) in ALND (P < 0.0001). Acute complications occurred during the first 2 years and were AWS, seroma, and wound infection. Incidences of seroma 5/111 (4.5%) in SLND and 16/115 (13.9%) in ALND (P < 0.02, respectively) and wound infection 3/111 (2.7%) in SLND and 10/115 (8.7%) in ALND (P < 0.05, respectively) differed significantly. AWS was not statistically different between the groups. At 10 years, the only chronic complications decreased were range of motion of the shoulder 46/111 (41.4%) in SLND and 92/115 (80.0%) in ALND (P < 0.0001), paresthesia 12/111 (10.8%) in SLND and 39/115 (33.9%) in ALND (P < 0.0001), and lymphedema assessed by patients 10/111 (10.0%) in SLND and 39/115 (33.9%) in ALND (P < 0.0001). Chronic lymphedema, assessed by clinicians, occurred in 6/111 (5.4%) in SLND and 21/115 (18.3%) in ALND cohorts, respectively (P < 0.0001).
Conclusions: Our mature findings support that in patients with negative axillary nodal status SLND and breast RT provide excellent long-term cure rates while avoiding morbidities associated with ALND or addition of axillary RT field.