Sentinel lymph node biopsy in breast cancer: Canadian practice patterns

Background: Recent data suggest sentinel lymph node biopsy (SLNBx) for invasive breast cancer (IBC) is widely performed in the United States, often outside of a clinical trial. We sought to describe SLNBx practice patterns in Canada, as well as criteria for abandonment of concurrent axillary lymph node dissection. Methods: All active (n = 1172) general surgeons in Canada were sent a 31-item questionnaire. Results: Of the 519 respondents who treated IBC, 138 (27%) performed SLNBx, whereas 378 (73%) did not. Surgeons who did not perform SLNBx most commonly cited a lack of adequate resources (64%). Of the 138 surgeons who performed SLNBx, 16% participated in one of the ongoing multicenter clinical trials. Of the 39 (28%) surgeons who abandoned routine concurrent axillary lymph node dissection, 20 (51%) performed <30 combined procedures before performing SLNBx alone. On multivariate analysis, surgical oncology training (P = .005), increasing proportion of practice devoted to breast disease (P < .001), and number of days per week in the operating room (P < .001) were associated with the use of SLNBx. Conclusions: In contrast to the United States, SLNBx for IBC in Canada was not as common, and few surgeons participated in clinical trials. Fellowship-trained surgical oncologists and surgeons with a high exposure to breast disease seemed to be most involved in the development of SLNBx for IBC.