Surgeon attitudes toward the omission of axillary dissection in early breast cancer

IMPORTANCE: The American College of Surgeons Oncology Group (ACOSOG) Z0011 study demonstrated the safety of sentinel node biopsy alone in clinically node-negative women with metastases in 1 or 2 sentinel nodes treated with breast conservation. Little is known about surgeon perspectives regarding when axillary lymph node dissection (ALND) can be omitted. OBJECTIVES: To determine surgeon acceptance of ACOSOG Z0011 findings, identify characteristics associated with acceptance of ACOSOG Z0011 results, and examine the association between acceptance of the Society of Surgical Oncology and American Society for Radiation Oncology negative margin of no ink on tumor and surgeon preference for ALND. DESIGN, SETTING, AND PARTICIPANTS: A survey was sent to 488 surgeons treating a population-based sample of women with early-stage breast cancer (N = 5080). The study was conducted from July 1, 2013, to August 31, 2015. MAIN OUTCOMES AND MEASURES: Surgeons were categorized as having low, intermediate, or high propensity for ALND according to the outer quartiles of ALND scale distribution. A multivariable linear regression model was used to confirm independent associations. RESULTS: Of the 488 surgeons invited to participate, 376 (77.0%) responded and 359 provided complete information regarding propensity for ALND derived from 5 clinical scenarios. Mean surgeon age was 53.7 (range, 31-80) years; 277 (73.7%) were male; 142 (37.8%) treated 20 or fewer breast cancers annually and 108 (28.7%) treated more than 50. One hundred seventy-five (49.0%) recommended ALND for 1 macrometastasis. Of low-propensity surgeons who recommended ALND, only 1 (1.1%) approved ALND for any nodal metastases compared with 69 (38.6%) and 85 (95.5%) of selective and high-propensity surgeons (P < .001), respectively. In multivariable analysis, lower ALND propensity was significantly associated with higher breast cancer volume (21-50: −0.19; 95% CI, −0.39 to 0.02; >51: −0.48; 95% CI, −0.71 to −0.24; P < .001), recommendation of a minimal margin width (1-5 mm: −0.10; 95% CI, −0.43 to 0.22; no ink on tumor: −0.53; 95% CI, −0.82 to −0.24; P < .001), participation in a multidisciplinary tumor board (1%-9%: −0.25; 95% CI, −0.55 to 0.05; >9%: −0.37; 95% CI, −0.63 to −0.11; P = .02), and Los Angeles Surveillance, Epidemiology, and End Results site (−0.18; 95% CI, −0.35 to −0.01; P = .04). CONCLUSIONS AND RELEVANCE: This study shows substantial variation in surgeon acceptance of more limited surgery for breast cancer, which is associated with higher breast cancer volume and multidisciplinary interactions, suggesting the potential for overtreatment of many patients and the need for education targeting lower-volume breast surgeons.