The Influence of Hospital and Surgeon Factors on the Prevalence of Axillary Lymph Node Evaluation in Ductal Carcinoma In Situ.

IMPORTANCE Although axillary lymph node evaluation is standard of care in the surgical management of invasive breast cancer, a benefit has not been demonstrated in ductal carcinoma in situ (DCIS). Despite uncertainty regarding the efficacy, axillary evaluation is often performed in women with DCIS. OBJECTIVE To determine the incidence of axillary evaluation in women with DCIS and identify clinical, hospital, and surgeon-related factors associated with axillary evaluation. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional analysis conducted from January 2006 through December 2012 of medical records contained in the Perspective database for women with DCIS who underwent breast-conserving surgery (BCS) or mastectomy. A total of 35,591 women aged 18 to 90 years were included in the analysis. MAIN OUTCOMES AND MEASURES Receipt or nonreceipt of surgical axillary evaluation, categorized as sentinel lymph node biopsy (SLNB), axillary lymph node dissection (ALND), or none. Analyses were stratified by surgery type, and multivariable regression analysis was used to identify factors associated with axillary evaluation. RESULTS Of women identified with DCIS, 26,580 (74.7%) underwent BCS while 9011 (25.3%) underwent mastectomy; 17.7% undergoing BCS and 63.0% undergoing mastectomy had an axillary evaluation. Rates of axillary evaluation increased over time with mastectomy (2006, 56.6%; 2012, 67.4%) and were relatively stable with BCS (2006, 18.5%; 2012, 16.2%). Rates of ALND decreased in women undergoing mastectomy (2006, 20.0%; 2012, 10.7%) and BCS (2006, 1.2%; 2012, 0.3%), with increasing use of SLNB. In a multivariable analysis, hospital factors including nonteaching hospital (risk ratio [RR], 1.17; 95% CI, 1.05-1.30) and urban location (RR, 1.15; 95% CI, 1.03-1.29) influenced axillary evaluation with mastectomy. Surgeon volume was the most significant predictor of axillary evaluation among women undergoing BCS (mid vs low volume: RR, 0.87; 95% CI, 0.70-0.94; high vs low volume: RR, 0.54; 95% CI, 0.44-0.65). CONCLUSIONS AND RELEVANCE Despite guidelines recommending against axillary lymph node evaluation in women with DCIS undergoing BCS and uncertainty regarding its use with mastectomy, SLNB or ALND is performed frequently. Given the additional morbidity and cost of these procedures, alternative surgical approaches or prospective evaluation of the clinical benefit of axillary evaluation in women with DCIS is needed.