Background: Current guidelines suggest consideration of sentinel lymph node biopsy (SLNB) for patients with ductal carcinoma in situ (DCIS) undergoing mastectomy. Our objective was to identify factors influencing the utilization of SLNB in this population.
Methods: We used the Surveillance Epidemiology and End Results database to identify all women with breast DCIS treated with mastectomy from 2000 to 2008. We excluded patients without histologic confirmation, those diagnosed at autopsy, those who had axillary lymph node dissections performed without a preceding SLNB, and those for whom the status of SLNB was unknown. We used multivariate logistic regression reporting odds ratios (OR) and 95% confidence intervals (CI) to evaluate the relationship of patient- and tumor-related factors to the likelihood of undergoing SLNB.
Results: Of 20,177 patients, 51% did not receive SLNB. Factors associated with a decreased likelihood of receiving a SLNB included advancing age (OR 0.66; 95% CI 0.62-0.71), Asian (OR 0.75; CI 0.68-0.83) or Hispanic (OR 0.84; 95% CI 0.74-0.96) race/ethnicity, and history of prior non-breast (OR 0.57; 95% CI 0.53-0.61). Factors associated with an increased likelihood of receiving a SLNB included treatment in the east (OR 1.28; 95% CI 1.17-1.4), intermediate (OR 1.25; 95% CI 1.11-1.41), high (OR 1.84; 95% CI 1.62-2.08) grade tumors, treatment after the year 2000, and DCIS size 2-5 cm (OR 1.54; 95% CI 1.42-1.68) and >5 cm (OR 2.43; 95% CI 2.16-2.75).
Conclusions: SLNB is increasingly utilized in patients undergoing mastectomy for DCIS, but disparities in usage remain. Efforts at improving rates of SLNB in this population are warranted.