Influence of rurality on lymph node assessment among women diagnosed with ductal carcinoma in situ and treated with mastectomy, SEER 2000-2015.

ABSTRACT

PURPOSE: Despite recommendations from national organizations supporting the use of lymph node assessment (LNA) among patients with ductal carcinoma in situ (DCIS) at time of mastectomy, variation in practice patterns across the United States has been observed. However, few studies have evaluated LNA differences and rurality. METHODS: Data from the SEER Patterns of Care studies were used to identify women who underwent mastectomy for newly diagnosed DCIS during 2000, 2005, 2010, and 2015. Weighted multivariate logistic regression was used to evaluate the association between rural-urban residence and the use of LNA. A subgroup analysis was performed comparing the use of axillary lymph node dissection (ALND) versus sentinel lymph node biopsy (SLNB). RESULTS: Of the 504 patients included in the analysis, approximately 81% underwent LNA at time of mastectomy with lower rates of use observed among rural patients (66%) versus urban patients (82%). In multivariate analysis, LNA increased over time (p < 0.0001), and rural patients were less likely to receive LNA compared to urban patients [adjusted odds ratio (aOR) = 0.19; 95% confidence interval (CI) 0.06-0.66]. However, the likelihood of undergoing ALND relative to SLNB was lower among rural compared to urban patients (aOR = 0.16; 95% CI 0.03-0.73). CONCLUSIONS: Over time, the use of LNA with mastectomy has increased among DCIS patients. However, significant rural-urban differences in the use and type of LNA persist. The findings of this study highlight the importance of continued research aimed at examining the impact of rurality on the receipt of high-quality cancer care.