How radiation oncologist accessibility influences treatment choice and quality in early-stage breast cancer: A SEER database analysis.

6031 Background: Mastectomy and breast conserving therapy (BCT, partial mastectomy and adjuvant radiotherapy) are equivalent in survival for treatment of early stage breast cancer. This study evaluated the impact of radiation oncologist accessibility on choice of mastectomy versus BCT, and the receipt of radiotherapy after BCT. Methods: In the NCI SEER database, breast cancer cases from 2004-2008 were selected with the following criteria: T2N1M0 or less, lobular or ductal histology, and treatment with simple mastectomy or partial mastectomy (+/-) adjuvant radiation. The HRSA Area Resource File was combined to define average radiation oncologist density (ROD, number of radiation oncologists/100K people) by county over the same time period. Tumor characteristics, demographic information, and ROD were evaluated with respect to mastectomy rates and receipt of radiation therapy after BCT in univariate and multivariate analyses. Results: In the 118,961 cases analyzed, mastectomy was performed 33.3% of the time relative to BCT. After adjustment for demographic and tumor variables, the odds of having mastectomy versus BCT were inversely associated with ROD (OR [95% CI] = 0.94 [0.93-0.96]; p<0.001). Adjuvant radiation therapy was not administered in 23.4% of BCT cases. Likewise, the odds of having BCT without adjuvant radiation were inversely associated with ROD (0.96 [0.95-0.98]; p<0.001, table). Conclusions: There was a significant, inverse and linear relationship between ROD and mastectomy rates independent of demographic and tumor variables. An inverse trend was also observed for the omission of radiotherapy after BCT. Access to radiation oncologists was a factor in surgical choice and receiving appropriate BCT in early stage breast cancer. [Table: see text]