LAUSR

and in-line with SEER analysis, we find radiotherapy use to be associated with worse survival outcomes in EMPD patients. As previously suggested, radiation treatment benefit may be reduced due to lack of standardized guidelines for its use and its selection for aggressive cancer phenotypes. While it is possible that radiotherapy was used to treat patients with more severe malignancy or increased frailty, we have controlled for a number of tumor-specific factors and comorbidities in our analysis to partly address these explanations. We have also accounted for chemotherapy and immunotherapy use, previously not considered in SEER-based analysis. Extramammary Paget’s disease cases with prior malignancy, as well as cases with underlying perineal cancers, were not included. Such design minimized the likelihood of including cases in which negative postoperative margins are difficult to achieve. We believe our approach has been successful since survival outcome did not appear to vary by sex. After the model was adjusted for other factors, there was no difference in survival for surgically and nonsurgically treated patients. The lack of difference in survival may be attributed to the indolent course of disease or use of alternative modalities such as topical chemotherapy and immunotherapy. While our analysis was limited by the small number of patients undergoing those treatments, the preliminary findings offer some promise.