A retrospective study on Mohs micrographic surgery combined with adjuvant radiotherapy in the treatment of extramammary Paget's disease: analysis of 87 patients.

Purpose: This retrospective study assessed the effectiveness of Mohs micrographic surgery (MMS) combined with adjuvant radiotherapy for the treatment of extramammary Paget's disease (EMPD).

Methods: This retrospective study included 87 patients with pathologically confirmed EMPD and complete follow-up data who were treated at the Radiation Therapy Department of Peking University First Hospital between January 2012 and December 2021. The surgical approach for the primary lesion involved MMS, followed by postoperative radiotherapy with doses ranging from 50 to 60 Gy administered over 25-30 fractions. Lymph node dissection was performed on selected patients exhibiting clinical lymphatic metastasis. The primary endpoint of this study was the disease-specific survival (DSS) rate, while secondary endpoints included local recurrence-free survival (LRFS). Survival rates were calculated using the Kaplan-Meier method and statistically analyzed using the log-rank test.

Results: The study population comprised 78 men and 9 women. The median age was 65 years (range: 44-84). The median follow-up period was 71 months (range: 5-139). The 1-, 3-, 5-, and 10-year DSS rates were 99%, 95%, 92%, and 92%, respectively. The LRFS rates at 1, 3, 5, and 10 years were 100%, 100%, 97%, and 94%, respectively. The LNM rates at 1, 3, 5, and 10 years were 1.1%, 2.3%, 5.7%, and 5.7%, respectively. The DM rates at 1, 3, 5, and 10 years were 1.1%, 5.7%, 8.0%, and 9.2%, respectively.

Conclusion: The combination of MMS and adjuvant radiotherapy offers excellent local control in the treatment of extramammary Paget's disease. Key messages What is already known on this topic: Surgical excision is the established primary treatment for extramammary Paget's Disease (EMPD). However, the role of adjuvant radiotherapy in improving outcomes was not definitively established. What this study adds: This study provides robust evidence that adjuvant radiotherapy combined with surgical excision significantly improves local disease control rates in EMPD compared to surgery alone. How this study might affect practice: These findings strongly support the integration of adjuvant radiotherapy into the standard management paradigm for EMPD, particularly for cases with risk factors for local recurrence.