Clinical characteristics and risk factors of invasion in extramammary Paget's disease of the vulva.

PURPOSE This study aimed to evaluate the risk factors of recurrence and invasive disease in patients with extramammary Paget's disease of the vulva (EPDV). METHODS We performed a retrospective analysis of patients who were initially diagnosed with EPDV in Fudan University Shanghai Cancer Center between May 2006 and March 2019. RESULTS Thirty-eight patients were initially diagnosed with EPDV in our institution. Among them, 29 had intraepithelial EPDV, 8 had intraepithelial EPDV with stromal invasion, and 1 had an underlying vulvar adenocarcinoma. In total, 8 (21%) patients had 12 recurrences. Of these eight patients, four had one recurrence, while other four had two recurrences. Intraepidermal EPDV recurred nine times, while intraepidermal EPDV with invasive disease recurred thrice. The first and second recurrence intervals were 62.1 (9-146) months and 22 (15-28) months, respectively. The rate of invasive disease was 23.7% (9/38) for primary EPDV and 25% (3/12) for recurrent ones. We determined that the presence of invasive disease was associated with a history of more than 10 years (p = 0.02) and inversely correlated with positive margins (p = 0.037), However, invasive disease had no statistical relations with age (p = 0.438), recurrence (p = 0.642), and lesion diameter (p = 0.08). CONCLUSIONS EPDV with a history of more than 10 years was associated with invasive disease. Close and long-term follow-up are recommended to identify those who require further treatment.