Incidence and survival of Extramammary Paget’s Disease from the Surveillance, Epidemiology, and End Results (SEER) database

Background

Extramammary Paget’s Disease (EMPD) is a rare intraepithelial neoplasm that often presents in anogenital regions, primarily affecting older, female, and Asian patients. Clinical progression is insidious, with delay in diagnosis up to years common. This study sought to investigate contemporary trends in incidence and survival across sexes.

Methods

Retrospective review of EMPD patients in 22 SEER registries from 2004 to 2020. Cases were categorized by primary disease site. Additional data included race, sex, ethnicity, age, disease stage, treatment type, and time to treatment. Age-adjusted incidence rates were calculated from 2000 to 2020. Kaplan-Meier curves estimated survival and univariable and multivariable Cox proportional hazards models examined factors associated with all-cause mortality.

Results

3608 patients were included: 1179 male and 2429 female. 76.2 % of patients had documented treatment with 32.4 % experiencing a 3 + month delay. Incidence was greatest among Asian patients, with a rate 2x greater than white patients, however, the APC was only significant among white patients (+1.22 %). Ten-year survival estimate was 63.0 % in female patients versus 53.4 % in male patients (p < 0.001). On multivariable analysis, older age, advanced stage, and treatment delay were associated with worsened overall survival, while surgery alone decreased the risk of mortality in comparison to no cancer-directed treatment.

Conclusions

Over the past 20 years, the incidence of EMPD has risen across sexes, with survival significantly worsened by older age, advanced stage, and delay in treatment. In addition, primary surgical treatment, when performed early with complete resection, may decrease the long-term mortality risk.