Treatment outcomes in a large cohort of patients with invasive Extramammary Paget's disease

Abstract

Objective: The outcome of patients with invasive Extramammary Paget's disease (EMPD) is poorly studied. The goal of the current study was to analyze the incidence, treatment approaches and outcome of patients with invasive EMPD.

Methods: We searched the SEER program database for patients diagnosed with invasive EMPD between 1973 and 2007. Demographic data, outcome and therapeutic modalities were included in the analysis. Disease specific survival (DSS) was calculated from the time of original diagnosis.

Results: 1439 patients were diagnosed with invasive EMPD. Most patients (80.4%) had localized disease, while 17.1% had locoregional spread, and 2.5% had distant disease. 1230 (86.4%) patients underwent site directed surgery, and 92 (6.4%) patients radiotherapy. 139 (9.7%) patients did not undergo any surgery or radiation therapy. The 5-year DSS was 94.9% for localized disease, 84.9% for regional disease and 52.5% for distant disease. Multivariate analysis showed a significantly shorter DSS associated with older age and advanced stage treatment modality (HR for death 1.07 and 2.5). Site directed surgery was associated with a significantly improved outcome when compared to patients who underwent no intervention (HR 0.44). Patients who received radiation, alone or in combination with site directed surgery, did not fare any better than patients who underwent surgery alone.

Conclusions: The DSS of patients with invasive EMPD is generally favorable. A poor outcome was associated with older age, advanced stage and treatment modality. The association between a shortened DSS and the use of radiotherapy, alone or in combination with surgery, is surprising and warrants further investigation.