Primary malignancies of the epididymis: clinical characteristics and prognostic factors

INTRODUCTION We sought to describe clinical characteristics and identify prognostic factors among patients with primary malignancies of the epididymis (PMEs).

The Surveillance, Epidemiology, and End Results (SEER) database (1975-2015) was queried to identify patients with PME. Descriptive statistics and multivariable Cox proportional hazards models were used.

Eighty-nine patients with PME were identified. Median age was 57 years (5-85), and median overall survival (OS) was 16.8 years. The most commonly represented histologies were rhabdomyosarcoma (19.1%), B-cell lymphoma (16.9%), leiomyosarcoma (16.9%), and liposarcoma (12.4%). In multivariable analysis, tumor size ≥ 4 cm was associated with worse OS (HR = 4.46, p = 0.01) compared to tumors < 4 cm. Patients with nonsarcomatoid histology had OS similar to patients with sarcomatoid histology (HR = 0.95, p = 0.92). Disease with regional invasion (HR = 5.19, p = 0.007) and distant metastasis (HR = 29.80, p = 0.0002) had worse OS compared to localized disease. Receipt of radiotherapy was associated with enhanced OS (HR = 0.10, p = 0.006), whereas receipt of chemotherapy was not associated with OS.

We describe the largest cohort of PMEs to date. Larger lesions and tumor stage were independently associated with poor overall survival, while receipt of radiotherapy was associated with enhanced overall survival.