Incidence and prognosis factors of extragonadal choriocarcinoma in males: a population-based study

BACKGROUND: Choriocarcinoma usually occurs in females and sometimes occurs in the testicles of males. Extragonadal choriocarcinoma in males was previously described in case reports, and our understanding of this type of cancer has remained limited. The purpose of this study was to explore the incidence, treatment and prognostic factors of extragonadal choriocarcinoma in males. MATERIALS AND METHODS: Two cohorts were identified from the Surveillance, Epidemiology, and End Results (SEER) Program by histology, tumor site and sex. One cohort of 115 patients was created using the SEER nine registries (1973–2014) to estimate the incidence. The other cohort of 197 patients was created using the SEER 18 registries (1973–2013) to estimate the patient demographics and survival. RESULTS: The median age at diagnosis was 30 years. The most common primary tumor location was the mediastinum followed by the retroperitoneum and the brain. Approximately 23% of patients underwent beam radiation therapy, whereas 63.5% underwent surgery. The estimated one- and 5-year cause-specific survival rates were 49% and 35%, respectively. The multivariate analysis showed that the age at diagnosis, ie, a younger age of 0–19 years old, and the primary tumor site, ie, the brain, were the independent prognostic factors and were correlated with a favorable prognosis. The median survival time of patients was 186 months, 13 months and 4 months in the 0–19, 20–49 and 50+ years of age, respectively. CONCLUSION: Extragonadal choriocarcinoma in males is a rare malignancy with a poor prognosis. A young age at diagnosis and primary tumor site in the brain were the independent prognostic factors.