[Single-Institution Experience with 25 Cases of Extragonadal Germ Cell Tumors].

Extragonadal germ cell tumors are rare and have a poorer prognosis compared to testicular germ cell tumors. Although the therapeutic options are similar to those for advanced testicular germ cell tumors, there is uncertainty regarding the efficacy of first-line treatment and effective therapeutic options for second-line treatment or beyond due to the limited cases treated. We retrospectively studied 25 cases of extragonadal germ cell tumorstreated between April 1999 and March 2020. Prognosis was poor in cases that progressed to tertiary treatment, had nonseminomatous tumors, or were categorized as having a poor prognosis according to the International Germ Cell Classification. The findings of this case series indicate that achieving complete remission by up to second-line treatment through multidisciplinary treatment, including surgical resection, is important to avoid cancer mortality.