Ingrid Glimelius

Both ovarian and testicular germ cell tumors (GCTs) arise from the primordial germ cell and share many similarities. Both malignancies affect mainly young patients, show remarkable responsiveness to cisplatin‐based therapy, and have an excellent prognosis, which also highlights the importance of minimizing long‐term side effects. However, certain differences can be noted: The spreading of the disease differs, and the staging system and treatment recommendations are dissimilar. Moreover, the prognosis for ovarian GCTs is significantly inferior to that for testicular cancer, as exemplified in this review comparing the survival in Swedish patients diagnosed with testicular (1995–2022) and ovarian (1990–2018) GCTs. The 5‐year overall survival in ovarian GCTs was 85.2%, versus 98.2% for testicular GCTs. How can this be explained? One reason may be the difference in knowledge, experience, and evidence because the incidence rate of testicular cancer is more than 15 times that of ovarian GCTs. Given the rarity of the disease in women and the lack of established guidelines, a comprehensive understanding of the disease and treatment decisions is challenging. The main objective of this review is to derive insights from testicular GCTs (seminoma and non‐seminoma) by reviewing etiological, tumor biological, and clinical knowledge, and to thereafter suggest actions for ovarian GCTs based on this. We hypothesize that by adopting specific treatment strategies from testicular GCTs—including de‐escalating adjuvant chemotherapy for low‐risk patients and implementing more standardized and intensive treatment protocols in cases of relapse—we can improve the prognosis and minimize long‐term side effects in ovarian GCT patients.