A 22-year-old unmarried woman presents with abdominal distension and pelvic pain. Imaging reveals a large ovarian mass. Serum α-fetoprotein (AFP) is elevated at 850 ng/mL, and β-hCG is normal. Histopathology confirms yolk sac tumor (endodermal sinus tumor) of the ovary. What is the drug of choice for first-line chemotherapy?

## First-Line Chemotherapy for Ovarian Germ Cell Tumors **Key Point:** BEP (bleomycin, etoposide, cisplatin) is the standard first-line regimen for malignant ovarian germ cell tumors, including yolk sac tumor, dysgerminoma, and mixed germ cell tumors. ### Rationale for BEP **High-Yield:** This regimen is adopted from testicular germ cell tumor protocols and has been successfully adapted for ovarian germ cell malignancies, achieving cure rates >90% even in advanced stages. **Clinical Pearl:** Yolk sac tumor (endodermal sinus tumor) is the most common malignant ovarian germ cell tumor in children and young women. It produces AFP, which serves as a tumor marker for monitoring treatment response and recurrence. ### Treatment Approach 1. **Surgery first** — Unilateral salpingo-oophorectomy (USO) with staging in young women to preserve fertility 2. **Chemotherapy** — BEP × 3–4 cycles depending on stage and risk factors 3. **Monitoring** — Serial AFP and β-hCG levels; imaging surveillance ### Why BEP Works | Component | Role | Notes | |-----------|------|-------| | Bleomycin | DNA damage, apoptosis | Pulmonary toxicity risk; baseline PFTs required | | Etoposide | Topoisomerase II inhibitor | Synergistic with cisplatin | | Cisplatin | DNA cross-linking | Nephrotoxicity, ototoxicity; hydration mandatory | **Mnemonic:** **BEP = Best for Egg-derived Pathology** (germ cell tumors arise from primordial germ cells) **Warning:** Do NOT confuse with ovarian epithelial cancers (which use carboplatin + paclitaxel). Germ cell tumors are chemosensitive and require platinum-based combination therapy, not single-agent or non-platinum regimens.