A 62-year-old woman with stage IIIC high-grade serous ovarian adenocarcinoma has completed 6 cycles of paclitaxel + carboplatin and achieved a complete radiologic response. What is the preferred maintenance therapy to prolong progression-free survival?

Explanation

## Maintenance Therapy in Advanced Epithelial Ovarian Cancer **Key Point:** When BRCA mutation and HRD status are **not specified**, bevacizumab remains the appropriate default maintenance therapy for advanced high-grade serous EOC after complete/partial response to platinum-taxane chemotherapy, based on GOG-218 and ICON7 trials. Olaparib is preferred **only when BRCA1/2 mutation or HRD positivity is documented**. ### Why Bevacizumab is Correct Here The stem deliberately omits BRCA/HRD status. Per current NCCN and ESMO guidelines, the maintenance algorithm is: 1. **BRCA1/2 mutated** → Olaparib (± bevacizumab per PAOLA-1) 2. **HRD positive (BRCA wild-type)** → Olaparib ± bevacizumab 3. **HRD negative / unknown** → Bevacizumab monotherapy (if bevacizumab was used in first-line) OR observation Since no molecular status is provided, bevacizumab is the **default standard-of-care** maintenance choice in this clinical scenario. ### Evidence Base **GOG-218 Trial (Burger et al., 2011 — NEJM):** - Bevacizumab added to carboplatin/paclitaxel and continued as maintenance improved median PFS: 10.3 → 14.7 months (HR 0.717, p<0.001) - Established bevacizumab maintenance as a standard option for stage III–IV EOC **ICON7 Trial (Perren et al., 2011 — NEJM):** - Confirmed PFS improvement with bevacizumab maintenance (HR 0.81) - Greatest benefit in high-risk patients (stage III/IV with suboptimal debulking) **SOLO-1 Trial (Moore et al., 2018 — NEJM):** - Olaparib maintenance in **BRCA1/2-mutated** advanced EOC: median PFS not reached vs. 13.8 months (HR 0.30) - Applicable **only** to BRCA-mutated patients — not the default when status is unknown ### Maintenance Therapy Decision Algorithm | Molecular Status | Preferred Maintenance | Trial Evidence | |---|---|---| | BRCA1/2 mutated | Olaparib | SOLO-1 | | HRD positive (BRCA wt) | Olaparib ± bevacizumab | PAOLA-1 | | HRD negative / **unknown** | **Bevacizumab** | GOG-218, ICON7 | | No bevacizumab in chemo | Observation | — | ### Why Other Options Are Incorrect - **Olaparib (B):** Correct only if BRCA mutation or HRD positivity is confirmed — not stated in this stem. Assuming BRCA status without documentation is clinically inappropriate. - **Pegylated liposomal doxorubicin (C):** Used for **recurrent** platinum-sensitive/resistant disease, not as first-line maintenance therapy. - **Observation alone (D):** Inferior to bevacizumab in high-risk advanced EOC; not recommended as standard of care per NCCN guidelines. **Clinical Pearl:** The question tests the principle that maintenance therapy selection is **biomarker-driven**. When BRCA/HRD status is unknown or negative, bevacizumab is the evidence-based default. Always test for BRCA/HRD before finalizing maintenance strategy — but when the question omits this data, bevacizumab is the correct answer. **Reference:** DeVita, Hellman & Rosenberg's Cancer: Principles & Practice of Oncology, 11th ed.; NCCN Guidelines Ovarian Cancer v2.2024; GOG-218 (NEJM 2011); SOLO-1 (NEJM 2018).