The PORTEC-3 trial established the benefit of chemotherapy added to radiotherapy in high-risk endometrial cancer. Which molecular subgroup showed the GREATEST benefit from adjuvant chemotherapy + radiotherapy over radiotherapy alone?

• A POLE ultra-mutated endometrial cancer
• B MMR-deficient/microsatellite instability-high endometrial cancer
• C p53-abnormal (TP53-mutant) serous-like endometrial cancer ✓
• D NSMP (no specific molecular profile) endometrial cancer

Explanation

Translational analysis from PORTEC-3 demonstrated that the p53-abnormal (serous-like) molecular subtype derived the greatest benefit from combined chemotherapy and external beam radiotherapy compared with radiotherapy alone, with significant improvement in 5-year failure-free survival. POLE ultra-mutated tumours have an excellent prognosis regardless of adjuvant therapy; MSI-H tumours benefit from immunotherapy (pembrolizumab); NSMP tumours showed intermediate benefit. This supports molecular classification-guided treatment.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.