The PORTEC-3 trial compared chemotherapy-radiotherapy vs radiotherapy alone in high-risk endometrial cancer. The molecular subgroup that derived the greatest benefit from combined treatment (chemoradiation) in terms of overall survival was:

• A POLE-ultramutated tumours
• B Mismatch repair deficient (MMRd) tumours
• C Copy number low (NSMP) tumours
• D p53-mutated (copy number high) tumours ✓

Explanation

PORTEC-3 molecular analysis (TCGA/ProMisE classification) showed that the p53-mutated (TP53abn, copy number high/serous-like) subgroup derived the greatest benefit from adjuvant chemoradiation over radiotherapy alone in terms of both recurrence-free and overall survival. POLE-ultramutated tumours have an excellent prognosis regardless of adjuvant treatment and may not need chemotherapy. MMRd tumours benefited less from chemoradiation and may benefit more from immunotherapy. This molecular stratification now guides adjuvant therapy decisions.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.