PORTEC Trials Recommendations for Endometrial Cancer Management

Overview of PORTEC Trials

• The National Comprehensive Cancer Network recommends participation in PORTEC trials for patients with high-risk endometrial cancer, particularly those with stage III disease or serous histology, as these patients show the greatest survival benefit from combined chemoradiotherapy versus radiotherapy alone 1
• PORTEC-1 evaluated external beam radiation therapy (EBRT) versus observation in intermediate-risk endometrial cancer, showing improved locoregional control but no overall survival benefit 2
• PORTEC-2 compared EBRT versus vaginal brachytherapy in high-intermediate risk patients, demonstrating equivalent vaginal and pelvic control with less toxicity with brachytherapy 3, 4
• PORTEC-3 investigated combined chemoradiotherapy versus radiotherapy alone in high-risk endometrial cancer, showing improved failure-free survival and overall survival with combined therapy 1

Patient Selection Criteria

• Patients with stage I, grade 3 with deep myometrial invasion, lymphovascular space invasion (LVSI), or both may be considered for participation in PORTEC-3 or similar trials 1
• Patients with stage II or III disease may be considered for participation in PORTEC-3 or similar trials 1
• Patients with stage I-III with serous or clear cell histology may be considered for participation in PORTEC-3 or similar trials 1

Treatment Approaches Based on PORTEC Trials

• For high-risk endometrial cancer, combined chemoradiotherapy is recommended, with EBRT (48.6 Gy in 1.8 Gy fractions) and concurrent cisplatin (50 mg/m²) followed by 4 cycles of carboplatin/paclitaxel, showing improved failure-free survival and overall survival 1
• For high-intermediate risk endometrial cancer, vaginal brachytherapy alone is the standard recommendation due to equivalent local control and reduced toxicity compared to EBRT 3, 4

Molecular Classification Impact

• Recent molecular analysis of PORTEC-3 samples has identified four molecular subgroups with significant prognostic implications, including p53 abnormal, POLE-ultramutated, MMR-deficient, and no specific molecular profile 1

Common Pitfalls and Caveats

• PORTEC-1 and PORTEC-2 specifically excluded patients with 1998 FIGO stage 1C and grade 3 endometrial carcinoma, so recommendations for this higher-risk subset remain controversial 3, 4
• The ongoing PORTEC-4a trial may further refine treatment recommendations based on molecular profiling 1