6/29/23, 1:42 AM PORTEC-3 (post-hoc) Pathway Feedback Search Clinical Topics Home Studies PORTEC 3 (post-hoc) PORTEC 3 (post-hoc) Disease Endometrial cancer Trial question Is chemoradiotherapy superior to radiotherapy alone in women with high-risk endometrial cancer? Study design Multi-center Open label RCT Population 660 female patients Inclusion criteria: women with high-risk endometrial cancer Key exclusion criteria: uterine sarcoma or carcinosarcoma; previous malignancy, except for non- melanomatous skin cancer, within the past 10 years; previous pelvic radiotherapy; previous hormonal therapy or chemotherapy; bulky cervical involvement with radical hysterectomy Interventions N=330 chemoradiotherapy (two cycles of cisplatin 50 mg/m given IV during radiotherapy, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m given IV) N=330 radiotherapy alone (48.6 Gy in 1.8 Gy fractions given on 5 days per week) Primary outcome Overall survival at 5 years 81.4 % 81.4 76.1 61.1 % 40.7 % Significant increase 20.4 % NNT = 19 0.0 % https://web.pathway.md/studies/recmhFJr2NOD81DfB 1/2 6/29/23, 1:42 AM PORTEC-3 (post-hoc) Pathway Chemoradiotherapy Radiotherapy alone Significant increase in overall survival at 5 years (81.4% vs. 76.1%; HR 1.43, 95% CI 1.03 to 1.96) Secondary outcomes Significant increase in failure-free survival at 5 years (76.5% vs. 69.1%; HR 1.43, 95% CI 1.06 to 1.92) Significant decrease in distant metastases as first site of recurrence (21.4% vs. 29.1%; HR 0.74, 95% CI 0.55 to 0.99) No significant difference in isolated pelvic recurrence as first site of recurrence (0.9% vs. 0.9%; HR 0.75, 95% CI 0.17 to 3.33) Safety outcomes No significant difference in grade 3 adverse events at 5 years. Significant differences in grade 2 or worse adverse events at 5 years (38% vs. 23%), persistence of sensory neuropathy (6% vs. 0%). Conclusion In women with high-risk endometrial cancer, chemoradiotherapy was superior to radiotherapy alone with respect to overall survival at 5 years. Reference Stephanie M de Boer, Melanie E Powell, Linda Mileshkin et al. Adjuvant chemoradiotherapy versus radiotherapy alone in women with high-risk endometrial cancer (PORTEC-3): patterns of recurrence and post-hoc survival analysis of a randomised phase 3 trial. Lancet Oncol. 2019 Sep;20(9):1273- 1285. Open reference URL https://web.pathway.md/studies/recmhFJr2NOD81DfB 2/2