PORTEC-3 (post-hoc analysis)
Trial question
Is chemoradiotherapy superior to radiotherapy alone in patients with high-risk endometrial cancer?
Study design
Multi-center
Open label
RCT
Population
660 female patients.
Inclusion criteria: female patients 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/m² given IV during radiotherapy, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m² 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%
76.1%
81.4 %
61.1 %
40.7 %
20.4 %
0.0 %
Chemoradiotherapy
Radiotherapy
alone
Significant
increase ▲
NNT = 18
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 female patients 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.
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