From the Lancet:
The PORTEC 2 efficacy results are published. These were previously reported at ASCO 2008, and to review, this was a randomized trial of 427 patients >= 60 years of age with IC grade 1 or 2, IB grade 3, or any age and IIA disease (excluding grade 3 with >50% myometrial invasion). After surgery they were randomized between vaginal brachytherapy (7Gy q week x 3, or 30Gy LDR) and WPRT (46Gy, 2Gy/day). Note the inclusion criteria; this excludes the IC grade 3 risk group which at the time of the trial design were at too high of a risk not to treat with WPRT. This is especially relevant as these patients had no nodal dissection.
5-year vaginal recurrence was 1.8% (95% CI 0.6—5.9) for VBT and 1.6% (0.5—4.9) for EBRT (hazard ratio [HR] 0.78, 95% CI 0.17—3.49; p=0·74). 5-year LR was 5.1% (2.8—9.6) for VBT and 2.1% (0.8—5.8) for WPRT (HR 2.08, 0.71—6.09; p=0.17); 1.5% (0.5—4.5) versus 0.5% (0.1—3.4) for isolated pelvic recurrence (HR 3·.0, 0.32—29.9; p=0.30). 5 year rate of distant metastasis was no different (8.3% [5.1—13.4] vs 5.7% [3.3—9.9]; HR 1.32, 0.63—2.74; p=0.46). 5yr OS was 84.8% (95% CI 79.3—90.3] vs 79.6% [71.2—88.0]; HR 1·17, 0·69—1·98; p=0·57, and DFS was 82.7% (76.9—88.6) vs 78.1% (69.7—86.5); HR 1.09, 0.66—1.78; p=0.74.
This, in light of the previous toxicity data presented in the JCO, they make a strong case of VBT alone in most stage I endometrial cancer.
[Articles] Vaginal brachytherapy versus pelvic external beam radiotherapy for patients with endometrial cancer of high-intermediate risk (PORTEC-2): an open-label, non-inferiority, randomised trial: "After surgery for intermediate-risk endometrial carcinoma, the vagina is the most frequent site of recurrence. This study established whether vaginal brachytherapy (VBT) is as effective as pelvic external beam radiotherapy (EBRT) in prevention of vaginal recurrence, with fewer adverse effects and improved quality of life."