NCDB Chemo-RT

Background

National Cancer Data Base retrospective analysis, N=2,118, primary squamous cell carcinoma of the vagina treated with definitive RT ± concurrent chemotherapy, 1998–2011. Examines survival impact of adding chemotherapy to RT.

Interventions and follow up

Arm A (CRT): EBRT + concurrent chemotherapy (platinum-based majority) + brachytherapy
Arm B (RT alone): EBRT ± brachytherapy without chemotherapy
Primary endpoint: Overall survival
mFollow up: Median ~3.5 yr

Results

5-yr OS: CRT ~57% vs RT alone ~44%, HR 0.76 (95% CI 0.64–0.90), P<.001 on multivariable analysis
Propensity-matched OS: CRT benefit persisted across stages II–IVA
Stage I: No significant OS difference between CRT and RT alone

Adverse events

Toxicity data: Not available (administrative database)
Inferred (from cervical CRT data): Higher hematologic and GI/GU toxicity with concurrent chemotherapy

Conclusions

Adding concurrent chemotherapy to RT is associated with significantly improved OS in stage II–IVA squamous cell carcinoma of the vagina (HR 0.76), mirroring locally advanced cervical cancer and supporting extrapolation of cisplatin-based concurrent chemoradiation to vaginal cancer.

Key Limitations

Retrospective NCDB analysis subject to selection bias (healthier patients more likely to receive chemotherapy); no chemotherapy agent/dose, RT dose/technique, or brachytherapy-specific data; residual confounding by stage/performance status despite propensity-matching; OS endpoint subject to competing mortality; heterogeneous chemotherapy.

Clinical Context

Strongest available evidence for concurrent chemoradiation in vaginal cancer in the absence of randomized trials. Supports concurrent weekly cisplatin (40 mg/m²) with EBRT followed by brachytherapy for stage II–IVA disease per ASCO/ESMO-aligned practice; stage I upper-vaginal disease may be managed with RT alone or surgery given no demonstrated CRT OS benefit.

References