In a retrospective analysis from the Soft Tissue Sarcoma Committee of the Children’s Oncology Group (COG) reported in the Journal of Clinical Oncology, Luo et al found that whole-lung irradiation (WLI) was associated with significantly better event-free survival vs no WLI in patients with newly diagnosed rhabdomyosarcoma and lung metastases.
Study Details
The study included data on patients enrolled in four COG protocols between 1999 and 2013 at multiple U.S. sites. All patients were to receive WLI at 15 Gy in 10 daily fractions simultaneously with radiation to the primary site. Event-free and overall survival were compared between patients who received WLI and those who did not receive WLI despite protocol requirements.
Key Findings
Among 143 patients included in the analysis, 65 (45.5%) received WLI and 78 (54.5%) did not receive WLI. There were no statistically significant differences in known prognostic factors between those who did and did not receive WLI.
Event-free survival at 5 years was 38.3% (95% confidence interval [CI] = 24.8%–51.8%) in the WLI group vs 25.2% (95% CI = 13.8%–36.6%) in the no-WLI group (P = .0496). Overall survival at 5 years was 45.5% (95% CI = 31.8%–59.3%) in the WLI group vs 32.4% (95% CI = 20.4%–44.4%) in the no-WLI group (P = .08).
In exploratory subgroup analyses, a benefit of WLI vs no WLI was observed among patients aged ≥ 10 years (n = 83, 58.0%) for both 5-year event-free survival (hazard ratio [HR] = 1.90, 95% CI = 1.14–3.16) and 5-year overall survival (HR = 2.06, 95% CI = 1.21–3.52).
The investigators concluded: “WLI is associated with improved [event-free survival] in patients with rhabdomyosarcoma with lung metastases. These results highlight the potential importance of WLI and need for more stringent protocol compliance for administering WLI.”
Leo Y. Luo, MD, of Vanderbilt University Medical Center, Nashville, is the corresponding author of the Journal of Clinical Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute and St Baldrick’s Foundation. For full disclosures of the study authors, visit ascopubs.org.
