“We found that RT use was associated with a modest survival benefit, and that this benefit was limited to patients treated with high complexity regimens,” the researchers report. However, they add, “RT treatment was also associated with an increased risk of serious adverse events.
The authors of the report in Lung Cancer published online September 5 point out that 40% of NSCLC cases in the U.S. present as stage III disease, and many are considered inoperable. While chemoradiotherapy is the standard of care in such cases, radiation alone is often administered to elderly patients who are not suitable for dual therapy.
To assess the potential benefit and tolerability of this approach, Dr. Keith Sigel, at Mount Sinai School of Medicine in New York, and colleagues analyzed data from the Surveillance, Epidemiology, and End Results (SEER) registry. The team identified 10,376 patients over 65 years of age with unresected stage III NSCLC who were not treated with chemotherapy. Within that group 6468 patients received lone RT.
Median overall survival was 9 months in the RT group compared with 7 months in the untreated group (p<0.001). After adjusting for propensity scores, RT was associated with significantly improved survival with a mortality hazard ratio of 0.87, the investigators found.
Further analysis showed that the survival benefit was only significant in patients who received complex radiotherapy (hazard ratio, 0.83), and not in those who received intermediate complexity RT (HR, 1.05)
Compared to untreated patients, RT patients were much more likely to be hospitalized for pneumonitis (adjusted odds ratio, 88.8) and esophagitis (aOR, 8.3). Still, overall rates of these adverse events were low; pneumonitis occurred in 2.2% of the RT group versus <1% in the untreated group, while corresponding rates of esophagitis were 1.1% versus <1%, according to the report.
“While these findings should be interpreted with caution given the possibility of selection bias, they suggest that increased use of RT alone may improve survival of elderly patients with stage III disease who are not candidates for combined chemoradiation,” Dr. Sigel and colleagues conclude.
They add, “Although results from RCTs are needed to confirm these results, physicians should discuss the potential risks and benefits of this therapy with their elderly stage III lung cancer patients.”