Many older patients with stage III lung cancer who received radiation therapy fared no better than those who did not receive radiation therapy, according to a new study in the journal Cancer.

Patients with locally advanced non-small cell lung cancer (NSCLC) usually undergo surgery to have tumors removed. However, because of a high risk of recurrence after surgery, many treating oncologists order postoperative radiation therapy (PORT) to reduce the risk of recurrence in these patients. The use of PORT has been controversial. Some studies have suggested a survival benefit in these patients, but the findings have not been confirmed through other trials.

The authors of a new study used the Surveillance, Epidemiology, and End Results (SEER) registry, which is linked to enrollment in Medicare, to identify 1307 stage III NSCLC patients with N2 lymph node involvement who were diagnosed between 1992 and 2005. The authors compared the survival in patients who received PORT with those who did not.

Of the 1307 patients reviewed in the study, 710 (54%) received PORT. The authors performed a propensity score analysis, which did not reveal an improved survival in patients who received PORT. After adjusting for chemotherapy receipt and propensity scores, the hazard ratio (HR) was 1.13 (95% CI, .99-1.30). Similar HRs were observed in several stratified analyses that adjusted for chemotherapy receipt after adjusting for propensity scores, such as patients who received intermediate-complexity RT planning (HR=1.10; 95% CI, .94-1.27), and adjusting for time trends (HR=1.07; 95% CI, .93-1.24).

“Our results show that we need more information about the potential benefits of radiation therapy before it is used routinely to treat this subset of lung cancer patients,” said Juan Wisnivesky, MD, DrPH, an associate professor of General Internal Medicine at Mt. Sinai School of Medicine in New York City in a statement released with the study on Monday.

The authors noted that lymph node involvement plays a large role in determining which patients undergo lung cancer resection. However, the authors noted that they were unable to measure other important secondary outcomes, such as increased disease-free survival and lower rates of local recurrence, because SEER did not provide data regarding disease recurrence.