Preventive cranial irradiation therapy significantly reduces risk for brain metastases in patients who respond to chemotherapy for advanced-stage small cell lung cancer, according to a presentation at the annual meeting of the American Society of Clinical Oncology.

“Our data suggest that all patients with extensive small cell lung cancer who respond to chemotherapy could benefit from prophylactic cranial irradiation,” said lead author Ben Slotman, MD, PhD, Professor of radiation oncology at VU University, Amsterdam. “Because improvements in treatment results for patients with advanced small cell lung cancer have been minimal in the past two decades, these findings represent a significant advance.”

Previous studies had established that preventive irradiation could decrease risk for brain metastases and prolong survival in patients with early-stage disease, but the current study was the first to test the hypothesis in patients with more advanced disease.

In the current study, researchers compared results for 143 patients with advanced small cell lung cancer whose tumors shrank in response to chemotherapy and who then received cranial irradiation with results for 143 similar patients who did not receive irradiation. Irradiation therapy was given daily for one to two weeks at doses comparable with those used to treat brain metastases. Side effects were mild and included nausea, vomiting, and mild headache.

At one year, the irradiation group had significantly fewer symptomatic brain metastases than the control group, 14.6 percent versus 40.4 percent, a decrease in risk of roughly two thirds. In addition, 27.1 percent of irradiation patients were alive at one year compared with 13.3 percent of control patients.