Patients with locally advanced lung cancer who received a course of radiation therapy (RT) to the brain at the completion of their lung cancer treatment were less likely to develop brain metastases within the first year after treatment, according to research from the Radiation Therapy Oncology Group (RTOG) presented today at the 2009 American Society of Clinical Oncology (ASCO) meeting in Orlando, Fla.
As the treatment for locally advanced non-small cell lung cancer (NSCLC) has improved, researchers are finding that patients have an increased risk of developing brain metastases without a relapse of lung cancer. To develop a consensus on how to address this risk, RTOG mounted a phase III study to compare prophylactic cranial irradiation (PCI) versus observation in patients with stage III NSCLC without progression of disease after loco-regional treatment with surgery and/or radiation therapy with or without chemotherapy. PCI was delivered once daily at 2 Gy per fraction to 30 Gy.
The primary endpoint of the study was overall survival, accordign to the presenters. Secondary endpoints were disease-free survival and the impact of PCI on incidence of central nervous system (CNS) metastases, neuropsychological function and quality of life.
Total accrual was 356 patients of the targeted 1,058 between Sept. 19, 2002 and Aug. 30, 2007. The study was closed early due to slow accrual, however 340 patients were evaluable.
Although the study, RTOG 0214, closed without meeting its accrual objective, an analysis of the 356 patients entered on the study found that patients who did not receive PCI were two and a half times more likely to develop brain metastases than those who did receive PCI, according to study's lead author and principal investigator Elizabeth Gore, MD, from the Medical College of Wisconsin in Milwaukee.
The results showed that PCI in patients without progressive disease after loco-regional therapy for III NSCLC significantly decreases the rate of CNS metastases. The study did not show a statistically significant difference in overall survival or disease-free survival, she added.
"Although this study did not show a statistically significant difference in survival between the two groups of patients, we were able to show that PCI significantly decreased the incidence of brain metastases during the first year post-treatment," Gore said. "We plan a future analysis of the impact of PCI on neuropsychological function and quality of life and we expect that analysis will influence the recommendations regarding the standard use of PCI."
RTOG, a U.S. national clinical trials group funded by the National Cancer Institute (NCI), is a clinical research component of the American College of Radiology (ACR).