August 4, 2009 (San Francisco, California) — When researchers began the RTOG 0214 study in 2001, their intent was to show conclusively whether prophylactic cranial irradiation (PCI) improves survival in patients with advanced nonsmall-cell lung cancer (NSCLC). Although the scientists never met their accrual goal — the trial randomized just 340 patients to PCI or observation — the results might still have a decided impact on oncology practice, according to researchers here at the 13th World Conference on Lung Cancer, organized by the International Association for the Study of Lung Cancer.
The trial's initial results — announced at this year's American Society of Clinical Oncology meeting — showed no significant difference in overall survival rate between patients randomized to PCI and those randomized to observation. However, patients in the observation group were twice as likely to develop brain metastases after 1 year (18% vs 7.7%; P = .004). At the meeting, the researchers announced results related to the secondary end points of their study, including disease-free survival, neurocognitive function, and quality of life.
Patients in the study had stage IIIA or IIIB lung cancer without disease progression after loco-regional treatment with surgery and/or radiation therapy with or without chemotherapy. PCI was delivered at a total once-daily dose of 30 Gy at 2 Gy/fraction.
Although there was no difference in disease-free survival between the PCI and observation groups at 1 year, there was a trend toward improved disease-free survival in PCI patients, although it did not reach statistical significance (56.4% vs 51.2%). The researchers also found no difference in quality of life between the 2 groups after using several measures, and there was no difference in the patients' Mini-Mental Status Examination scores. However, when the researchers tested patients with the Hopkins Verbal Learning Test, they found that there was a significantly greater deterioration in immediate recall (P = .03) and delayed recall (P = .008) in PCI patients after 1 year.
There was also no clear difference in quality of life between the PCI and observation groups when age was taken into account or when patients with and without brain metastases were compared. "This prospective study does show the benefits of PCI, and the data should be considered when doctors discuss this treatment with their patients," said lead researcher Alexander Sun, MD, radiation oncologist at Princess Margaret Hospital at the University of Toronto in Ontario. Dr. Sun noted that longer follow-up is needed on RTOG 0214 patients to truly assess the risks and benefits of PCI. More follow-up data on patients' neurocognitive function will be presented at this year's American Society for Therapeutic Radiology and Oncology meeting, he said.
"This study gives us quite an encouraging picture for the future," said Françoise Mornex, MD, PhD, from the Centre Hospitalier Lyon Sud in France, moderator of the session at which the clinical trial was presented. "With this kind of sequential approach, the toxicity is reasonable and the dose is safe."
"With advanced NCSLC patients, there is always the danger of [central nervous system] failure. When you compare PCI to no PCI for these patients, you just see better results," she added. However, Dr. Mornex noted that memory loss and neurological changes can be attributed to PCI and should be kept in mind when planning treatment. "You have to remember in this study that the benefit of PCI was very real, and it could change practice in the future," she said.
Dr. Sun and Dr. Mornex have disclosed no relevant financial relationships.
13th World Conference on Lung Cancer (WCLC): Abstract C6.6. Presented August 2, 2009.
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