WEDNESDAY, Aug. 15 (HealthDay News) -- Radiation treatment focused on the brain boosts the survival of people with lung cancer that has spread significantly, a Dutch study shows.
That's because lung cancer often spreads to the brain, forming tiny colonies that are too small to be seen by standard imaging techniques. Radiation treatment kills those micro-colonies before they have a chance to grow, experts say.
"We already knew from studies in the 1980s that cranial radiation was useful in lung cancer patients who were in complete remission," said study lead researcher Dr. Ben Slotman, chair of the department of radiation oncology at VU University Medical Center in Amsterdam.
Prior studies have found that cranial radiation gives about a 5 percent improvement in survival for such patients.
The new report, published in the Aug. 16 issue of the New England Journal of Medicine, described the results of a trial of cranial radiation treatment of a different group of people with lung cancer -- those whose tumors had spread extensively, despite chemotherapy.
There were 286 patients in the trial. Half got standard treatment, and the other half got doses of radiation directed at the head.
"The one-year survival rate was 13 percent in the group that did not get radiation and 27 percent in the group that did," Slotman reported.
In addition, only 14.6 percent of those getting radiation therapy developed metastases -- new cancer colonies -- in the brain, compared to 40.4 percent of those who did not get the treatment. Overall, cranial radiation increased the patient's average survival time from 5.4 months to 6.7 months.
Side effects of the radiation therapy were minimal, Slotman said. "There were some headaches and nausea," he said. "These were all temporary and did not influence the quality of life."
All the patients in the trial had small-cell lung cancer, a fast-growing form of the malignancy, and had received four to six cycles of chemotherapy. The disease had spread beyond the lungs in 70 percent of the cases.
Slotman said the message from the study is clear: "Prophylactic cranial radiation should now be offered routinely to all responding small-cell lung cancer patients with extensive disease."
However, current recommendations suggest the use of cranial radiation only if a lung cancer appears to have disappeared completely with the combination of chemotherapy and radiation therapy to the chest.
But that recommendation remains controversial, said Dr. Andrew Turrisi, professor of radiation oncology at Wayne State University, Detroit. The controversy centers on "not whether there should be [such] treatment, but how much and how long," he said.
Experts fear that cranial irradiation might cause brain damage, and a trial to determine the therapy that prolongs survival without causing such damage is having trouble enrolling patients because of those fears, Turrisi said.
But the results of the new trial provide "astounding information," he said, showing benefits with no visible damage. "But it still doesn't answer the major question: Is it safe for the long term?" Turrisi said.
Still, he applauded the Dutch team for the study. "I don't see any Achilles' heel in the work they have done," Turrisi said.
There's more on lung cancer at the National Cancer Institute.
SOURCES: Ben Slotman, M.D., chairman, department of radiation oncology, VU University Medical Center, Amsterdam, The Netherlands; Andrew Turrisi, M.D., professor, radiation oncology, Wayne State University, Detroit; Aug. 16, 2007, New England Journal of Medicine