Anybody who has ever heard of radiation hormesis will not be as surprised as these doctors were
Lung cancer patients were given new hope yesterday, thanks to an Australian breakthrough... The good news came in the form of a study published in the journal Cancer which found that low doses of radiation, given every weekday for one or two weeks, could improve outcomes for non-small-cell lung cancer. The cancer was one of the deadliest and most common forms of lung cancer, according to radiation oncologist Michael Mac Manus from Melbourne's Peter MacCallum Cancer Centre.
Associate Prof Mac Manus and his colleagues were amazed to find that some patients with advanced tumours lived for as long as five years with the new treatment. Usually they would have been expected to live less than six months. "All experienced doctors will have come across an occasional case where a patient has survived for a long time when they shouldn't have, so we thought we would look at a very large database of patients with incurable lung cancer to see how many of them survived," Prof Mac Manus said. "We were surprised to find that 1.1 per cent survived for five years. Some of them survived for 10 years and (one of) the patients appears to have been cured. "The long-term survival was an unexpected effect of the radiotherapy. "We expected it to be virtually zero."
The study looked at more than 2000 patients diagnosed with lung cancer who were at such an advanced stage their illness was considered incurable. All had received low doses of radiation to relieve pain and other symptoms but the average survival for such patients was generally less than six months. Prof Mac Manus was "very surprised and amazed" to find about one-in-100 actually lived for five years or more after radiotherapy.
He was now hoping to extend the research by comparing the molecular biology and genetics of the tumours in a bid to identify in advance the patients most likely to survive with less intensive treatment. "If we can understand what the mechanism is, we might be able to develop some new treatments based on that," he said. Although more research was needed, he said cancer specialists might be reluctant to leave radiation out of the treatment package for late-stage lung cancer patients in future because of the findings. "The bottom line is that even patients generally considered as having incurable disease have some hope," Prof Mac Manus said.
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