Jan. 14 (UPI) -- Many older cancer patients whose disease has spread to other parts of the body continue to receive high-dose radiation therapy, despite guidelines that recommend against its use under these conditions, an analysis published Friday by JAMA Health Forum found.
In the review of data for more than 500,000 radiotherapy doses, or radiation treatments, administered to Medicare beneficiaries, nearly 4% of the patients involved died within 90 days of their last session, the researchers said.
Of those who died, all had cancer that had metastasized to the brain or bones, and more than half were older and 22% received 10 or more radiation treatments near the end of their lives, the data showed.
Current treatment guidelines recommend against using radiation therapy in people with metastatic cancer, or disease that has spread from its original location to other parts of the body, the researchers said.
"Despite multiple national guidelines advise against their use, approximately one in five patients received extended or long courses, or greater than 10 treatments, of radiation therapy for bone or brain metastases near the end of life," study co-author Dr. Patricia Santos told UPI by email.
"No patient, regardless of how long they are expected to live, should be subjected to protracted treatment schedules that are not evidence-based," said Santos, a resident physician at Memorial Sloan-Kettering Cancer Center in New York City.
The guidelines are designed primarily to preserve quality of life in those likely to die from the disease because radiation therapy, which applies high doses of radiation to tumors, can cause serious side effects -- including severe fatigue, hair loss and nausea and vomiting, according to the National Cancer Institute.
These side effects occur because radiation therapy not only kills or slows the growth of cancer cells, but it also can affect nearby healthy cells, the institute says.
Among the patients who died soon after treatment, 22% received radiation treatment that was not recommended in current guidelines, either because of their age or because their cancer had spread, the data showed.
More than half of the patients in the study, 53%, were ages 65 to 74 years, the researchers said.
In addition, about half had bone metastases, or cancer that had spread to their bones, while the other half had disease that had spread to their brains, according to the researchers.
"More extensive treatment does not always mean better outcomes," Santos said.
"When given outside of the appropriate setting, overtreatment or unnecessary treatment can greatly increase the potential risk for harm, with minimal or no proven benefit," she said.