Only 19% of those whose lymph nodes were treated with radiation after surgery experienced recurrence of melanoma in their lymph nodes over the following two years.
In contrast, the cancer returned in 31% of people who did not have radiation after surgery, says Bryan Burmeister, MD, associate professor of radiation oncology at Princess Alexandra Hospital in Brisbane, Australia.
Looked at another way, this means people treated with radiation have about a 40% lower risk of relapse over two years, he says.
None of the participants suffered serious side effects from the radiation.
"This is the only real advance in the management of melanoma in 15 years," Burmeister tells WebMD.
The findings were presented at the annual meeting of the American Society for Radiation Oncology (ASTRO).
People With Melanoma Urged to Talk With Doctors About Radiation
"Results of this trial confirm the place of radiation therapy in the treatment of high-risk melanoma patients," Burmeister says.
"It's important that doctors offer it to their patients. [If they don't], I encourage patients with melanoma to talk to their doctors about whether radiation should be added to their treatment plan," he says.
The study did not answer the question of whether people who get radiation actually live longer. "For that, we need to study larger numbers of patients," Burmeister says.
Outgoing ASTRO president Tim R. Williams, MD, a private practitioner in Boca Raton, Fla., tells WebMD that the findings will change how he treats people with melanoma.
"Melanoma is one of the most deadly cancers. This is the first good thing I have seen for the treatment of melanoma in a long time," he says.
During the radiation therapy, a beam or multiple beams of radiation are directed through the skin to the cancer and surrounding areas to kill off tumor cells that linger after surgery. The treatments are generally painless, much like receiving an X-ray.