Radiation Rx prevents melanoma’s invasion of lymph nodes

ABSTRACT: Patients and radiation oncologists should discuss adding radiation to melanoma treatment regimen.

CHICAGO-Radiation of the lymph nodes of high-risk melanoma patients appears to significantly reduce the risk that cancer will recur in those nodes, researchers said at ASTRO 2009. The study was deemed practice-changing, representing the first advance in the management of melanoma in nearly two decades.

“Results of this trial now confirm the place of radiation therapy in the management of patients who have high-risk features following surgery for melanoma involving the lymph nodes,” said Bryan Burmeister, MD, associate professor of radiation oncology at Princess Alexandra Hospital in Brisbane, Australia. “This is the first real advance in the management of melanoma in 15 years since the use of interferon.”

Dr. Burmeister’s study was conducted among 250 patients at 16 centers in Australia, New Zealand, Brazil, and the Netherlands. Of the 217 evaluable patients, 109 underwent radiation therapy and 108 were observed. About 19% of melanoma patients treated with radiation of the lymph nodes after surgery experienced recurrence of melanoma in those lymph nodes, but the cancer returned in about 31% of patients who did not have radiation, Dr. Burmeister said. The difference was statistically significant (P = .04).

Dr. Burmeister said the aim of the study was to determine whether radiation treatment could prevent cancer recurrence in the lymph nodes. Persons at high risk for recurrence were those in whom pathologists discovered cancer involvement in at least one parotid lymph node, in at least two cervical or axillary lymph nodes, or in at least three groin lymph nodes. Patients were also deemed high-risk if extranodal spread of tumor was seen or if the minimum metastatic node diameter was 3 cm in the neck or axilla or 4 cm in the groin (abstract 3).

After lymphadenectomy, patients were randomized to receive radiation therapy at a dose of 48 Gy in 20 fractions or initial observation. They were given radiation treatment within 12 weeks of surgery, he said. The median overall survival of the patients who underwent surgery alone was 47 months vs 31 months for patients who underwent surgery and received radiation therapy. However that difference did not reach statistical significance (P = .14).

“In some institutions, radiation treatment is routine protocol, while in others, the protocol has been either for patients to just be observed, or receive some type of adjuvant chemotherapy or immunotherapy,” he explained.

Dr. Burmeister added that he would encourage patients with melanoma to talk to their doctors about whether radiation should be added to their treatment plan. “Adding radiation to the treatment of high-risk melanoma patients is a viable option,” he said.

Commenting on the study at ASTRO was Benjamin Movsas, MD, chairman of the department of radiation oncology at Henry Ford Hospital in Detroit.

“This is a practice-changing study,” Dr. Movsas said. “Our goal as radiation oncologists is to prevent local recurrence of cancer, and this is what radiation in high-risk melanoma cases appears to do.”

He described the Australian study as a well-designed, controlled clinical trial that offered level one evidence of the value of radiation therapy in melanoma.

“Whether to radiate these lymph nodes had been an ongoing controversy,” Dr. Movas said. “Now there is some objective data that this benefits patients.”