In Nodal Metastatic Melanoma, Radiation May Be New Standard of Care

Nick Mulcahy

November 03, 2009

November 3, 2009 — In melanoma patients with lymph node involvement, the use of radiation following lymphadectomy provided "dramatic improvement in local control" and "may be the new standard of care" for these patients.

This enthusiastic assessment came from the discussant of a new 217-patient melanoma study that was presented during the plenary session here at the American Society for Radiation Oncology (ASTRO) 51st Annual Meeting.

The discussant, Matthew Ballo, MD, from the University of Texas MD Anderson Cancer Center in Houston, was commenting on a phase 2 Australian study that shows, for the first time, that adjuvant radiation reduces the chance of melanoma returning.

This is the only real advance in the treatment of melanoma in the past 15 years.

In the randomized trial, melanoma patients treated with radiation after surgery had a statistically significantly lower risk of the disease returning to the lymph nodes than patients who did not receive radiation (19% vs 31%). Median follow-up was 27 months.

Dr. Ballo called the results "high-level evidence," purposely echoing the National Comprehensive Cancer Network's guidelines' terminology.

Dr. Bryan Burmeister (Courtesy of ASTRO)

"I believe this is the only real advance in the treatment of melanoma in the past 15 years — since interferon came out," said lead study author Bryan Burmeister, MD, from Princess Alexandra Hospital in Brisbane, Australia, at an ASTRO press conference. He also believes that clinicians should now offer all nodal metastatic melanoma patients the option of radiation after surgery if they are at high risk for local recurrence.

"Eighty percent of patients who have lymph node dissection are at high risk of recurrence," he said.

Dr. Burmeister also noted that radiation is part of the routine protocol at some institutions, but that its effectiveness has never been proven.

"Until the trial was done, there has been a question about the value of radiation," he said.

Lymph node relapse or recurrence was the primary end point of the trial, and overall survival was one of the secondary end points.

"There is no evidence of a difference in overall survival between the radiation-therapy and observation groups," Dr. Burmeister told the audience at the plenary session.

We cannot ignore the lack of overall survival benefit.

This fact caused Dr. Ballo to temper his praise of the adjuvant therapy: "We cannot ignore the lack of overall survival benefit."

Dr. Ballo also noted that the trial needs "longer-term results", especially with regard to late toxicity, which is another secondary end point. Those toxicities include edema.

At High Risk for Recurrence

The multicenter study was undertaken in Queensland, Australia — "the melanoma capital of the world," said Dr. Burmeister.

The 217 patients all had completely resected nodal metastatic melanoma and were randomized to adjuvant radiotherapy (n = 109) and observation (n = 108). The patients had to have a minimum number of harvested nodes (partotid and neck, 2 to 25; axilla, 10; groin, 6).

They were at "significant risk" for lymph node field relapse based on any of the following:

  • positive lymph nodes (at least 1 for partotid, 2 for neck and axilla, and 3 for groin)

  • maximum lymph node size (30 mm or greater for partotid, neck, and axilla; 40 mm or greater for groin)

  • extra-nodal spread

Dr. Ballo suggested that these requirements might have helped preclude any improvement in overall survival. "The disease burden may have been too high," he said.

The external-beam radiotherapy after lymphadectomy consisted of 48 Gy in 20 fractions over 4 weeks, said Dr. Burmeister.

There was a statistically significant improvement in lymph node field control with radiotherapy; 20 radiotherapy and 34 observation patients relapsed regionally (hazard ratio, 1.77; 95% confidence interval, 1.02 - 3.08; P = .041).

The early acute toxicity appeared "minimal," said Dr. Burmeister, with radiation dermatitis being the most common grade 3 adverse effect at 2 weeks. There were no grade 4 toxicities at either 2 or 6 weeks, he added.

The researchers have disclosed no relevant financial relationships.

American Society for Radiation Oncology (ASTRO) 51st Annual Meeting: Abstract 3. Presented November 2, 2009.

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