Author Interviews, Lancet, Melanoma, Radiation Therapy / 23.07.2015
Melanoma: Lymph Node Radiation After Lymphadenectomy Did Not Improve Survival
MedicalResearch.com Interview with:
Michael A Henderson
MBBS BMedSc MD FRACS
Professor of Surgery, University of Melbourne
Deputy Director Division of Cancer Surgery
Head Skin and Melanoma Service
Division of Cancer Surgery
Peter MacCallum Cancer Centre
East Melbourne Victoria Australia
Medical Research: What is the background for this study? What are the main findings?
Dr. Henderson: A number of retrospective reviews of adjuvant radiotherapy after lymphadenectomy for patients at high risk of further lymph node field relapse had all suggested that the risk of lymph node field relapse was reduced but there was controversy about whether there was any impact on survival. In addition many clinicians were concerned about the side effects of radiotherapy and in the absence of a proven survival benefit were reluctant to recommend it. Previously a phase 2 trial of adjuvant radiotherapy conducted by one of our co-authors Prof Bryan Burmiester confirmed that the morbidity of lymph node field radiotherapy was limited and the risks of recurrence was reduced. On that basis the current ANZMTG TROG randomised multicentre trial was initiated.
In summary this final report updates information on overall survival, lymph node field relapse etc and provides information for the first time on long term toxicity of treatment, quality of life and lymphedema. Adjuvant lymph node field radiotherapy for patients at high risk of further lymph node field relapse reduces the risk of further lymph node field relapse by 50% but it has no effect on survival. Although radiotherapy toxicity was common (3 in 4 patients), mostly involving skin and subcutaneous tissue it was mild-to-moderate in severity and had little impact upon the patient's quality of life as measured by the FACT-G quality of life tool. Specific regional symptoms were more common in the radiated group. Limb volume measurements confirmed a significant but modest increase for patients receiving inguinal radiation (15%) but not for axillary radiation.
In the design of this trial, a decision was made to allow patients in the observation arm who developed an isolated lymph node field relapse to be salvaged by surgery and or radiotherapy. There were only two patients in the radiotherapy arm who developed an isolated lymph node field relapse and both died of metastatic disease. In the observation arm 26 patients developed an isolated lymph node field relapse and the majority (23) achieved lymph node field control with a combination of surgery and or radiotherapy. The five-year survival FROM development of a lymph node field relapse in this group was 34% which is comparable to the overall survival of the entire cohort (42% five-year overall survival). This information whilst a subset analysis suggests that if it would be reasonable in some patients to consider a policy of observation only, reserving further surgery and or radiotherapy for a second relapse.
(more…)