ASCO 2015: Complete Lymph Node Dissection Does Not Improve Survival in Patients With Melanoma and Micrometastases
For patients with melanoma and micrometastases, as shown by positive sentinel lymph node biopsy, complete lymph node dissection did not improve survival, according to results of a randomized study presented at the 2015 ASCO Annual Meeting (Abstract LBA9002). “This is the first study which questions the general recommendation of complete lymph node dissection in patients with positive nodes. We cannot confirm this recommendation and we expect that the surgical practice will change,” senior study author Claus Garbe, MD, stated at a press briefing. Dr. Garbe is Professor of Dermatology at the University of Tübingen in Tübingen, Germany.
Dr. Garbe cautioned, however, that “it is possible that this surgery may provide a smaller survival advantage than this study could detect,” which may factor into discussions with patients about whether complete lymph node dissection is right for them. The side effects of complete lymph node dissection include infection, nerve damage, and lymphedema. According to the study authors, lymphedema can occur in more than 20% of patients and persist long term in 5% to 10% of patients.
The study included only patients with micrometastases; the median tumor thickness was 2.4 mm. According to the authors, complete lymph node dissection will continue to be recommended for patients with larger, clinically detectable metastases.
Closely Monitored for Disease Recurrence
Following surgery to remove the primary tumor, 483 patients with stage III melanoma and a positive sentinel lymph node biopsy were randomly assigned to observation only or complete lymph node dissection. “Recruitment was more difficult than expected, and we needed 9 years in order to recruit 483 patients,” Dr. Garbe noted.
Patients in the observation group were closely monitored for signs of disease recurrence, with a lymph node ultrasound exam every 3 months and CT/MRI or PET scans every 6 months. Patients in the complete lymph node dissection group followed the same schedule of follow-up after complete lymph node dissection.
At a median follow-up of 35 months, 14.6% of patients in the observation group developed lymph node regional metastases vs 8.3% in the complete lymph node dissection group. However, the differences in 3-year and 5-year recurrence-free survival, distant metastases-free survival, and melanoma-specific survival were not statistically significant between the two groups. In this study, a survival difference of 10% or higher between the two treatment groups was considered statistically significant based on the study design.
The trial results “will likely be very relevant to a large proportion of our patients diagnosed with melanoma, especially those who are dealing with a positive sentinel lymph node biopsy,” commented ASCO spokesperson and press briefing moderator Don S. Dizon, MD. Dr. Dizon is Clinical Co-Director of Gynecologic Oncology and Director of the Oncology Sexual Health Clinic at Massachusetts General Hospital, Boston.
Ongoing Study Looking at Smaller Survival Differences
Another analysis of this study is planned in 3 years, but Dr. Garbe said that it is unlikely that the overall findings of the study will change, because prior research has shown that roughly 80% of melanoma recurrences are within the first 3 years of initial diagnosis.
Another ongoing complete lymph node dissection randomized trial, MSLT-II, is much larger and designed to detect an even smaller (5%) difference in survival. The final results from that study are not expected until 2022.
The current study received funding from German Cancer Aid. Dr. Garbe reported honoraria from Amgen Research Munich GmbH, Bristol-Myers Squibb, GlaxoSmithKline, Merck Co, Inc, Novartis Healthcare A/S, and Roche Pharma; consulting or advisory roles with Amgen Research Munich GmbH, Bristol-Myers Squibb, GlaxoSmithKline, Merck Co, Inc, Novartis Healthcare A/S, and Roche Pharma AG; research funding from Bristol-Myers Squibb, GlaxoSmithKline, and Roche Pharma AG; and travel, accommodations, expenses from Amgen Research Munich GmbH, Bristol-Myers Squibb, GlaxoSmithKline, Merck Co, Inc, Novartis Healthcare A/S, and Roche Pharma AG. For full disclosures of the study authors, view the study abstract at abstract.asco.org.
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