No Survival Increase in Melanoma With Completion Dissection for Sentinel Node Mets

June 22, 2017

Patients with node-positive intermediate-thickness melanoma had an increased rate of regional disease control when undergoing completion lymph-node dissection for sentinel node metastases, however, there was no increase in melanoma-specific survival.

Patients with node-positive intermediate-thickness melanoma had an increased rate of regional disease control when undergoing completion lymph-node dissection for sentinel node metastases, however, there was no increase in melanoma-specific survival, according to the results of a study published in the New England Journal of Medicine.

“Overall, some value may be derived from immediate completion lymph-node dissection with regard to staging and an increased rate of regional disease control,” wrote Mark B. Faries, MD, of the John Wayne Cancer Institute at Saint John’s Health Center, Santa Monica, California, and colleagues. “However this value comes at the cost of increased complications.”

Almost one-quarter of patients in the study who underwent dissection experienced lymphedema compared with less than 10% in patients who did not, the study showed.

Evidence has shown that sentinel lymph-node biopsy was associated with fewer recurrences of melanoma, and the procedure is the standard of care in appropriately selected patients. According to the study, immediate completion lymph-node dissection is recommended in patients with sentinel node metastases. However, evidence supporting this practice is lacking.

In this international trial, Faries and colleagues randomly assigned patients with sentinel node metastases to immediate completion lymph-node dissection or nodal observation with ultrasonography. The primary endpoint was melanoma-specific survival. Data was available for 1,934 patients in the intention-to-treat analysis and 1,755 patients in the per-protocol analysis.

Immediate completion lymph-node dissection was not associated with an increased melanoma-specific survival. With a median follow-up of 43 months, in the per-protocol analysis, the mean 3-year melanoma-specific survival was 86% for the dissection group and 86% for the observation patients. No significant difference was found between the groups even after adjustment for other prognostic factors.

At 3 years, disease-free survival was slightly increased in patients who underwent dissection compared with observation (68% vs 63%; P = .05 by log-rank test). The researchers noted that the results of this secondary outcome analysis “must be viewed cautiously given the lack of significance for the primary endpoint.” This increase was due to an increased rate of disease control in the regional nodes at 3 years for patients in the dissection group compared with the observation group (92% vs 77%; P < .001).

Nonsentinel node metastases, found in 11.5% of patients assigned to dissection, were strong, independent prognostic factors for recurrence (hazard ratio, 1.78; P = .005).

Patients in the dissection group were more likely to experience adverse events. At the most recent follow-up, 24.1% of patients who underwent dissection had experienced lymphedema compared with 6.3% of patients assigned observation (P < .001).

“The advantages of immediate completion lymph-node dissection are tempered by the complications of the procedure,” the researchers wrote. “As expected, there were significantly more complications among patients who underwent completion lymph-node dissection than among those who did not, although the adverse events associated with the surgical procedure were often transient. Although a complete assessment and comparison of lymphedema with other complications would require additional follow-up, we think that the decreased overall number of dissections among patients in the observation group will translate into decreased complications.”