MSLT-II trial

Background

Phase III RCT of 1,939 patients with resected cutaneous melanoma and a positive sentinel-lymph-node (SLN) biopsy, addressing whether completion lymph-node dissection (CLND) improves survival over nodal observation.

Interventions and follow up

Arm A: Completion lymph-node dissection (CLND)
Arm B: Observation with clinical assessment and nodal ultrasound
Primary endpoint: Melanoma-specific survival
Median follow-up: 43mo

Results

3-yr melanoma-specific survival: 86% vs 86% (CLND vs observation); HR 1.08, 95%CI 0.88-1.34, P=.42
3-yr disease-free survival: 68% vs 63%, P=.05
Nodal recurrence: 69% lower with CLND; HR 0.31, 95%CI 0.24-0.41, P<.001
3-yr regional nodal disease control: 92% vs 77%, P<.001
Distant metastasis-free survival: HR 1.10, 95%CI 0.92-1.31, P=.31

Adverse events

Lymphedema: significantly more common with CLND vs observation, 24.1% vs 6.3%, P<.001
Lymphedema severity (overall): mild 64%, moderate 33%, severe 3%

Conclusions

CLND improved regional disease control and provided prognostic staging information but did not improve melanoma-specific survival in patients with a positive SLN, at the cost of substantially increased lymphedema.

Key Limitations

Median follow-up of 43mo may underestimate late melanoma-specific deaths; predominantly low-volume SLN tumor burden may limit applicability to high-volume nodal disease; conducted in the pre-modern-adjuvant-therapy era.

Clinical Context

Practice-changing: established nodal observation with ultrasound surveillance as standard for SLN-positive melanoma, sparing routine CLND. Concordant with DeCOG-SLT. ASCO/SSO guidelines now endorse observation in this setting.

References