Sentinel-node biopsy, a minimally invasive procedure for regional melanoma staging, was evaluated in a phase 3 trial.
Researchers have evaluated outcomes in 2001 patients with primary cutaneous melanomas randomly assigned to undergo wide excision and nodal observation, with lymphadenectomy for nodal relapse ( observation group ), or wide excision and sentinel-node biopsy, with immediate lymphadenectomy for nodal metastases detected on biopsy ( biopsy group ).
No significant treatment-related difference in the 10-year melanoma-specific survival rate was seen in the overall study population ( 20.8% with and 79.2% without nodal metastases ).
Mean 10-year disease-free survival rates were significantly improved in the biopsy group, as compared with the observation group, among patients with intermediate-thickness melanomas, defined as 1.20 to 3.50 mm (71.3% vs 64.7%; hazard ratio for recurrence or metastasis, HR=0.76; P=0.01 ), and those with thick melanomas, defined as greater than 3.50 mm ( 50.7% vs 40.5%; HR=0.70; P=0.03 ).
Among patients with intermediate-thickness melanomas, the 10-year melanoma-specific survival rate was 62.1% among those with metastasis versus 85.1% for those without metastasis ( hazard ratio for death from melanoma, 3.09; P less than 0.001 ); among patients with thick melanomas, the respective rates were 48.0% and 64.6% ( HR=1.75; P=0.03 ).
Biopsy-based management improved the 10-year rate of distant disease–free survival ( hazard ratio for distant metastasis, HR=0.62; P=0.02 ) and the 10-year rate of melanoma-specific survival ( hazard ratio for death from melanoma, 0.56; P=0.006 ) for patients with intermediate-thickness melanomas and nodal metastases.
Accelerated-failure-time latent-subgroup analysis was performed to account for the fact that nodal status was initially known only in the biopsy group, and a significant treatment benefit persisted.
In conclusion, biopsy-based staging of intermediate-thickness or thick primary melanomas provides important prognostic information and identifies patients with nodal metastases who may benefit from immediate complete lymphadenectomy.
Biopsy-based management prolongs disease-free survival for all patients and prolongs distant disease–free survival and melanoma-specific survival for patients with nodal metastases from intermediate-thickness melanomas. ( Xagena )
Morton DL et al, N Engl J Med 2014; 370:599-609