Does Stage Migration Occur as a Consequence of Omitting Completion Lymph Node Dissection for Melanoma?

INTRODUCTION: Completion lymph node dissection (CLND) is no longer recommended routinely in the treatment of melanoma. CLND omission may understage patients for whom the distinction between stage IIIA and IIIB-C could alter adjuvant therapy recommendations. The aim of this study is to determine if stage migration has occurred with the declining use of CLND.

METHODS: Patients with clinically node-negative ≥ T1b cutaneous melanoma were identified from the National Cancer Database (NCDB) from 2012 to 2018. CLND utilization and changes in AJCC staging were analyzed. Patients undergoing sentinel lymph node biopsy (SLNB) alone were compared with those undergoing SLNB + CLND.

RESULTS: Overall, 68,933 patients met inclusion criteria and 60,536 underwent SLNB, of which 9031 (14.9%) were tumor positive. CLND was performed in 3776 (41.8%). Patients undergoing CLND were younger (58 versus 62 years, p < 0.0001) and more likely male (61.5% versus 57.9%, p = 0.0005). Patients were more likely to have an N classification >N1a if they received SLNB + CLND (36.8%) versus SLNB alone (19.3%), p < 0.0001. This translated to a small difference in stage IIIA patients between groups (SLNB alone 34.0%, SLNB + CLND 31.8%, p < 0.0001). Of the patients with T1b/T2a tumors who would be upstaged from IIIA to IIIC with identification of additional positive nodes, IIIC incidence was only slightly higher after SLNB + CLND compared with SLNB alone (4.4% versus 1.1%, p < 0.0001). CLND utilization dramatically decreased from 59% in 2012 to 12.6% in 2018, p < 0.0001. However, the incidence of stage IIIA disease for all patients remained stable over the 7-year study period.

CONCLUSIONS: While the utilization of CLND after positive SLNB has declined dramatically in the last 7 years, stage migration that may affect adjuvant therapy decisions has not occurred to a clinically meaningful degree.