Melanoma
Zachary J. Senders, MD
Surgical Oncology Fellow
University of Louisville
Louisville, Kentucky, United States
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Records with cutaneous melanoma T1b or greater (thickness > 0.8 mm or with ulceration) and clinically node negative were identified from the NCDB from years 2012-2018. Three cohorts were defined: 1) patients undergoing no lymph node procedure, 2) patients undergoing SLN biopsy only, and 3) patients undergoing SLN biopsy and CLND. Trends in the utilization of CLND and changes in AJCC staging categories over time were analyzed. Comparisons were made over time and across clinicopathologic factors using chi-square testing.
Results: We identified 68,933 patients that met inclusion criteria. 60,536 underwent SLNB of which 9,031 (14.9%) were tumor-positive. A total of 3,776 (41.8%) underwent CLND. Patients receiving CLND were younger (58 vs 62, p < 0.0001) and more likely to be male (61.5% vs 57.9%, p=0.0005). Patients were more likely to have a higher N-classification (N2a-3a) if they received CLND (36.8%) compared to SLN biopsy alone (19.3%), p < 0.0001. This translated to a small difference in the proportion of stage IIIA patients between the two groups (SLN-alone 34.0%, CLND 31.8%, p< 0.0001). Of the patients with stage T1b or T2a primary tumors, for whom the detection of additional positive lymph nodes would lead to upstaging from IIIA to IIIC, the incidence of IIIC disease was only slightly higher in those who underwent CLND compared to SLNB alone (4.4% vs 1.1%, p< 0.0001). The use of CLND dramatically decreased from 59% in 2012 to 12.6% in 2018, p < 0.0001. However, the incidence of Stage IIIA disease remained stable over the 7-year study period (p=0.29, Figure).
Conclusions: While the utilization of CLND after a positive SLNB has declined dramatically in the last seven years, stage migration that may affect adjuvant therapy decisions has not occurred to a significant degree.