The following is a summary of “Sentinel lymph node biopsy in patients with T1a cutaneous malignant melanoma: A multicenter cohort study,” published in the January 2023 issue of Dermatology by Shannon, et al.

The generally low chance of positive makes sentinel lymph node biopsy for T1a cutaneous melanoma not commonly advised. There were poorly defined prognostic variables for positive sentinel lymph nodes (SLN+) in the cohort. For a study, researchers sought to identify risk variables for SLN+ in T1a melanoma patients.

From 2001 to 2020, patients with pathologic T1a (<0.80 mm, nonulcerated) cutaneous melanoma who had extensive local excision with sentinel lymph node biopsy at 5 high-volume melanoma clinics were included in the research. Univariate and multivariable logistic regression models were used to examine the patient and tumor features related to SLN+. Age was divided into groups of ≤42 and >42 years (25 percentile cutoff).

A total of 4.4% (N = 43) of the 965 patients diagnosed had SLN+. Age ≤42 years (7.5% vs 3.7%, odds ratio [OR], 2.14; P =.03), head/neck primary tumor site (9.2% vs 4%, OR, 2.75; P =.04), lymphovascular invasion (21.4% vs 4.2%, OR, 5.64; P =.01), and ≥2 mitoses/mm2 (8.2% vs 3.4%, OR, 2.31; P =.03) were linked to 18.4% of patients under 42 years old with ≥2 mitoses/mm2 (N = 38) were SLN+.

SLN+ was not common in T1a melanomas patients, although it did appear to be associated with younger age, lymphovascular invasion, mitogenicity, and head/neck primary location.