Patient age is an important factor in estimating lymph node (LN) positivity in thin melanoma independent of traditional pathologic factors, according to a recent study. Therefore, age should be taken into consideration when selecting patients for nodal biopsy. A retrospective cohort study using the National Cancer Database, an oncology database representing patients from >1,500 hospitals throughout the US, was performed (2010-2013). 8,772 patients with clinical stage I 0.50 to 1.0 mm thin melanoma undergoing wide excision and surgical evaluation of regional LNs were included. Researchers found:

• Of the total cohort, 333 patients had nodal metastases, for an overall positivity rate of 3.8%.
• 4,087 (54.0%) patients were women; median age was 56 years in patients with negative LNs and 52 years in those with positive LNs.
• In multivariable analysis, younger age, female sex, thickness of ≥0.76 mm, increasing Clark level, mitoses, ulceration, and lymphovascular invasion were independently associated with LN positivity.
• In decision tree analysis, patient age was identified as an important risk stratifier for LN metastases, after mitoses and thickness.