Risk factors and patterns of recurrence after sentinel lymph node biopsy for thin melanoma

Area of Science:

• Melanoma research
• Oncology
• Surgical pathology

Background:

• Thin melanoma (AJCC 8 T1 stage ≤1.0 mm) with negative sentinel lymph node biopsy (SLNB) generally has an excellent prognosis.
• However, a subset of these patients experiences recurrence and mortality.
• Identifying specific risk factors is crucial for improved patient management.

Purpose of the Study:

• To determine risk factors for any type of recurrence (local/in-transit, nodal, distant) in thin melanoma patients with negative SLNB.
• To assess survival outcomes in this patient cohort.
• To inform surveillance strategies for high-risk individuals.

Main Methods:

• Retrospective review of thin melanomas with negative SLNB between 1999 and 2018.
• Collection of clinicopathologic characteristics of primary tumors.
• Analysis of recurrence patterns and survival outcomes using multivariate Cox regression.

Main Results:

• Eighteen out of 209 patients (8.6%) experienced recurrence over a median follow-up of 62 months.
• Distant recurrence was observed in 5.3% of patients.
• Significant risk factors for recurrence included head and neck primary site (HR 3.52), ulceration (HR 10.8), and mitotic rate (HR 1.39).

Conclusions:

• Thin melanoma patients with negative SLNB are at risk for recurrence, particularly those with specific adverse features.
• Ulceration, primary tumor location on the head or neck, and elevated mitotic rate are significant predictors of recurrence.
• Heightened surveillance is recommended for these high-risk thin melanoma patients.