BRAF immunohistochemistry predicts sentinel lymph node involvement in intermediate thickness melanomas.

Area of Science:

• Oncology
• Dermatology
• Pathology

Background:

• Sentinel lymph node biopsy (SNB) is crucial for melanoma staging.
• Current selection for SNB in intermediate thickness melanomas relies on clinicopathological features.
• Only 20-25% of patients undergoing SNB have nodal metastasis.

Purpose of the Study:

• To evaluate if tissue biomarkers and clinicopathological parameters predict sentinel node involvement.
• To assess the role of these markers in melanoma disease outcome.
• To improve patient selection for SNB.

Main Methods:

• A case-control study of 140 intermediate thickness melanoma patients (Breslow 0.9-4.0mm).
• Analysis of clinicopathological parameters (ulceration, mitotic count, regression) and biomarker immunoreactivity (FMNL-2, ezrin, BRAF V600E).
• Correlation analysis for sentinel node involvement and survival, including superficial spreading melanoma subtype.

Main Results:

• BRAF V600E status (p=0.010) and mitotic count (p=0.036) correlated with sentinel lymph node involvement.
• Sentinel node biopsy status independently predicted recurrence-free survival (RFS), melanoma-specific survival (MSS), and overall survival (OS).
• In superficial spreading melanomas, BRAF V600E positivity was linked to poorer RFS and OS.

Conclusions:

• BRAF immunohistochemistry can aid in selecting intermediate thickness melanoma patients for SNB.
• Combining Breslow thickness, mitotic count, and BRAF status identifies high-survival superficial spreading melanomas.
• These findings enhance prognostic accuracy and SNB selection criteria.