Sentinel lymph node tumour burden using digital cell count estimation predicts outcomes in melanoma

Area of Science:

• Oncology
• Pathology
• Digital Pathology

Background:

• Cutaneous melanoma frequently metastasizes to sentinel lymph nodes (SLNs).
• Current methods for characterizing micrometastatic tumor burden in SLN biopsies lack standardization and do not quantify cell counts.
• Existing criteria for SLN evaluation do not incorporate cellularity.

Purpose of the Study:

• To digitally quantify metastatic tumor burden in SLN biopsies using software analysis.
• To correlate digital cell count data with established SLN evaluation criteria.
• To assess the relationship between quantified tumor burden and patient prognosis.

Main Methods:

• Analysis of 246 SLN biopsies (63 positive, 183 negative for melanoma).
• Digital cell counting of the largest metastatic focus and total tumor burden within SLNs.
• Correlation of cell counts with Rotterdam, Starz, and Dewar criteria.

Main Results:

• Digital cell counting validated against existing criteria (Rotterdam: r=0.91, Starz: r=0.78).
• Increased cell count in metastatic deposits correlated significantly with established criteria (P<0.01).
• Higher cell counts were associated with reduced metastasis-free survival (HR=2.29).

Conclusions:

• Computerized cell count analysis provides a standardized method for quantifying melanoma SLN tumor burden.
• Digital cell counting is a valuable tool for the prognostication of outcomes in patients with melanoma undergoing SLN biopsy.