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Soo Park, MD
Soo Park, MD
Posted: Wednesday, September 4, 2024
The results of a single-center, real-world, retrospective observational study, which were published in the Journal of the European Academy of Dermatology and Venereology, seemed to support PD-L1 expression as a predictive biomarker for adjuvant immune checkpoint inhibitor therapy response stratification in patients with melanoma. However, according to Christoffer Gebhardt, MD, of the University Medical Center Hamburg-Eppendorf, Germany, the origin of the tumor tissue should be considered.
“The cell type relevant for the predictive value of PD-L1 expression is tissue-specific,” the investigators remarked. “Immune cells are important in primary tumors, while tumor cells are key in metastases.”
The investigators performed anti–PD-L1 staining on primary (n = 49) and metastatic (n = 55) tumor tissue samples collected at the University Skin Cancer Center Hamburg from 104 analysis-eligible, treatment-naive patients with stage II to IV disease who were yet to undergo adjuvant anti–PD-1 immune checkpoint inhibitor therapy. An equal number of patients who did and did not experience a relapse were observed; patient characteristics were found to be balanced between these groups. Immune cell, tumor positivity, and combined positive scores were determined at multiple cutoff levels for different tumor tissue locations by independent pathologic physician quantification, and they were correlated with therapeutic outcomes.
Based on a tumor tissue origin–independent analysis, relapse-free survival outcomes did not significantly differ among the positive and negative subgroups stratified for immune cell, tumor positivity, and combined positive scores at multiple cutoff levels. A multivariable univariate Cox proportional hazards regression analysis revealed that, at a cutoff level of 1%, positive immune cell scores in primary tumor tissue (hazard ratio [HR] = 0.23; P = .007) and tumor positivity scores in metastatic tumor tissue (HR = 0.37; P = .014) significantly and independently predicted favorable relapse-free survival outcomes.
“The present results should be validated in a multicenter cohort,” the investigators concluded.
Disclosure: For full disclosures of the study authors, visit onlinelibrary.wiley.com.
Journal of the European Academy of Dermatology and Venereology
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