Validation of Melanoma Immune Profile (MIP), a Prognostic Immune Gene Prediction Score for Stage II-III Melanoma

Purpose: Biomarkers are needed to stratify patients with stage II-III melanoma for clinical trials of adjuvant therapy because, while immunotherapy is protective, it also confers the risk of severe toxicity. We previously defined and validated a 53-immune gene melanoma immune profile (MIP) predictive both of distant metastatic recurrence (DMR) and of disease-specific survival (DSS). Here, we test MIP on a third independent population. Methods: A retrospective cohort of 78 patients with stage II-III primary melanoma was analyzed using the nanoString assay to measure expression of 53 target genes and MIP score was calculated. Statistical analysis correlating MIP with disease-specific survival, overall survival, distant metastatic recurrence, and distant metastasis-free interval was performed using receiver operating characteristic curves, Kaplan-Meier (KM) curves, and standard univariable and multivariable Cox proportional hazards models. Results: MIP significantly distinguished patients with distant metastatic recurrence from those without distant metastatic recurrence using ROC curve analysis (AUC=0.695, p=0.008). We defined high and low risk groups based on the cutoff defined by this ROC curve and find that MIP correlates with both DSS and OS by ROC curve analysis (AUC=0.719, p=0.004 and AUC=0.698, p=0.004, respectively). Univariable Cox regression reveals that a high-risk MIP score correlates with DSS (p=0.015, HR=3.2). Conclusion: MIP identifies patients with low risk of death from melanoma and may constitute a clinical tool to stratify stage II-III melanoma patients for enrollment in clinical trials.

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