Comprehensive analysis of body composition features in melanoma patients treated with tyrosine kinase inhibitors.

BACKGROUND: The introduction of tyrosine kinase inhibitors (TKI) has greatly improved the management of metastatic melanoma. Recent studies have uncovered a relationship between the body mass index (BMI) and outcome of patients with metastatic melanoma. However, conflicting results have challenged the relevance of this finding. In the current work, we aim to dissect body composition features of melanoma patients treated with TKI to evaluate their value as biomarkers. PATIENTS AND METHODS: We analyze body composition features via CT scans in a retrospective cohort of 57 patients with non-resectable stage III/IV melanoma receiving first-line treatment with TKI in our department, focusing on the impact of body composition on treatment efficacy and occurrence of adverse events. RESULTS: In uni- and multivariate analyses, we identify an association between the visceral adipose tissue gauge index (VATGI) and survival. We furthermore profile additional body composition features including sarcopenia, which was also associated with a shorter overall survival. Finally, we detected an enrichment of cases with fatigue in patients with low VATGI. CONCLUSIONS: Our study represents the first exploratory study evaluating the suitability of body composition measurements as biomarkers for melanoma patients treated with TKI. Our data suggest a putative use of VATGI as a biomarker predicting patient outcome.

Low skeletal muscle mass predicts melanoma-specific survival in melanoma patients treated with adjuvant immune checkpoint blockade.

PURPOSE: Adjuvant immunotherapy with immune checkpoint blockade(ICB) has greatly reduced the risk of recurrence and metastatic spread in early and advanced melanoma. However, not all patients benefit from adjuvant treatment: many patients show disease recurrence despite therapy, while those without recurrence harbor the risk for potentially irreversible adverse events. Biomarkers to select patients benefitting most from adjuvant therapy are currently lacking. As body composition assessment using CT images has shown promising results as a prognostic biomarker in stage IV melanoma, we aim to study the applicability of body composition parameters also in adjuvant melanoma treatment. METHODS: We analyze body composition features via CT scans in a retrospective cohort of 109 patients with resected stage IIB-IV melanoma receiving an adjuvant first-line treatment with ICB in our department. In this analysis, we focus on the impact of body composition, especially the presence of low skeletal muscle mass (LSMM), on patients' survival and occurrence of adverse events (AEs). RESULTS: In uni- and multivariate analyses, we identify an association between CT-measured LSMM and melanoma-specific survival in patients treated with adjuvant ICB. Furthermore, LSMM is associated with a lower risk for therapy-related AEs, especially hypothyroidism, fatigue, and xerostomia. Conventional serological biomarkers e.g. S100 and LDH and measures of adipose tissue compartments did not show a correlation with survival or the occurrence of AEs. CONCLUSIONS: LSMM constitutes a novel biomarker for melanoma-specific survival in patients treated with adjuvant ICB.

Subcutaneous Fat Abundance and Density Are Associated with an Enhanced Response to Immunotherapy in Metastatic Melanoma: A Retrospective Cohort Study.

RATIONALE AND OBJECTIVES: Despite the impressive efficacy of immune checkpoint inhibitors (ICIs) in the treatment of metastatic melanoma, not all patients respond to therapy. In addition, ICI harbors the risk for serious adverse events (AEs), highlighting the need for novel biomarkers predicting treatment response and occurrence of AEs. Recently, the identification of enhanced response to ICI in obese patients has indicated that body composition might influence treatment efficacy. The aim of the current study is to assess radiologic measurements of body composition as biomarkers for treatment response and AEs to ICI in melanoma. MATERIALS AND METHODS: In the current work, we analyze adipose tissue abundance and density, as well as muscle mass via computed tomography scans in a retrospective cohort of 100 patients with non-resectable stage III/IV melanoma receiving first-line treatment with ICI in our department. From these, we investigate the impact of the subcutaneous adipose tissue gauge index (SATGI) and other parameters of body composition on treatment efficacy and occurrence of AEs. RESULTS: Low SATGI was associated with prolonged progression-free survival (PFS) in univariate and multivariate analyses (hazard ratio 2.56 [95% CI 1.18-5.55], P = .02), as well as an enhanced objective response rate (50.0% vs 27.1%; P = .02). Further analysis with a random forest survival model highlighted a nonlinear relationship between SATGI and PFS with a clear separation into high- and low-risk cohorts separated by the median. Finally, a significant enrichment of cases with vitiligo, but no other AEs, was observed in the SATGI-low cohort (11.5% vs 0%; P = .03). CONCLUSION: We identify SATGI as a biomarker predicting treatment response to ICI without increased risk for severe AEs in melanoma.