The role of Sentinel Lymph Node Biopsy (SLNB) is pivotal in the contemporary staging of cutaneous melanoma. In this review, we examine advanced molecular testing platforms like gene expression profiling (GEP) and immunohistochemistry (IHC) as tools for predicting the prognosis of sentinel lymph nodes. We compare these innovative approaches with traditional staging assessments. Additionally, we delve into the shared genetic and protein markers between GEP and IHC tests and their relevance to melanoma biology, exploring their prognostic and predictive characteristics. Finally, we assess alternative methods to potentially obviate the need for SLNB altogether. Progress in adjuvant melanoma therapy has diminished the necessity of Sentinel Lymph Node Biopsy (SLNB) while underscoring the importance of accurately identifying high-risk stage I and II melanoma patients who may benefit from additional anti-tumor interventions. The clinical application of testing through gene expression profiling (GEP) or immunohistochemistry (IHC) is gaining traction, with platforms such as DecisionDx, Merlin Assay (CP-GEP), MelaGenix GEP, and Immunoprint coming into play. Currently, extensive validation studies are in progress to incorporate routine molecular testing into clinical practice. However, due to significant methodological limitations, widespread clinical adoption of tissue-based molecular testing remains elusive at present. While various tissue-based molecular testing platforms have the potential to stratify the risk of sentinel lymph node positivity (SLNP), most suffer from significant methodological deficiencies, including limited sample size, lack of prospective validation, and limited correlation with established clinicopathological variables. Furthermore, the genes and proteins identified by individual gene expression profiling (GEP) or immunohistochemistry (IHC) tests exhibit minimal overlap, even when considering the most well-established melanoma mutations. However, there is hope that the ongoing prospective trial for the Merlin Assay may safely reduce the necessity for SLNB procedures if successful. Additionally, the MelaGenix GEP and Immunoprint tests could prove valuable in identifying high-risk stage I-II melanoma patients and potentially guiding their selection for adjuvant therapy, thus potentially reducing the need for SLNB. Due to the diverse study designs employed, effective comparisons between GEP or IHC tests are challenging, and to date, there is no study directly comparing the clinical utility of these respective GEP or IHC tests.

Background: The treatment of melanoma has been revolutionized by the use of immune checkpoint inhibition (ICI), but many patients do not benefit. Furthermore, immune‐related adverse events may occur during therapy. A predictive biomarker is needed to reliably identify patients benefitting. In lung, renal cell and bladder cancer early C‐reactive protein (CRP) kinetics were shown to be a predictive biomarker for ICI.Objective: Here, we investigate early CRP kinetics as predictive biomarker for ICI in melanoma patients.Methods: Two independent prospectively collected cohorts were analysed: Cohort 1 (n = 87) with advanced and Cohort 2 (n = 99) with completely resected melanoma. Patients were stratified by in the dynamics of CRP after ICI initiation: A doubling of baseline CRP within 30 days followed by at least a 30% drop within 3 months was classified as a CRP flare. If no doubling of CRP was reported, but a 30% drop within 3 months, patients were classified as CRP responders and all others as CRP non‐responders. Analysed factors included clinical characteristics like S100B and LDH. Median follow‐up was 1.5 and 1.7 years for Cohorts 1 and 2.Results: In Cohort 1 CRP flare (n = 12), CRP responders (n = 43) and CRP non‐responders (n = 32) with a progression‐free survival (PFS) of 0.7, 0.6 and 0.2 years (p = 0.017) and an overall survival (OS) of 2.2, 1.5 and 1.0 years (p = 0.014), respectively. Multivariable Cox analysis showed an independent risk reduction of progression for CRP responders by 62% compared to CRP non‐responders (p = 0.001). In Cohort 2 CRP flare (n = 13), CRP responders (n = 70) and CRP non‐responders (n = 16) the log‐rank analysis showed a significant difference between OS and recurrence‐free survival (RFS) curves (p = 0.046 and p = 0.049).Conclusion: Early CRP kinetics could indicate a response to ICI with improved OS and RFS/PFS. CRP flare and CRP response indicating significantly improved outcomes compared to CRP non‐responders.

Background: Immune checkpoint inhibition has revolutionized melanoma therapy, but many patients show primary or secondary resistance. Biomarkers are, therefore, urgently required to predict response prior to the initiation of therapy and to monitor disease progression. Methods: In this prospective study, we analyzed the serum C-C motif chemokine ligand 20 (CCL20) concentration using an enzyme-linked immunosorbent assay. Blood was obtained at baseline before the initiation of immunotherapy with anti-PD-1 monotherapy or Nivolumab and Ipilimumab in advanced melanoma patients (stages III and IV) enrolled at the University Medical Center Hamburg-Eppendorf. The CCL20 levels were correlated with clinico-pathological parameters and disease-related outcomes. Results: An increased C-C motif chemokine ligand 20 (CCL20) concentration (≥0.34 pg/mL) at baseline was associated with a significantly impaired progression-free survival (PFS) in the high-CCL20 group (3 months (95% CI: 2–6 months) vs. 11 months (95% CI: 6–26 months)) (p = 0.0033) and could be identified as an independent negative prognostic factor for PFS in univariate (Hazard Ratio (HR): 1.98, 95% CI 1.25–3.12, p = 0.004) and multivariate (HR: 1.99, 95% CI 1.21–3.29, p = 0.007) Cox regression analysis, which was associated with a higher risk than S100 (HR: 1.74). Moreover, high CCL20 levels were associated with impaired overall survival (median OS not reached for low-CCL20 group, p = 0.042) with an HR of 1.85 (95% CI 1.02–3.37, p = 0.043) in univariate analysis similar to the established prognostic marker S100 (HR: 1.99, 95% CI: 1.02–3.88, p = 0.043). Conclusions: CCL20 may represent a novel blood-based biomarker for the prediction of resistance to immunotherapy that can be used in combination with established strong clinical predictors (e.g., ECOG performance score) and laboratory markers (e.g., S100) in advanced melanoma patients. Future prospective randomized trials are needed to establish CCL20 as a liquid biopsy-based biomarker in advanced melanoma.

Background: Immune checkpoint inhibition (ICI) is the standard treatment for advanced melanoma patients. Despite its high efficacy compared to previous treatment options, immune-related adverse events (irAEs) occur frequently. While most of the patients experience mild to moderate irAEs, some patients develop severe to lethal irAEs under ICI treatment; hence, biomarkers are urgently required. Methods: In this retrospective single-center study, 157 advanced melanoma patients treated with ICI at the University Medical Center Hamburg–Eppendorf were included. IrAEs were correlated with clinico-pathological parameters, disease-related outcomes, and irAE-free survival. Results: In our cohort, 130 out of 157 patients receiving immunotherapy experienced irAE, of which more than half experienced irAE Grade ≥ 3. The most common irAE independent of its grade included cutaneous irAE, colitis, endocrine irAE, and hepatitis. Patients experiencing irAE had significantly longer progression-free survival (PFS) and overall survival (OS) compared to patients who did not experience irAE under ICI therapy. Stratification by irAE groups revealed that musculoskeletal irAEs are associated with the longest, whereas myocarditis is associated with the shortest OS and PFS. IrAE was a significant beneficial prognosticator for PFS in univariate, but not in multivariate Cox regression analysis. With respect to OS, the occurrence of irAE was an independent prognostic factor among ECOG status ≥ 2 and uveal melanoma. ROC analysis demonstrated that D-dimers have moderate predictive capability for irAE occurrence. Cox regression analysis demonstrated that elevated D-dimers and PD-1 monotherapy vs. CTLA-4 and PD-1 combination regimen are the only independent prospective prognostic markers for irAE-free survival. Conclusions: Our study demonstrates that different irAE across the irAE spectrum have a different impact on the PFS and OS of advanced melanoma patients. D-dimers may be used as a blood-based biomarker for irAE prediction, warranting future validation in multi-center studies.

Targeted therapies (TT) improve outcomes in BRAF-mutant melanoma. Pre-clinical data suggest that anticoagulation (AC) and platelet aggregation inhibition (PAI) may have antitumoral effects. We evaluated the impact of concomitant AC or PAI on outcomes in patients receiving TT. We analyzed 1296 patients with unresectable stage III-IV BRAF-mutant melanoma treated with BRAF plus MEK inhibitors (2016-2024) in the prospective multicenter ADOReg registry. Patients were categorized as receiving no antithrombotic therapy (ATT; n = 1125), PAI (n = 73; acetylsalicylic acid or clopidogrel), or AC (n = 98; direct oral anticoagulants, low-molecular-weight heparin, or vitamin K antagonists). Median follow-up was 1.3 years. Compared with patients without ATT, those receiving AC had significantly improved 12-month progression-free survival (PFS; HR 0.55, 95 % CI 0.39-0.78, p = 0.001) and overall survival (OS; HR 0.35, 95 % CI 0.19-0.64, p = 0.001). Direct oral anticoagulants showed the most pronounced PFS benefit (HR 0.40, 95 % CI 0.25-0.64, p < 0.001). PAI was not associated with a significant difference in PFS, but multivariable Cox regression indicated a reduced hazard of death (HR 0.48, 95 % CI 0.27-0.87, p = 0.015). Concomitant AC, particularly factor Xa-inhibiting direct oral anticoagulants, was associated with improved survival in melanoma patients undergoing TT. These findings support prospective trials evaluating AC as concomitant therapy in advanced melanoma.