Predictors of germline status for hereditary melanoma: 5 years of multi-gene panel testing within the Italian Melanoma Intergroup.

BACKGROUND: The incidence of cutaneous melanoma is increasing in Italy, in parallel with the implementation of gene panels. Therefore, a revision of national genetic assessment criteria for hereditary melanoma may be needed. The aim of this study was to identify predictors of susceptibility variants in the largest prospective cohort of Italian high-risk melanoma cases studied to date. MATERIALS AND METHODS: From 25 Italian centers, we recruited 1044 family members and germline sequenced 940 cutaneous melanoma index cases through a shared gene panel, which included the following genes: CDKN2A, CDK4, BAP1, POT1, ACD, TERF2IP, MITF and ATM. We assessed detection rate according to familial status, region of origin, number of melanomas and presence and type of non-melanoma tumors. RESULTS: The overall detection rate was 9.47% (5.53% analyzing CDKN2A alone), ranging from 5.14% in sporadic multiple melanoma cases (spoMPM) with two cutaneous melanomas to 13.9% in familial cases with at least three affected members. Three or more cutaneous melanomas in spoMPM cases, pancreatic cancer and region of origin predicted germline status [odds ratio (OR) = 3.23, 3.15, 2.43, P < 0.05]. Conversely, age > 60 years was a negative independent predictor (OR = 0.13, P = 0.008), and was the age category with the lowest detection rate, especially for CDKN2A. Detection rate was 19% when cutaneous melanoma and pancreatic cancer clustered together. CONCLUSIONS: Gene panel doubled the detection rate given by CDKN2A alone. National genetic testing criteria may need a revision, especially regarding age cut-off (60) in the absence of strong family history, pancreatic cancer and/or a high number of cutaneous melanomas.

Acral lentiginous melanoma histotype predicts outcome in clinical stage I-II melanoma patients: an International multicenter study.

BACKGROUND: In the American Joint Committee on Cancer (AJCC) classification, acral lentiginous melanoma (ALM) histotype ALM is not included as an independent prognostic factor; in small series its negative prognostic impact on disease-free survival (DFS) and overall survival (OS) has been linked to the greater Breslow thickness (BT). PATIENTS AND METHODS: The study was carried out at four referral melanoma centers (three Italian and one Polish). Clinical consecutive patients with stage I-II melanoma, who were diagnosed, treated, and followed up between January 1998 and March 2018 in annotated specific databases were included. RESULTS: Overall, 6734 were evaluable, 4349 with superficial spreading melanoma (SSM), 2132 with nodular melanoma (NM), and 253 with ALM. At univariable analysis, a statistically significant worse DFS [hazard ratio (HR) 2.72, 95% confidence interval (CI) 2.24-3.30; P < 0.001] and OS (HR 2.67, 95% CI 2.15-3.32; P < 0.001) were found in patients with ALM compared with SSM. Similarly, the NM histotype was associated with a worse prognosis compared with the SSM histotype (DFS: HR 2.29, 95% CI 2.08-2.52; P < 0.001 and OS: HR 2.21, 95% CI 1.99-2.46; P < 0.001). At multivariable analysis, after adjusting for age, sex, BT, ulceration, and the sentinel lymph node status, a statistically significant worse DFS [adjusted HR (aHR; ALM versus SSM) 1.25, 95% CI 1.02-1.52; P = 0.028] was confirmed for patients with ALM. For patients with NM, instead, no impact of histology was found in terms of DFS [aHR (NM versus SSM) 1.04, 95% CI 0.93-1.15; P = 0.513] and OS [aHR (NM versus SSM) 0.96, 95% CI 0.86-1.08; P = 0.548]. CONCLUSIONS: ALM is associated with a worse long-term DFS. Our results could have important clinical implications for patients' stratification in future clinical trials and the incorporation of ALM histotype in the new AJCC classification as an independent prognostic factor.

Immune checkpoint inhibitor associated vitiligo and its impact on survival in patients with metastatic melanoma: an Italian Melanoma Intergroup study.

BACKGROUND: Checkpoint inhibitors in melanoma can lead to self-immune side-effects such as vitiligo-like depigmentation (VLD). Beyond the reported association with favorable prognosis, there are limited data regarding VLD patient features and their echo on the therapeutic outcomes. METHODS: To assess the association between VLD and a series of clinical and biological features as well as therapeutic outcomes, we built an observational cohort study by recruiting patients who developed VLD during checkpoint inhibitors. RESULTS: A total of 148 patients from 15 centers (101 men, median age 66 years, BRAF mutated 23%, M1c 42%, Eastern Cooperative Oncology Group (ECOG) status 0/1 99%, normal lactate dehydrogenase 74%) were enrolled. VLD was induced by ipilimumab, programmed cell death-1 (PD-1) inhibitors, and their combination in 32%, 56%, and 12%, respectively. The median onset was 26 weeks and it was associated with other skin and nonskin toxicities in 27% and 28%, respectively. After 3 years of VLD onset, 52% (95% confidence interval 39% to 63%) were progression free and 82% (95% confidence interval 70% to 89%) were still alive. The overall response rate was 73% with 26% complete response. Univariable analysis indicated that BRAF V600 mutation was associated with a better overall survival (P = 0.028), while in multivariable analysis a longer progression-free survival was associated with BRAF V600 (P = 0.093), female sex (P = 0.008), and M stage other than 1a (P = 0.024). When VLD occurred, there was a significant decrease of white blood cell (WBC) count (P = 0.05) and derived WBC-to-lymphocytes ratio (dWLR; P = 0.003). A lower monocyte count (P = 0.02) and dWLR (P = 0.01) were also reported in responder patients. CONCLUSIONS: Among VLD population, some features might help to identify patients with an effective response to immunotherapy, allowing clinicians to make more appropriate choices in terms of therapeutic options and duration.

The prognostic impact of the extent of ulceration in patients with clinical stage I-II melanoma: a multicentre study of the Italian Melanoma Intergroup (IMI).

BACKGROUND: The presence of ulceration has been recognized as an adverse prognostic factor in primary cutaneous melanoma (PCM). OBJECTIVES: To investigate whether the extent of ulceration (EoU) predicts relapse-free survival (RFS) and overall survival (OS) in PCM. MATERIALS AND METHODS: We retrieved data for 477 patients with ulcerated PCM from databases of the Italian Melanoma Intergroup. Univariate and multivariable Cox proportional hazard models were used to assess the independent prognostic impact of EoU. RESULTS: A significant interaction emerged between Breslow thickness (BT) and EoU, considering both RFS (P < 0·0001) and OS (P = 0·0006). At multivariable analysis, a significant negative impact of EoU on RFS [hazard ratio (HR) (1-mm increase) 1·26, 95% confidence interval (CI) 1·08-1·48, P = 0·0047] and OS [HR (1-mm increase) 1·25, 95% CI 1·05-1·48, P = 0·0120] was found in patients with BT ≤ 2 mm, after adjusting for BT, age, tumour-infiltrating lymphocytes, sentinel lymph node status and mitotic rate. No impact of EoU was found in patients with 2·01-4 mm and > 4 mm BT. CONCLUSIONS: This study demonstrates that EoU has an independent prognostic impact in PCM and should be recorded as a required element in pathology reports.

Network indirect comparison of 3 BRAF + MEK inhibitors for the treatment of advanced BRAF mutated melanoma.

BACKGROUD: Synergistic combinations between BRAF and MEK inhibitors, such as dabrafenib plus trametinib, vemurafenib plus cobimetinib or encorafenib plus binimetinib, represent the current standard of care in metastatic or locally advanced BRAF V600 mutated malignant melanomas (MM). However, no studies explored the direct head-to-head comparison between the three different combinations. In this paper, we performed a network meta-analysis to evaluate their efficacy in terms of overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and safety profile. METHOD: We performed a systematic review of the literature about published first line trials of BRAF and MEK inhibitors doublets in advanced mutated malignant melanoma. We compared then the results with an adjusted indirect analysis of randomized-controlled trials. Our primary survival outcome was OS. Secondary endpoints were PFS, ORR, G3-4 toxicities described in at least 5% of patients in experimental arms. RESULTS: We identified three phase-3 trials: coBRIM (vemurafenib and cobimetinib), COMBI-v (dabrafenib and trametinib) and Columbus study (encorafenib and binimetinib) for a total of 1230 included patients. The control arm was vemurafenib in all studies. The indirect comparison revealed no statistically differences for OS, PFS and ORR across trials, while safety profile differed between the three couples of agents. CONCLUSION: This indirect adjusted meta-analysis suggests a similar efficacy and a slightly different safety profile, related to specific molecular properties of the three different BRAF and MEK inhibitors currently approved in the management of advanced MM.

The status of PD-L1 and tumor-infiltrating immune cells predict resistance and poor prognosis in BRAFi-treated melanoma patients harboring mutant BRAFV600.

BACKGROUND: BRAF inhibitors (BRAFi) improve survival in metastatic melanoma patients (MMP) but the duration of clinical benefit is limited by development of drug resistance. Here, we investigated whether the expression of programmed death-ligand 1 (PD-L1) and the density of tumor-infiltrating mononuclear cells (TIMC) predict the occurrence of resistance, hence affecting the clinical outcome in BRAFi-treated MMP. METHODS: PD-L1 expression (cutoff 5%) was analyzed by immunohistochemistry with two different antibodies in BRAF(V600)-mutated formalin-fixed and paraffin-embedded samples from 80 consecutive MMP treated with BRAFi at a single institution. TIMC were evaluated by conventional hematoxylin and eosin staining. RESULTS: Forty-six and 34 patients received vemurafenib and dabrafenib, respectively. Membranous expression of PD-L1 was detected in 28/80 (35%) of patients. At multivariate analysis, absence of tumoral PD-L1 staining [odd ratio (OR) 10.8, 95% confidence interval (CI) 2.7-43.3, P < 0.001] and the presence of TIMC (OR 6.5, 95% CI 1.7-24.3, P < 0.005) were associated with a better response to treatment. Median progression-free survival (PFS) and overall survival were 10 and 15 months, respectively. By multivariate assessment, PD-L1 expression [hazard ratio (HR) 4.3, 95% CI 2.1-8.7, P < 0.0001] and absence of TIMC (HR 2.5, 95% CI 1.4-4.7, P < 0.002) correlated with shorter PFS. PD-L1 overexpression (HR 6.2, 95% CI 2.8-14.2, P < 0.0001) and absence of TIMC (HR 3.1, 95% CI 1.5-6.5, P < 0.002) were independent prognostic factors for melanoma-specific survival. CONCLUSION: Our results provide the first proof-of-principle evidence for the predictive and prognostic relevance of PD-L1 immunohistochemical expression and density of immune cell infiltration in BRAF(V600)-mutated MMP treated with BRAFi.

PD-L1 marks a subset of melanomas with a shorter overall survival and distinct genetic and morphological characteristics.

BACKGROUND: Programmed cell death ligand 1 (PD-L1) is a cell surface molecule that plays a critical role in suppressing immune responses, mainly through binding of the PD-1 receptor on T lymphocytes. PD-L1 may be expressed by metastatic melanoma (MM). However, its clinical and biological significance remains unclear. Here, we investigated whether expression of PD-L1 in MM identifies a biologically more aggressive form of the disease, carrying prognostic relevance. PATIENTS AND METHODS: PD-L1 expression was analyzed by immunohistochemistry using two different antibodies in primary tumors and paired metastases from 81 melanoma patients treated at a single institution. Protein expression levels were correlated with PD-L1 mRNA, BRAF mutational status and clinical outcome. PD-L1(+) and PD-L1(-) subsets of the A375 cell line were stabilized in vitro and compared using gene expression profiling and functional assays. Results were confirmed using xenograft models. RESULTS: PD-L1 membrane positivity was detected in 30/81 (37%) of patients. By multivariate analysis, Breslow thickness and PD-L1 membrane positivity were independent risk factors for melanoma-specific death {PD-L1 5% cutoff [hazard ratio (HR) 3.92, confidence interval (CI) 95% 1.61-9.55 P < 0.003], PD-L1 as continuous variable (HR 1.03, 95% CI 1.02-1.04 P < 0.002)}. PD-L1 expression defined a subset of the BRAF-mutated A375 cell line characterized by a highly invasive phenotype and by enhanced ability to grow in xenograft models. CONCLUSIONS: PD-L1 is an independent prognostic marker in melanoma. If confirmed, our clinical and experimental data suggest that PD-L1(+) melanomas should be considered a disease subset with distinct genetic and morpho-phenotypic features, leading to enhanced aggressiveness and invasiveness.