The biology behind prognostic factors of cutaneous melanoma

The Challenge of Classifying Metastatic Cell Properties by Molecular Profiling Exemplified with Cutaneous Melanoma Cells and Their Cerebral Metastasis from Patient Derived Mouse Xenografts

The prediction of metastatic properties from molecular analyses still poses a major challenge. Here we aimed at the classification of metastasis-related cell properties by proteome profiling making use of cutaneous and brain-metastasizing variants from single melanomas sharing the same genetic ancestry. Previous experiments demonstrated that cultured cells derived from these xenografted variants maintain a stable phenotype associated with a differential metastatic behavior: The brain metastasizing variants produce more spontaneous micro-metastases than the corresponding cutaneous variants. Four corresponding pairs of cutaneous and metastatic cells were obtained from four individual patients, resulting in eight cell-lines presently investigated. Label free proteome profiling revealed significant differences between corresponding pairs of cutaneous and cerebellar metastases from the same patient. Indeed, each brain metastasizing variant expressed several apparently metastasis-associated proteomic alterations as compared with the corresponding cutaneous variant. Among the differentially expressed proteins we identified cell adhesion molecules, immune regulators, epithelial to mesenchymal transition markers, stem cell markers, redox regulators and cytokines. Similar results were observed regarding eicosanoids, considered relevant for metastasis, such as PGE2 and 12-HETE. Multiparametric morphological analysis of cells also revealed no characteristic alterations associated with the cutaneous and brain metastasis variants. However, no correct classification regarding metastatic potential was yet possible with the present data. We thus concluded that molecular profiling is able to classify cells according to known functional categories but is not yet able to predict relevant cell properties emerging from networks consisting of many interconnected molecules. The presently observed broad diversity of molecular patterns, irrespective of restricting to one tumor type and two main classes of metastasis, highlights the important need to develop meta-analysis strategies to predict cell properties from molecular profiling data. Such base knowledge will greatly support future individualized precision medicine approaches.

Tumor infiltrating lymphocytes: The regulator of melanoma evolution

Melanoma is the most severe type of skin cancer and its incidence has increased in the last decades. In the United States, it is the 6th most common cancer in both men and women. Prognosis for patients with melanoma depends on the stage of the disease at the time of diagnosis and it can be influenced by the immunologic response. Melanoma has been historically considered an immunogenic malignancy. It often contains great amount of immune cells (different subsets of T-cells, dendritic cells, macrophages, neutrophils, mast cells, B lymphocytes), which may reflect a continuous intercommunication between host and tumor. It is not established if tumor-infiltrating lymphocytes (TILs) are induced by tumor cells or by other components of the microenvironment or when they are a host direct immunologic reaction. It has been observed that in many cases, the presence of a dense TIL is associated with good prognosis. The pattern and activation state of the cells which constitute TIL is variable and modulates the clinical outcome. An important step in the understanding of tumor immunobiology is the analysis of the populations and subsets of immune cells that form TIL. Besides its prognostic significance, after approval of cytotoxic T lymphocyte antigen 4, programmed cell death-1 and programmed death-1 ligand antibodies for the treatment of melanoma, the assessment of immune infiltrate composition has become even more captivating, as it could provide new target molecules and new biomarkers for predicting the effect of the treatment and disease outcome in patients treated with immunotherapy. In this review we discuss current state of knowledge in the field of immune cells that infiltrate melanoma, resuming the potential of TIL components to become prognostic markers for natural evolution, for response to drugs or valuable targets for new medication.

Histopathologic variables differentially affect melanoma survival by age at diagnosis

We evaluated clinical, phenotypic, behavioral, and histopathologic variables in relationship to melanoma-specific survival by age at diagnosis among 650 population-based melanoma patients in Connecticut, with 20 years of follow-up. Only one variable, skin awareness, was significantly associated with melanoma mortality in both groups. The variables that differed between the age-groups were anatomic site, Breslow thickness, histologic subtype, mitoses, tumor-infiltrating lymphocytes (TILs), and solar elastosis. Head and neck melanoma, Breslow thickness, nodular melanoma, and solar elastosis were all significantly more likely to be associated with mortality among the older subjects; among the younger subjects, the presence of mitoses was associated with an increased probability of dying and TILs were associated with a reduced risk of mortality.

Loss of E-cadherin as Part of a Migratory Phenotype in Melanoma Is Associated With Ulceration

It has been suggested that embryogenic properties of migratory cells are reactivated during wound healing and metastasis in adults. This might explain the association between wound-induced inflammation and poor survival in patients with ulcerated melanoma. Linking inflammation with a migratory phenotype, we characterize the infiltration of innate inflammatory cells, loss of cell-to-cell adhesion (E-cadherin), factors associated with extracellular matrix degradation [matrix metalloproteinase-9 (MMP-9), and neutrophil elastase (NE)], and spindle-shaped cell morphology, between ulcerated (n = 179) and nonulcerated (n = 206) melanoma. In addition, the presence of "extravascular migratory metastasis" (angiotropism) and tumor-vessel density were evaluated as important factors for tumor cell dispersal in ulcerated melanoma. We showed a correlation between expression of the granulocyte marker cd66b+ and the expression of NE and MMP-9, reflecting activated neutrophils. Ulcerated melanoma correlated with a low global E-cadherin score (P = 0.041) and weak-spot score (P = 0.0004). Thus, 28% of the nonulcerated, 42% of the minimally/moderately ulcerated melanoma, and 53% of the excessively ulcerated melanoma presented low scores as opposed to a high E-cadherin score. In addition, the presence of ulceration was correlated with angiotropism (P < 0.0001) and spindle-shaped morphology (P = 0.021). There were no differences in MMP-9 expression or intratumoral vessel density between the ulcerated and nonulcerated group. In conclusion, expression of migratory cell properties showed a highly heterogeneous pattern, which was associated with ulcerated areas and inflammatory cells, in general and with neutrophils in particular. We, therefore, suggest that wound-associated inflammation may be involved in the induction of migratory cell transition and tumor cell dispersal in ulcerated melanoma.

Effect of biology on the outcome of female melanoma patients

The aim of the present study was to investigate plausible explanations for the favorable outcome of female melanoma patients and determine the effect of biology on this outcome. Data from 1,169 cutaneous melanoma patients were retrospectively analyzed. Cox proportional hazards models were used and the confounding factors on the survival difference were analyzed by a forward step multivariate modification method. The majority of the factors contributing to poor prognosis were significantly more pronounced in male melanoma patients. After the survival advantage of female patients (P=0.0001 on univariate analysis) was confounded (P=0.708 on multivariate analysis) following adjustment for the prognostic factors, two factors (neurotropism and vertical growth phase) were identified as the confounders, and this effect was attributed to the small number of patients in the groups of these two variables. The already known female advantage in melanoma survival was not affected by other prognostic factors, and female sex remained an independent predictor of good survival in melanoma. This sex-related independent survival advantage was attributed to a biological characteristic that has not yet been fully elucidated, but may be more closely associated with host-related rather than melanoma-related factors.

Can 18F-FDG PET/CT predict recurrence in patients with cutaneous malignant melanoma?

The aim of this study was to evaluate the prognostic significance of maximum standardized uptake value (SUVmax) of primary cutaneous malignant melanoma (CMM) lesions by 18F-FDG positron emission tomography/ computerized tomography (PET/ CT) in terms of recurrence. Patients, methods: 37 CMM patients (17 men, mean age: 61.7 ± 13.6 years) that underwent PET/CT at presentation were enrolled in this study. Recurrence was determined by histological confirmation or by radiological and clinical follow- up for at least 8 months after curative surgery. Clinical variables such as age, sex, clinical stage, and primary lesion location, thickness, and ulceration, and SUVmax values were analyzed with respect to their usefulness for predicting recurrence. Results: SUVmax was found to be significantly higher in patients with ulceration of primary lesion of CMM (p = 0.004) and in patients with a stage ≥ III (p < 0.000). Patients that experience recurrence had a significantly higher mean SUVmax value (4.9 ± 2.9) than patients who did not (2.1 ± 1.5, p = 0.024). ROC analysis showed that a SUVmax cut-off value 2.2 had high sensitivity (88.9%) and specificity (67.9%) for predicting recurrence. Kaplan-Meier analysis identified ulceration of primary lesion (p = 0.034), stage ≥ III (p = 0.019) and SUVmax ≥ 2.2 (p = 0.002) as predictors of recurrence. However, Cox proportional-hazards analysis showed that only SUVmax (p = 0.025, relative risk 11.063) significantly predicted recurrence. Conclusion: Preoperative SUVmax of primary lesion was found to be the most potent predictor of recurrence in CMM patient. Patients with high SUV max of primary lesion should be followed meticulously for recurrence.

Associations of Statins and Diabetes with Diagnosis of Ulcerated Cutaneous Melanoma

Ulcerated primary melanomas are associated with an inflammatory tumor microenvironment. We hypothesized that systemic proinflammatory states and anti-inflammatory medications are also associated with a diagnosis of ulcerated melanoma. In a cross-sectional study of 787 patients with newly diagnosed clinical stage IB or II melanoma, we estimated odds ratios for the association of proinflammatory factors (high body mass index, diabetes, cardiovascular disease, hypertension, and smoking) or the use of anti-inflammatory medications (statins, aspirin, corticosteroids, and nonsteroidal anti-inflammatory drugs), with ulcerated primary melanoma using regression models and subgroup analyses to control for melanoma thickness and mitotic rate. On the basis of information from 194 patients with ulcerated and 593 patients with nonulcerated primary melanomas, regular statin users had lower likelihood of a diagnosis of ulcerated primary melanoma (odds ratio 0.67, 95% confidence interval 0.45-0.99), and this association remained after adjusting for age, sex, thickness, and mitosis. When analysis was limited to melanomas that were ≤2 mm thick and had ≤2 mitoses/mm2 (40 ulcerated; 289 without ulceration), patients with diabetes had significantly raised odds of diagnosis of ulcerated melanoma (odds ratio 2.90, 95% confidence interval 1.07-7.90), adjusted for age, sex, body mass index, and statin use. These findings support our hypotheses that statin use is inversely associated, and diabetes is positively associated, with ulcerated melanoma.

Autophagic UVRAG Promotes UV-Induced Photolesion Repair by Activation of the CRL4(DDB2) E3 Ligase

UV-induced DNA damage, a major risk factor for skin cancers, is primarily repaired by nucleotide excision repair (NER). UV radiation resistance-associated gene (UVRAG) is a tumor suppressor involved in autophagy. It was initially isolated as a cDNA partially complementing UV sensitivity in xeroderma pigmentosum (XP), but this was not explored further. Here we show that UVRAG plays an integral role in UV-induced DNA damage repair. It localizes to photolesions and associates with DDB1 to promote the assembly and activity of the DDB2-DDB1-Cul4A-Roc1 (CRL4(DDB2)) ubiquitin ligase complex, leading to efficient XPC recruitment and global genomic NER. UVRAG depletion decreased substrate handover to XPC and conferred UV-damage hypersensitivity. We confirmed the importance of UVRAG for UV-damage tolerance using a Drosophila model. Furthermore, increased UV-signature mutations in melanoma correlate with reduced expression of UVRAG. Our results identify UVRAG as a regulator of CRL4(DDB2)-mediated NER and suggest that its expression levels may influence melanoma predisposition.

The avidity of tumor-specific T cells amplified by a plasmacytoid dendritic cell-based assay can predict the clinical evolution of melanoma patients

The advent of immune checkpoint blockers and targeted therapies has changed the outcome of melanoma. However, many patients experience relapses, emphasizing the need for predictive and prognostic biomarkers. We developed a strategy based on plasmacytoid dendritic cells (pDCs) loaded with melanoma tumor antigens that allows eliciting highly efficient antitumor T-cell responses. We used it to investigate antitumor T-cell functionality in peripheral blood mononuclear cells and tumor-infiltrating lymphocytes from melanoma patients. The pDCs elicited tumor-specific T cells in different proportions and displaying diverse functional features, dependent upon the stage of the disease, but independent of the histological parameters at diagnosis. Strikingly, the avidity of the MelA-specific T cells triggered by the pDCs was found to predict patient relapse time and overall survival. Our findings highlighted unexplored aspects of antitumor T-cell responsiveness in melanoma, and revealed for the first time the structural avidity of tumor-specific T cells as a crucial feature for predicting clinical evolution.

M1 and M2 macrophages' clinicopathological significance in cutaneous melanoma

Skin malignant melanoma (MM) is an aggressive cancer with an increasing incidence with limited therapies in advanced stages. Tumor-associated macrophages (TAMs) are the major immune constituent of the MM microenvironment and contribute toward its prognosis. TAMs' characterization and localization in human cancer is important to understand cancer progression and to identify molecular personalized therapies. M2 TAMs in stage I-II MMs are associated with worse prognostic parameters. A comprehensive M1-macrophage and M2-macrophage intratumoral localization and quantification in all stages of skin MMs is documented here with its clinical significance. To highlight immune pathways and possible early indicators of MM progression, we evaluated the number of M1 and M2 TAMs and intratumoral distribution in a large series of skin MMs. CD68 double immunostaining with MRP8-14 or inducible nitric oxide synthase (M1 macrophages) and with CD163 or CD204 (M2 macrophages) was performed in 94 stage I-IV skin MMs with a long duration of follow-up. The accumulation and distribution of M1 and M2 TAMs in intratumoral nests, stroma, and at the invasive front was correlated with clinicopathological variables. Since the early stage of MMs, M1 intratumoral macrophages were fewer than the M2 population; their recruitment was rapidly and progressively overwhelmed by an increase in M2 TAMs during MM progression. Independent of their intratumoral distribution, the accumulation of both M1 and M2 TAMs is associated with poor prognostic indicators and patients' survival. M1-recruited macrophages shift to the M2 phenotype early in MM development, possibly induced by high inducible nitric oxide synthase intratumoral increase peculiarly occurring since the initial MM stages. M2-recruited TAMs overwhelm M1 accumulation in all stages of MM progression, thus favoring neoplastic growth and dissemination. Independent of their intratumoral distribution, the prevalent accumulation of M2 TAMs in MM is statistically confirmed to be a poor indicator of patients' outcome and a potential target of immune therapies.

Epidemiology of cutaneous melanoma in Sweden-Stage-specific survival and rate of recurrence

Cutaneous malignant melanoma (CMM) incidence is increasing globally, making a thorough understanding of the disease and its outcomes essential for optimizing care even more urgent. In this population-based, retrospective study, we investigated stage-specific survival and recurrence/progression rates of CMM among patients diagnosed in Stockholm County Council during 2005-2012, before the wide introduction of targeted therapy. A total of 3,554 CMM patients from the Stockholm Melanoma Register were included. Information on comorbidities, progression, death, and treatments was obtained from nationwide registers and hospital electronic medical records. Unadjusted 5-year survival varied from 91.4% for stage I to 24.6% for stage IV patients. Stage, age and gender were predictors of survival, with gender an independent predictor of survival for stages IA and IIA. 74.6% of patients remained recurrence/progression-free during follow-up, with 5-year recurrence/progression-free survival rates varying from 85.3% to 12.9% among stages I and IV patients, respectively. In addition to stage, male gender, and age, circulatory system comorbidities increased the risk for recurrence/progression. No statistically significant differences in progression rate for operated and non-operated patients could be detected, possibly due to high rate (98.9%) of surgery. Our estimates of survival and recurrence rates are consistent with historical and global expectations and can serve as a baseline to gauge population-level improvements with use of novel melanoma treatments.

Host kinin B1 receptor plays a protective role against melanoma progression

Melanoma is a very aggressive tumor that arises from melanocytes. Late stage and widely spread diseases do not respond to standard therapeutic approaches. The kallikrein-kinin system (KKS) participates in biological processes such as vasodilatation, pain and inflammatory response. However, the role of KKS in tumor formation and progression is not completely understood. The role of the host kinin B1 receptor in melanoma development was evaluated using a syngeneic melanoma model. Primary tumors and metastasis were respectively induced by injecting B16F10 melanoma cells, which are derived from C57BL/6 mice, subcutaneously or in the tail vein in wild type C57BL/6 and B1 receptor knockout mice (B1^−/−). Tumors developed in B1^−/− mice presented unfavorable prognostic factors such as increased incidence of ulceration, higher levels of IL-10, higher activation of proliferative pathways such as ERK1/2 and Akt, and increased mitotic index. Furthermore, in the metastasis model, B1^−/− mice developed larger metastatic colonies in the lung and lower CD8⁺immune effector cells when compared with WT animals. Altogether, our results provide evidences that B1^−/− animals developed primary tumors with multiple features associated with poor prognosis and unfavorable metastatic onset, indicating that the B1 receptor may contribute to improve the host response against melanoma progression.

Immune biomarkers are more accurate in prediction of survival in ulcerated than in non-ulcerated primary melanomas

INTRODUCTION

Ulcerated melanomas may have a unique biology and microenvironment. We test whether markers of immune infiltration correlate with clinical outcome in ulcerated compared to non-ulcerated primary melanoma tumors.

METHODS

Sixty-two stage II-III cutaneous melanomas, 32 ulcerated and 30 non-ulcerated, were analyzed for tumor-infiltrating lymphocytes (TILs). Immunohistochemistry (IHC) was performed for CD2, a marker previously shown to correlate with overall survival (OS) and recurrence-free survival (RFS) in this patient population. IHC using antibody, VE1, to BRAF V600E was also performed on a subset of 41 tumors to assess the relationship of BRAF mutation to immune markers.

RESULTS

We found, using Cox regression models, that the presence of TILs was associated with improved OS (p = 0.034) and RFS (p = 0.002) in ulcerated melanoma tumors, but not in non-ulcerated melanoma (p = 0.632, 0.416). CD2 expression also was correlated with improved OS (p = 0.021) and RFS (p = 0.001) in ulcerated melanoma, but no relationship was seen in non-ulcerated melanoma (p = 0.427, 0.682). In this small population, BRAF status did not correlate with TILs or CD2+ count.

CONCLUSION

Our data show that immune markers including TILs and CD2 count correlate more closely with survival in ulcerated melanomas than that in non-ulcerated melanomas. We propose that immune biomarkers may be particularly relevant to ulcerated, as compared to non-ulcerated, melanomas and that this merits study in larger populations.

The clinicopathological and gene expression patterns associated with ulceration of primary melanoma

Ulceration of primary melanomas is associated with poor prognosis yet is reported to predict benefit from adjuvant interferon. To better understand the biological processes involved, clinicopathological factors associated with ulceration were determined in 1804 patients. From this cohort, 348 primary tumor blocks were sampled to generate gene expression data using a 502-gene cancer panel and 195 blocks were used for immunohistochemistry to detect macrophage infiltration and vessel density. Gene expression results were validated using a whole genome array in two independent sample sets. Ulceration of primary melanomas was associated with more proliferative tumors, tumor vessel invasion, and increased microvessel density. Infiltration of tumors with greater number of macrophages and gene expression pathways associated with wound healing and up-regulation of pro-inflammatory cytokines suggests that ulceration is associated with tumor-related inflammation. The relative benefit from interferon reported in patients with ulcerated tumors may reflect modification of signaling pathways involved in inflammation.

Molecular pathology of cutaneous melanoma

Cutaneous melanoma is associated with strong prognostic phenotypic features, such as gender, Breslow's thickness and ulceration, although the biological significance of these variables is largely unknown. It is likely that these features are surrogates of important biological events rather than directly promoting cutaneous melanoma progression. In this article, we address the molecular mechanisms that drive these phenotypic changes. Furthermore, we present a comprehensive overview of recurrent genetic abnormalities, both germline and somatic, in relation to cutaneous melanoma subtypes, ultraviolet exposure and anatomical localization, as well as pre-existing and targeted therapy-induced mutations that may contribute to resistance. The increasing knowledge of critically important oncogenes and tumor-suppressor genes is promoting a transition in melanoma diagnosis, in which single-gene testing will be replaced by multiplex and multidimensional analyses that combine classical histopathological characteristics with the molecular profile for the prognostication and selection of melanoma therapy.

Neuropilin-2 gene expression correlates with malignant progression in cutaneous melanoma

BACKGROUND

It is currently not possible to predict the metastatic potential of early-stage melanoma lesions by histological examination alone; however, a significant number of thin melanomas will progress over time to advanced disease. Molecular biomarkers that could identify patients with melanoma at high risk at the time of original diagnosis would contribute significantly to improved patient outcomes and increased survival. Neuropilin-2 (NRP2), a cell surface receptor involved in tumour-associated angiogenesis and lymphangiogenesis, has recently been shown to be expressed in melanoma.

OBJECTIVES

To evaluate the potential value of NRP2 gene transcript levels as biomarkers for malignant melanoma progression.

METHODS

We measured NRP2 gene expression in a panel of formalin-fixed paraffin-embedded tissue specimens consisting of naevi, primary melanomas and metastatic melanomas using quantitative reverse transcriptase-polymerase chain reaction technique.

RESULTS

NRP2 levels are clearly segregated among the groups of naevi, primary and metastatic melanoma samples with a statistical trend towards increasing NRP2 gene expression correlating with disease progression. Logistic regression analysis reveals that the probability of malignant progression increases with elevated levels of NRP2 (odds ratio of 2·60 with confidence interval 1·29-5·21). Within the group of primary melanomas, there is a positive correlation (r = 0·823) between NRP2 expression and Breslow depth. This correlation was validated in an independent sample set of patients with melanoma.

CONCLUSIONS

This preliminary study strongly supports the significance of NRP2 as a useful biomarker for malignant progression of melanoma, which may be useful for early identification of patients with melanoma at high risk.

Melanoma risk loci as determinants of melanoma recurrence and survival

Background

Steadily high melanoma mortality rates urge for the availability of novel biomarkers with a more personalized ability to predict melanoma clinical outcomes. Germline risk variants are promising candidates for this purpose; however, their prognostic potential in melanoma has never been systematically tested.

Methods

We examined the effect of 108 melanoma susceptibility single nucleotide polymorphisms (SNPs), associated in recent GWAS with melanoma and melanoma-related phenotypes, on recurrence-free survival (RFS) and overall survival (OS), in 891 prospectively accrued melanoma patients. Cox proportional hazards models (Cox PH) were used to test the associations between 108 melanoma risk SNPs and RFS and OS adjusted by age at diagnosis, gender, tumor stage, histological subtype and other primary tumor characteristics.

Results

We identified significant associations for rs7538876 (RCC2) with RFS (HR = 1.48, 95% CI = 1.20-1.83, p = 0.0005) and rs9960018 (DLGAP1) with both RFS and OS (HR = 1.43, 95% CI = 1.07-1.91, p = 0.01, HR = 1.52, 95% CI = 1.09-2.12, p = 0.01, respectively) using multivariable Cox PH models. In addition, we developed a logistic regression model that incorporates rs7538876, rs9960018, primary tumor histological type and stage at diagnosis that has an improved discriminatory ability to classify 3-year recurrence (AUC = 82%) compared to histological type and stage alone (AUC = 78%).

Conclusions

We identified associations between melanoma risk variants and melanoma outcomes. The significant associations observed for rs7538876 and rs9960018 suggest a biological implication of these loci in melanoma progression. The observed predictive patterns of associated variants with clinical end-points suggest for the first time the potential for utilization of genetic risk markers in melanoma prognostication.

Do not underestimate nucleotide excision repair: it predicts not only melanoma risk but also survival outcome

Nucleotide excision repair (NER) removes UV-induced DNA damage and other bulky DNA lesions thereby maintaining genomic integrity. Dr. Qingyi Wei’s group demonstrated over the last decade that NER fidelity and single nucleotide polymorphisms (SNPs) in NER genes constitute melanoma risk biomarkers. In this issue (Li et al.) they provide evidence that SNPs in NER genes may also predict melanoma survival.

Outcome of clinical stage III melanoma patients with FDG-PET and whole-body CT added to the diagnostic workup

BACKGROUND

Combined whole-body FDG-PET and CT provide the most comprehensive staging of melanoma patients with palpable lymph node metastases (LNM). The aim of this study is to analyze survival of FDG-PET and CT negative or positive melanoma patients and to assess which factors have independent prognostic impact on survival of these patients.

METHODS

Patients with palpable and histologically or cytologically proven LNM of melanoma, referred to participating hospitals for examination with FDG-PET and CT, were selected from a previous study. Melanoma-specific survival (MSS) and disease-free period (DFP) were analyzed for FDG-PET and CT positive and negative patients using the Kaplan-Meier method. Cox-regression analysis was performed to analyze which patient or melanoma characteristics had significant impact on MSS or DFP.

RESULTS

For all 252 patients 5-year MSS was 38.2%. For FDG-PET and CT negative and positive patients 5-year MSS was 47.6 and 16.9%, respectively. Disease-free period for FDG-PET and CT negative patients was 46.0% after 5 years. Gender, a positive FDG-PET and CT, LNM in axilla compared to head or neck, and presence of extranodal growth were independent factors for worse MSS in all patients. Positive FDG-PET and CT was the most important prognostic factor for MSS with a hazard ratio of 2.54 (95% CI, 1.55-4.17, P<0.001).

CONCLUSIONS

Staging melanoma patients with palpable LNM is more accurate when whole-body FDG-PET and CT is added to the diagnostic workup. Hence, FDG-PET and CT, preferably combined, are indicated in the staging of clinical stage III melanoma patients.

Sex Is an Independent Prognostic Indicator for Survival and Relapse/Progression-Free Survival in Metastasized Stage III to IV Melanoma: A Pooled Analysis of Five European Organisation for Research and Treatment of Cancer Randomized Controlled Trials

Purpose

To study sex differences in survival and progression in patients with stage III or IV metastatic melanoma and to compare our results with published literature.

Patients and Methods

Data were retrieved from three large, randomized, controlled trials of the European Organisation for Research and Treatment of Cancer in patients with stage III and two trials in patients with stage IV melanoma. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs for females compared with males, adjusted for different sets of confounders for stage III and stage IV, respectively.

Results

In 2,734 stage III patients, females had a superior 5-year disease-specific survival (DSS) rate compared with males (51.5% v 43.3%), an adjusted HR for DSS of 0.85 (95% CI, 0.76 to 0.95), and an adjusted HR for relapse-free survival of 0.86 (95% CI, 0.77 to 0.95). In 1,306 stage IV patients, females also exhibited an advantage in DSS (2-year survival rate, 14.1% v 19.0%; adjusted HR, 0.81; 95% CI, 0.72 to 0.92) as well as for progression-free survival (adjusted HR, 0.79; 95% CI, 0.70 to 0.88). This female advantage was consistent across pre- and postmenopausal age categories and across different prognostic subgroups. However, the female advantage seems to become smaller in patients with higher metastatic tumor load.

Conclusion

The persistent independent female advantage, even after metastasis to lymph nodes and distant sites, contradicts theories about sex behavioral differences as an explanation for this phenomenon. A biologic sex trait seems to profoundly influence melanoma progression and survival, even in advanced disease.

Polymorphisms of nucleotide excision repair genes predict melanoma survival

Melanoma is the most highly malignant skin cancer, and nucleotide excision repair (NER) is involved in melanoma susceptibility. In this analysis of 1,042 melanoma patients, we evaluated whether genetic variants of NER genes may predict survival outcome of melanoma patients. We used genotyping data of 74 tagging single-nucleotide polymorphisms (tagSNPs) in eight core NER genes from our genome-wide association study (including two in XPA, 14 in XPC, three in XPE, four in ERCC1, 10 in ERCC2, eight in ERCC3, 14 in ERCC4, and 19 in ERCC5) and evaluated their associations with prognosis of melanoma patients. Using the Cox proportional hazards model and Kaplan-Meier analysis, we found a predictive role of XPE rs28720291, ERCC5 rs4150314, XPC rs2470458, and ERCC2 rs50871 SNPs in the prognosis of melanoma patients (rs28720291: AG vs. GG, adjusted hazard ratio (adjHR)=11.2, 95% confidence interval (CI) 3.04-40.9, P=0.0003; rs4150314: AG vs. GG, adjHR=4.76, 95% CI 1.09-20.8, P=0.038; rs2470458: AA vs. AG/GG, adjHR=2.11, 95% CI 1.03-4.33, P=0.040; and rs50871: AA vs. AC/CC adjHR=2.27, 95% CI 1.18-4.35, P=0.015). Patients with an increasing number of unfavorable genotypes had markedly increased death risk. Genetic variants of NER genes, particularly XPE rs28720291, ERCC5 rs4150314, XPC rs2470458, and ERCC2 rs50871, may independently or jointly modulate survival outcome of melanoma patients. Because our results were based on a median follow-up of 3 years without multiple test corrections, additional large prospective studies are needed to confirm our findings.

The immune system--a hidden treasure for biomarker discovery in cutaneous melanoma

This chapter describes how skin immune system (SIS) is specifically involved in the development of cutaneous melanoma. Local immune surveillance is presented as a complex process that comprises markers to be monitored in disease's evolution and in therapy. The ranking of tissue or soluble immune markers in a future panel of diagnostic/prognostic panel are evaluated. Taking into account the difficulties of cutaneous melanoma patients' management, this chapter shows the immune surveillance at the skin level, the conditions that favor the tumor escape from the immunological arm, the immune pattern of skin melanoma with diagnostic/prognostic relevance, the circulatory immune markers, and, last but not least, how immune markers are used in immune-therapy monitoring. The chapter cannot be exhaustive but will give the reader a glimpse of the complex immune network that lies within tumor escape and where to search for immune-therapeutical targets in skin melanoma.

Superior Outcome of Women With Stage I/II Cutaneous Melanoma: Pooled Analysis of Four European Organisation for Research and Treatment of Cancer Phase III Trials

Purpose

Several studies observed a female advantage in the prognosis of cutaneous melanoma, for which behavioral factors or an underlying biologic mechanism might be responsible. Using complete and reliable follow-up data from four phase III trials of the European Organisation for Research and Treatment of Cancer (EORTC) Melanoma Group, we explored the female advantage across multiple end points and in relation to other important prognostic indicators.

Patients and Methods

Patients diagnosed with localized melanoma were included in EORTC adjuvant treatment trials 18832, 18871, 18952, and 18961 and randomly assigned during the period of 1984 to 2005. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs for women compared with men, adjusted for age, Breslow thickness, body site, ulceration, performed lymph node dissection, and treatment.

Results

A total of 2,672 patients with stage I/II melanoma were included. Women had a highly consistent and independent advantage in overall survival (adjusted HR, 0.70; 95% CI, 0.59 to 0.83), disease-specific survival (adjusted HR, 0.74; 95% CI, 0.62 to 0.88), time to lymph node metastasis (adjusted HR, 0.70; 95% CI, 0.51 to 0.96), and time to distant metastasis (adjusted HR, 0.69; 95% CI, 0.59 to 0.81). Subgroup analysis showed that the female advantage was consistent across all prognostic subgroups (with the possible exception of head and neck melanomas) and in pre- and postmenopausal age groups.

Conclusion

Women have a consistent and independent relative advantage in all aspects of the progression of localized melanoma of approximately 30%, most likely caused by an underlying biologic sex difference.

Sox4-mediated Dicer expression is critical for suppression of melanoma cell invasion

We previously reported reduced expression of Sox4 in metastatic melanoma and its role in suppression of cell migration and invasion through inhibition of NF-κB p50. Sox4 can also bind to the promoter sequence of Dicer, a miRNA biogenesis factor. Interestingly, altered expression of Dicer was also observed in cancers. However, the potential mechanisms which regulate Dicer expression and its potential significance in melanoma progression are unknown. Here we studied the regulation of Dicer expression by Sox4 and its role in suppression of melanoma invasion. Our data showed that Sox4 positively regulates Dicer expression by binding to its promoter sequences and enhancing its activity. We found that knockdown of Dicer enhances the matrigel invasion of melanoma cells by at least 2-fold. In addition, we revealed that overexpression of exogenous Dicer reverts the enhanced melanoma cell invasion upon Sox4 knockdown. Furthermore, we examined the expression of Dicer protein in a large set of melanocytic lesions (n=504) at different stages by tissue microarray and found that Dicer expression is inversely correlated with melanoma progression (P < 0.0001). Consistently, reduced Dicer expression was correlated with a poorer overall and disease-specific 5-year survival of patients (P = 0.015 and 0.0029, respectively). In addition, we found a significant correlation between expression of Sox4 and Dicer proteins in melanoma biopsies (P = 0.009), further indicating the regulation of Dicer expression by Sox4. Finally, we revealed that knockdown of Sox4 induces a major change in the expression pattern of miRNAs in melanoma cells, mainly due to reduced expression of Dicer. Our results pinpoint the regulation of Dicer expression by Sox4 in melanoma and the critical role of Dicer in suppression of melanoma invasion. Our findings on Sox4 regulated miRNA biogenesis pathway may aid toward the development of novel targeted therapeutic approaches for melanoma.

MicroRNAs in the pathogenesis of malignant melanoma

Cutaneous malignant melanoma is the most aggressive and lethal form of skin cancer. Over the past decades, its incidence has been increasing by 3-8% per year in western countries while mortality has stabilized. Melanoma is a heterogenous disease and can be subclassified based on distinct clinical characteristics, histopathological features and mutation patterns within NRAS and BRAF genes. Recent data indicate that microRNAs (miRNAs) are involved in the pathogenesis of malignant melanoma. MiRNAs are small, non-coding, regulatory RNA molecules expressed in a tissue and cell specific manner and are known to play a crucial role in cell homeostasis and carcinogenesis. MiRNAs might prove to be powerful cancer biomarkers and future therapeutic targets. In this review, we focused on the miRNA involvement in four molecular pathways known to be deregulated in malignant melanoma, including the RAS-RAF-MEK-ERK pathway, the p16(INK4A) -CDK4-RB pathway, the PIK3-AKT pathway and the MITF pathway.

Towards a quantitative understanding of the MITF-PIAS3-STAT3 connection

Background

Expression of the two transcription factors microphthalmia-associated transcription factor (MITF) and signal transducer and activator of transcription 3 (STAT3) are tightly connected to cell proliferation and survival, and are important for melanocyte development. The co-regulation of MITF and STAT3 via their binding to a common inhibitor Protein Inhibitor of Activated STAT3 (PIAS3) is intriguing. A better quantitative understanding of this regulation is likely to be important for elucidation of the melanocyte biology.

Results

We present a mathematical model describing the MITF-PIAS3-STAT3 signalling network. A default parameter set was developed, partly informed by the literature and partly by constraining the model to mimic reported behavioural features of the system. In addition, a set of experiment-specific parameters was derived for each of 28 experiments reported in the literature. The model seems capable of accounting for most of these experiments in terms of observed temporal development of protein amounts and phosphorylation states. Further, the results also suggest that this system possesses some regulatory features yet to be elucidated.

Conclusions

We find that the experimentally observed crosstalk between MITF and STAT3 via PIAS3 in melanocytes is faithfully reproduced in our model, offering mechanistic explanations for this behaviour, as well as providing a scaffold for further studies of MITF signalling in melanoma.

Chronic inflammation promotes myeloid-derived suppressor cell activation blocking antitumor immunity in transgenic mouse melanoma model

Tumor microenvironment is characterized by chronic inflammation represented by infiltrating leukocytes and soluble mediators, which lead to a local and systemic immunosuppression associated with cancer progression. Here, we used the ret transgenic spontaneous murine melanoma model that mimics human melanoma. Skin tumors and metastatic lymph nodes showed increased levels of inflammatory factors such as IL-1β, GM-CSF, and IFN-γ, which correlated with tumor progression. Moreover, Gr1(+)CD11b(+) myeloid-derived suppressor cells (MDSCs), known to inhibit tumor reactive T cells, were enriched in melanoma lesions and lymphatic organs during tumor progression. MDSC infiltration was associated with a strong TCR ζ-chain down-regulation in all T cells. Coculturing normal splenocytes with tumor-derived MDSC induced a decreased T-cell proliferation and ζ-chain expression, verifying the MDSC immunosuppressive function and suggesting that the tumor inflammatory microenvironment supports MDSC recruitment and immunosuppressive activity. Indeed, upon manipulation of the melanoma microenvironment with the phosphodiesterase-5 inhibitor sildenafil, we observed reduced levels of numerous inflammatory mediators (e.g., IL-1β, IL-6, VEGF, S100A9) in association with decreased MDSC amounts and immunosuppressive function, indicating an antiinflammatory effect of sildenafil. This led to a partial restoration of ζ-chain expression in T cells and to a significantly increased survival of tumor-bearing mice. CD8 T-cell depletion resulted in an abrogation of sildenafil beneficial outcome, suggesting the involvement of MDSC and CD8 T cells in the observed therapeutic effects. Our data imply that inhibition of chronic inflammation in the tumor microenvironment should be applied in conjunction with melanoma immunotherapies to increase their efficacy.

Intratumoral neutrophils and plasmacytoid dendritic cells indicate poor prognosis and are associated with pSTAT3 expression in AJCC stage I/II melanoma

BACKGROUND

Tumor cell and host immune cell interaction plays a key role in carcinogenesis. Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in cancer and believed to be an important mediator of tumor-induced immunosuppression. This paper aims to describe the prognostic impact of neutrophil and dendritic cell infiltration in primary melanoma and the association of this infiltration with activated STAT3 (pSTAT3) in primary melanoma cells.

METHODS

Formalin-fixed, paraffin-embedded primary melanomas from 186 stage-I/II melanoma patients surgically resected from 1997 to 2000. Infiltrating neutrophils (CD66b), dendritic cells (CD123+ and DC-LAMP+), T-lymphocytes (CD8) and pSTAT3 melanoma cell expression were studied by immunohistochemistry and evaluated as present or absent. DC-LAMP+ cell infiltration was evaluated as absent/few versus dense. Study endpoints: relapse-free survival, melanoma-specific, and overall survival.

RESULTS

The median observation time was 12.2 years (range, 10.4-14.2 years). Fifty-one deaths were observed of which 38 (20%) were melanoma-specific. In a multivariate Cox proportional hazards model including ulceration and melanoma thickness, neutrophil and CD123+ dendritic cell infiltration were independently associated with poor prognosis (CD66b: hazard ratio [HR] = 3.13; 95% confidence interval [CI], 1.43-6.83; P = .004; CD123: HR = 2.45; 95% CI, 1.22-4.92; P = .012). The association between melanoma cell pSTAT3 expression and immune infiltration (neutrophils and CD123+ cells) was strong. pSTAT3 expression, CD8 and DC-LAMP infiltration were not independently associated with poor prognosis.

CONCLUSIONS

Neutrophil infiltration and CD123+ dendritic cell infiltration in primary melanoma are independently associated with poor prognosis. Melanoma cell expression of pSTAT3 is strongly associated with the surrounding immune infiltrate.

Neuropeptide Y expression in cutaneous melanoma

BACKGROUND

Neuropeptide Y (NPY) is widely found in the nervous system and has a role in numerous physiologic processes. In addition, NPY receptors are expressed in neuroendocrine tumors, breast cancer, prostate cancer, kidney cancer, and some types of sarcomas. Different neuropeptides, particularly α-melanocyte-stimulating hormone (MSH), seem to play a role in the pathogenesis of melanoma.

OBJECTIVE

We sought to analyze the expression of NPY in cutaneous melanoma, its association with clinical and histologic features, and its correlation with α-MSH.

METHODS

This was an observational study of the immunohistochemical expression of NPY and α-MSH in tissue samples of cutaneous melanomas, different types of melanocytic nevi, and melanoma metastases diagnosed from 2004 to 2008 in San Jorge Hospital, Huesca, Spain.

RESULTS

A total of 184 lesions were studied: 49 primary cutaneous melanomas, 12 melanoma metastases (9 cutaneous and 3 lymphatic), and 123 melanocytic nevi. Immunostaining revealed that levels of NPY and α-MSH were significantly higher in melanomas than in melanocytic nevi (P < .001). Melanoma metastases were negative for both neuropeptides. Nodular melanomas showed the highest median percentage of NPY positive cells (75% [20-95]) followed by superficial spreading melanoma (25% [2-92]), whereas lentigo maligna were negative (0% [0-0]). Significant, direct associations between NPY expression and vertical growth (P = .0141) and presence of metastasis (P = .0196) were observed. NPY and α-MSH were positively correlated in cutaneous melanoma (0.49, P < .001).

LIMITATIONS

The sample size of melanomas was not very large.

CONCLUSION

Our study demonstrates that NPY is significantly expressed in melanomas, especially the nodular type, being associated with invasiveness independently of proliferative markers such as thickness, ulceration, and mitotic index.

Is primary melanoma ulceration a factor of good response to adoptive immunotherapy?

BACKGROUND

Primary melanoma ulceration is a factor of poor prognosis at the local and regional stage. The physiopathological mechanisms which explain its prognostic impact are still little known. However, two recent studies suggest that it could be a predictive factor of good response to a non-specific immunotherapy (interferon-alpha) and to an active immunotherapy (vaccine).

OBJECTIVE

The aim of this study was to determine whether ulceration could be a factor of good prognosis in the context of an adoptive immunotherapy with tumour infiltrating lymphocytes (TIL) in stage III regional lymph node metastatic melanoma (sixth American Joint Committee on Cancer staging system) and whether it was associated with an improvement in the effectiveness of this treatment compared with the control group.

METHODS

We have included all the patients treated in open prospective randomized TIL vs. control protocols in our unit from 1997 to 2009. Clinical data were derived retrospectively from patient files. Statistical analysis was performed using log-rank tests, Cox models and tests for interaction.

RESULTS

A total of 144 patients were included. In the group of 80 patients treated with TIL, primary melanoma ulceration remained a pejorative factor for relapse-free and overall survival in univariate and multivariate analysis. The presence of ulceration did not change the effectiveness of TIL treatment in comparison with the control group with regards to relapse-free and overall survival.

CONCLUSION

Our study demonstrates that primary melanoma ulceration does not have any impact on the response to TIL adoptive immunotherapy and thus does not confirm its positive prognostic value suggested by two other immunotherapy approaches.

What does ulceration of a melanoma mean for prognosis?

Ulceration of a primary cutaneous melanoma is clearly associated with worse prognosis, although the underlying mechanisms are not well understood. Recent studies have shown that the presence of ulceration may predict response to adjuvant IFN in high-risk patients. As molecular pathways continue to be elucidated, it is possible that continued study of ulceration will provide insight into potential therapeutic strategies, or will predict response to novel targeted therapies. Future investigation into melanoma ulceration is warranted.