Immune response in melanoma: an in-depth analysis of the primary tumor and corresponding sentinel lymph node

Tumor infiltrating lymphocytes in primary melanoma are associated with a better prognosis

BACKGROUND

The relationship between tumor infiltrating lymphocytes (TIL) and survival in melanoma is poorly understood. We present a large multicenter study assessing the association between TIL and survival.

METHODS

The Sentinel Lymph Node Working Group database was queried from 1993 to 2024 for cases with known TIL and survival data. TIL was analyzed dichotomously and stratified as non-brisk, brisk, and absent. Clinicopathologic factors were correlated with melanoma-specific survival (MSS), overall survival (OS), and recurrence-free survival (RFS).

RESULTS

Among 4957 patients, TIL was present in 3980 (80.2 ​%) of patients. TIL was prognostic of MSS (p ​= ​0.0033), OS (p ​= ​0.0053), and RFS (p ​= ​0.0011). In the stratified analysis, brisk TIL was more strongly associated with MSS, OS, and RFS than non-brisk TIL (all p ​< ​0.04). Among patients with a positive sentinel lymph node, TIL was prognostic of MSS, OS, and RFS (all p ​< ​0.03).

CONCLUSIONS

TIL is strongly predictive of survival in melanoma and may be useful in risk stratification when deciding whether risks of adjuvant therapy outweigh benefits for certain patients.

The tumor immune microenvironment in primary cutaneous melanoma

Melanoma is an immunogenic tumor. The melanoma tumor immune microenvironment (TIME) is made up of a heterogenous mix of both immune and non-immune cells as well as a multitude of signaling molecules. The interactions between tumor cells, immune cells and signaling molecules affect tumor progression and therapeutic responses. Understanding the composition and function of the TIME in primary cutaneous melanoma is useful for prognostication and therapeutic decisions. This review provides an overview of the components of the TIME in primary cutaneous melanoma, and their influence on clinical outcomes.

Lymph node metastasis in cancer: Clearing the clouds to see the dawn

Lymph node metastasis (LNM) is often regarded as an indicator of poor prognosis in various cancers. Despite over three centuries of exploration since its discovery, the molecular mechanisms underlying LNM remain inconclusive. This review summarizes the molecular mechanisms of LNM, using the "PUMP+" principle for clarification. Pathological examination remains the gold standard for LNM diagnosis, yet there is a need to explore early diagnostic strategies that can effectively improve patient outcomes. With the advent of immunotherapy, discussions on the fate of lymph nodes (LN) have emerged, emphasizing the importance of preserving LN integrity prior to immunotherapy. This, in turn, poses higher demands for diagnostic accuracy and precision treatment of LNM. This review comprehensively discusses the molecular mechanisms, diagnostic methods, and treatment strategies for cancer lymph node metastasis, along with current bottlenecks and future directions in this field.

Long-term Outcomes of Regressed or "Burnt Out" Primary Testicular Germ Cell Tumors

OBJECTIVE

To review the presentation and long-term oncologic outcomes of patients with regressed ("burnt out") primary testicular germ cell tumors (GCT). Certain testicular GCT can present with complete regression of the primary tumor. It is not well established if this is associated with more aggressive disease or worse oncologic outcomes.

METHODS

We queried our prospectively maintained testicular cancer clinical database at a tertiary cancer center and identified patients without prior chemotherapy who had regressed primary GCT at radical orchiectomy from 1990 to 2023. All specimens were reviewed by a genitourinary pathologist at diagnosis. Long-term clinical outcomes were reported by Kaplan-Meier method.

RESULTS

Fifty-six patients met inclusion criteria; at diagnosis, 17 had no evidence of extra-testicular disease and 39 had advanced (clinical stage [CS] II+) GCT. All CSx (no viable disease or germ cell neoplasia in situ at orchiectomy, and no evidence of advanced disease) and CS0 patients were managed with surveillance and had 5-year recurrence-free survival (RFS) of 88% (95% CI: 39%, 98%). All patients with CS II+ disease underwent primary treatment with surgery (n = 5) or first-line chemotherapy (n = 34). Two- and 5-year RFS for patients with CSII+ disease was 94% (95% CI: 78%, 98%) and 90% (95% CI: 72%, 97%), respectively.

CONCLUSION

Patients with regressed primary testicular GCT often present with advanced disease, possibly due to lack of early clinical signs from the primary tumor. Our analysis shows excellent long-term oncologic outcomes similar to those reported in the literature for patients with viable primary testicular GCT.

High-risk histopathologic features in local advanced conjunctival melanoma

PURPOSE

To identify high-risk histopathologic and molecular features of local recurrence, nodal metastasis, distant metastasis (DM) and disease-specific death (DSD) in conjunctival melanoma (CoM).

METHODS

Ninety patients with pathologically diagnosed CoM between 2008 and 2023 were enrolled. Immunohistochemistry staining of BRAFV600E, NRASQ61R, CD117, PD-1 and PD-L1 was performed in 65 and 45 patients, respectively. Cox regression and Kaplan-Meier survival analysis were conducted to identify risk factors for local recurrence, nodal metastasis, DM and DSD.

RESULTS

Pathologically, ulceration (hazard ratio [HR]: 3.170; 95% CI: 1.312-7.659; p = 0.01) and regression (HR: 3.196; 95% CI: 1.094-9.335; p = 0.034) were risk factors for DM. Tumour thickness ≥ 4 mm (HR: 4.889; 95% CI: 1.846-12.946; p = 0.001) and regression (HR: 4.011; 95% CI: 1.464-10.991; p = 0.007) were risk factors for DSD. For patients with tumour thickness < 4 mm, the presence of ulceration indicated a higher risk of nodal metastasis (log-rank p = 0.0011), DM (log-rank p = 0.00051) and DSD (log-rank p = 0.02). Patients with regression (+)/tumour-infiltrating lymphocytes (TILs) (+) had a higher risk for DM (log-rank p = 0.011) and DSD (log-rank p = 0.0032). Molecularly, the positive rate of BRAFV600E, NRASQ61R, CD117, PD-1 and PD-L1 was 40.00% (26/65), 43.08% (28/65), 70.77% (46/65), 46.67% (21/45) and 28.89% (13/45), respectively. Positive BRAFV600E was identified as an independent risk factor for DM (HR: 2.533; 95% CI: 1.046-6.136, p = 0.039). The expression level of BRAFV600E was positively correlated with vascular invasion (p = 0.01), as well as the expression levels of PD-1 (p = 0.038) and PD-L1 (p = 0.049).

CONCLUSIONS

Tumour thickness ≥ 4 mm, ulceration, the coexistence of regression and TILs, and positive BRAFV600E were risk factors for poor prognosis of CoM patients. Besides, expression level of BRAFV600E was positively correlated with the expression levels of PD-1 and PD-L1.

Influence of regression, its extent and tumor-infiltrating lymphocytes on sentinel node status, relapse, and survival in a 10-year retrospective study of melanoma patients

This case-control study seeks to investigate the influence of histological findings, specifically regression, its extent and tumor-infiltrating lymphocyte (TILs), on result of sentinel lymph node (SLN) biopsy, 5-year melanoma-specific survival (MSS), and relapse-free survival (RFS). We included all patients with cutaneous melanoma who underwent SLN biopsy at the Melanoma Center of the University of Brescia, following the Italian Association of Medical Oncology National guidelines from January 2008 to August 2018. Regression and its extent (<75 or ≥75%) and the presence of TILs were reevaluated by a trained dermatopathologist, adhering to the 2017 College of American Pathologists Cancer Protocol for Skin Melanoma. These patients were followed up for 5 years. Our study uncovered significant associations between regression and male sex ( P  < 0.05), melanoma location on the trunk, upper limbs, and back ( P  = 0.001), ulceration ( P  < 0.05), lower Breslow thickness ( P  = 0.001), and the presence of lymphocytic infiltration (both brisk and nonbrisk) ( P  < 0.001). Regression and its extent, however, did not appear to affect SLN positivity ( P  = 0.315). Similarly, our data did not reveal a correlation between TILs and result of SLN biopsy ( P  = 0.256). When analyzing MSS and RFS in relation to the presence or absence of regression and TILs, no statistically significant differences were observed, thus precluding the need for logistic regression and Kaplan-Meier curve analysis. This study's findings underscore that regression and TILs do not appear to exert an influence on sentinel lymph node status, MSS, or RFS in our cohort of patients.

The Use of Immune Regulation in Treating Head and Neck Squamous Cell Carcinoma (HNSCC)

Immunotherapy has emerged as a promising new treatment modality for head and neck cancer, offering the potential for targeted and effective cancer management. Squamous cell carcinomas pose significant challenges due to their aggressive nature and limited treatment options. Conventional therapies such as surgery, radiation, and chemotherapy often have limited success rates and can have significant side effects. Immunotherapy harnesses the power of the immune system to recognize and eliminate cancer cells, and thus represents a novel approach with the potential to improve patient outcomes. In the management of head and neck squamous cell carcinoma (HNSCC), important contributions are made by immunotherapies, including adaptive cell therapy (ACT) and immune checkpoint inhibitor therapy. In this review, we are focusing on the latter. Immune checkpoint inhibitors target proteins such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) to enhance the immune response against cancer cells. The CTLA-4 inhibitors, such as ipilimumab and tremelimumab, have been approved for early-stage clinical trials and have shown promising outcomes in terms of tumor regression and durable responses in patients with advanced HNSCC. Thus, immune checkpoint inhibitor therapy holds promise in overcoming the limitations of conventional therapies. However, further research is needed to optimize treatment regimens, identify predictive biomarkers, and overcome potential resistance mechanisms. With ongoing advancements in immunotherapy, the future holds great potential for transforming the landscape of oral tumor treatment and providing new hope for patients.

Tumour regression predicts better response to interferon therapy in melanoma patients: a retrospective single centre study

We hypothesise that regression may have an impact on the effectiveness of adjuvant IFN therapy, based on its role in the host immune response. Our purpose is to investigate regression and ulceration as prognostic factors in case of interferon-alpha (IFN)-treated melanoma patients. We followed 357 IFN-treated melanoma patients retrospectively, investigating progression-free survival (PFS) and overall survival (OS) depending on the presence of ulceration and regression. A Kaplan-Meier analysis was performed, and we used a Cox regression analysis to relate risk factors. The survival function of the Cox regression was used to measure the effect of regression and ulceration on PFS and OS depending on the Breslow thickness (T1-T4) of the primary tumour. Regression was significantly positively related to PFS ( P  = 0.0018, HR = 0.352) and OS ( P  = 0.0112, HR = 0.380), while ulceration showed a negative effect (PFS: P  = 0.0001, HR = 2.629; OS: P  = 0.0003, HR = 2.388). They influence survival independently. The most favourable outcome was measured in the regressed/non-ulcerated group, whereas the worse was in the non-regressed/ulcerated one. Of risk factors, Breslow thickness is the most significant predictor. The efficacy of regression is regardless of Breslow thickness, though the more favourable the impact of regression was in the thicker primary lesions. Our results indicate that regression is associated with a more favourable outcome for IFN-treated melanoma patients, whereas ulceration shows an inverse relation. Further studies are needed to analyse the survival benefit of regression in relation to innovative immune checkpoint inhibitors.

Sentinel lymph node assessment in melanoma: current state and future directions

Assessment of sentinel lymph node status is an important step in the evaluation of patients with melanoma for both prognosis and therapeutic management. Pathologists have an important role in this evaluation. The methodologies have varied over time, from the evaluation of dimensions of metastatic burden to determination of the location of the tumour deposits within the lymph node to precise cell counting. However, no single method of sentinel lymph node tumour burden measurement can currently be used as a sole independent predictor of prognosis. The management approach to sentinel lymph node-positive patients has also evolved over time, with a more conservative approach recently recognised for selected cases. This review gives an overview of past and current status in the field with a glimpse into future directions based on prior experiences and clinical trials.

Regression in cutaneous melanoma: histological assessment, immune mechanisms and clinical implications

Tumour regression is an immunologically driven process that results in complete or partial disappearance of tumour cells. This can be observed in histological sections as replacement of tumour cells with fibrosis, angiogenesis, and a variable inflammatory infiltrate. In primary cutaneous melanoma, the prognostic significance of regression has been debated for decades, in part because inconsistent histological criteria are used in prognostication studies. It is broadly accepted that CD8+ T lymphocytes are the primary effectors of the anti-tumour response, but the interplay between melanoma and the immune system is complex, dynamic, and incompletely understood. Sustained progress in unravelling the pathogenesis of melanoma regression has led to the identification of therapeutic targets, culminating in the development of immune checkpoint inhibitors for the management of advanced disease. Modern techniques allow for high-resolution spatial analyses of the tumour microenvironment. Such studies may lead to better understanding of the immune drivers of melanoma regression, thereby facilitating the search for new prognostic and predictive biomarkers to assist clinical decision-making.

Subcapsular Sinus Macrophages Promote Melanoma Metastasis to the Sentinel Lymph Nodes via an IL1α-STAT3 Axis

During melanoma metastasis, tumor cells originating in the skin migrate via lymphatic vessels to the sentinel lymph node (sLN). This process facilitates tumor cell spread across the body. Here, we characterized the innate inflammatory response to melanoma in the metastatic microenvironment of the sLN. We found that macrophages located in the subcapsular sinus (SS) produced protumoral IL1α after recognition of tumoral antigens. Moreover, we confirmed that the elimination of LN macrophages or the administration of an IL1α-specific blocking antibody reduced metastatic spread. To understand the mechanism of action of IL1α in the context of the sLN microenvironment, we applied single-cell RNA sequencing to microdissected metastases obtained from animals treated with the IL1α-specific blocking antibody. Among the different pathways affected, we identified STAT3 as one of the main targets of IL1α signaling in metastatic tumor cells. Moreover, we found that the antitumoral effect of the anti-IL1α was not mediated by lymphocytes because Il1r1 knockout mice did not show significant differences in metastasis growth. Finally, we found a synergistic antimetastatic effect of the combination of IL1α blockade and STAT3 inhibition with stattic, highlighting a new immunotherapy approach to preventing melanoma metastasis.

Histological regression in melanoma: impact on sentinel lymph node status and survival

Regression in melanoma is an immunological phenomenon that results in partial or complete replacement of the tumor with variably vascular fibrous tissue, often accompanied by pigment-laden macrophages and chronic inflammation. In some cases, tumor-infiltrating lymphocytes (TILs) may represent the earliest phase of this process. The prognostic significance of regression has long been a matter of debate, with inconsistent findings reported in the literature to date. This study sought to determine whether regression in primary cutaneous melanomas predicted sentinel lymph node (SLN) status and survival outcomes in a large cohort of patients managed at a single centre. Clinical and pathological parameters for 8,693 consecutive cases were retrieved. Associations between regression and SLN status, overall survival (OS), melanoma-specific survival (MSS) and recurrence-free survival (RFS) were investigated using logistic and Cox regression. Histological evidence of regression was present in 1958 cases (22.5%). Regression was significantly associated with lower Breslow thickness, lower mitotic rate, and absence of ulceration (p < 0.0001). Multivariable analysis showed that regression in combination with TILs independently predicted a negative SLN biopsy (OR 0.33; 95% C.I. 0.20-0.52; p < 0.0001). Patients whose tumors showed both regression and TILs had the highest 10-year OS (65%, 95% C.I. 59-71%), MSS (85%, 95% C.I. 81-89%), and RFS (60%, 95% C.I. 54-66%). On multivariable analyses, the concurrent presence of regression and TILs independently predicted the lowest risk of death from melanoma (HR 0.69; 95% C.I. 0.51-0.94; p = 0.0003) as well as the lowest rate of disease recurrence (HR 0.71; 95% C.I. 0.58-0.85; p < 0.0001). However, in contrast, in the subgroup analysis of Stage III patients, the presence of regression predicted the lowest OS and RFS, with MSS showing a similar trend. Overall, these findings indicate a prognostically favorable role of regression in primary cutaneous melanoma. However, in Stage III melanoma patients, regression may be a marker of more aggressive disease.

Regression in melanoma is significantly associated with a lower regional recurrence rate and better recurrence-free survival

BACKGROUND AND OBJECTIVES

The prognostic significance of regression in predicting melanoma recurrences is unknown. We present a large multicenter study correlating regression with recurrence.

METHODS

The Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with regression data. Clinicopathologic factors were correlated with overall and first-site of recurrence and with recurrence-free survival (RFS).

RESULTS

There were 4790 patients and the median follow-up was 39.6 months. Regression and recurrences were seen in 1081 (22.6%) and 773 (16.1%) cases, respectively. First-site locoregional and distant recurrences were seen in 412 (8.6%) and 352 (7.3%) patients, respectively. Regression was seen in 15.8% and 24.7% of all cases with and without recurrences (p < 0.0001), respectively, while regression was seen in 14.3% and 17.9% of first-site locoregional and distant recurrent cases, respectively, compared with 23.3% and 22.9% of patients with regression and without first-site locoregional and distant recurrences, respectively (p = 0.29). On multivariable analysis, after controlling for age, gender, thickness, ulceration, lymphovascular invasion, and sentinel lymph node status, regression significantly predicted improved RFS (p = 0.004) and fewer first-site regional recurrences (p = 0.017).

CONCLUSION

Our data suggest that regression is a favorable prognostic marker in melanoma and predicts significantly better RFS and decreased first-site regional recurrences.

Immune Characters and Plasticity of the Sentinel Lymph Node in Colorectal Cancer Patients

Purpose

This study is aimed at immunologically characterizing sentinel lymph nodes (SNs) in colorectal cancer (CRC) patients and identifying changes in immunological phenotype and function of SNs isolated from the tumor immunosuppressive microenvironment.

Methods

A total of 53 pairs of matched SNs and non-SNs (NSNs) were collected by using a lymph node tracer dye. Flow cytometry was performed to detect the immunophenotype of T cells as well as the expression of activation and inhibitory markers. Differential expression and distribution of characteristic immune cell markers were analyzed by multiplex immunohistochemistry (mIHC). Transcriptomics analysis was conducted to compare the differences in the expression of immune-related genes among lymph nodes. The ex vivo culture of lymph nodes was carried out to examine changes in immunological phenotypes and functions.

Results

Compared with NSNs, SNs harbored a significantly higher percentage of regulatory T cells (Tregs) but a lower proportion of MoMDSCs. As indicated in the mIHC assays, Tregs, T follicular helper (Tfh) cells, and M2 macrophages were mainly distributed in cortical areas, germinal centers, and subcapsular sinus areas, respectively, while significantly higher numbers of Tregs and Tfh cells were detected in SNs as compared to NSNs. Moreover, GSEA revealed that T cell activation genes and CD8+ T cell exhaustion-related genes are enriched in SNs and NSNs, respectively. The ex vivo culture led to an increase in the proportion of CD4+ cells, while activating T cells in SNs. In addition, SNs displayed a higher increase in the expression of cytokines IFN-γ, TNF-α, and sFas than NSNs.

Conclusion

SNs are shown to be in an immune active state in vivo, while highly expressing inhibitory cytokines and suppressive markers. The ex vivo culture enhanced antitumor immunological function of SN-T cells, providing a starting material for adoptive cell therapy for CRC.

Association of Histologic Regression With a Favorable Outcome in Patients With Stage 1 and Stage 2 Cutaneous Melanoma

Importance

Although regression is commonly observed in cutaneous melanoma, it is uncertain whether it is associated with patient prognosis.

Objective

To determine whether histologically confirmed regression was associated with better or worse survival in patients with primary cutaneous melanoma.

Design, Setting, and Participants

This cohort study analyzed data from 2 large cohorts of adults (one in the Netherlands and the other in Australia) with histologically proven, stage 1 and 2 primary, invasive cutaneous melanoma with known regression status treated between 2000 and 2014, with median follow-up times of 4.5 and 11.1 years for the Dutch and Australian cohorts, respectively. For the Dutch patients, population-based data from PALGA, the Dutch Pathology Registry, were used, and follow-up data were retrieved from the Netherlands Cancer Registry. For the Australian patients, data from the database of a large, specialized melanoma treatment center were used.

Main Outcomes and Measures

Multivariable Cox proportional hazards analyses were performed per cohort to assess recurrence-free survival (RFS) and overall survival (OS), and subgroup analyses according to Breslow thickness category and melanoma subtype were performed.

Results

A total of 17 271 Dutch patients and 4980 Australian patients were included. In both cohorts, survival outcomes were better for patients with disease regression. For Dutch patients, the hazard ratio (HR) for those with disease regression was 0.55 (95% CI, 0.48-0.63; P < .001) for RFS and 0.87 (95% CI, 0.79-0.96; P = .004) for OS; for the Australian patients, the HR was 0.61 (95% CI, 0.52-0.72; P < .001) for RFS and 0.73 (95% CI, 0.64-0.84; P < .001) for OS. Subgroup analyses showed that the presence of regression improved RFS within thin and intermediate Breslow thickness melanomas in both cohorts. For patients with superficial spreading melanoma (SSM) subtype, regression improved RFS and OS in both cohorts. For Dutch patients with SSM, the HR for those with disease regression was 0.54 (95% CI, 0.46-0.63; P < .001) for RFS and 0.86 (95% CI, 0.76-0.96; P = .009) for OS; for the Australian patients with SSM, the HR was 0.67 (95% CI, 0.52-0.85; P = .001) for RFS and 0.72 (95% CI, 0.59-0.88; P = .001) for OS.

Conclusions and Relevance

In 2 large patient cohorts from 2 different continents, regression was a favorable prognostic factor for patients with stage 1 and 2 melanomas, especially in those with thin and intermediate thickness tumors and those with SSM subtype.

Immune Checkpoint Therapy: Tumor Draining Lymph Nodes in the Spotlights

Tumor-draining lymph nodes play a paradoxical role in cancer. Surgeons often resect these sentinel lymph nodes to determine metastatic spread, thereby enabling prognosis and treatment. However, lymph nodes are vital organs for the orchestration of immune responses, due to the close encounters of dedicated immune cells. In view of the success of immunotherapy, the removal of tumor-draining lymph nodes needs to be re-evaluated and viewed in a different light. Recently, an important role for tumor-draining lymph nodes has been proposed in the immunotherapy of cancer. This new insight can change the use of immune checkpoint therapy, particularly with respect to the use in neoadjuvant settings in which lymph nodes are still operational.

Dissecting the immune landscape of tumor draining lymph nodes in melanoma with high-plex spatially resolved protein detection

BACKGROUND

In melanoma patients, microscopic tumor in the sentinel lymph-node biopsy (SLN) increases the risk of distant metastases, but the transition from tumor in the SLN to metastatic disease remains poorly understood.

METHODS

Fluorescent staining for CD3, CD20, CD11c, and DNA was performed on SLN tissue and matching primary tumors. Regions of interest (ROI) were then chosen geometrically (e.g., tumor) or by fluorescent cell subset markers (e.g., CD11c). Each ROI was further analyzed using NanoString Digital Spatial Profiling high-resolution multiplex profiling. Digital counts for 59-panel immune-related proteins were collected and normalized to account for system variation and ROI area.

RESULTS

Tumor regions of SLNs had variable infiltration of CD3 cells among patients. The patient with overall survival (OS) > 8 years had the most CD11c- and CD3-expressing cells infiltrating the SLN tumor region. All patients had CD11c (dendritic cell, DC) infiltration into the SLN tumor region. Selecting ROI by specific cell subtype, we compared protein expression of CD11c cells between tumor and non-tumor/normal tissue SLN regions. Known markers of DC activation such as CD86, HLA-DR, and OX40L were lowest on CD11c cells within SLN tumor for the patient with OS < 1 year and highest on the patient with OS > 8 years.

CONCLUSION

We demonstrate the feasibility of profiling the protein expression of CD11c cells within the SLN tumor. Identifying early regulators of melanoma control when the disease is microscopically detected in the SLN is beneficial and requires follow-up studies in a larger cohort of patients.

Prognostic significance of regression and mitotic rate in head and neck cutaneous melanoma

Importance

While regression is a commonly reported microscopic feature of melanoma, its prognostic significance is unclear.

Objective

To examine the impact of regression on sentinel node status and the likelihood of recurrence in primary cutaneous melanoma of the head and neck.

Design

Retrospective analysis of 191 adults who underwent surgical management for primary cutaneous melanoma of the head and neck between May 2002 and March 2019.

Setting

Tertiary academic center.

Participants

Patients appropriate for the study were identified by the Academic Health Center Information Exchange using a list of current procedural terminology codes. One hundred and ninety‐one cases of invasive melanoma of the head and neck were included from 830 patients identified. Clinical features assessed for each patient included age, sex, location of primary lesion, date of diagnosis, and current disease status (alive with or without disease). Histologic features assessed were histological melanoma subtype (nodular vs non‐nodular), Breslow thickness, Clark level, presence/absence of ulceration, mitotic rate per square millimeter, and regression. If applicable, sentinel lymph node biopsy (SLNB) status, date of recurrence, interval treatments, and date of death related to melanoma were recorded. Exclusion criteria included melanoma outside the anatomic parameters of head and neck, ocular or choroidal melanoma, mucosal melanoma, metastatic melanoma to the head or neck with no known primary tumor, melanoma of the head or neck with no surgical intervention, and non‐melanoma skin cancers of the head and neck.

Intervention/Exposure

Surgery for cutaneous melanoma of the head and neck.

Main Outcome(s) and Measure(s)

The association between presence of regression and Breslow thickness, sentinel node status, and recurrence.

Results

Of the 191 patients identified, 30.9% were female and 69.1% were male with a mean age at diagnosis of 62.6 (range 20‐97) years. Mean Breslow thickness was 1.2 mm in those with regression and 2.0 mm in those without regression. In patients with regression, 17.6% had a positive sentinel node, and 13.0% experienced a recurrence. In patients without regression, 26.5% had a positive sentinel node, and 31.4% experienced a recurrence. When adjusted for other factors above, regression was not associated with positive sentinel node (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.13‐2.00) or recurrence (OR = 0.33, CI = 0.07‐1.01). Mitotic rate >2 was associated with recurrence (OR = 2.71, CI = 1.11‐6.75, P = .03).

Conclusions and Relevance

Patients with presence of regression had thinner melanomas and trended toward decreased rates of sentinel node positivity and recurrence, suggesting regression may not be a negative prognostic indicator in patients with cutaneous melanoma of the head and neck.

Reporting regression in primary cutaneous melanoma. Part 2: prognosis, evaluation and management

The effect of histological regression on patient prognosis for primary cutaneous melanoma is controversial. Some authors hypothesize that regression indicates a robust systemic immune response and may decrease risk of metastasis. Others argue that histological regression calls into question a T0 diagnosis because there may have been an invasive component of the melanoma that is no longer visible but is still active. The literature to date does not suggest that histological regression is associated with increased risk of positive sentinel lymph node status, metastasis or increased risk of mortality. Thus, the presence of histological regression should not change patient staging, evaluation or management. The criteria used for reporting regression have varied dramatically across studies, and standardized reporting is needed to foster evidence-based practices in the future.

The tumour immune landscape and its implications in cutaneous melanoma

The field of tumour immunology has rapidly advanced in the last decade, leading to the advent of effective immunotherapies for patients with advanced cancers. This highlights the critical role of the immune system in determining tumour development and outcome. The tumour immune microenvironment (TIME) is highly heterogeneous, and the interactions between tumours and the immune system are vastly complex. Studying immune cell function in the TIME will provide an improved understanding of the mechanisms underpinning these interactions. This review examines the role of immune cell populations in the TIME based on their phenotype, function and localisation, as well as contextualising their position in the dynamic relationship between tumours and the immune system. We discuss the function of immune cell populations, examine their impact on patient outcome and highlight gaps in current understanding of their roles in the TIME, both in cancers in general and specifically in melanoma. Studying the TIME by evaluating both pro-tumour and anti-tumour effects may elucidate the conditions which lead to tumour growth and metastasis or immune-mediated tumour regression. Moreover, an in-depth understanding of these conditions could contribute to improved prognostication, more effective use of current immunotherapies and guide the development of novel treatment strategies and therapies.

Risk Factors for Lymphatic and Hematogenous Dissemination in Patients With Stages I to II Cutaneous Melanoma

Importance

The lymphatic and the hematogenous pathways have been proposed for disease progression in cutaneous melanoma, but association with recurrence has not been studied separately to date.

Objective

To identify the risk factors associated with lymphatic and hematogenous metastasis.

Design, Setting, and Participants

This retrospective cohort study included 1177 patients with malignant melanoma treated at Instituto Valenciano de Oncología, València, Spain. Data were retrieved from the melanoma database from January 1, 2000, through December 31, 2015, and analyzed from June 1 to 30, 2018.

Exposure

Malignant melanoma at stages I to II.

Main Outcomes and Measures

Analyses of survival free of lymphatic and hematogenous metastasis were performed using Kaplan-Meier curves and Cox proportional hazards regression.

Results

For the 1177 patients included in the study analysis (51.1% women; median age at diagnosis, 55 years [interquartile range, 42-68 years), median follow-up was 75 months (interquartile range, 33-121 months); 108 (9.2%) developed lymphatic metastasis, and 108 (9.2%) developed hematogenous metastasis. In the multivariate analysis, being older than 55 years (hazard ratio [HR], 1.9; 95% CI, 1.2-3.1), tumor in the head/neck (HR, 1.7; 95% CI, 1.0-2.9) and acral locations (HR, 2.4; 95% CI, 1.3-4.5), greater Breslow thickness (HR for >4.00 mm, 5.4; 95% CI, 2.4-12.4), and presence of vascular invasion (HR, 3.2; 95% CI, 0.9-10.6) were associated with lymphatic spreading. Hematogenous metastasis was associated with greater Breslow thickness (HR for >4.00 mm, 10.4; 95% CI, 3.6-29.7), the absence of regression (HR, 0.1; 95% CI, 0.0-1.0), TERT promoter mutations (HR, 2.9; 95% CI, 1.5-5.7), and BRAF mutations (HR, 1.9; 95% CI, 1.1-3.6).

Conclusions and Relevance

Risk factors associated with lymphatic and hematogenous metastasis differ. Follow-up and adjuvant treatment strategies may therefore need to be adapted to individual clinical, histopathologic, and molecular characteristics.

Tumor infiltrating lymphocytes in malignant melanoma - allies or foes?

This is an overview of current problematics regarding the role of tumor infiltrating lymphocytes (TILs) in malignant melanomas. Various and often conflicting data have been published, correlating tumor type, stage, prognosis, as well as sex and age of patients. This is partly due to heterogeneity in scaling systems and unstandardized TILs grading but also due to changes of tumor-host interactions. Melanomas are an immunologically heterogeneous group with variability of TILs, where distinct gene expression patterns were found in tumors with absent, and/or non- brisk TIL grade versus brisk TIL grade. However, the presence of TILs alone appears to be inadequate for implicating them as immunologically functional. Further characterisation of TIL phenotype and function is warranted. This especially concerns, evaluation of TILs of the suppressor phenotype but rather than as a prognostic factor, more for prediction of targeted immunotherapy.

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.

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.

Current controversies in early-stage melanoma: Questions on incidence, screening, and histologic regression

In the first article in this continuing medical education series we review controversies and uncertainties relating to the epidemiology and initial diagnosis of localized cutaneous melanoma (ie, stage 0, I, or II). Many of these issues are unsettled because of conflicting evidence. Melanoma incidence appears to be increasing, yet its basis has not been fully explained. Despite the advantages of early detection, the US Preventive Services Task Force does not recommend skin screening for the general population. Occasionally, biopsy specimens of melanoma will show histologic regression, but the prognostic importance of this phenomenon is uncertain. Some practitioners recommend obtaining a sentinel lymph node biopsy specimen for thin melanomas showing regression, although this histologic finding is not part of the staging system for thin melanomas. Our goal is to provide the clinician who cares for patients with (or at risk for) melanoma with up-to-date contextual knowledge to appreciate the multiple sides of each controversy so that they will be better informed to discuss these issues with their patients and their families.

Automated phosphopeptide enrichment from minute quantities of frozen malignant melanoma tissue

To acquire a deeper understanding of malignant melanoma (MM), it is essential to study the proteome of patient tissues. In particular, phosphoproteomics of MM has become of significant importance because of the central role that phosphorylation plays in the development of MM. Investigating clinical samples, however, is an extremely challenging task as there is usually only very limited quantities of material available to perform targeted enrichment approaches. Here, an automated phosphopeptide enrichment protocol using the AssayMap Bravo platform was applied to MM tissues and assessed for performance. The strategy proved to be highly-sensitive, less prone to variability, less laborious than existing techniques and adequate for starting quantities at the microgram level. An Fe(III)-NTA-IMAC-based enrichment workflow was applied to a dilution series of MM tissue lysates. The workflow was efficient in terms of sensitivity, reproducibility and phosphosite localization; and from only 12.5 μg of sample, more than 1,000 phosphopeptides were identified. In addition, from 60 μg of protein material the number of identified phosphoproteins from individual MM samples was comparable to previous reports that used extensive fractionation methods. Our data set included key pathways that are involved in MM progression; such as MAPK, melanocyte development and integrin signaling. Moreover, tissue-specific immunological proteins were identified, that have not been previously observed in the proteome of MM-derived cell lines. In conclusion, this workflow is suitable to study large cohorts of clinical samples that demand automatic and careful handling.

Immunohistochemical Analysis of Foxp3+, CD4+, CD8+ Cell Infiltrates and PD-L1 in Oral Squamous Cell Carcinoma

The immunoexpression of the PD-L1 and the number of immune infiltrating cells have been shown to be a significant prognostic factors in various human cancers. Immunohistochemical method was used to examine the immunoexpression of PD-L1 and number of Foxp3+, CD4+, CD8+ cells in 78 cases of oral squamous cell carcinomas (OSCCs): with better prognosis - OSCCBP (n = 37), and with poorer prognosis - OSCCPP (n = 41), and 18 cases of normal mucosa as a control. The immunoexpression of PD-L1 and the mean number of Foxp3+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. The mean number of CD4+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. CD8+ cells were significantly more numerous in OSCCBP group in comparison to OSCCPP and control group. In both OSCCPP and OSCCBP groups there were positive significant correlations between number of Foxp3+ and CD4+ cells. We found positive correlations between the immunoexpression of PD-L1 and numbers of Foxp3+ cells, and negative correlation between the immunoexpression of PD-L1 and numbers of CD8+ cells in both OSCCPP and OSCCBP groups. We found also significant positive correlation between immunoexpression of PD-L1 and the number of CD4+ cells in OSCCPP group. In conclusion, our findings support the hypothesis of involvement of Tregs and PD-L1 in OSCC development and progression.

Histological immune response patterns in sentinel lymph nodes involved by metastatic melanoma and prognostic significance

BACKGROUND

To further characterize the micromorphometric immunological pattern to metastatic melanoma in sentinel lymph node (SLN) biopsies and completion lymph node (CLN) dissections and their relation to 5-year overall survival (OS).

METHODS

Retrospective cohort of 49 patients from 1996 to 2005 with a positive SLN who underwent CLN dissection (CLD) was studied. Micromorphometric characteristics included follicular center count (FCC)/profile, sinus histiocytosis, metastatic size, tumor infiltrating lymphocytes (intranodal), paracortical dendritic cells, germinal center reaction and morphology. Comparison of Kaplan-Meier survival curves used the exact log-rank statistic.

RESULTS

In the high-FCC (n = 5-51) vs the low-FCC (n < 5) lymph nodes, a delayed separation occurred at 3 years, with 5-year OS rates being 73% vs 54% in the high- and low-FCC groups, respectively. Improved survival up to 3 years was also noted in CLDs that showed a higher FCC when compared to the prior SLN. Patients with metastatic deposits >2 mm had significantly lower 5-year survival (both <.001).

CONCLUSIONS

Nodal micromorphometric features (ie, FCC) are probably related to host immune response to metastasis. Quantitative evaluation of lymphoid follicular centers could provide valuable prognostic information to help to stratify patients.

Regression and Sentinel Lymph Node Status in Melanoma Progression

BACKGROUND The purpose of this study was to assess the role of regression and other clinical and histological features for the prognosis and the progression of cutaneous melanoma. MATERIAL AND METHODS Between 2005 and 2016, 403 patients with melanoma were treated and followed at our Department of Dermatology. Of the 403 patients, 173 patients had cutaneous melanoma and underwent sentinel lymph node (SLN) biopsy and thus were included in this study. RESULTS Histological regression was found in 37 cases of melanoma (21.3%). It was significantly associated with marked and moderate tumor-infiltrating lymphocyte (TIL) and with negative SLN. Progression of the disease occurred in 42 patients (24.2%). On multivariate analysis, we found that a positive lymph node and a Breslow index higher than 2 mm were independent variables associated with disease free survival (DFS). These variables together with a mild TIL were significantly correlated with overall survival (OS). The presence of regression was not associated with DFS or OS. CONCLUSIONS We could not demonstrate an association between regression and the outcome of patients with cutaneous melanoma. Tumor thickness greater than 2 mm and a positive SLN were associated with recurrence. Survival was influenced by a Breslow thickness >2 mm, the presence of a mild TIL and a positive SLN status.

Prognostic role of histological regression in primary cutaneous melanoma: a systematic review and meta-analysis

The prognostic significance of histological regression in primary melanoma has been debated for many years. We aim to review the evidence to see how histological regression may affect prognosis. A systematic review was performed by searching in MEDLINE, Scopus and the Cochrane Library from 1 January 1966 to 1 August 2015. All studies reporting hazard ratios or data on survival and histological regression were included. Primary random-effects meta-analyses were used to summarize outcome measures. Heterogeneity was assessed using the χ² -test and I² -statistic. To assess the potential bias of small studies we used funnel plots and the Begg and Mazumdar adjusted rank correlation method. Summaries of survival outcomes were measured as hazard ratios or relative risk of death at 5 years according to the presence of histological regression of primary melanoma. In total, 183 articles were reviewed out of 1876 retrieved. Ten studies comprising 8557 patients were included. Patients with histological regression had a lower relative risk of death (0·77, 95% confidence interval 0·61-0·97) than those without. Examination of the funnel plot did not provide evidence of publication bias. The results showed that histological regression is a protective factor for survival.

Favourable prognostic role of histological regression in stage III positive sentinel lymph node melanoma patients

BACKGROUND

Sentinel lymph node (SLN)-positive melanoma patients are a heterogeneous group of patients with survival rates ranging from ∼20 to over 80%. No data are reported concerning the role of histological regression on survival in stage III melanoma.

METHODS

The study included 365 patients with positive SLN from two distinct hospitals. The model was developed on patients from 'AOU Città della Salute e della Scienza di Torino', and externally validated on patients from IRCCS of Candiolo. Survival analyses were carried out according to the presence of regression and adjusted for all other prognostic factors.

RESULTS

Among patients followed at 'AOU Città della Salute e della Scienza di Torino' (n=264), the median follow-up time to death or censoring (whatever two events occurred earlier) was 2.7 years since diagnosis (interquartile range: 1.3-5.8). In all, 79 patients died from melanoma and 11 from other causes. Histological regression (n=43) was associated with a better prognosis (sub-HR=0.34, CI 0.12-0.92), whereas the other factors above showed an inverse association. In the external validation, the concordance index was 0.97 at 1 year and decreased to 0.66 at 3 years and to 0.59 at 5 years. Adding histological regression in the prognostic model increased the discriminative ability to 0.75 at 3 years and to 0.62 at 5 years. Finally, using a cutoff of 20% for the risk of death led to a net re-classification improvement of 15 and 11% at 3 and 5 years after diagnosis, respectively.

CONCLUSIONS

Histological regression could lead to an improvement in prognostic prediction in patients with stage III-positive SLN melanoma.

Melanoma Sequentially Suppresses Different DC Subsets in the Sentinel Lymph Node, Affecting Disease Spread and Recurrence

Melanoma exerts immune-suppressive effects to facilitate tumor progression and metastatic spread. We studied these effects on dendritic cell (DC) and T-cell subsets in 36 melanoma sentinel lymph node (SLN) from 28 stage I-III melanoma patients and determined their clinical significance. Four conventional DC subsets, plasmacytoid DCs, and CD4⁺, CD8⁺, and regulatory T cells (Tregs), were analyzed by flow cytometry. We correlated these data to clinical parameters and determined their effect on local and distant melanoma recurrence, with a median follow-up of 75 months. In stage I and II melanoma, increased Breslow thickness (i.e., invasion depth of the primary melanoma) was associated with progressive suppression of skin-derived migratory CD1a⁺ DC subsets. In contrast, LN-resident DC subsets and T cells were only affected once metastasis to the SLN had occurred. In stage III patients, increased CD4:CD8 ratios in concert with the accumulation of Tregs resulted in decreased CD8:Treg ratios. On follow-up, lower frequencies of migratory DC subsets proved related to local melanoma recurrence, whereas reduced maturation of LN-resident DC subsets was associated with distant recurrence and melanoma-specific survival. In conclusion, melanoma-mediated suppression of migratory DC subsets in the SLN precedes local spread, whereas suppression of LN-resident DC subsets follows regional spread and precedes further melanoma dissemination to distant sites. This study offers a rationale to target migratory as well as LN-resident DC subsets for early immunotherapeutic interventions to prevent melanoma recurrence and spread. Cancer Immunol Res; 5(11); 969-77. ©2017 AACR.

PDL1 expression in desmoplastic melanoma is associated with tumor aggressiveness and progression

BACKGROUND

The prognostic role of programmed death ligand 1 (PDL1), CD8, and forkhead box p3 (FoxP3) expression in desmoplastic melanomas is unclear.

METHODS

We correlated PDL1, p53, and Ki-67 expression with CD8⁺ and FoxP3⁺ immune infiltrates with clinicopathologic variables and patient outcomes in a series of 66 desmoplastic melanomas.

RESULTS

Tumoral PDL1 expression (≥25%), which was seen in 21% of patients (14 of 66), significantly correlated with mixed histology, tumor thickness, mitoses, recurrence, and metastasis. According to linear regression analysis, tumoral PDL1 expression correlated with thickness (P = .0041); p53 expression (P = .019); Ki-67 proliferation index (P = .0018); and tumoral CD8 (P = .0084), stromal CD8 (P < .0001), and FoxP3 (P < .0001) T-cell counts. According to univariate analyses, PDL1 expression of 25% or higher correlated with shorter progression-free survival (P < .0001) and melanoma-specific survival (P = .034). According to multivariate analyses, PDL1 expression of 25% or more (P = .026) and mixed histology (P = .039) independently predicted shorter progression-free survival, and presence of lymphovascular invasion predicted shorter overall survival (P = .018).

LIMITATIONS

Small study size.

CONCLUSION

Tumoral and stromal CD8⁺ and FoxP3⁺ lymphocyte counts correlated with tumoral PDL1 expression, which is supportive of an adaptive immune response. PDL1 expression in desmoplastic melanoma was associated with tumor aggressiveness and progression. Although PDL1 expression is typically low in melanoma, its frequency and level of expression in desmoplastic melanoma may identify a subset of melanomas that are likely to respond to immunotherapy.

Innate immunity in cutaneous melanoma

The skin immune system is composed of a vast network of immune cells, including lymphocytes, macrophages, neutrophils, dendritic cells and Langerhans cells, which not only are involved in inflammatory responses but also contribute to homeostatic function and may participate in the various steps of carcinogenesis. Many studies support the notion that innate immunity has a key role in the development, growth and prognosis of cutaneous malignant melanoma (MM), through the release of pro- and/or anti-inflammatory cytokines and tumour growth factors. The tumour environment in a major subset of cutaneous MM shows evidence of a T cell-infiltrated phenotype, but there is less known about the presence and the phenotype of other immune system cells. Response to immunotherapy is largely correlated with the presence of T cells in the tumour microenvironment, while the regulation exerted by stromal components such as macrophages and mast cells has been less investigated. In the current report, we review the recent literature, focusing our attention on the role of macrophages, dendritic cells, mast cells and natural killer cells in orchestrating MM progression, to better understand tumour immunobiology. The identification of new therapeutic targets and the application of approaches aimed at modulating crosstalk between immune and tumour cells, could have a crucial impact on immunotherapy and result in better clinical outcome. We hope this review will be helpful in cutaneous MM research.

Melanoma: tumor microenvironment and new treatments

In the recent past years, many discoveries in the tumor microenvironment have led to changes in the management of melanoma and it is rising up hopes, specially, to those in advanced stages. FDA approved seven new drugs from 2011 to 2014. They are: Vemurafenib, Dabrafenib and Trametinib, kinases inhibitors used for patients that have BRAFV600E mutation; Ipilimumab (anti-CTLA4), Pembrolizumab (anti-PD-1) and Nivolumab (anti-PD-1), monoclonal antibodies that stimulate the immune system; and Peginterferon alfa-2b, an anti-proliferative cytokine used as adjuvant therapy. In this article, we will review the molecular bases for these new metastatic melanoma therapeutic agents cited above and also analyze new molecular discoveries in melanoma study, as Cancer-Testis antigens (CT). They are capable of induce humoral and cellular immune responses in cancer patients and because of this immunogenicity and their restrict expression in normal tissues, they are considered an ideal candidate for vaccine development against cancer. Among CT antigens, NY-ESO-1 is the best characterized in terms of expression patterns and immunogenicity. It is expressed in 20-40% of all melanomas, more in metastatic lesions than in primary ones, and it is very heterogeneous inter and intratumoral. Breslow index is associate with NY-ESO-1 expression in primary cutaneous melanomas, but its relation to patient survival remains controversial.

High Interleukin 27 Production is Associated with Early Clinical Stage and Localized Disease in Patients with Melanoma

BACKGROUND

The immune response in patients with melanoma is an important focus of research due to the tumor's resistance and immunotherapy possibilities. IL-27 is one of the cytokines with antitumor properties. The role of IL-27 in the pathogenesis of melanoma is still unclear. The aim of this study was to examine the association between serum IL-27 levels and the clinical parameters of melanoma patients.

METHODS

The IL-27 concentration was determined by com mercial ELISA in serum samples from melanoma patients (n=72) and healthy control subjects (n=44). Patients were classified according to AJCC clinical stage, TNM stage, the length of progression-free interval (PFI) and the extent of the disease (localized or widespread).

RESULTS

Average IL-27 values were increased in patients with early stages of melanoma compared to patients with terminal stages and control values. The highest IL-27 concentration was found in stage IIa. Patients in stages III and IV had significantly lower values of IL-27 compared to control. Patients with localized melanoma and shorter PFI had insignificantly increased IL-27 levels compared to patients with widespread disease and longer PFI. Patients with metastatic disease and stage TNM4 had significantly lower average IL-27 values compared to control. Patients with high production of IL-27 (>1000 pg/mL) were most numerous in IIa AJCC stage, with initial tumor size TNM2 and in the group of patients with localized disease.

CONCLUSIONS

High levels of IL-27 in patients with melanoma are associated with the initial stages and lo calized disease.

The lymph node pre-metastatic niche

Lymph node metastases occur frequently during the progression of many types of cancer, and their presence often reflects poor prognosis. The drainage of tumor-derived factors such as antigens, growth factors, cytokines, and exosomes through the lymphatic system to the regional lymph nodes plays an important role in the pre-metastatic conditioning of the microenvironment in lymph nodes, making them receptive and supportive metastatic niches for disseminating tumor cells. Modified immunological responses and remodeling of the vasculature are the most studied tumor-induced pre-metastatic changes in the lymph node microenvironment that promote metastasis, although other metastasis-relevant alterations are also starting to be studied. Here, I review our current understanding of the lymph node pre-metastatic niche, how tumors condition this niche, and the relevance of this conditioning for our understanding of the process of metastasis.

Nodal metastasis in cervical cancer occurs in clearly delineated fields of immune suppression in the pelvic lymph catchment area

In cervical cancer, high frequencies of regulatory T cells (Tregs) and immunosuppressive PD-L1⁺CD14⁺ antigen-presenting cells dominate the microenvironment of tumor-positive lymph nodes (LN+). It is unknown whether this is restricted to LN+ or precedes metastasis, emanating from the primary tumor and spreading through tumor-draining lymph nodes (TDLNs). To investigate immunosuppression in the lymphatic basin of cervical tumors, all dissected TDLNs of five cervical cancer patients (in total 9 LN+ and 74 tumor-negative lymph nodes (LN−)) were analyzed for FoxP3⁺ Tregs, CD8⁺ T cells, HLA-DR⁺- and PD-L1⁺ myeloid cells by immunohistochemistry.

Tregs and PD-L1⁺ cells were found to form an immunosuppressive cordon around metastatic tumor cells. Importantly, whereas high HLA-DR⁺- and PD-L1⁺ cell rates were strongly associated with LN+, elevated Treg levels and decreased CD8⁺ T cell/Treg ratios were found similar in LN+ and adjacent LN−, as compared to LN− at more distant anatomical localizations. These data suggest that delineated fields of Treg-associated immune suppression in anatomically co-localized TDLNs enable metastasis by creating metastatic niches. This may be of importance for decision-making regarding (surgical) intervention in cervical cancer. Future efforts should include the implementation of immunotherapeutic regimens to overcome this immune suppression, establish loco-regional control and halt systemic tumor spread.

Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis

Histological regression in primary cutaneous melanoma occurs in 10-35% of cases. Although a large body of literature exists to suggest that histological regression serves very little purpose in predicting biologic behaviour with melanoma, recognizing the presence of regression at clinical and histological ground may still retain some value in grading melanoma aggressiveness. In the current review, a comprehensive overview of the main aspects of regression will be provided. Histologically, many classifications have been reported so far, but all of them only agreed on the presence of an infiltrate of lymphocytes admixed with pigment-laden macrophages underlying an atrophic epidermis with flattened rete ridges. Upon dermoscopy, regression is also named Blue White Scar-like areas and could be variably admixed with granularity or peppering. Almost fully regressed lesions represent a main diagnostic issue in dermoscopy, and thus, confocal microscopy can be of help to identify whether the tumour is melanocytic or not. The clinical utility of regression as a prognostic factor has been challenged recently. Nowadays, evidences showed that it is less likely associated to SLN metastases.

What Is New in Melanoma Genetics and Treatment?

New therapies for advanced melanoma have led to major advances, which, for the first time, showed improved survival for patients with this very challenging neoplasm. These new treatments are based on gene-targeted therapies or stimulation of immune responses. However, these treatments are not without challenges in terms of resistance and toxicity. Physicians should be aware of these side effects as prompt treatment may save lives. Melanoma genetics is also unravelling new genetic risk factors involving telomere genes as well as new gene pathways at the somatic level which may soon become therapeutic targets. It is also shedding new light onto the pathology of this tumour with links to neural diseases and longevity.

Prognostic Role of Multiple Lymphatic Basin Drainage in Sentinel Lymph Node-Negative Trunk Melanoma Patients: A Multicenter Study from the Italian Melanoma Intergroup

BACKGROUND

Multiple lymphatic basin drainage (MLBD) is frequently observed in patients with trunk melanoma undergoing sentinel lymph node (SLN) biopsy. Conflicting data regarding the prognostic association of MLBD in SLN-negative patients have been reported. This study aimed to investigate the prognostic role of MLBD in patients with negative SLN biopsy.

METHODS

Retrospective data from 656 melanoma patients who underwent a SLN biopsy (1991-2012) at six Italian centers were gathered in a multicenter database. MLBD was defined as lymphoscintigraphic and intraoperative identification of an SLN in more than one nodal basin. Clinical and pathologic variables were recorded and analyzed for their impact on survival.

RESULTS

SLN-negative patients with MLBD were at lower risk of melanoma recurrence [hazard ratio (HR) 0.73, P = 0.05) and melanoma-related death (HR 0.68, P = 0.001) independent of common staging features. Multivariable Cox analyses of disease-free interval (DFI) and disease-specific survival (DSS) showed that MLBD maintained a favorable role and ulceration an unfavorable role. Histologic regression was independently associated only with DFI. When survival was stratified according to presence of MLBD, histologic regression and Breslow thickness <2 mm were associated with improved DFI (5-year DFI: 96.9 vs. 66,1 %, respectively; HR 0.48, P < 0.001) and DSS (5-year DSS: 96.7 vs. 71.8 %, respectively; HR 0.52, P = 0.005) compared to patients without these three favorable parameters.

CONCLUSIONS

Patients with negative SLN biopsy results have better prognosis when two or more lymphatic basins are identified and analyzed. Further research is required to investigate the mechanisms behind this evidence.

Study of the immunophenotype of the inflammatory cells in melanomas with regression and halo nevi

The pathogenesis and prognostic implications of regression in melanoma are not well understood. It has traditionally been considered an immunologically mediated phenomenon. Improvement in the knowledge of the mechanisms that lead to regression may prove to be of great value in an era in which treatments oriented to the augmentation of the host's immunity against melanoma have demonstrated excellent clinical results. This study was designed to improve the understanding of the mechanisms underlying melanoma regression and the differences between similar situations in benign melanocytic nevus. The study sample consisted of 77 lesions: 62 melanomas and 15 halo nevi. The following markers were included in the study: CD4, CD8, FoxP3, PD1, CD123, granzyme, and TIA-1. Staining was evaluated in 5 categories, according to the percentage of labeled cells. Granzyme, PD1, and TIA-1 stained significantly more cells in halo nevi than in melanomas with regression (P < 0.01). The ratio CD123/TIA-1 was higher in melanomas than in halo nevi (1 vs. 0.67, P < 0.05). Regression in the 62 melanomas was categorized as early in 14 cases and late in 48 cases. Early regression was associated with a higher percentage of CD123, CD4, and TIA-1 staining than late regression. The inflammatory infiltrate found in halo nevi is characterized by a higher number of active cytotoxic T cells and regulatory PD1-positive T cells than the infiltrate found in melanoma with regression. CD123 staining was higher in early regression than in late regression, suggesting the presence of a tolerogenic mechanism in this phenomenon's initiation phase.

Is sentinel node susceptibility to metastases related to nodal immune modulation?

Sentinel lymph nodes (SLNs), the initial site of regional metastases, directly receive lymph containing immune-modulatory cytokines and tumor cells from primary melanomas. Immune-suppressed SLNs are ideal for studies of tissue susceptibility to metastases. They show reduced antigen-presenting dendritic cells, activated T cells, high endothelial venules, and transvenular immigration of T cells. Tumor-induced immune suppression contributes to establishment of nodal metastases. SLNs may serve as an effective model to study reversal of tumor-induced immune suppression. We reviewed this topic in Nature Reviews of Immunology in 2006. We here summarize the Nature paper and provide additional results from ongoing studies and the recent literature.

Prognostic differences across sexes in melanoma patients: what has changed from the past?

Differences across the sexes include epidemiological trends, distribution of clinical features and prognostic relevance in melanoma patients. The aims of this single-institution hospital-based cohort study were as follows: to assess the trends over time of the male/female ratio; to analyse the clinicopathologic features according to sex and their modifications following the introduction in 1999 of sentinel lymph node biopsy; to ascertain the metastatic pathways across sexes and the prognostic role of sex in the disease-free interval (DFI), disease-specific survival (DSS) and survival after recurrence. The patient population included 4310 stage I-II melanoma patients, diagnosed, treated and followed up in our institution from 1975. Patients were divided into two groups on the basis of the introduction of sentinel lymph node biopsy in 1999. A female prevalence was observed until 1999; thereafter, the male/female ratio approached 1 (period 1999-2003), with a subsequent increasing trend suggesting a potential male prevalence. Longer DFI and DSS were observed after 1999 and men showed greater improvement compared with women. In multivariate analyses, sex showed a lower impact on DFI and survival after recurrence following the introduction on sentinel lymph node biopsy. No sex-related differences in terms of DSS were observed before and after 1999 among patients with melanoma located on the trunk. However, among patients with primary lesions not located on the trunk, sex maintained a significant prognostic role in both groups. The results of this study suggest that in the last few years, the prognosis of men could have improved more than that in women. The changing surgical/therapeutic interventions can influence sex disparities in melanoma.

The changes of angiogenesis and immune cell infiltration in the intra- and peri-tumoral melanoma microenvironment

Malignant melanoma (MM) urgently needs identification of new markers with better predictive value than currently-used clinical and histological parameters. Cancer cells stimulate the formation of a specialized tumor microenvironment, which reciprocally affects uncontrolled proliferation and migration. However, this microenvironment is heterogeneous with different sub-compartments defined by their access to oxygen and nutrients. This study evaluated microvascular density (MVD), CD3+ lymphocytes (TILs) and FOXP3+ T-regulatory lymphocytes (Tregs) on formalin-fixed paraffin-embedded tissue sections using light microscopy. We analyzed 82 malignant melanomas, divided according to the AJCC TNM classification into four groups--pT1 (35), pT2 (17), pT3 (18) and pT4 (12)--and 25 benign pigmented nevi. All parameters were measured in both the central areas of tumors (C) and at their periphery (P). A marked increase in all parameters was found in melanomas compared to nevi (p = 0.0001). There was a positive correlation between MVD, TILs, FOXP3+ Tregs and the vertical growth phase. The results show that MVD, TILs and FOXP3+ Tregs substantially influence cutaneous melanoma microenvironment. We found significant topographic differences of the parameters between central areas of tumors and their boundaries.

Genetic associations of the interleukin locus at 1q32.1 with clinical outcomes of cutaneous melanoma

BACKGROUND

Due to high melanoma immunogenicity, germline genetic variants in immune pathways have been studied for association with melanoma prognosis. However, limited candidate selection, inadequate power, or lack of independent validation have hampered the reproducibility of these prior findings, preventing personalised clinical applicability in melanoma prognostication. Our objective was to assess the prognostic utility of genetic variants in immunomodulatory pathways for prediction of melanoma clinical outcomes.

METHODS

We genotyped 72 tag single nucleotide polymorphisms (SNPs) in 44 immunomodulatory genes in a population sample of 1022 melanoma patients and performed Cox regression analysis to test the association between SNPs and melanoma recurrence-free (RFS) and overall survival (OS). We have further investigated the most significant associations using a fine mapping strategy and followed with functional analyses in CD4+ T cells in a subset of 75 melanoma patients.

RESULTS

The most significant associations were found with melanoma OS for rs3024493 in IL10 at chromosome 1q32.1 (heterozygous HR 0.58, 95% CI 0.39 to 0.86; p=0.0006), a variant previously shown to be linked with autoimmune conditions. Multiple additional SNPs at 1q32.1 were also nominally associated with OS confirming at least two independent association signals in this locus. In addition, we found rs3024493 associated with the downregulation of interleukin 10 (IL10) secretion in CD4+ T cells.

CONCLUSIONS

We discovered novel associations of IL10 with melanoma survival at 1q32.1, suggesting this locus should be considered as a novel melanoma prognostic biomarker with potential for aiding melanoma patient management. Our findings also provide further support for an alternative role of IL10 in stimulation of anti-tumour immune response.

High expression of FOXP3 in primary melanoma is associated with tumour progression

BACKGROUND

The antitumour immune response plays an important role in the prognosis of melanoma. High numbers of circulating regulatory T cells have been associated with rapid disease progression.

OBJECTIVES

To assess the influence of forkhead box protein (FOXP)3, CD1a and langerin expression on the prognosis of primary melanoma.

METHODS

We analysed 185 primary melanomas by immunohistochemical staining for expression of the regulatory T-cell marker FOXP3 and the dendritic cell markers langerin and CD1a, and correlated marker expression with clinical outcome.

RESULTS

Disease-free survival and overall survival were significantly longer in patients expressing low levels of FOXP3 in the primary melanoma, whereas they were associated with high expression of CD1a. The negative prognostic value of FOXP3 expression was independent of the Breslow tumour thickness. Langerin expression did not correlate with the clinical outcome.

CONCLUSIONS

High expression of FOXP3 in the primary melanoma may be used as an additional independent prognostic marker for early tumour progression in patients with melanoma.