The prognostic significance of tumor-infiltrating lymphocytes for primary melanoma varies by sex

Tumor-infiltrating lymphocytes as a prognostic and predictive factor for Melanoma

INTRODUCTION

Tumor-infiltrating lymphocytes (TILs) have been investigated as prognostic factors in melanoma. Recent advancements in assessing the tumor microenvironment in the setting of more widespread use of immune checkpoint blockade have reignited interest in identifying predictive biomarkers. This review examines the function and significance of TILs in cutaneous melanoma, evaluating their potential as prognostic and predictive markers.

AREAS COVERED

A literature search was conducted on papers covering tumor infiltrating lymphocytes in cutaneous melanoma available online in PubMed and Web of Science from inception to 1 December 2023, supplemented by citation searching. This article encompasses the assessment of TILs, the role of TILs in the immune microenvironment, TILs as a prognostic factor, TILs as a predictive factor for immunotherapy response, and clinical applications of TILs in the treatment of cutaneous melanoma.

EXPERT OPINION

Tumor-infiltrating lymphocytes play a heterogeneous role in cutaneous melanoma. While they have historically been associated with improved survival, their status as independent prognostic or predictive factors remains uncertain. Novel methods of TIL assessment, such as determination of TIL subtypes and molecular signaling, demonstrate potential for predicting therapeutic response. Further, while their clinical utility in risk-stratification in melanoma treatment shows promise, a lack of consensus data hinders standardized application.

Tumoral inflammatory infiltrate does not predict metastases in thin primary cutaneous melanomas

BACKGROUND

In cutaneous melanomas in general, tumor inflammatory infiltrate (TII) can protect against distant metastases, but there is no consensus when only thin primary cutaneous melanomas (TPCM) are considered.

OBJECTIVE

To investigate the presence of TII in TPCM and the relationship between TII and the occurrence of metastases.

METHODS

Case-control study including 50 patients with TPCM, 22 metastatic (MC group) and 28 non-metastatic (NMC group). The presence of TII was evaluated and, if present, qualified as mild, moderate or marked.

RESULTS

The mean age was 50.7 years in the MC and 56.2 years in the NMC group (p = 0.234), and the male sex predominated in the MC group (63.6%). The average Breslow thickness was higher in the MC when compared to that observed in the NMC (respectively 0.8 vs. 0.6 mm, p = 0.012). The presence of ulceration occurred in 22.7% of the MC and 17.9% of the NMC (p = 0.732). TII was present in all 50 TPCM, being marked or moderate in 67.9% of the NMC and 54.5% in the MC group (p = 0.503). In the multivariate analysis, the presence of moderate and marked TII had an Odds Ratio (OR) of 0.57 (95% Confidence Interval [CI]: 0.18‒1.8) and adjusted OR of 0.68 (95% CI 0.13‒3.99).

STUDY LIMITATIONS

Small sample size.

CONCLUSIONS

TII was present in all TPCM (with and without metastases), and it was not possible to demonstrate a protective effect of TII against the appearance of metastases.

Downregulated annexin A1 expression correlates with poor prognosis, metastasis, and immunosuppressive microenvironment in Ewing's sarcoma

OBJECTIVE

Ewing's sarcoma (ES) is a common bone malignancy in children and adolescents that severely affects the prognosis of patients. The aim of this study was to identify novel biomarkers and potential therapeutic targets for ES.

METHODS

Highly prognosis-related hub genes were identified by independent prognostic analysis in the GSE17679 dataset. We then performed survival analysis, Cox regression analysis and clinical correlation analysis on the key gene and validated them with the GSE63157, GSE45544 and GSE73166 datasets. Differentially expressed genes (DEGs) were screened based on the high and low expression of key gene, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, Gene Set Enrichment Analysis (GSEA), and Gene Set Variation Analysis (GSVA) were performed to explore the underlying mechanisms of ES, and significant module genes were established based on protein-protein interaction (PPI) networks. Furthermore, the correlations between module genes and the immune microenvironment were analyzed and the correlations between the key gene and immune infiltration levels in sarcoma were investigated using TIMER and TISIDB. Finally, the expression levels of these key genes in ES cell lines (RD-ES and A673 cells) were further validated by real-time quantitative PCR (RT-qPCR). CCK-8 and EdU assays were performed to assess the effect of ANXA1 knockdown on RD-ES cell proliferation.

RESULTS

ANXA1 was identified as a key gene for ES prognosis. The overall survival (OS) time of patients with low ANXA1 expression was shorter, and the expression level of ANXA1 in the metastatic group was significantly lower than that in the primary group (P<0.01). Additionally, the abundance of 12 immune cells in the ANXA1 low-expression group was significantly lower than that in the high-expression group (all P<0.05), which may be related to the inhibition of the immune microenvironment. A PPI network was constructed based on 96 DEGs to further identify the five ANXA1-related module genes (COL1A2, MMP9, VIM, S100A11 and S100A4). The expression levels of ANXA1, COL1A2, MMP9, VIM, S100A11 and S100A4 were significantly different between ES cell lines and mesenchymal stem cells after validation in two ES cell lines (all P<0.01). Among these genes, ANXA1, COL1A2, MMP9, VIM and S100A4 were significantly associated with the prognosis of ES patients (all P<0.05). Importantly, ANXA1 knockdown significantly promoted the proliferation of RD-ES cells, which may explain the susceptibility to ES metastasis in the ANXA1 low-expression group.

CONCLUSIONS

ANXA1 may serve as an independent prognostic biomarker for ES patients and is associated with metastasis and the immunosuppressive microenvironment in ES, which needs to be validated in further studies.

Mechanisms of resistance to immune checkpoint inhibitors in melanoma: What we have to overcome?

Marching into the second decade after the approval of ipilimumab, it is clear that immune checkpoint inhibitors (ICIs) have dramatically improved the prognosis of melanoma. Although the current edge is already high, with a 4-year OS% of 77.9% for adjuvant nivolumab and a 6.5-year OS% of 49% for nivolumab/ipilimumab combination in the metastatic setting, a high proportion of patients with advanced melanoma have no benefit from immunotherapy, or experience an early disease relapse/progression in the first few months of treatment, surviving much less. Reasonably, the primary and acquired resistance to ICIs has entered into the focus of clinical research with positive (e.g., nivolumab and relatlimab combination) and negative feedbacks (e.g., nivolumab with pegylated-IL2, pembrolizumab with T-VEC, nivolumab with epacadostat, and combinatorial triplets of BRAF/MEK inhibitors with immunotherapy). Many intrinsic (intracellular or intra-tumoral) but also extrinsic (systematic) events are considered to be involved in the development of this resistance to ICIs: i) melanoma cell immunogenicity (e.g., tumor mutational burden, antigen-processing machinery and immunogenic cell death, neoantigen affinity and heterogeneity, genomic instability, melanoma dedifferentiation and phenotypic plasticity), ii) immune cell trafficking, T-cell priming, and cell death evasion, iii) melanoma neovascularization, cellular TME components(e.g., T_regs, CAFs) and extracellular matrix modulation, iv) metabolic antagonism in the TME(highly glycolytic status, upregulated CD39/CD73/adenosine pathway, iDO-dependent tryptophan catabolism), v) T-cell exhaustion and negative immune checkpoints, and vi) gut microbiota. In the present overview, we discuss how these parameters compromise the efficacy of ICIs, with an emphasis on the lessons learned by the latest melanoma studies; and in parallel, we describe the main ongoing approaches to overcome the resistance to immunotherapy. Summarizing this information will improve the understanding of how these complicated dynamics contribute to immune escape and will help to develop more effective strategies on how anti-tumor immunity can surpass existing barriers of ICI-refractory melanoma.

Lower Expression of GBP2 Associated With Less Immune Cell Infiltration and Poor Prognosis in Skin Cutaneous Melanoma (SKCM)

Guanylate binding protein 2 (GBP2) could bind to guanine nucleotides (GMP, GDP, and GTP) and exhibits antiviral activity against influenza virus through the innate immune response. Some researchers have demonstrated that the value of GBP2 in predicting the prognosis of multiple cancers and the complex correlation with immune response. However, the correlation of GBP2 to prognosis and immune cell infiltration level were unknown in skin cutaneous melanoma (SKCM). The GBP2 expression in multiple cancers were evaluated through Tumor Immune Estimation Resource (TIMER) and Oncomine. We also evaluated the influence of GBP2 on overall survival in multiple caners through GEPIA, TIMER, and tissue microarray. The correlation between GBP2 expression level and immune cell or gene markers of immune infiltration level was explored on TIMER and GEPIA. Gene set enrichment analysis was performed using the TCGA dataset. The GBP2 expression level represented a significant reduction and the GBP2 expression was lower compared with the SKCM-Metastasis with P<0.01. Lower GBP2 expression was significantly correlated with the poor overall survival of SKCM patients. Simultaneously, higher GBP2 expression predicted the better SKCM-free survival with P=0.019. GBP2 expression was positively correlated with the infiltration cells of B-cell, CD8+ T-cell, CD4+ T-cell, macrophage, neutrophil, and dendritic cell in SKCM. And there was a significant negative correlation between the expression of GBP2 and DNA methylation in the cBioPortal database (P=3.39e-42). Gene set enrichment analysis revealed that GBP2 was closely correlated with multiple pathways of immune response in cancer. In conclusion, Lower expression of GBP2 associated with less immune cell infiltration and poor prognosis in SKCM and the high promoter methylation of GBP2 represented a promising biomarker for poor prognostication in SKCM.

Prognostic Significance of Primary Tumor-Infiltrating Lymphocytes in a Contemporary Melanoma Cohort

BACKGROUND

The prognostic impact of tumor-infiltrating lymphocytes (TILs) on outcomes and treatment efficacy for patients with melanoma in the contemporary era remains poorly characterized.

METHODS

Consecutive patients who underwent wide excision and sentinel lymph node biopsy for cutaneous melanoma 1 mm thick or thicker at a single institution were identified (2006-2019). The patients were stratified based on primary tumor TIL status as brisk (bTILs), non-brisk (nbTILs), or absent (aTILs). Associations between patient factors and outcomes were analyzed using multivariable analysis.

RESULTS

Of the 1017 patients evaluated, 846 (83.2 %) had primary TILs [nbTILs (n = 759, 89.7 %) and bTILs (n = 87, 10.3 %)]. In the multivariable analysis, the patients with any type of TILs had higher rates of regression [odds ratio (OR), 1.86; p = 0.016], lower rates of acral lentiginous histology (OR, 0.22; p < 0.001), and lower rates of SLN positivity (OR, 0.64; p = 0.042) than those without TILs. The multivariable analysis found no association between disease-specific survival and bTILs [hazard ratio (HR), 1.04; p = 0.927] or nbTILs (HR, 0.89; p = 0.683). An association was found between bTILs and recurrence-free survival (RFS) advantage [bTILs (HR 0.46; p = 0.047), nbTILs (HR 0.71; p = 0.088)], with 5-year RFS rates of 84 % for bTILs, 71.8 % for nbTILs, and 68.4 % for aTILs (p = 0.044). For the 114 immune checkpoint blockade (ICB)-naïve patients who experienced a recurrence treated with ICB therapy, no association was observed between progression-free survival and bTILs (HR, 0.64; p = 0.482) or nbTILs (HR, 0.58; p = 0.176).

CONCLUSIONS

The prognostic significance of primary TILs in the contemporary melanoma era appears complex. Further studies characterizing the phenotype of TILs and their association with regional metastasis and responsiveness to ICB therapy are warranted.

Is the presence of tumor-infiltrating lymphocytes predictive of outcomes in patients with melanoma?

BACKGROUND

The significance of tumor-infiltrating lymphocytes (TILs) in melanoma is debated. This article presents a multicenter, retrospective study assessing the predictive and prognostic value of TILs.

METHODS

The Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with known TIL data. TILs were categorized as absent or present, which included nonbrisk (NB), brisk (B), and present but unspecified TIL levels. Clinicopathologic factors were correlated with TILs, sentinel lymph node (SLN) status, and melanoma-specific survival (MSS).

RESULTS

Overall, 3203 patients were included. The median thickness was 1.5 mm, and 469 cases had SLN metastases. TILs were present in 2458 cases (76.7%), with NB, B, and unspecified TILs seen in 1691 (68.8%), 691 (28.1%), and 76 (3.1%), respectively. Multivariable analysis showed that the presence of TILs significantly predicted a negative SLN biopsy (P < .05). The median follow-up was 25.2 months. MSS was significantly better for cases with TILs than cases without TILs (P < .001). According to multivariable analysis, age, gender, thickness, mitotic rate, ulceration, lymphovascular invasion, and SLN status were significantly prognostic of MSS (all P values < .05). Although TILs were not prognostic of MSS, when multiple imputation was used and the SLN status was excluded, the presence of TILs was significantly prognostic of improved MSS (hazard ratio, 0.78; 95% confidence interval, 0.64-0.95; P = .0154).

CONCLUSIONS

TILs are a favorable marker because their presence significantly predicts a negative SLN, and the absence of TILs may be a prognostic marker of worse survival in patients with a positive SLN but not a negative SLN. TILs may also serve as a prognostic marker of survival when the SLN status is not considered.

Reduced Interleukin-17-Expressing Cells in Cutaneous Melanoma

Characterization of tumor associated lymphocytes (TILs) in tumor lesions is important to obtain a clear definition of their prognostic value and address novel therapeutic opportunities. In this work, we examined the presence of T helper (Th)17 lymphocytes in cutaneous melanoma. We performed an immunohistochemical analysis of a small cohort of primary melanomas, retrospectively selected. Thereafter, we isolated TILs from seven freshly surgically removed melanomas and from three basal cell carcinomas (BCC), as a comparison with a non-melanoma skin cancer known to retain a high amount of Th17 cells. In both studies, we found that, differently from BCC, melanoma samples showed a lower percentage of Th17 lymphocytes. Additionally, TIL clones could not be induced to differentiate towards the Th17 phenotype in vitro. The presence or absence of Th17 cells did not correlate with any patient characteristics. We only observed a lower amount of Th17 cells in samples from woman donors. We found a tendency towards an association between expression by melanoma cells of placenta growth factor, angiogenic factors able to induce Th17 differentiation, and presence of Th17 lymphocytes. Taken together, our data indicate the necessity of a deeper analysis of Th17 lymphocytes in cutaneous melanoma before correlating them with prognosis or proposing Th17-cell based therapeutic approaches.

Assessing the Prognostic Significance of Tumor-Infiltrating Lymphocytes in Patients With Melanoma Using Pathologic Features Identified by Natural Language Processing

Importance

Although tumor-infiltrating lymphocytes (TILs) are an important histopathologic characteristic reflecting host immune response in patients with melanoma, their prognostic value remains controversial. Because manual review of medical records is labor intensive, a survival analysis using a large patient cohort with comprehensive clinical and histopathologic characteristics is lacking.

Objective

To assess the prognostic significance of TILs among patients with cutaneous melanoma using a large cohort established through natural language processing (NLP) algorithms.

Design, Setting, and Participants

This retrospective cohort study analyzed the medical records of 14 436 patients with cutaneous melanoma at Brigham and Women's Hospital between June 1, 2004, and December 31, 2019. Patients were followed up to death or censored at their last clinical visit.

Main Outcome and Measures

The primary outcome was overall survival (OS). Survival analysis was conducted using Kaplan-Meier curves, the log-rank test, and Cox proportional hazards regression analysis.

Results

A total of 14 436 patients with cutaneous melanoma were identified in the institution's pathology information system. Using NLP, we established a study cohort of 2624 patients (1462 men [55.7%]; median age, 61 years [interquartile range, 50-72 years]) who had vertical growth phase melanoma with TIL status scored. Absent TILs were identified in 434 patients (16.5%), nonbrisk TILs in 1916 patients (73.0%), and brisk TILs in 274 patients (10.4%). The 5-year survival rate was 71.0% (95% CI, 65.5%-76.9%) among patients with an absence of TILs, 73.8% (95% CI, 71.1%-76.5%) among patients with nonbrisk TILs, and 85.2% (95% CI, 80.0%-90.7%) among patients with brisk TILs. Brisk TILs were significantly associated with improved OS (adjusted hazard ratio, 0.63; 95% CI, 0.42-0.95; P = .03; 14.2% OS advantage at 5 years), and nonbrisk TILs were not associated with improved OS (adjusted hazard ratio, 0.87; 95% CI, 0.68-1.11; P = .25), compared with the absence of TILs.

Conclusions and Relevance

This study provides evidence based on a large patient cohort from a single institution that suggests that brisk TILs represent an independent prognostic factor for OS among patients with primary cutaneous melanoma. The study also suggests that NLP is a highly efficient tool to facilitate large-scale analyses that involve free-text clinical data.

Unraveling the Relevance of ARL GTPases in Cutaneous Melanoma Prognosis through Integrated Bioinformatics Analysis

Cutaneous melanoma (CM) is the deadliest skin cancer, whose molecular pathways underlying its malignancy remain unclear. Therefore, new information to guide evidence-based clinical decisions is required. Adenosine diphosphate (ADP)-ribosylation factor-like (ARL) proteins are membrane trafficking regulators whose biological relevance in CM is undetermined. Here, we investigated ARL expression and its impact on CM prognosis and immune microenvironment through integrated bioinformatics analysis. Our study found that all 22 ARLs are differentially expressed in CM. Specifically, ARL1 and ARL11 are upregulated and ARL15 is downregulated regardless of mutational frequency or copy number variations. According to TCGA data, ARL1 and ARL15 represent independent prognostic factors in CM as well as ARL11 based on GEPIA and OncoLnc. To investigate the mechanisms by which ARL1 and ARL11 increase patient survival while ARL15 reduces it, we evaluated their correlation with the immune microenvironment. CD4+ T cells and neutrophil infiltrates are significantly increased by ARL1 expression. Furthermore, ARL11 expression was correlated with 17 out of 21 immune infiltrates, including CD8+ T cells and M2 macrophages, described as having anti-tumoral activity. Likewise, ARL11 is interconnected with ZAP70, ADAM17, and P2RX7, which are implicated in immune cell activation. Collectively, this study provides the first evidence that ARL1, ARL11, and ARL15 may influence CM progression, prognosis, and immune microenvironment remodeling.

Clinical Significance of Tumor Microenvironment in Acral Melanoma: A Large Single-Institution Study of Caucasians

Background: The presence of tumor-infiltrating lymphocytes (TILs) in many studies is associated with a better prognosis in melanoma patients. Programmed death-ligand 1 (PD-L1) expression has a significant value in predicting several cancers, but its role in melanoma remains ambiguous. The study aims to report a comprehensive analysis of TILs characteristics and their impact on survival in primary acral melanoma (AM). Methods: Clinical and pathological features and survival outcomes were investigated in 70 patients with AM. Immunohistochemical quantitative analysis of TILs, including expression of CD4, CD8, FOXP3, PD-1, and PD-L1, on melanoma cells was performed. Results: Kaplan-Meier analysis showed significant differences in overall survival (OS) for CD4+ (p = 0.021), CD8+ (p = 0.037), FOXP3+ (p = 0.007), and TILs density (p = 0.043). In univariate analysis of immunohistochemical features, FOXP3, CD4, CD8, PD-1, and Melanoma Institute of Australia (MIA) grading TILs (grade, density, and distribution) were correlated with survival. The higher density of FOXP3-positive cells was an independent factor associated with better survival. Conclusions: High TILs content (classed as brisk Clark scale and marked/diffuse TILs MIA grade) regardless of its immunophenotype was associated with better survival outcomes in AM. PD-L1 expression on tumor cells did not influence OS and was independent of clinical and pathological characteristics. We demonstrated that TILs are significant biomarkers in sentinel lymph node status prediction.

Automated digital TIL analysis (ADTA) adds prognostic value to standard assessment of depth and ulceration in primary melanoma

Accurate prognostic biomarkers in early-stage melanoma are urgently needed to stratify patients for clinical trials of adjuvant therapy. We applied a previously developed open source deep learning algorithm to detect tumor-infiltrating lymphocytes (TILs) in hematoxylin and eosin (H&E) images of early-stage melanomas. We tested whether automated digital (TIL) analysis (ADTA) improved accuracy of prediction of disease specific survival (DSS) based on current pathology standards. ADTA was applied to a training cohort (n = 80) and a cutoff value was defined based on a Receiver Operating Curve. ADTA was then applied to a validation cohort (n = 145) and the previously determined cutoff value was used to stratify high and low risk patients, as demonstrated by Kaplan–Meier analysis (p ≤ 0.001). Multivariable Cox proportional hazards analysis was performed using ADTA, depth, and ulceration as co-variables and showed that ADTA contributed to DSS prediction (HR: 4.18, CI 1.51–11.58, p = 0.006). ADTA provides an effective and attainable assessment of TILs and should be further evaluated in larger studies for inclusion in staging algorithms.

Exploration of the Immune-Related Signatures and Immune Infiltration Analysis in Melanoma

In the present study, we aimed to investigate immune-related signatures and immune infiltration in melanoma. The transcriptome profiling and clinical data of melanoma were downloaded from The Cancer Genome Atlas database, and their matched normal samples were obtained from the Genotype-Tissue Expression database. After merging the genome expression data using Perl, the limma package was used for data normalization. We screened the differentially expressed genes (DEGs) and obtained immune signatures associated with melanoma by an immune-related signature list from the InnateDB database. Univariate Cox regression analysis was used to identify potential prognostic immune genes, and LASSO analysis was used to identify the hub genes. Next, based on the results of multivariate Cox regression analysis, we constructed a risk model for melanoma. We investigated the correlation between risk score and clinical characteristics and overall survival (OS) of patients. Based on the TIMER database, the association between selected immune signatures and immune cell distribution was evaluated. Next, the Wilcoxon rank-sum test was performed using CIBERSORT, which confirmed the differential distribution of immune-infiltrating cells between different risk groups. We obtained a list of 91 differentially expressed immune-related signatures. Functional enrichment analysis indicated that these immune-related DEGs participated in several areas of immune-related crosstalk, including cytokine-cytokine receptor interactions, JAK-STAT signaling pathway, chemokine signaling pathway, and Th17 cell differentiation pathway. A risk model was established based on multivariate Cox analysis results, and Kaplan-Meier analysis was performed. The Kruskal-Wallis test suggested that a high risk score indicated a poorer OS and correlated with higher American Joint Committee on Cancer-TNM (AJCC-TNM) stages and advanced pathological stages (P < 0.01). Furthermore, the association between hub immune signatures and immune cell distribution was evaluated in specific tumor samples. The Wilcoxon rank-sum test was used to estimate immune infiltration density in the two groups, and results showed that the high-risk group exhibited a lower infiltration density, and the dominant immune cells included M0 macrophages (P = 0.023) and activated mast cells (P = 0.005).

Prognostic significance of sentinel node biopsy status in cutaneous melanoma: a 21-years prospective study from a single institution

AIM

To analyze the accuracy of the sentinel lymphatic node biopsy (SLNB) and to investigate predictive factors for sentinel node (SN) status and prognostic factors for recurrence-free survival (RFS) and disease-specific survival (DSS) in patients with melanoma.

MATERIAL AND METHODS

Between June 1997 and June 2017, 440 consecutive patients, who underwent SLNB by a single surgical team, were prospectively included. Descriptive and survival analysis were performed.

RESULTS

119 of 440 patients (26%) had positive SN. SLNB's false-negative rate was 6.3%. Breslow thickness, Clark´s level, ulceration and histological subtype were statistically significant predictive factors of SN metastases. In a multivariate analysis, positive SN (HR = 2.21, p = 0.01), deeper Breslow thickness (HR = 2.05, p = 0.013), male gender (RR = 2.05, p = 0.02), and higher Clark's level (HR = 2.30, p = 0.043) were significantly associated with decreased RFS; and positive SN (HR = 2.58, p < 0.001), deeper Breslow thickness (HR = 2.57, p = 0.006) and male gender (HR = 1.93, p = 0.006) were associated with lower DSS.

CONCLUSION

SLNB is a reliable and reproducible procedure with high sensitivity (93.7%). Positive SN metastases, Breslow thickness and male gender were statistically associated with poorer outcomes. Male gender was an independent prognostic factor of tumor thickness or SN status.

High level of TILs is an independent predictor of negative sentinel lymph node in women but not in men

Factors that are most associated with positive lymph node status in melanoma are Breslow thickness and ulceration. However, there are other factors that have been little explored and could help in the identification of "at risk patients" harbouring occult metastasis. The objective of this study was to determine whether intensity of tumour-infiltrating lymphocytes (TILs) in a cohort study (N = 4133) is an independent predictor of sentinel lymph node (SLN) status in patients with primary cutaneous melanoma. Of the patients with cutaneous melanoma who resulted negative for nodal metastasis, 50.7% had moderate/marked TILs versus 27.7% among those patients who resulted positive for nodal metastasis. In the multivariate analysis, controlling for sex, age, mitotic rate, ulceration and Breslow, high levels of TILs in primary invasive melanoma was associated with a lower risk of developing SLN metastasis (OR 0.46; 95% CI 0.23-0.95, p = 0.037). When the analysis was stratified by sex, the protective effect of moderate/marked TIL remained only for women (OR 0.30; 95% CI 0.10-0.93, p = 0.037) but not for men (OR 0.51; 95% CI 0.19-1.34, p = 0.172). Other independent predictors of negative lymph node were low Breslow thickness (≤ 2.0 mm) and low mitotic rate. Besides predicting a negative lymph node response, TILs were also associated with a decreased risk of 10-year mortality among females with positive lymph node. Our findings suggest that high level of TILs is an independent predictor of negative SLN status among women. Further research is warranted to confirm our findings.

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.

PCC0208018 exerts antitumor effects by activating effector T cells

Poor prognosis is associated with melanoma due to immunosuppression profiles, suggesting that immune alterations have an important role in the occurrence, growth, and metastasis of melanoma. Here, we found that PCC0208018, a small-molecule compound, enhanced T cell proliferation and activation to release interferon gamma (IFN-γ) and interleukin-2 (IL-2) without blocking the programmed cell death 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) binding and did not directly affect tumor cell viability in vitro. Furthermore, PCC0208018 increased the phosphorylation of protein kinase B (PKB/AKT) as well as extracellular regulated protein kinases (ERK) in human peripheral blood mononuclear cells (PBMCs) in vitro. The secretion of cytokines induced by PCC0208018 was significantly suppressed by the PI3K inhibitor GDC-0941. In B16-F10 melanoma-harboring mice, PCC0208018 significantly inhibited tumor growth as well as increasing CD3⁺, CD3⁺CD4⁺, and CD3⁺CD8⁺ T cell abundance in tumors without affecting PD-L1 expression. This study showed that PCC0208018 potentially increased PBMCs proliferation and function by activating the phosphatidylinositol 3 kinase (PI3K)/AKT and mitogen-activated protein kinase (MEK)/ERK pathways to exert antitumor effects.

Multifaceted Role of the Placental Growth Factor (PlGF) in the Antitumor Immune Response and Cancer Progression

The sharing of molecules function that affects both tumor growth and neoangiogenesis with cells of the immune system creates a mutual interplay that impairs the host’s immune response against tumor progression. Increasing evidence shows that tumors are able to create an immunosuppressive microenvironment by recruiting specific immune cells. Moreover, molecules produced by tumor and inflammatory cells in the tumor microenvironment create an immunosuppressive milieu able to inhibit the development of an efficient immune response against cancer cells and thus fostering tumor growth and progression. In addition, the immunoediting could select cancer cells that are less immunogenic or more resistant to lysis. In this review, we summarize recent findings regarding the immunomodulatory effects and cancer progression of the angiogenic growth factor namely placental growth factor (PlGF) and address the biological complex effects of this cytokine. Different pathways of the innate and adaptive immune response in which, directly or indirectly, PlGF is involved in promoting tumor immune escape and metastasis will be described. PlGF is important for building up vascular structures and functions. Although PlGF effects on vascular and tumor growth have been widely summarized, its functions in modulating the immune intra-tumoral microenvironment have been less highlighted. In agreement with PlGF functions, different antitumor strategies can be envisioned.

Prognostic value of tumor-infiltrating lymphocytes in melanoma: a systematic review and meta-analysis

Tumor-infiltrating lymphocytes (TILs) are associated with prognosis in various tumors. However, it remains controversial whether the presence of TILs is related to an improved prognosis in melanoma. This meta-analysis confirmed the favorable prognostic role of the CD3+, CD4+, CD8+, FOXP3+, and CD20+ TILs in the overall survival of melanoma patients and found an association between the TILs present and improved overall survival. Additionally, subgroup analysis demonstrated that brisk TILs were obviously associated with OS, RFS and DSS/MSS. Thus, TILs may be a predictive biomarker in melanoma. This analysis will provide more insight into the study of TILs and predictive biomarker.

A new perspective: Exploring future therapeutic strategies for cancer by understanding the dual role of B lymphocytes in tumor immunity

Our previous understanding of the role of B lymphocytes in tumor immunity is its antitumor effects. However, further evidence indicates B lymphocytes can also promote tumorigenesis by modulating immune responses. Therefore, the increasingly complex role of B lymphocytes in tumor immunity may become an important factor in tumor immunotherapy. In this review, we describe the development of B cells in tumor microenvironments. We then focus on the most controversial issues of the biological functions of B lymphocytes. Finally, we nominate B cells as therapeutic targets, which should open broad perspectives for the development of their clinical applications.