PD-L1 expression in tumour-infiltrating lymphocytes is a poor prognostic factor for primary acral melanoma patients

Programmed Cell Death Ligand 1 Immunohistochemical Expression and Cutaneous Melanoma: A Controversial Relationship

Cutaneous melanoma (CM) is traditionally considered one of the most "immunogenic" tumors, eliciting a high immune response. However, despite the presence of tumor-infiltrating lymphocytes (TILs), melanoma cells use strategies to suppress antitumor immunity and avoid being eliminated by immune surveillance. The PD-1 (programmed death-1)/PD-L1 (programmed death-ligand 1) axis is a well-known immune escape system adopted by neoplastic cells. Therefore, immunotherapy with PD-1 and PD-L1 inhibitors is quickly becoming the main treatment approach for metastatic melanoma patients. However, the clinical utility of PD-L1 expression assessment in CM is controversial, and the interpretation of PD-L1 scores in clinical practice is still a matter of debate. Nonetheless, the recent literature data show that by adopting specific PD-L1 assessment methods in melanoma samples, a correlation between the expression of such a biomarker and a positive response to PD-1-based immunotherapy can be seen. Our review aims to describe the state-of-the-art knowledge regarding the prognostic and predictive role of PD-L1 expression in CM while also referring to possible biological explanations for the variability in its expressions and related treatment responses.

Association of NRAS mutations and tertiary lymphoid structure formation with clinical outcomes of adjuvant PD-1 inhibitors for acral melanoma

OBJECTIVES

This study evaluates the efficacy of programmed death-1 (PD-1) inhibitors as adjuvant therapy for acral melanoma (AM) and the predictive value of genetic mutations and tertiary lymphoid structures (TLSs).

METHODS AND RESULTS

A single-center retrospective longitudinal cohort study was conducted between October 1, 2018, and September 31, 2022. Patients with stages II-III completely resected AM were treated with at least two doses of adjuvant PD-1 inhibitors. A total of 44 participants were included in the final analysis, of which 41 patients with stage III. The median follow-up time, median relapse-free survival (RFS), and median distance metastasis-free survival (DMFS) for all patients were 18.4 months, 21.6 months, and 30.6 months, respectively. 21 (47.7%) and 20 (45.5%) patients were intravenously administered pembrolizumab and toripalimab, respectively. There were no significant differences in RFS (24.4 months vs. 18.9 months, p = 0.432) or DMFS (30.6 months vs. not reached, p = 0.865) between the pembrolizumab and toripalimab groups, respectively. The median DMFS (41.1 months vs. 9.0 months, p < 0.001) in the wild-type NRAS group was significantly longer than that in the NRAS mutation group. Overall, different levels of TLSs infiltration did not significantly affect patient survival. Only three people discontinued treatment due to adverse events. No treatment-related death occurred during the study period.

CONCLUSION

Our study suggests that adjuvant toripalimab and pembrolizumab therapy have comparable efficacies in patients with AM and are both well tolerated. Adjuvant monotherapy with PD-1 inhibitors may not be appropriate for AM with NRAS mutations.

Immunohistochemical Expression of Programmed Cell Death Ligand 1 (PD-L1) in Human Cutaneous Malignant Melanoma: A Narrative Review with Historical Perspectives

Programmed death-ligand 1 (PD-L1) is the primary ligand of the receptor programmed death-1 (PD-1) which is constitutively expressed or activated in myeloid, lymphoid (T, B and NK), normal epithelial cells, and cancer. The PD-1/PD-L1 interaction is crucial for the physiological development of immunological tolerance but also in the development of the cancer. Among these, malignant melanoma represents a tumour in which the immunohistochemical expression of PD-L1 is important to guide future therapeutic choices based on the presence/absence of expression. Various clones have been used over time for immunohistochemical determination, and different results and heterogeneity remain among the various studies in the literature. We perform a narrative review of the present studies in order to discuss and take stock of what certain achievements have been made in this field, what challenges remain, and what possible solutions can be found.

PD-L1, CD4+, and CD8+ Tumor-Infiltrating Lymphocytes (TILs) Expression Profiles in Melanoma Tumor Microenvironment Cells

(1) Background: Because melanoma is an aggressive tumor with an unfavorable prognosis, we aimed to characterize the PD-L1 expression in melanomas in association with T cell infiltrates because PD-1/PD-L1 blockade represents the target in treating melanoma strategy. (2) Methods: The immunohistochemical manual quantitative methods of PD-L1, CD4, and CD8 TILs were performed in melanoma tumor microenvironment cells. (3) Results: Most of the PD-L1 positive, expressing tumors, have a moderate score of CD4+ TILs and CD8+TILs (5-50% of tumor area) in tumoral melanoma environment cells. The PD-L1 expression in TILs was correlated with different degrees of lymphocytic infiltration described by the Clark system (X² = 8.383, p = 0.020). PD-L1 expression was observed often in melanoma cases, with more than 2-4 mm of Breslow tumor thickness being the associated parameters (X² = 9.933, p = 0.014). (4) Conclusions: PD-L1 expression represents a predictive biomarker with very good accuracy for discriminating the presence or absence of malign tumoral melanoma cells. PD-L1 expression was an independent predictor of good prognosis in patients with melanomas.

The Association of CD8+ Cytotoxic T Cells and Granzyme B+ Lymphocytes with Immunosuppressive Factors, Tumor Stage and Prognosis in Cutaneous Melanoma

The immunosuppressive tumor microenvironment (TME) consists of suppressive cells producing a variety of immunomodulatory proteins, such as programmed death ligand 1 (PD-L1) and indoleamine-2,3-dioxygenase (IDO). Although granzyme B (GrB) is known to convey the cytolytic activities of CD8+ cytotoxic lymphocytes, it is also expressed by other cells, such as regulatory T and B cells, for immunosuppressive purposes. The role of GrB+ lymphocytes in melanoma has not been examined extensively. In this study, benign, premalignant, and malignant melanocytic tumors were stained immunohistochemically for CD8 and GrB. PD-L1 was also stained from malignant samples that had accompanying clinicopathological data. The association of CD8+ and GrB+ lymphocytes with PD-L1 expression, tumor stage, prognosis, and previously analyzed immunosuppressive factors were evaluated. Our aim was to obtain a more comprehensive perception of the immunosuppressive TME in melanoma. The results show that both CD8+ and GrB+ lymphocytes were more abundant in pT4 compared to pT1 melanomas, and in lymph node metastases compared to primary melanomas. Surprisingly, a low GrB/CD8 ratio was associated with better recurrence-free survival in primary melanomas, which indicates that GrB+ lymphocytes might represent activated immunosuppressive lymphocytes rather than cytotoxic T cells. In the present study, CD8+ lymphocytes associated positively with both tumor and stromal immune cell PD-L1 and IDO expression. In addition, PD-L1+ tumor and stromal immune cells associated positively with IDO+ stromal immune and melanoma cells. The data suggest that IDO and PD-L1 seem to be key immunosuppressive factors in CD8+ lymphocyte-predominant tumors in CM.

The current landscape of predictive and prognostic biomarkers for immune checkpoint blockade in ovarian cancer

Immune checkpoint blockade (ICB) therapy has evoked a prominent shift in anticancer therapy. Durable clinical antitumor activity to ICB has been observed in patients with ovarian cancer (OC). However, only a subset of patients derive clinical benefit, and immune-related adverse events (irAEs) caused by ICB therapy can lead to permanent tissue damage and even fatal consequences. It is thus urgent to develop predictive biomarkers to optimize patient outcomes and minimize toxicity risk. Herein, we review current predictive and prognostic biomarkers for checkpoint immunotherapy in OC and highlight emerging biomarkers to guide treatment with ICB. The prevalent biomarkers, such as PD-L1 expression status, tumor-infiltrating lymphocytes, mutational burden, and immune gene signatures, are further discussed. We provide a state-of-the-art survey on prognostic and predictive biomarkers for checkpoint immunotherapy and offer valuable information for guiding precision immunotherapy

Appraisal of clinicopathological prognosticators in advanced acral lentiginous melanoma with characterization of PD-L1 and CD8/CD4 immunoprofiles

OBJECTIVE

Acral lentiginous melanoma is the most common subtype of cutaneous melanoma in Asian countries. This study aims to clarify the associations between certain histologic and immunohistochemical parameters, and identify their prognostic values.

METHODS

We assessed several histologic features and conducted immunohistochemical study of programmed cell death ligand 1 (clone 22C3) and CD8/CD4 in 61 Taiwanese patients with Stage III/IV, non-BRAF acral lentiginous melanomas.

RESULTS

A total of 41 males and 20 females were included, with a median age of 74 years. The majority of tumors occurred at nonungual locations (86.9%), with 'foot' being the most frequently affected site (85.2%). Positive programmed cell death ligand 1 staining (combined positive score ≥ 10) was significantly associated with the status of tumor-infiltrating lymphocytes (P = 0.036). Lack of skin ulceration was linked to the immunoexpression of CD8/CD4-high (P = 0.004). A superior clinical outcome was found in the tumor-infiltrating lymphocytes-present group (P = 0.011), and among which, CD8/CD4-high was significantly correlated with better survival (P < 0.001). Combined survival analysis revealed that the PD-L1(-) TIL(+) CD8/CD4-high subgroup was associated with favorable prognosis, and cases with PD-L1(+) TIL(-) showed the worst disease specific survival (P < 0.001). In the univariate analysis, lymphovascular invasion (P = 0.002), skin ulceration (P = 0.002), tumor-infiltrating lymphocytes (P = 0.015) and CD8/CD4 status (P < 0.001) were significant prognostic factors. At the multivariate level, the statuses of CD8/CD4-low (P < 0.001) and lymphovascular invasion (P = 0.014) represented the independent poor prognosticators.

CONCLUSION

For advanced, non-BRAF acral lentiginous melanomas, comprehensive assessments of these microscopic traits, along with CD8/CD4 and PD-L1 immunoprofiles, may help guide the clinicians and patients through treatment decisions.

Clinical features, molecular pathology, and immune microenvironmental characteristics of acral melanoma

Acral melanoma (AM) has unique biology as an aggressive subtype of melanoma. It is a common subtype of melanoma in races with darker skin tones usually diagnosed at a later stage, thereby presenting a worse prognosis compared to cutaneous melanoma. The pathogenesis of acral melanoma differs from cutaneous melanoma, and trauma promotes its development. Compared to cutaneous melanomas, acral melanomas have a significantly lighter mutational burden with more copy number variants. Most acral melanomas are classified as triple wild-type. In contrast to cutaneous melanomas, acral melanomas have a suppressive immune microenvironment. Herein, we reviewed the clinical features, genetic variants, and immune microenvironmental characteristics of limbic melanomas to summarise their unique features.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

The Role of the Tumor Microenvironment and Treatment Strategies in Colorectal Cancer

Colorectal cancer (CRC) has the second highest mortality rate among all cancers worldwide. Surgery, chemotherapy, radiotherapy, molecular targeting and other treatment methods have significantly prolonged the survival of patients with CRC. Recently, the emergence of tumor immunotherapy represented by immune checkpoint inhibitors (ICIs) has brought new immunotherapy options for the treatment of advanced CRC. As the efficacy of ICIs is closely related to the tumor immune microenvironment (TME), it is necessary to clarify the relationship between the immune microenvironment of CRC and the efficacy of immunotherapy to ensure that the appropriate drugs are selected. We herein review the latest research progress in the immune microenvironment and strategies related to immunotherapy for CRC. We hope that this review helps in the selection of appropriate treatment strategies for CRC patients.

More than just acral melanoma: the controversies of defining the disease

Acral melanoma (AM) is a malignant cutaneous melanocytic tumour specifically located on the palms, soles, and nail apparatus, which are areas of glabrous (hairless) skin. Acral lentiginous melanoma, a subtype of AM, represents a histopathological subtype diagnosis of cutaneous melanoma with unique morphological and structural features. Despite clear definitions, the misuse of these terms and the inconsistency in reporting the histopathological features of AM cases have become a major obstacle to the study of the disease. In this review, we discuss the epidemiology, histopathological features, prognosis, and genetic profile of AM, highlighting the differences observed when histopathological subtypes are considered. The increasing global effort to characterise AM cases from ethnically diverse populations would benefit greatly from a more consistent classification of the disease.

Expression, prognostic significance and therapeutic implications of PD-L1 in gliomas

The advent of checkpoint immunotherapy, particularly with programmed death‐1 (PD‐1) and programmed death‐ligand 1 (PD‐L1) inhibitors, has provided ground‐breaking results in several advanced cancers. Substantial efforts are being made to extend these promising therapies to other refractory cancers such as gliomas, especially glioblastoma, which represents the most frequent and malignant glioma and carries an exceptionally grim prognosis. Thus, there is a need for new therapeutic strategies with related biomarkers. Gliomas have a profoundly immunosuppressive tumour micro‐environment and evade immunological destruction by several mechanisms, one being the expression of inhibitory immune checkpoint molecules such as PD‐L1. PD‐L1 is recognised as an important therapeutic target and its expression has been shown to hold prognostic value in different cancers. Several clinical trials have been launched and some already completed, but PD‐1/PD‐L1 inhibitors have yet to show convincing clinical efficacy in gliomas. Part of the explanation may reside in the vast molecular heterogeneity of gliomas and a complex interplay within the tumour micro‐environment. In parallel, critical knowledge about PD‐L1 expression is beginning to accumulate including knowledge on expression levels, testing methodology, co‐expression with other checkpoint molecules and prognostic and predictive value. This article reviews these aspects and points out areas where biomarker research is needed to develop more successful checkpoint‐related therapeutic strategies in gliomas.

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.

Complete response to immunotherapy combined with an antiangiogenic agent in multiple hepatic metastases after radical surgery for advanced gallbladder cancer: a case report

Most advanced gallbladder cancers (GBCa) are unresectable or metastatic once diagnosed, and even patients who undergo surgery have a high risk of recurrence and metastasis. Immunotherapy, especially immune checkpoint inhibitors (ICIs), combined with an antiangiogenic agent, is an emerging prospective treatment for GBCa. However, the efficacy and safety of this combination therapy have not yet been investigated. We report the case of a 70-year-old female patient with recurrent metastatic GBCa (stage IVB) after radical surgery. Immunohistochemical examination revealed that 10% of the tumor cells expressed programmed cell death protein-1 (PD-1) and programmed cell death receptor ligand 1 (PD-L1). Whole-exome sequencing showed cancer tissues with a low tumor mutational burden (TMB) and microsatellite stability (MSS). The patient received Camrelizumab (200 mg, every three weeks) and Apatinib (40 mg/d). The clinical and immunological responses were observed, and the patient achieved a complete response after five cycles. This is the first case describing the efficacy and safety of Camrelizumab plus Apatinib in a GBCa patient with weak PD-1 and PD-L1 expression, and low TMB and MSS. The treatment had a tolerable safety profile and a complete response in the patient. Also, we found that the cluster of differentiation (CD)16+CD56+natural killer (NK) cell ratio in peripheral blood was increased after the combined treatment. Immunotherapy with antiangiogenic drugs may be a potential treatment option for patients with recurrent GBC or GBCa.

The relationships between PD-L1 expression, CD8+ TILs and clinico-histomorphological parameters in malignant melanomas

INTRODUCTION

Malignant melanomas (MM) are often connected with the expression of PD-L1 protein and the presence of tumor-infiltrating lymphocytes (TILs), however, their impact on prognosis remains controversial. Due to their supposed clinical significance and lack of convincing data, we decided to establish the relationships between CD8 + TIL count, PD-L1 level and certain clinical and histopathological parameters in patients with malignant melanoma, especially those associated with unfavorable prognosis.

MATERIALS AND METHODS

We performed immunohistochemistry for PD-L1 and CD8 on 56 formalin-fixed paraffin-embedded specimens from patients with cutaneous and metastatic malignant melanomas. PD-L1 expression levels were determined by immunohistochemistry (clone 28-8) and subsequently the tumor proportion scores (TPS) were evaluated. CD8 + TIL expressions were classified as either grade 0, 1+, 2+ or 3+, based on the density and distribution of the infiltrating lymphocytes.

RESULTS

The PD-L1 expression was detected in 20 out of 56 cases (35,71 %). The expression of PD-L1 on tumor cells was significantly increased with higher TILs infiltration in the tumor microenvironment (p = 0,038). Lower TIL score corresponds with poor prognostic clinicopathological parameters such as higher number of mitotic figures (p = 0,005), Clark's level (p = 0,007) and Breslow's depth (p = 0,010).

CONCLUSIONS

Our results suggest a favorable prognostic value for CD8 + TIL infiltration. Moreover, TIL density was strongly correlated and geographically associated to PD-L1 expression. This analysis provides more insight into the role of TIL count and PD-L1 level in MM and their relationship with each other and association with other prognostic indicators.

A pooled analysis of the prognostic value of PD-L1 in melanoma: evidence from 1062 patients

Background

Programmed death-ligand 1 (PD-L1) was the first identified ligand of programmed death-1 (PD-1). PD-1/PD-L1 interactions inhibit T cell-mediated immune responses, limit cytokine production, and promote tumor immune escape. Recently, many studies have investigated the prognostic value of PD-L1 expression in patients with melanoma. However, the results of these analyses remain a subject of debate. We have therefore carried out a meta-analysis to identify the prognostic role of PD-L1 in melanoma.

Methods

A thorough medical literature search was performed in the databases PubMed, Web of Science, and Embase until October 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated to evaluate the correlation between PD-L1 overexpression and prognosis. Publication bias was evaluated using Begg’s test and Egger’s test.

Results

Thirteen articles with 1062 enrolled patients were included in this meta-analysis. High PD-L1 expression did not correlate with overall survival (OS) (HR = 0.93, 95% CI 0.57–1.52, P = 0.781) or progression-free survival (PFS) (HR = 0.82, 95% CI 0.43–1.54, P = 0.535). However, PD-L1 overexpression correlated with the absence of lymph node (LN) metastasis (OR = 0.46, 95% CI 0.22–0.95, P = 0.036). Further, there was no significant relationship between PD-L1 expression and sex (OR = 1.29, 95% CI 0.90–1.84, P = 0.159), age (OR = 0.90, 95% CI 0.51–1.57, P = 0.708), or Eastern Cooperative Oncology Group Performance Status (OR = 0.55, 95% CI 0.06–4.83, P = 0.592).

Conclusions

This meta-analysis suggested that PD-L1 expression did not predict an inferior prognosis in patients with melanoma. However, high PD-L1 expression was associated with absence of LN metastasis in such patients.

Tumour Microenvironment in Skin Carcinogenesis

Tumour microenvironment is a complex system comprising cells and molecules that will provide the necessary conditions for tumour development and progression. Cells residing in the tumour microenvironment gain specific phenotypes and specific functions that are pro-tumorigenic. Tumour progression is in fact a combination between tumour cell characteristics and its interplay with tumour microenvironment. This dynamic network will allow tumour cells to grow, migrate and invade tissues. In the present chapter, we are highlighting some traits that characterise tumour microenvironment in basal cell carcinoma, squamous cell carcinoma and cutaneous melanoma. In skin cancers, there are some common tumour microenvironment characteristics such as the presence of tumour-associated macrophages and regulatory T lymphocytes that are non-tumour cells promoting tumorigenesis. There are also skin cancer type differences in terms of tumour microenvironment characteristics. Thus, markers such as macrophage migration inhibitory factor in melanoma or the extraordinary diverse genetic make-up in the cancer-associated fibroblasts associated to squamous cell carcinoma are just a few of specific traits in skin cancer types. New technological advances for evaluation of tumour environment are presented. Thus, non-invasive skin imaging techniques such as reflectance confocal microscopy can evaluate skin tumour inflammatory infiltrates for density and cellular populations. Analysing tumour micromedium in depth may offer new insights into cancer therapy and identify new therapy targets.

Clinicopathological and prognostic significance of programmed death ligand 1 expression in Korean melanoma patients

Programmed death ligand 1 (PD-L1) expression provides significant value to predict prognosis and response following immunotherapy in several types of cancers. However, its clinicopathological and prognostic significance in melanoma remains unclear. PD-L1 and the number of tumor infiltrating lymphocytes (TILs) were investigated in 63 Korean patients with melanoma based on the melanoma scoring system. We also compared the results using the PD-L1 antibodies—22C3 and E1L3N clones. In addition, BRAF gene mutation was detected using anti-BRAF antibody and real-time polymerase chain reaction. Overall, 29 (46.0%), 16 (25.4%), and 18 (28.6%) patients exhibited the acral lentiginous type, nodular type, and other histological subtypes of melanoma, respectively. PD-L1 expression was detected in 37 (58.7%) cases and was closely associated with a CD8+TIL^high phenotype (P < 0.001). Combined survival analysis depending on PD-L1 and CD8+TILs status showed that the PD-L1-/CD8+TIL^high group demonstrated the best survival outcome, whereas patients with PD-L1+/CD8+ TIL^low showed the worst prognosis (P = 0.039). However, PD-L1+/CD8+ TIL^low was not an independent prognostic factor. The 22C3 and E1L3N clones showed a high concordance rate (kappa value, 0.799). BRAF mutation status was not correlated with PD-L1 expression. We suggest that evaluation of the combined status of PD-L1 and TIL might be useful to predict the survival of patients with melanoma.

Immune response and evasion mechanisms in lip carcinogenesis: An immunohistochemical study

OBJECTIVES

Programmed death ligand-1 (PD-L1) and human leukocyte antigen-G (HLA-G) are considered immune checkpoint molecules that inhibit T-cell effectiveness, contributing to tumor immune escape. This study investigated PD-L1, HLA-G, CD8, and granzyme B (GrB) expression at different stages of lip carcinogenesis.

DESIGN AND RESULTS

Forty cases of lip squamous cell carcinoma (LSCC), 55 actinic cheilitis (AC), and 10 healthy lip mucosa (HLM) were submitted to immunohistochemistry. Semiquantitative (PD-L1, HLA-G), and quantitative (CD8, GrB) analysis were performed. PD-L1 and HLA-G expression in neoplastic cells/keratinocytes and stroma/connective tissue was significantly higher in LSCC and AC, compared to HLM (p<0.05). PD-L1 was not associated with clinicopathological features of the lesions. HLA-G expression by malignant cells was significantly higher in LSCCs with distant metastasis (p = 0.041).CD8⁺ and GrB⁺ cell numbers progressively increased from HLMs to LSCC, with AC exhibiting intermediate numbers (p<0.01). Most LSCCs showed coexistence of PD-L1⁺ and CD8⁺ cells (72.5%). PD-L1 was directly correlated to CD8⁺ and GrB⁺ lymphocytic infiltration in LSCCs (p<0.05). Low cytotoxic immune response was associated with lymph node metastasis in LSCC (p<0.05).

CONCLUSIONS

PD-L1 and HLA-G-mediated immune evasion mechanisms are likely to occur from early pre-malignant to advanced malignant stages of lip carcinogenesis, which might provide a rationale for therapeutic blockade of these pathways. PD-L1 expression in LSCCs was correlated with the cytotoxic markers, suggesting that PD-L1 may appear as an escape mechanism in response to an active antitumor response.

PD-L1 Expression in Men with Penile Cancer and its Association with Clinical Outcomes

BACKGROUND

It has been hypothesized that PD-L1 expression in tumor cells and tumor-infiltrating immune (TII) cells may contribute to tumor progression by inhibiting antitumor immunity.

OBJECTIVE

To investigate the association between PD-L1 expression in tumor cells and TII cells and clinical outcomes in penile cancer.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 222 men treated for penile squamous cell carcinoma (SqCC) at Örebro University Hospital between 1984 and 2008 with long-term follow-up (median 34 mo) was evaluated for PD-L1 expression in tumor cells and TII cells via immunohistochemistry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Association between clinicopathological features and PD-L1 expression was estimated using χ² and Fisher's exact tests. For survival analyses, Kaplan-Meier curves with log-rank tests and multivariate Cox proportional hazards regression models were used.

RESULTS AND LIMITATIONS

We found that 32.1% of the tumors and 64.2% of the TII cells expressed PD-L1. Our data demonstrate that penile SqCC patients with PD-L1-positive tumor cells or TII cells are at significant risk of lower cancer-specific survival and that the prognostic value of PD-L1 expression was strongest for tumor cell positivity. The use of tissue microarrays rather than whole sections may be viewed as a limitation.

CONCLUSIONS

Tumor PD-L1 expression independently identifies penile SqCC patients at risk of poor clinical outcomes.

PATIENT SUMMARY

We investigated how many patients with penile cancer had tumors that manufactured PD-L1, a protein that decreases the ability of the immune system to fight cancer. We found that up to one-third of penile tumors make this protein. Patients whose tumors make PD-L1 have more aggressive penile cancer and worse clinical outcomes.

A reliable and feasible way to predict the benefits of Nivolumab in patients with non-small cell lung cancer: a pooled analysis of 14 retrospective studies

Objective: Nivolumab has been used for treating non-small cell lung cancer (NSCLC) worldwide. Whether neutrophil-lymphocyte ratio (NLR) can predict the prognosis of NSCLC treated with Nivolumab is still under debate. This meta-analysis was to assess the significance of NLR as a predictive factor in NSCLC patients receiving Nivolumab. Methods: Databases including PubMed, Embase, and the Cochrane library were searched to identify eligible studies evaluating the role of NLR in predicting prognosis of NSCLC treated with Nivolumab until March 2018 without language restrictions. The meta-analysis was performed using hazard ratio (HR) of progression free survival (PFS) and overall survival (OS) in NSCLC patients with various NLR. Results: A total of 14 retrospective studies consisting of 1225 NSCLC patients were included. The combined results showed that relatively higher baseline NLR was associated with poor PFS (HR = 1.44; 95% confidence interval (CI):1.18-1.77; p < 0.05) and OS (HR = 1.75; 95% CI: 1.33-2.30; p < 0.05) after treatment of Nivolumab. Subgroup analysis suggested that NLR ≥ 5 was more reliable for PFS (HR = 1.73; 95%CI: 1.14, 2.62; p < 0.05) and OS (HR = 1.76; 95%CI: 1.47, 2.10; p < 0.05). In addition, post-treatment NLR also had predictive roles for PFS (HR = 3.17; 95%CI: 1.48, 6.82; p < 0.05) and OS (HR = 2.26; 95%CI: 1.05, 4.86; p < 0.05). Conclusion: Our findings suggest that NLR can be used as a prognostic biomarker for NSCLC treating with Nivolumab, and the recommended cutoff value of NLR is 5.