Prognostic significance of programmed death ligand-1 immunohistochemical expression in esophageal cancer: A meta-analysis of the literature

PD-L1-expressing cancer-associated fibroblasts induce tumor immunosuppression and contribute to poor clinical outcome in esophageal cancer

The programmed cell death 1 protein (PD-1)/programmed cell death ligand 1 (PD-L1) axis plays a crucial role in tumor immunosuppression, while the cancer-associated fibroblasts (CAFs) have various tumor-promoting functions. To determine the advantage of immunotherapy, the relationship between the cancer cells and the CAFs was evaluated in terms of the PD-1/PD-L1 axis. Overall, 140 cases of esophageal cancer underwent an immunohistochemical analysis of the PD-L1 expression and its association with the expression of the α smooth muscle actin, fibroblast activation protein, CD8, and forkhead box P3 (FoxP3) positive cells. The relationship between the cancer cells and the CAFs was evaluated in vitro, and the effect of the anti-PD-L1 antibody was evaluated using a syngeneic mouse model. A survival analysis showed that the PD-L1+ CAF group had worse survival than the PD-L1- group. In vitro and in vivo, direct interaction between the cancer cells and the CAFs showed a mutually upregulated PD-L1 expression. In vivo, the anti-PD-L1 antibody increased the number of dead CAFs and cancer cells, resulting in increased CD8+ T cells and decreased FoxP3+ regulatory T cells. We demonstrated that the PD-L1-expressing CAFs lead to poor outcomes in patients with esophageal cancer. The cancer cells and the CAFs mutually enhanced the PD-L1 expression and induced tumor immunosuppression. Therefore, the PD-L1-expressing CAFs may be good targets for cancer therapy, inhibiting tumor progression and improving host tumor immunity.

Mechanisms and clinical implications in renal carcinoma resistance: narrative review of immune checkpoint inhibitors

Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cell carcinoma. The prognosis for patients with ccRCC has improved over recent years with the use of combination therapies with an anti-programmed death-1 (PD-1) backbone. This has enhanced the quality of life and life expectancy of patients with this disease. Unfortunately, not all patients benefit; eventually, most patients will develop resistance to therapy and progress. Recent molecular, biochemical, and immunological research has extensively researched anti-angiogenic and immune-based treatment resistance mechanisms. This analysis offers an overview of the principles underpinning the resistance pathways related to immune checkpoint inhibitors (ICIs). Additionally, novel approaches to overcome resistance that may be considered for the trial context are discussed.

Roles of PTEN inactivation and PD-1/PD-L1 activation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer in China and developing countries. The purpose of this review is to summarize the roles of inactivation of the tumor suppressor gene, phosphatase and tensin homolog (PTEN), and activation of the programmed cell death protein 1 (PD-1) upon binding to its ligand (PD-L1) in the promotion of ESCC. Studies of ESCC performed in vitro and in vivo indicated that PTEN and PD-L1 function in the regulation of cell proliferation, invasion, and migration; the epithelial-mesenchymal transition; resistance to chemotherapy and radiotherapy; and the PI3K/AKT signaling pathway. Certain genetic variants of PTEN are related to susceptibility to ESCC, and PTEN and PD-L1 also function in ESCC progression and affect the prognosis of patients with ESCC. There is also evidence that the expression of PD-L1 and PTEN are associated with the progression of certain other cancers. Future studies should further examine the relationship of PD-L1 and PTEN and their possible interactions in ESCC.

Prognostic significance of T-cell-inflamed gene expression profile and PD-L1 expression in patients with esophageal cancer

Purpose

The ability of the T‐cell–inflamed gene expression profile (GEP) to predict clinical outcome in esophageal cancer (EC) is unknown. This retrospective observational study assessed the prognostic value of GEP and programmed death ligand 1 (PD‐L1) expression in patients with EC treated in routine clinical practice.

Methods

Tumor samples of 294 patients from three centers in Denmark, South Korea, and the United States, collected between 2005 and 2017, were included. T‐cell–inflamed GEP score was defined as non‐low or low using a cutoff of −1.54. A combined positive score (CPS) ≥10 was defined as PD‐L1 expression positivity. Associations between overall survival (OS) and GEP status and PD‐L1 expression were explored by Cox proportional hazards models adjusting for age, sex, histology, stage, and performance status.

Results

Median age was 65 years; 63% of patients had adenocarcinoma (AC) and 37% had squamous cell carcinoma (SCC). Thirty‐six percent of tumors were GEP non‐low, with higher prevalence in AC (46%) than SCC (18%). Twenty‐one percent were PD‐L1–positive: 32% in South Korean samples versus 16% in non‐Asian samples and 26% in SCC versus 18% in AC. GEP scores and PD‐L1 CPS were weakly correlated (Spearman’s R = 0.363). OS was not significantly associated with GEP status (non‐low vs low; adjusted hazard ratio, 0.91 [95% CI, 0.69–1.19]) or PD‐L1 expression status.

Conclusion

Neither GEP nor PD‐L1 expression was a prognostic marker in Asian and non‐Asian patients with EC.

PD-L1 as a biomarker of response to immune-checkpoint inhibitors

Immune-checkpoint inhibitors targeting PD-1 or PD-L1 have already substantially improved the outcomes of patients with many types of cancer, although only 20-40% of patients derive benefit from these new therapies. PD-L1, quantified using immunohistochemistry assays, is currently the most widely validated, used and accepted biomarker to guide the selection of patients to receive anti-PD-1 or anti-PD-L1 antibodies. However, many challenges remain in the clinical use of these assays, including the necessity of using different companion diagnostic assays for specific agents, high levels of inter-assay variability in terms of both performance and cut-off points, and a lack of prospective comparisons of how PD-L1⁺ disease diagnosed using each assay relates to clinical outcomes. In this Review, we describe the current role of PD-L1 immunohistochemistry assays used to inform the selection of patients to receive anti-PD-1 or anti-PD-L1 antibodies, we discuss the various technical and clinical challenges associated with these assays, including regulatory issues, and we provide some perspective on how to optimize PD-L1 as a selection biomarker for the future treatment of patients with solid tumours.

Clinical Significance of Programmed Death Ligand-1 Expression in Esophageal Squamous Cell Carcinoma

BACKGROUND

The aim of this study was to evaluate the association between the expression of programmed death ligand-1 (PD-L1) and clinical outcomes in patients with surgically resected esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

We included 76 patients with primary ESCC who underwent surgical resection between January 2009 and December 2014 at National Defense Medical College Hospital. Using the tumor tissues, we evaluated PD-L1 expression in tumor cells and stromal reactive lymphocytes via immunohistochemistry. Furthermore, the relationship between PD-L1 expression and the clinicopathological status of patients with ESCC was investigated.

RESULTS

PD-L1 expression in tumor cells was detected in 39.5% of the patients. In addition, 51.3% of the patients had PD-L1-positive stromal reactive lymphocytes and exhibited significantly longer overall survival than those with lack of PD-L1 expression in stromal reactive lymphocytes (median survival time, 56.0 versus 27.3 mo; log-rank test, P = 0.04). Patients with lack of PD-L1 expression in both tumor cells and stromal reactive lymphocytes showed worse overall survival than those with the PD-L1-positive expression in tumor cells and/or stromal reactive lymphocytes (P = 0.02).

CONCLUSIONS

PD-L1-positive expression in stromal reactive lymphocytes, rather than in tumor cells, is associated with a longer survival in patients with ESCC.

Immune Checkpoint Inhibitors in Esophageal Cancers: are we Finally Finding the Right Path in the Mist?

Esophageal cancer remains a challenging disease due to limited treatment options and poor prognosis. In recent years, immune checkpoint inhibitors (ICI) have been proven to be safe and effective in the treatment of highly lethal malignancies, such as non-small cell lung cancer and melanoma. Recent clinical trials also showed promising activity in immune checkpoint inhibitors in pretreated advanced esophageal carcinoma and a potentially significant impact on the outcome of selected patients, independently of histology. Combination studies evaluating immunotherapy and chemotherapy and, in localized disease, radiotherapy are in progress and will hopefully confirm their promises in the near future. However, reliable predictive biomarkers are still lacking. Indeed, at present, the role of programmed cell death ligand 1 expression and other factors (such as microsatellite instability and tumor mutational burden) as predictive biomarkers of benefit to immune checkpoint inhibitors is still controversial. Our aim was to explore the rationale of ICIs in esophageal cancer, review the results already available in multiple settings, and investigate future perspectives with single-agent and combination strategies.

Tiam1 high expression is associated with poor prognosis in solid cancers: A meta-analysis

BACKGROUND

A number of studies have attempted to determine the prognostic value of T-cell lymphoma invasion and metastasis-inducing factor 1 (Tiam1) in patients with solid cancers, but the reported results were of inconsistency. Thus, we performed a systematic review and meta-analysis to exhaustively evaluate the prognostic role of Tiam1 expression in patients with solid cancers.

METHODS

We retrieved literature published in between 1994 and April 22th, 2019 through searching PubMed, Web of Science and China national knowledge infrastructure (CNKI). Hazard ratios (HRs) coupled with 95% confidence intervals (95% CIs) were used to assess the relationship of Tiam1 expression and overall survival (OS), and disease-free survival (DFS).

RESULTS

A total of 2647 patients with solid cancers in 20 studies were enrolled in our meta-analysis eventually. The pooled results showed that Tiam1 high expression was closely correlated with poor OS (HR = 2.17, 95% CI: 1.80-2.61, P = .000) and DFS (pooled HR = 1.95, 95% CI = 1.58-2.40, P = .000). Moreover, our subgroup analysis and sensitivity analysis demonstrated the reliability and stability of our pooled results.

CONCLUSION

In conclusion, this meta-analysis confirmed that Tiam1 higher expression positively correlated with OS and DFS, suggesting that Tiam1 may act as a valuable prognostic predictor and therapeutic target for patients with solid cancers. Nevertheless, in future more homogeneous and prospective studies should be performed to further support our findings.

Immune checkpoint inhibitors: a new era for esophageal cancer

Introduction: The poor prognosis for patients with esophageal cancer (EC) requires evolving current treatment regimens. Immune checkpoint inhibitors show clinical efficacy and a great safety profile in multiple tumors. And the monoclonal antibodies that target programmed death receptor-1/programmed death receptor ligand-1 or the cytotoxic T lymphocyte antigen-4 pathway has shown potential curable effect of EC. Areas covered: This review article covers the prognostic significance of immune checkpoint expression, the accumulating current clinical studies of checkpoint inhibitors in esophageal cancer patients, and future directions. Expert opinion: Many clinical studies have reported favorable survival results with manageable toxicity of anti-programmed death receptor-1/programmed death receptor ligand-1 and anti-cytotoxic T lymphocyte antigen-4 treatment. More results are expected from future clinical studies. It is believed that combining chemoradiotherapy and immune checkpoint inhibitors can induce safe and efficient anti-tumor immune responses and can be a promising therapeutic strategy.

Prognostic markers in salivary gland cancer and their impact on survival

BACKGROUND

The role of molecular markers in salivary gland carcinoma (SGC) is not well understood. We evaluated molecular marker expression and their prognostic value.

METHODS

Immunohistochemical analysis of 124 tumor specimens was performed to determine expression of androgen (AR), estrogen (ER), and progesterone (PR) receptors and epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), programmed death ligand 1 receptor (PD-L1), and PD-L1 in tumor-infiltrating mononuclear cell (TIMC). Survival outcomes (disease-free survival [DFS] and overall survival [OS]), pT and N classification, margin status, and treatment failure were assessed.

RESULTS

Most patients (78; 62.9%) had early-stage SGC. AR positivity and EGFR positivity were detected in 21.0% and 78.6%, respectively, of tumors. AR positivity and PD-L1 negativity were associated with locally advanced disease. PD-L1-negativity was associated with higher recurrence (38.5% vs 0%; P < .001) and worse DFS. OS and DFS were worse in patients with AR+ or HER2+ disease.

CONCLUSIONS

Several molecular markers-AR and HER2 positivity and PD-L1 negativity-were associated with worse clinical outcomes. Prospective, multi-institutional trials are needed to determine the prognostic value of these markers.

A good start of immunotherapy in esophageal cancer

Considering the benefits of immunotherapy in advanced melanoma, non–small cell lung cancer, renal cell carcinoma, bladder cancers, and refractory Hodgkin lymphoma, we begin to consider whether immunotherapy is effective for esophageal cancer, which is extremely malignant and has a poor prognosis. There are a large number of clinical trials to study the application of immunotherapy such as immune checkpoint inhibitors, peptide vaccine, adoptive T cell transfer and oncolytic virus in esophageal cancer. Some already have preliminary results and show the advantages of immunotherapy in esophageal cancer, while others are still in progress. This review aims to introduce the feasibility and current status of immunotherapy in esophageal cancer.