Systematic review and meta-analysis of immunohistochemical prognostic biomarkers in resected oesophageal adenocarcinoma

Predictive value of Leukocyte ImmunoTest (LIT™) in cancer patients: a prospective cohort study

Early diagnosis of cancer is crucial to initiate prompt treatment for better patient outcomes. The host immune function and its associated modulators are considered to be potential biomarkers for early cancer diagnosis. Immune and immune-checkpoint biomarkers have been reported to contribute to cancer development, while a high neutrophil-to-lymphocyte ratio has been shown to be associated with poor survival outcomes in a variety of cancers. One hundred sixty-one cancer patients were recruited to take a cost-effective novel Leukocyte ImmuneTest (LIT). LIT was measured to objectively determine the pre-treatment immune status of patients. The correlation between LIT and other conventional diagnostic markers or tumor-related variables was then investigated. Significant correlations between LIT and white blood cell count, smoking status, and tumor stage 4 were found. In addition, the LIT score significantly differentiated between malignant and benign tumors in this study population. Our work raises the possibility to use LIT for general screening surveillance before further costly specialized equipment is applied for cancer diagnosis.

High CD8+ tumour-infiltrating lymphocyte density associates with unfavourable prognosis in oesophageal adenocarcinoma following poor response to neoadjuvant chemoradiotherapy

AIMS

Determining prognosis following poor response to neoadjuvant chemoradiotherapy (nCRT) in oesophageal adenocarcinoma (OAC) remains challenging. An immunosuppressive tumour microenvironment (TME) as well as immune infiltrate density and composition are considered to play a critical role in the immune interaction between host and tumour and can predict therapy response and survival in many cancers, including gastrointestinal malignancies. The aim of this study was to establish the TME characteristics associated with survival following a poor response to nCRT.

METHODS AND RESULTS

The prognostic significance of OAC-associated CD3⁺ , CD4⁺ , CD8⁺ , forkhead box protein 3 (FoxP3⁺ ) and programmed cell death ligand 1 (PD-L1) expression was studied by immunohistochemistry and quantified by automated image analysis in 123 patients who underwent nCRT and curative resection. Results from good and poor responders were contrasted and immune infiltration was related to disease course in both groups. Subsequently a cohort of 57 patients with a moderate response to nCRT was analysed in a similar fashion. Tumour cell percentage positively correlated to immune infiltration markers. In good and moderate responders, none of the immune infiltrate parameters was associated with survival; in poor responders CD8⁺ was an independent negative predictor of OS in univariate analysis (P = 0.03) and high CD8⁺ infiltration was associated with worse OS (15 versus 32 months, P = 0.042).

CONCLUSION

A high CD8⁺ density is an independent biomarker of poor OS in poor responders to nCRT, but not in good and moderate responders. Our results suggest that patients with a poor response to nCRT but concomitant high CD8⁺ counts in the resection specimen require adjuvant therapy.

Distribution of tumor-infiltrating-T-lymphocytes and possible tumor-escape mechanisms avoiding immune cell attack in locally advanced adenocarcinomas of the esophagus

Introduction

The inflammatory microenvironment has emerged as one of the focuses of cancer research. Little is known about the immune environment in esophageal adenocarcinoma (EAC) and possible tumor-escape mechanisms to avoid immune cell attack.

Patients and methods

We measured T cell inflammation (CD3, CD8) in the microenvironment using a standardized software-based evaluation algorithm considering different predefined tumor areas as well as expression of MHC class 1 and PD-L1 on 75 analyzable primarily resected and locally advanced (≥ pT2) EACs. We correlated these findings statistically with clinical data.

Results

Patients with high amounts of T cell infiltration in their tumor center showed a significant survival benefit of 41.4 months compared to 16.3 months in T cell poor tumors (p = 0.025), although CD3 fails to serve as an independent prognostic marker in multivariate analysis. For the invasion zone, a correlation between number of T-cells and overall survival was not detectable. Loss of MHC1 protein expression on tumor cells was seen in 32% and PD-L1 expression using the combined positive score (CPS) in 21.2%. Most likely due to small numbers of cases, both markers are not prognostically relevant, even though PD-L1 expression correlates with advanced tumor stages.

Discussion

Our analyses reveal an outstanding, though not statistically independent, prognostic relevance of T-cell-rich inflammation in our group of EACs, in particular driven by the tumor center. For the first time, we describe that the inner part of the invasion zone in EACs shows significantly fewer T-cells than other tumor segments and is prognostically irrelevant. We also demonstrate that the loss of antigen presenting ability via MHC1 downregulation by the carcinoma cells is a common escape mechanism in EACs. Future work will need to show whether tumors with MHC class 1 loss respond less well to immunotherapy.

A conceptual framework for prognostic research

BACKGROUND

Prognostic research has many important purposes, including (i) describing the natural history and clinical course of health conditions, (ii) investigating variables associated with health outcomes of interest, (iii) estimating an individual's probability of developing different outcomes, (iv) investigating the clinical application of prediction models, and (v) investigating determinants of recovery that can inform the development of interventions to improve patient outcomes. But much prognostic research has been poorly conducted and interpreted, indicating that a number of conceptual areas are often misunderstood. Recent initiatives to improve this include the Prognosis Research Strategy (PROGRESS) and the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) Statement. In this paper, we aim to show how different categories of prognostic research relate to each other, to differentiate exploratory and confirmatory studies, discuss moderators and mediators, and to show how important it is to understand study designs and the differences between prediction and causation.

MAIN TEXT

We propose that there are four main objectives of prognostic studies - description, association, prediction and causation. By causation, we mean the effect of prediction and decision rules on outcomes as determined by intervention studies and the investigation of whether a prognostic factor is a determinant of outcome (on the causal pathway). These either fall under the umbrella of exploratory (description, association, and prediction model development) or confirmatory (prediction model external validation and investigation of causation). Including considerations of causation within a prognostic framework provides a more comprehensive roadmap of how different types of studies conceptually relate to each other, and better clarity about appropriate model performance measures and the inferences that can be drawn from different types of prognostic studies. We also propose definitions of 'candidate prognostic factors', 'prognostic factors', 'prognostic determinants (causal)' and 'prognostic markers (non-causal)'. Furthermore, we address common conceptual misunderstandings related to study design, analysis, and interpretation of multivariable models from the perspectives of association, prediction and causation.

CONCLUSION

This paper uses a framework to clarify some concepts in prognostic research that remain poorly understood and implemented, to stimulate discussion about how prognostic studies can be strengthened and appropriately interpreted.

Chemokines and their receptors as biomarkers in esophageal cancer

Esophageal cancer (EC) is one of the most lethal malignancies of the digestive tract and remains to be improved poor prognosis. Two histological subtypes, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), are major characteristics of EC. Deep understanding about both subtypes is essential to overcome EC. Here, we focus on chemokines and their receptors as biomarkers and their current applications for the prognosis in EC. We reviewed relevant articles identified using PubMed database for the chemokines and their receptors in EC analyzed by immunohistochemistry. The primary objective is to summarize evidences for them as prognostic biomarkers in EC. A total of twenty-one articles were reviewed after exclusion. Most studies have been done in ESCC, and less in EAC. CXCL12 and its receptor CXCR4 have been shown in both subtypes as biomarkers. CXCR7, CXCL8 and its receptor CXCR2, and CCL21 and its receptor CCR7 have been examined in ESCC. Although it was a small number of reports, CXCL10, CCL4, and CCL5 have been indicated to have anti-tumor effects in ESCC. Chemokines and their receptors have the potential to be the biomarkers in EC. Comparative studies between ESCC and EAC will reveal the similarity and difference in these two subtypes of EC. These studies may indicate whether these molecules play important roles in both subtypes or are unique to one or another.

Neutrophil-to-lymphocyte ratio as prognostic marker in esophageal cancer: a systematic review and meta-analysis

A high preoperative neutrophil-lymphocyte ratio (NLR) has been shown in several studies as a predictor of worse survival in many solid neoplasms, including esophageal cancer, but its impact remains unclear. The goal of this systematic review was to gain all the evidence about NLR in order to analyse its potential in predicting survival in esophageal cancer. Therefore, we conducted a systematic literature search of all relevant studies reporting data on NLR as prognostic marker in esophageal cancer patients. We considered overall survival (OS) as primary outcome, disease-free survival (DFS) and progression-free survival (PFS) as secondary outcomes. We included studies with a directly or indirectly available hazard ratio (HR), furthermore we used both fixed effect model and random effect model depending on heterogeneity. We included a total of 20 studies, published between 2011 and 2017, consisting of 6,457 patients. The NLR cut-off value ranges from 1.7 to 5. The HR for OS of all included studies was 1.60. The HR for DFS and PFS was 1.75 and 1.66 respectively. The survival sub-analysis about tumor characteristics, treatment modality, blood sample timing also confirmed NLR prognostic relevance with statistically significant results. The meta-analysis showed that high preoperative NLR is associated with worse survival in esophageal cancer, as shown in several solid tumors, but its use in the clinical practice is still underestimated. High-quality studies are needed to assess the most effective cut-off in survival prognostication and NLR relevance on postoperative complications.