The oesophageal adenocarcinoma tumour immune microenvironment dictates outcomes with different modalities of neoadjuvant therapy - results from the AGITG DOCTOR trial and the cancer evolution biobank

Prognostic immune markers in esophageal cancer patients managed with trimodal therapy

BACKGROUND

Esophageal cancer (ESC) is an aggressive disease which often presents at an advanced stage. Despite trimodal therapy, 40-50% patients can develop metastatic disease by 18 months. Identification of patients at risk for metastatic spread is challenging with need for improved prognostication. We investigated whether the immune landscape of pretreatment tissue was associated with relapse in ESC patients.

METHODS

Between April 2010 and October 2018, we identified 25 patients who had undergone trimodal therapy for ESC and had pretreatment biopsies suitable for analyses. We performed high-throughput multispectral immunofluorescence (mIF) analysis on formalin-fixed paraffin embedded biopsy samples. Analysis of 27 unique populations via immune and exhaustion mIF panels was performed and expression was normalized to total cell counts.

RESULTS

Of the 25 patients analyzed, the median follow-up time was 23.9 months, during which 12 (48%) patients suffered a relapse with a median time to progression of 13.1 months. mIF revealed higher expression of HLA-DR (p = 0.019), CD8/LAG3 (p = 0.046), and CD8/CTLA4 (p = 0.027) among patients without relapse. Time to progression (TTP) and disease-specific survival (DSS) were stratified by median expression of each significant subpopulation and formally tested by the log-rank test. Higher than median expression of HLA-DR (p = 0.027), CD8/LAG3 (p = 0.039), and CD8/CTLA4 (p = 0.039) were significantly associated with TTP. Similarly, HLA-DR (p = 0.0069) and CD8/CTLA4 (p = 0.036) were significantly associated with improved DSS, whereas no significant observations were found with CD8/LAG3 (p = 0.11) expression. Stromal, but not tumoral expression of CD163 and CD163/PDL1 were significantly associated with improved TTP and DSS.

CONCLUSIONS

High expression of HLA-DR, CD8/CTLA4, and stromal expression of CD163 and CD163/PDL1 within pretreatment biopsy ESC samples was associated with significantly reduced rates of relapse. Increased presence of these markers suggests that an improved immune landscape is associated with less aggressive disease and may provide an opportunity for risk-based treatment strategies.

The efficacy of neoadjuvant immunotherapy and lymphocyte subset predictors in locally advanced esophageal squamous cell carcinoma: A retrospective study

BACKGROUND

Despite the recognized therapeutic potential of programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors in advanced esophageal squamous cell carcinoma (ESCC), their role in neoadjuvant therapy and reliable efficacy biomarkers remain elusive.

MATERIALS AND METHODS

We retrospectively analyzed locally advanced ESCC patients who underwent surgery following a 2-cycle platinum and paclitaxel-based treatment, with or without PD-1 inhibitors (January 2020-March 2023). We assessed peripheral blood indexes and tertiary lymphoid structures (TLS) density to evaluate their impact on pathological response and prognosis, leading to a clinical prediction model for treatment efficacy and survival.

RESULTS

Of the 157 patients recruited, 106 received immunochemotherapy (ICT) and 51 received chemotherapy (CT) alone. The ICT group demonstrated a superior pathological response rate (PRR) (47.2% vs. 29.4%, p = 0.034) with comparable adverse events and postoperative complications. The ICT group also showed a median disease-free survival (DFS) of 39.8 months, unattained by the CT group. The 1-year DFS and overall survival (OS) rates were 73% and 91% for the ICT group, and 68% and 81% for the CT group, respectively. We found higher baseline activated T cells, lower baseline Treg cells, and a decreased posttreatment total lymphocyte and CD4+/CD8+ ratio predicted an enhanced PRR. Reduced posttreatment CD4+/CD8+ ratio and increased NK cells were associated with prolonged survival, while higher TLS density indicated poorer prognosis. Among ICT group, a lower posttreatment CD4+/CD8+ ratio indicated longer DFS and reduced posttreatment B cells indicated longer OS. A nomogram integrating these predictors was developed to forecast treatment efficacy and survival.

CONCLUSION

The combination of PD-1 inhibitors and chemotherapy appears promising for locally advanced ESCC. Evaluating the differentiation status and dynamic changes of peripheral blood immune cells may provide valuable predictive insights into treatment efficacy and prognosis.

Effect of the immune microenvironment on prognosis in oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is amongst the most lethal cancers worldwide, with poor treatment response leading to low survival rates. Recent improvements have been achieved by including the tumour microenvironment (TME) and patients' immune profiles in treatment decisions. We already know that patients with immune-enriched/inflamed TME have better survival outcomes. However, OAC TME is largely immunosuppressed and appears to be treatment-resistant. Immunotherapeutic strategies are already part of the therapeutic plans in OAC; a greater understanding of the immune microenvironment underlying oesophageal adenocarcinoma is needed if we are to exploit the inherent cancer-fighting capabilities of each patient's immune system. Therefore, implementing the crosstalks between the tumour and its microenvironment (TME) might be the key to improving overall survival. In this review, we discuss accumulated evidence regarding TME and immune checkpoint inhibitors in OAC, as well as recent and ongoing therapeutic attempts to improve patient treatment and outcomes at an individual level.

Mechanisms of tumor immunosuppressive microenvironment formation in esophageal cancer

As a highly invasive malignancy, esophageal cancer (EC) is a global health issue, and was the eighth most prevalent cancer and the sixth leading cause of cancer-related death worldwide in 2020. Due to its highly immunogenic nature, emer-ging immunotherapy approaches, such as immune checkpoint blockade, have demonstrated promising efficacy in treating EC; however, certain limitations and challenges still exist. In addition, tumors may exhibit primary or acquired resistance to immunotherapy in the tumor immune microenvironment (TIME); thus, understanding the TIME is urgent and crucial, especially given the im-portance of an immunosuppressive microenvironment in tumor progression. The aim of this review was to better elucidate the mechanisms of the suppressive TIME, including cell infiltration, immune cell subsets, cytokines and signaling pathways in the tumor microenvironment of EC patients, as well as the downregulated expression of major histocompatibility complex molecules in tumor cells, to obtain a better understanding of the differences in EC patient responses to immunotherapeutic strategies and accurately predict the efficacy of immunotherapies. Therefore, personalized treatments could be developed to maximize the advantages of immunotherapy.

Tumour microenvironment influences response to treatment in oesophageal adenocarcinoma

The poor treatment response of oesophageal adenocarcinoma (OAC) leads to low survival rates. Its increasing incidence makes finding more effective treatment a priority. Recent treatment improvements can be attributed to the inclusion of the tumour microenvironment (TME) and immune infiltrates in treatment decisions. OAC TME is largely immunosuppressed and reflects treatment resistance as patients with inflamed TME have better outcomes. Priming the tumour with the appropriate neoadjuvant chemoradiotherapy treatment could lead to higher immune infiltrations and higher expression of immune checkpoints, such as PD-1/PDL-1, CTLA4 or emerging new targets: LAG-3, TIM-3, TIGIT or ICOS. Multiple trials support the addition of immune checkpoint inhibitors to the current standard of care. However, results vary, supporting the need for better response biomarkers based on TME composition. This review explores what is known about OAC TME, the clinical significance of the various cell populations infiltrating it and the emerging therapeutical combination with a focus on immune checkpoints inhibitors.