Tumor-infiltrating neutrophils predict poor outcome in adenocarcinoma of the esophagogastric junction

Dissecting the inflammatory tumor microenvironment of esophageal adenocarcinoma: mast cells and natural killer cells are favorable prognostic factors and associated with less extensive disease

PURPOSE

Esophageal adenocarcinoma (EAC) remains a challenging and lethal cancer entity. A promising target for new therapeutic approaches, as demonstrated by the success of immune checkpoint inhibitors, are tumor-associated immune cells and the tumor microenvironment (TME). However, the understanding of the TME in esophageal cancer remains limited and requires further investigation.

METHODS

Over 900 EAC samples were included, including patients treated with primary surgery and neoadjuvant (radio-)chemotherapy. The immune cell infiltrates of mast cells (MC), natural killer cells (NK cells), plasma cells (PC), and eosinophilic cells (EC) were assessed semi-quantitatively and correlated with histopathological parameters and overall survival (OS).

RESULTS

A high presence of all four immune cell types significantly correlated with a less extensive tumor stage and a lower frequency of lymph node metastasis, and, in case of NK cells, with less distant metastasis. The presence of MC and NK cells was favorably associated with a prolonged OS in the total cohort (MC: p < 0.001; NK cells: p = 0.004) and patients without neoadjuvant treatment (MC: p < 0.001; NK cells: p = 0.01). NK cells were a favorable prognostic factor in the total cohort (p = 0.007) and in the treatment-naïve subgroup (p = 0.04). Additionally, MC were a favorable prognostic factor in patients with lymph node metastasis (p = 0.009).

CONCLUSION

Our results indicate a complex and important role of mast cells, NK cells, and the other assessed immune cells in the tumor microenvironment of EAC. Therefore, they are one further step to a better understanding of the immune cell environment and the potential therapeutic implications in this cancer entity.

Hyperactive neutrophils infiltrate vital organs of tumor bearing host and contribute to gradual systemic deterioration via upregulated NE, MPO and MMP-9 activity

Cancer is known to have systemic impact by targeting various organs that ultimately compromises the overall physiology of the host. Several reports have demonstrated the role of neutrophils in cancer wherein the focus has been drawn on the elevated neutrophil count in blood or at tumor loci. However, their role in mediating systemic effects during cancer progression has not been deciphered so far. Therefore, it is worthwhile to explore whether and how neutrophils contribute to systemic deterioration in cancer. To discern their systemic role, we evaluated neutrophil count and function at different stages of tumor growth in Dalton's Lymphoma mice model. Notably, our results displayed a gradual increase in Ly6G⁺ neutrophils in peripheral blood and their infiltration in vital organs including liver, lungs, spleen, kidney, lymph nodes and peritoneum of tumor bearing host. We showed remarkable alterations in histoarchitecture and serum enzyme levels that aggravated with tumor progression. We next examined neutrophil function by assessing its granular cargoes including neutrophil elastase (NE), myeloperoxidase (MPO), and matrix metalloproteinases (MMP-8 and MMP-9). Interestingly, blood neutrophils of tumor bearing mice exhibited a marked change in morphology with gradual increase in NE and MPO expression with tumor growth. In addition, we observed upregulated expression of NE, MPO, MMP-8 and MMP-9 in the vital organs of tumor bearing host. Taken together, our results demonstrate heightened infiltration and function of neutrophils in vital organs of tumor bearing host which possibly account for gradual systemic deterioration during cancer progression. Our findings thus implicate neutrophils as a potential therapeutic target that may help to reduce the overall fatality rate of cancer.

The effect of smoking on chronic inflammation, immune function and blood cell composition

Smoking is the number one risk factor for cancer mortality but only 15-20% of heavy smokers develop lung cancer. It would, therefore, be of great benefit to identify those at high risk early on so that preventative measures can be initiated. To investigate this, we evaluated the effects of smoking on inflammatory markers, innate and adaptive immune responses to bacterial and viral challenges and blood cell composition. We found that plasma samples from 30 heavy smokers (16 men and 14 women) had significantly higher CRP, fibrinogen, IL-6 and CEA levels than 36 non-smoking controls. Whole blood samples from smokers, incubated for 7 h at 37 °C in the absence of any exogenous stimuli, secreted significantly higher levels of IL-8 and a number of other cytokines/chemokines than non-smokers. When challenged for 7 h with E. coli, whole blood samples from smokers secreted significantly lower levels of many inflammatory cytokines/chemokines. However, when stimulated with HSV-1, significantly higher levels of both PGE₂ and many cytokines/chemokines were secreted from smokers' blood samples than from controls. In terms of blood cell composition, red blood cells, hematocrits, hemoglobin levels, MCV, MCH, MCHC, Pct and RDW levels were all elevated in smokers, in keeping with their compromised lung capacity. As well, total leukocytes were significantly higher, driven by increases in granulocytes and monocytes. In addition, smokers had lower NK cells and higher Tregs than controls, suggesting that smoking may reduce the ability to kill nascent tumor cells. Importantly, there was substantial person-to person variation amongst smokers with some showing markedly different values from controls and others showing normal levels of many parameters measured, indicating the former may be at significantly higher risk of developing lung cancer.

A systematic review and meta-analysis of prognostic biomarkers in resectable esophageal adenocarcinomas

Targeted therapy is lagging behind in esophageal adenocarcinoma (EAC). To guide the development of new treatment strategies, we provide an overview of the prognostic biomarkers in resectable EAC treated with curative intent. The Medline, Cochrane and EMBASE databases were systematically searched, focusing on overall survival (OS). The quality of the studies was assessed using a scoring system ranging from 0-7 points based on modified REMARK criteria. To evaluate all identified prognostic biomarkers, the hallmarks of cancer were adapted to fit all biomarkers based on their biological function in EAC, resulting in the features angiogenesis, cell adhesion and extra-cellular matrix remodeling, cell cycle, immune, invasion and metastasis, proliferation, and self-renewal. Pooled hazard ratios (HR) and 95% confidence intervals (CI) were derived by random effects meta-analyses performed on each hallmarks of cancer feature. Of the 3298 unique articles identified, 84 were included, with a mean quality of 5.9 points (range 3.5-7). The hallmarks of cancer feature 'immune' was most significantly associated with worse OS (HR 1.88, (95%CI 1.20-2.93)). Of the 82 unique prognostic biomarkers identified, meta-analyses showed prominent biomarkers, including COX-2, PAK-1, p14ARF, PD-L1, MET, LC3B, IGFBP7 and LGR5, associated to each hallmark of cancer.

Radiation-related lymphopenia as a new prognostic factor in limited-stage small cell lung cancer

The purpose of this study was to investigate whether the minimum absolute lymphocyte count during radiotherapy (min ALC) and the absolute lymphocyte count 1 month after radiotherapy (post ALC) could predict clinical outcome in limited-stage small cell lung cancer (LS-SCLC) patients. We analyzed 73 LS-SCLC patients treated with chemotherapy and radiotherapy; we collected data on the min ALC from 62 patients and on the post ALC from 60 patients. Both min ALC and post ALC were statistically significant predictors of overall survival in multivariate analysis (hazard ratio [95 % confidence interval] 2.67 [1.06-6.75], P = 0.038 and 2.62 [1.19-5.74], P = 0.016, respectively). The median overall survival of the patients with min ALC ≤297 and >297 cells/μL was 12.2 and 35.3 months, respectively (P < 0.001). Patients with post ALC ≤698 and >698 cells/μL had an overall survival of 19.3 and 46.9 months, respectively (P = 0.001). The median overall survival of the lymphopenia (min ALC ≤ 297 cells/μL or post ALC ≤ 698 cells/μL) and the non-lymphopenia group (min ALC > 297 cells/μL and post ALC > 698 cells/μL) was 19.0 and 131.7 months, respectively, while the median progression survival was 8.1 and 16.6 months, respectively (P < 0.001 and P = 0.001). Radiation-related lymphopenia could predict poor survival in LS-SCLC. Its prognostic role should be evaluated in further prospective studies.