Tumor Immune Microenvironment and Immunotherapy in Non-Small Cell Lung Cancer: Update and New Challenges

Non-small cell lung cancer (NSCLC) is a serious threat to the health of older adults. Despite the significant progress in immunotherapy, effective treatments for NSCLC remain limited. The development of tumors indicates failure in immune surveillance and the successful immune escape of tumor cells. Research on the tumor immune microenvironment (TIME) revealed these opposing immune processes and contributed to the discovery of new methods to suppress the immune escape and restore the immune surveillance functions. This paper aimed to provide updates on the current findings regarding the relevance of TIME in NSCLC treatment. It also aimed to introduce the TIME, immune editing, cancer immunotherapy, and new challenges. Based on the clinical data, the combination of neoadjuvant chemotherapy and immune checkpoint inhibitor (ICI) therapy is suitable for patients with NSCLC who are not eligible to undergo surgery. Combined ICI therapy after epidermal growth factor receptor (EGFR)/tyrosine kinase inhibitor (TKI) therapy should be considered in patients with EGFR mutations. Chemoradiotherapy may increase the density of CD8⁺ lymphocytes, which is significantly associated with better prognosis. For older patients and those with advanced-stage disease, regional tumor treatments, such as stereotactic radiation therapy and percutaneous cryoablation, may be more suitable, but further studies are needed to confirm this. In conclusion, restoring immune surveillance is as important as removing cancerous tissues; further studies that include the use of combined treatment methods, individualized treatment plans, and immunonutrition are warranted.

Nutritional Outcomes of Thoracic Duct Resection for Radical Esophagectomy by Assessing Body Composition Changes in One Year: A Single-Center Retrospective Study

BACKGROUND

Thoracic duct (TD) resection is performed when the tumor or a metastatic lymph node directly invades the TD, and is sometimes indicated for radical lymphadenectomy during esophagectomy in esophageal cancer patients. However, the effect of TD resection on nutritional status has not been established.

PATIENTS AND METHODS

In total, 174 consecutive patients from October 2015 to March 2019 who underwent radical esophagectomy for esophageal cancer in Toranomon Hospital were classified into thoracic duct preserved group (n = 51) and TD-resected (TD-R) group (n = 123). We compared laboratory data, body composition data from bioelectrical impedance analysis measured preoperatively and at 1 and 12 months after surgery, and postoperative complications between the two groups.

RESULTS

Clinical stage was significantly more advanced in the TD-R group. Total body weight, body mass index, and fat mass continuously decreased in the two groups over 12 months after surgery, and the decreases were statistically greater in the TD-R group at 12 months after surgery. Skeletal muscle mass and fat-free mass decreased over 1 month after surgery and stayed in a reduced state until 12 months after surgery without statistically significant differences between the two groups. TD resection did not increase incidence of postoperative complications (Clavien-Dindo classification ≥ grade III), but TD resection increased incidence of chylothorax.

CONCLUSIONS

Our results suggest that loss of body fat mass, which was a main contributor to body weight loss, was accelerated in the TD-R group, but TD resection does not deteriorate loss of muscle mass at 12 months after surgery.

Immune surveillance activation after neoadjuvant therapy for esophageal adenocarcinoma and complete response

After neoadjuvant chemoradiotherapy for esophageal adenocarcinoma, up to 29% of patients have a pathological complete response (pCR). What to do afterward is still under debate. The aim of this prospective study was to define which local markers of immune response might act as predictors of pCR and of recurrence after pCR. The peritumoral healthy mucosa of the surgical specimen was sampled at esophagectomy and analyzed by immunohistochemistry, flow cytometry and Real-Time PCR. One hundred and twenty-three patients received neoadjuvant therapy for esophageal adenocarcinoma and were included in the study. Significantly higher rate of natural killer (NK) cells (CD57+), intraepithelial CD8 + T lymphocytes and degranulating T- and NK-cells (CD107+) were observed in the healthy mucosa of patients with pCR. Moreover, pCR was characterized by a lower immune-check points gene expression level. T-cell activation markers mRNA levels were significantly lower in patients with pCR and recurrent disease, showing an excellent accuracy in the prediction of the postoperative recurrence. Costimulatory molecules mRNA relative levels tended to be lower in patients with pCR and recurrent disease, showing a good accuracy in the prediction of postoperative recurrence in patients with pCR. The immune profile identified in this study might further be tested in large prospective trials as marker of pCR after neoadjuvant therapy and as predictor of recurrence after pCR.

Enteral immunonutrition versus enteral nutrition for patients undergoing oesophagectomy: a systematic review and meta-analysis

OBJECTIVES

According to retrospective studies, oesophageal carcinoma is the second deadliest gastrointestinal cancer after gastric cancer. Enteral immunonutrition (EIN) has been increasingly used to enhance host immunity and relieve the inflammatory response of patients undergoing oesophagectomy; however, conclusions across studies remain unclear. We aimed to evaluate the effect of EIN on the clinical and immunological outcomes of patients undergoing oesophagectomy.

METHODS

Four electronic databases (MEDLINE, Embase, Web of Science and Cochrane Library) were used to search articles in peer-reviewed, English-language journals. The mean difference, relative risk or standard mean difference with 95% confidence interval were calculated. Heterogeneity was assessed by the Cochran's Q test and I2 statistic combined with the corresponding P-value. The analysis was carried out with RevMan 5.3.

RESULTS

Six articles were finally included, with a total of 320 patients with oesophageal cancer. The meta-analysis results showed that EIN did not improve clinical outcomes (such as infectious complications, pneumonia, surgical site infection, anastomotic leak and postoperative hospital stay) or immune indices [referring to C-reactive protein, interleukin (IL)-6, IL-8, tumour necrosis factor-α]. Descriptive analysis suggested that EIN also increased the serum concentrations of IgG and the percentage of the B-cell fraction. Thus, its impact on IL-8 and IL-6 remains inconsistent.

CONCLUSIONS

The early-stage impact of EIN on immunological status in patients undergoing oesophagectomy is still unclear. According to the results of this meta-analysis, whether EIN could improve the clinical outcomes or biological status after oesophagectomy compared to standard enteral nutrition is uncertain. Since the impact of EIN is unclear, current guidelines that strongly advise the use of EIN should be changed, as the utility of EIN is very uncertain. More appropriately powered clinical studies are warranted to confirm its effectiveness.

Appendix Tumor Microenvironment

The pathological features of the appendix tumors fundamentally recall those of the more frequent colorectal neoplasms, although with a higher relative incidence of carcinoids, due to the abundant presence of enteroendocrine cells in the appendix wall. Moreover, different types of lymphomas, Hodgkin and non-Hodgkin, arising from the extra-nodal mucosal-associated lymphatic tissue, can be encountered. The appendix tumor microenvironment (TME) consists of a cellular component and of a noncellular component: the former includes the immunocompetent cells, while the latter represents the support stroma. Particularly in carcinoids, the immune cell reaction can be explicated by tumor-infiltrating lymphocytes, which, in some circumstances, may arrange around and inside the tumor in a brisk fashion influencing favorably the prognosis. This active reaction has to be distinguished from any preexisting inflammatory condition of the appendix and from superimposed tumor complications, such as infection or ischemia. In practice, we consider the appendix TME a complex framework with immunological, mechanic, and metabolic functions, all supported by a marked neo-lymphoangiogenesis.

Correlation between PD-L1 expression and clinicopathological characteristics of non-small cell lung cancer: A real-world study of a large Chinese cohort

BACKGROUND

Programmed death ligand-1 (PD-L1) is a predictive marker of anti-programmed death protein 1 (PD-1)/PD-L1 therapies for non-small cell lung cancer (NSCLC). However, little is known between PD-L1 expression and the clinicopathological characteristics of NSCLC in the Chinese population in a real-world setting.

METHODS

We analyzed PD-L1 expression by immunohistochemistry (IHC) in NSCLC patients using the 22C3 clone on the Dako Autostainer Link 48 platform. We then examined the associations of PD-L1 expression with clinicopathological characteristics, stromal tumor-infiltrating lymphocytes (TILs) and major molecular features.

RESULTS

A total of 1,156 recently NSCLC specimens including 827 sequentially resected specimens and 293 biopsy specimens were enrolled in our study. PD-L1 high expression was observed in 9.7% of 827 NSCLC patients, including 6.5% with adenocarcinoma (ADC, n=690), and 27.4% with squamous cell carcinoma (SqCC, n=117). These results showed higher expression rates than those in archived samples (>5 years old, n=329), that were previously reported by our group (4.9%, 0.5%, and 13.9% in NSCLC, ADC, and SqCC, respectively). The prevalence of PD-L1 expression was lower in surgical resection samples than in small biopsy samples. PD-L1 high expression in the lung biopsy was less likely present in the primary cancer than in metastases, and was also associated with a high level of stromal TILs (P=0.029) and PD-L1-positive immune cells (IC) (P<0.001). Both PD-L1 high and low expressions were more frequent in EGFR-wild type than in mutant type (P<0.001).

CONCLUSIONS

This study demonstrates that expression of PD-L1 is linked to the type of tumor specimens, resection versus biopsy specimens, and biopsies of primary versus metastatic cancers. These findings have substantial implications for clinical practice.