Tumor-Infiltrating Lymphocytes as Biomarkers of Treatment Response and Long-Term Survival in Patients with Rectal Cancer: A Systematic Review and Meta-Analysis

Tumor Immune Microenvironment Biomarkers for Recurrence Prediction in Locally Advanced Rectal Cancer Patients after Neoadjuvant Chemoradiotherapy

BACKGROUND/OBJECTIVES

The tumor microenvironment (TME) has emerged as a significant prognostic factor. This study aimed to identify prognostic factors by combining clinicopathologic parameters and the TME biomarkers in patients who underwent surgery following neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC).

METHODS

CD8+ T cells, CXCR3, CXCL10, and α-smooth muscle actin (α-SMA) were analyzed via immunohistochemical staining. We also incorporated AI-powered digital pathology to assess the spatial TME. The associations between these biomarkers, clinicopathologic parameters, and survival outcomes were evaluated.

RESULTS

CD8+ T cell expression, CXCR3 expression in tumor-infiltrating lymphocytes (TILs), and immune phenotypes were correlated. LARC patients with a high expression of CD8+ T cells, CXCR3 in TILs, and an inflamed phenotype had a significantly better prognosis than their counterparts did. In the multivariate analysis, the expression of CD8+ T cells and the inflamed/immune-excluded phenotype were significant tumor immune microenvironment (TiME) biomarkers for recurrence-free survival (RFS) but not for overall survival (OS). Notably, patients with the immune-desert phenotype had a poor prognosis regardless of pathologic stage, even if postoperative chemotherapy was administered (p < 0.001).

CONCLUSIONS

CD8+ T cells and AI-powered immune phenotypes, alongside clinical factors, can guide personalized treatment in LARC patients receiving nCRT. A therapeutic strategy to modify the TiME after nCRT could help reduce recurrence after surgery.

Low CD8+ Density Variation and R1 Surgical Margin as Independent Predictors of Early Post-Resection Recurrence in HCC Patients Meeting Milan Criteria

Our study included 41 patients fulfilling the Milan criteria preoperatively and aimed to identify individuals at high risk of post-resection HCC relapse, which occurred in 18 out of 41 patients (43.9%), retrospectively. We analyzed whole slide images of CD8 immunohistochemistry with automated segmentation of tissue classes and detection of CD8+ lymphocytes. The image analysis outputs were subsampled using a hexagonal grid-based method to assess spatial distribution of CD8+ lymphocytes with regards to the epithelial edges. The CD8+ lymphocyte density indicators, along with clinical, radiological, post-surgical and pathological variables, were tested to predict HCC relapse. Low standard deviation of CD8+ density along the tumor edge and R1 resection emerged as independent predictors of shorter recurrence-free survival (RFS). In particular, patients presenting with both adverse predictors exhibited 100% risk of relapse within 200 days. Our results highlight the potential utility of integrating CD8+ density variability and surgical margin to identify a high relapse-risk group among Milan criteria-fulfilling HCC patients. Validation in cohorts with core biopsy could provide CD8+ distribution data preoperatively and guide preoperative decisions, potentially prioritizing liver transplantation for patients at risk of incomplete resection (R1) and thereby improving overall treatment outcomes significantly.

Molecular differentiation between complete and incomplete responders to neoadjuvant therapy in rectal cancer

Background

Neoadjuvant chemoradiotherapy (nCRT) is the standard treatment for locally advanced rectal cancer, but only 20-40% of patients completely respond to this treatment.

Methods

To define the molecular features that are associated with response to nCRT, we generated and collected genomic and transcriptomic data from 712 cancers prior to treatment from our own data and from publicly available data.

Results

We found that patients with a complete response have decreased risk of both local recurrence and future metastasis. We identified multiple differences in DNA mutations and transcripts between complete and incomplete responders. Complete responder tumors have a higher tumor mutation burden and more significant co-occurring mutations than the incomplete responder tumors. In addition, mutations in DNA repair genes (across multiple mechanisms of repair) were enriched in complete responders and they also had lower expression of these genes indicating that defective DNA repair is associated with complete response to nCRT. Using logistic regression, we identified three significant predictors of complete response: tumor size, mutations within specific network genes, and the existence of three or more specific co-occurrent mutations. In incompletely responder tumors, abnormal cell-cell interaction and increased cancer associated fibroblasts were associated with recurrence. Additionally, gene expression analysis identified a subset of immune hot tumors with worse outcomes and upregulated of immune checkpoint proteins.

Conclusions

Overall, our study provides a comprehensive understanding of the molecular features associated with response to nCRT and the molecular differences in non-responder tumors that later reoccur. This knowledge may provide critical insight for the development of precision therapy for rectal cancer.

Analysis of tumor microenvironment alterations in partially responsive rectal cancer patients treated with neoadjuvant chemoradiotherapy

PURPOSE

Achieving a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (NCRT) remains a challenge for most patients with rectal cancer. Exploring the potential of combining NCRT with immunotherapy or targeted therapy for those achieving a partial response (PR) offers a promising avenue to enhance treatment efficacy. This study investigated the impact of NCRT on the tumor microenvironment in locally advanced rectal cancer (LARC) patients who exhibited a PR.

METHODS

This was a retrospective, observational study. Five patients demonstrating a PR after neoadjuvant treatment for LARC were enrolled in the study. Biopsy samples before treatment and resected specimens after treatment were stained with a panel of 26 antibodies targeting various immune and tumor-related markers, each labeled with distinct metal tags. The labeled samples were then analyzed using the Hyperion imaging system.

RESULTS

Heterogeneity within the tumor microenvironment was observed both before and after NCRT. Notably, tumor-associated macrophages, CD4 + T cells, CD8 + T cells, CD56 + natural killer cells, tumor-associated neutrophils, cytokeratin, and E-cadherin exhibited slight increase in abundance within the tumor microenvironment following treatment (change ratios = 0.78, 0.2, 0.27, 0.32, 0.17, 0.46, 0.32, respectively). Conversely, the number of CD14 + monocytes, CD19 + B cells, CD45 + CD4 + T cells, collagen I, α-smooth muscle actin, vimentin, and β-catenin proteins displayed significant decreases post-treatment (change ratios = 1.73, 1.92, 1.52, 1.25, 1.52, 1.12, 2.66, respectively). Meanwhile, Foxp3 + regulatory cells demonstrated no significant change (change ratio = 0.001).

CONCLUSIONS

NCRT has diverse effects on various components of the tumor microenvironment in LARC patients who achieve a PR after treatment. Leveraging combination therapies may optimize treatment outcomes in this patient population.

Predictive Value of Tumor-Infiltrating Lymphocytes and Ki-67 for Pathological Response to Total Neoadjuvant Therapy in Rectal Cancer

PURPOSE

Patients with locally advanced rectal cancer (LARC) who underwent total neoadjuvant therapy (TNT) showed an increase in the percentage of complete pathological response (pCR). The purpose of this study was to determine the correlation between Ki-67, tumor-infiltrating lymphocytes (TIL), and TNT in LARC patients.

METHOD

In total, one hundred fifty-nine patients with LARC were included in this prospective study. The international working group was used to categorize the TIL into three groups based on the percentage and density of staining: group 0 (0-10%), group 1 (11-59%), and group 2 (≥ 60%). Ki-67 expression was classified as low (≤ 50%) or high (> 50%).

RESULT

Most patients had tumor grade III (74.2%) and T2-T3 (78.6%). Lymph node involvement (48.7%) and tumor size ≥ 3 cm were detected in approximately half of the patients. Forty-four percent of patients had a high Ki-67 index; 15.7% of patients belonged to group 1, and 21.4% belonged to group 2. pCR was detected in 18.2% of the patients. TIL and Ki-67 levels were significantly correlated with pCR (p = 0.001 and 0.003 for multivariate analysis and 0.001 and 0.03 for univariate analysis, respectively).

CONCLUSION

There was a statistically significant correlation between Ki-67, TIL, and pCR following TNT protocol, which may help maximize the therapeutic outcome.

Digitally assessed lymphocyte infiltration in rectal cancer biopsies is associated with pathological response to neoadjuvant therapy

A frequently used treatment strategy in locally advanced rectal cancer (RC) is neoadjuvant therapy followed by surgery. Patients treated with neoadjuvant therapy achieve varying pathological response, and currently, predicting the degree of response is challenging. This study examined the association between digitally assessed histopathological features in the diagnostic biopsies and pathological response to neoadjuvant therapy, aiming to find potential predictive biomarkers. 50 patients with RC treated with neoadjuvant chemotherapy and/or radiotherapy followed by surgery were included. Deep learning-based digital algorithms were used to assess the epithelium tumor area percentage (ETP) based on H&E-stained slides, and to quantify the density of CD3+ and CD8+ lymphocytes, as well as the CD8+/CD3+ lymphocyte percentage, based on immunohistochemically stained slides, from the diagnostic tumor biopsies. Pathological response was assessed according to the Mandard method. A good pathological response was defined as tumor regression grade (TRG) 1-2, and a complete pathological response was defined as Mandard TRG 1. Associations between the ETP and lymphocyte densities in the diagnostic biopsies and the pathological response were examined. The density of CD8+ lymphocytes, and the CD8+/CD3+ lymphocyte percentage, were associated with both good and complete response to neoadjuvant therapy, while the density of CD3+ lymphocytes was associated with complete response. The ETP did not correlate with response to neoadjuvant therapy. It is well-known that infiltration of lymphocytes in colorectal cancer is a prognostic biomarker. However, assessment of CD8+ and CD3+ lymphocytes in the diagnostic tumor biopsies of patients with RC may also be useful in predicting response to neoadjuvant therapy.

Intratumoral Budding and CD8-Positive T-cell Density in Pretreatment Biopsies as a Predictor of Response to Neoadjuvant Chemoradiotherapy in Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is the standard treatment for advanced rectal cancer. Yet, the response to CRT varies from complete response to zero tumor regression.

MATERIALS AND METHODS

The impact of intratumoral budding (ITB) and intratumoral CD8+ cell density on response to CRT and survival were evaluated in biopsy samples from 266 patients with advanced rectal cancer who were treated with long-course neoadjuvant CRT. The expression of epithelial-mesenchymal transition (EMT) markers was compared between patients with high and low ITB, using data from 174 patients with RNA sequencing.

RESULTS

High ITB was observed in 62 patients (23.3%). There was no association between ITB and CD8+ cell density. The multivariable logistic regression analysis showed that high CD8+ cell density (OR, 2.69; 95% CI, 1.45-4.98; P = .002) was associated with good response to CRT, whereas high ITB (OR, 0.33; 95% CI, 0.14-0.80; P = .014) was associated with poor response. Multivariable Cox regression analysis for survival showed that high CD8+ cell density was associated with better recurrence-free survival (HR, 0.41; 95% CI, 0.24-0.72; P = .002) and overall survival (HR, 0.36; 95% CI, 0.17-0.74; P = .005), but significance values for ITB were marginal (P = .104 for recurrence-free survival and P = .163 for overall survival). The expression of EMT-related genes was not significantly different between patients with high and low ITB.

CONCLUSION

ITB and CD8+ cell density in biopsy samples may serve as useful biomarkers to predict therapy response in patients with rectal cancer treated with neoadjuvant CRT.

Tumor-infiltrating lymphocytes, PD-L1, and MMR-deficiency combined characterization may identify subgroups of rectal cancer patients who would benefit from immunotherapy

INTRODUCTION

Mismatch repair deficiency, immunological fertility, and PD-L1 expression status are key histopathological and molecular features defining tumor responsiveness to immunotherapy and, eventually, prognosis. These were investigated in a series of locally advanced rectal cancer patients treated with postoperative chemotherapy and radiotherapy.

MATERIALS AND METHODS

Tumor-infiltrating lymphocyte (TIL) density was assessed in hematoxylin-eosin tissue sections. PD-L1 expression and the expression of MMR proteins (MLH1, PSM2, MSH2, and MSH6) were assessed with immunohistochemistry. Their association with histopathological variables (node involvement and tumor budding) and prognosis was assessed.

RESULTS

The TIL-density was significantly higher in the invading tumor front and was inversely related to tumor budding and directly with better overall survival (OS) and distant metastasis-free survival (DMFS) (p = 0.02 and 0.02, respectively). Cancer cell PD-L1 expression was related to high TIL-density (p < 0.01) but not to prognosis, although its overexpression defined a trend for poorer OS in patients with high TIL-density. High PD-L1 expression by stroma infiltrating immune cells was linked with better OS and DMFS (p = 0.007 and 0.001, respectively. MMR deficiency was recorded in 26.2 % of cases, and this was linked with higher TIL-density, but not with prognosis.

CONCLUSIONS

Dense intratumoral lymphocytic infiltration relates to a better prognosis in rectal cancer, although it is also linked with PD-L1 expression that may adversely modulate the anti-tumor effects of TILs. This latter subgroup of patients (high TIL-density/high cancer cell PD-L1 expression) could be an additional target for anti-PD-1/PD-L1 immunotherapy, along with the established subgroup of MMR deficient patients.

IMMUNOREACT 0: Biopsy-based immune biomarkers as predictors of response to neoadjuvant therapy for rectal cancer-A systematic review and meta-analysis

BACKGROUND

The main therapy for rectal cancer patients is neoadjuvant therapy (NT) followed by surgery. Immune biomarkers are emerging as potential predictors of the response to NT. We performed a meta-analysis to estimate their predictive significance.

METHODS

A systematic literature search of PubMed, Ovid MEDLINE and EMBASE databases was performed to identify eligible studies. Studies on patients with rectal cancer undergoing NT in which the predictive significance of at least one of the immunological markers of interest was assessed by immunohistochemistry (IHC) in pretreatment biopsies were included.

RESULTS

Seventeen studies reporting sufficient data met the inclusion criteria for meta-analysis. High levels of total CD3+, CD4+ and CD8+ tumor infiltrating lymphocytes (TILs), as well as stromal and intraepithelial CD8+ compartments, significantly predicted good pathological response to NT. Moreover, high levels of total (tumoral and immune cell expression) PD-L1 resulted associated to a good pathological response. On the contrary, high levels of intraepithelial CD4+ TILs were correlated with poor pathological response. FoxP3+ TILs, tumoral PD-L1 and CTLA-4 were not correlated to the treatment response.

CONCLUSION

This meta-analysis indicated that high-density TILs might be predictive biomarkers of pathological response in patients that underwent NT for rectal cancer.

Clinical and prognostic significance of perioperative change in red cell distribution width in patients with esophageal squamous cell carcinoma

BACKGROUND

Numerous studies have reported the prognostic significance of the red cell distribution width (RDW) in patients with esophageal squamous cell carcinoma (ESCC), but the relationship between the perioperative change in RDW (delta RDW) and survival in patients with ESCC after surgery has not been evaluated.

METHODS

A total of 594 patients with newly diagnosed ESCC after surgery were enrolled in the study. Delta RDW (delta RDW = Postoperative RDW-Preoperative RDW) was counted based on data within one week before surgery and two weeks after surgery. To investigate the relationship between delta RDW and overall survival (OS), the median delta RDW was chosen as the cut-off value.

RESULTS

99 (16.7%) patients had pathological stage 1a-1b, 202 (34.0%) patients had pathological stage 2a-2b, and 293 (49.3%) patients had pathological stage 3a-3c.There were 179 (30.1%) patients who had vessel invasive, and 415 (69.9%) patients without vessel invasive. There were 216 (36.4%) patients with nerve infiltration, and 378 (63.6%) without nerve infiltration. In univariate analysis, five parameters including delta RDW(≥ 0.44 vs.<0.44) (P = 0.039, HR = 1.337, 95% CI = 1.014-1.762) significantly correlated with worse OS. Multivariate analysis revealed that delta RDW(≥ 0.44 vs.<0.44) was an independent prognostic marker for OS (P = 0.033, HR = 1.356, 95% CI = 1.025-1.793). Kaplan-Meier curves showed that delta RDW ≥ 0.44 was significantly associated with worse OS (P = 0.039). Subgroup analysis suggested that delta RDW ≥ 0.44 indicated worse survival in patients with ESCC exclusively in these subtypes such as female patients, age > 60 patients, patients with lymph node metastasis, and patients with vessel invasive.

CONCLUSIONS

Perioperative change in red cell distribution width predicts worse survival in patients with ESCC after surgery.

Genetic Heterogeneity, Tumor Microenvironment and Immunotherapy in Triple-Negative Breast Cancer

Heterogeneity of triple-negative breast cancer is well known at clinical, histopathological, and molecular levels. Genomic instability and greater mutation rates, which may result in the creation of neoantigens and enhanced immunogenicity, are additional characteristics of this breast cancer type. Clinical outcome is poor due to early age of onset, high metastatic potential, and increased likelihood of distant recurrence. Consequently, efforts to elucidate molecular mechanisms of breast cancer development, progression, and metastatic spread have been initiated to improve treatment options and improve outcomes for these patients. The extremely complex and heterogeneous tumor immune microenvironment is made up of several cell types and commonly possesses disorganized gene expression. Altered signaling pathways are mainly associated with mutated genes including p53, PIK3CA, and MAPK, and which are positively correlated with genes regulating immune response. Of note, particular immunity-associated genes could be used in prognostic indexes to assess the most effective management. Recent findings highlight the fact that long non-coding RNAs also play an important role in shaping tumor microenvironment formation, and can mediate tumor immune evasion. Identification of molecular signatures, through the use of multi-omics approaches, and effector pathways that drive early stages of the carcinogenic process are important steps in developing new strategies for targeted cancer treatment and prevention. Advances in immunotherapy by remodeling the host immune system to eradicate tumor cells have great promise to lead to novel therapeutic strategies. Current research is focused on combining immune checkpoint inhibition with chemotherapy, PARP inhibitors, cancer vaccines, or natural killer cell therapy. Targeted therapies may improve therapeutic response, eliminate therapeutic resistance, and improve overall patient survival. In the future, these evolving advancements should be implemented for personalized medicine and state-of-art management of cancer patients.

CD3D Is an Independent Prognostic Factor and Correlates With Immune Infiltration in Gastric Cancer

The protein encoded by CD3D is part of the T-cell receptor/CD3 complex (TCR/CD3 complex) and is involved in T-cell development and signal transduction. Previous studies have shown that CD3D is associated with prognosis and treatment response in breast, colorectal, and liver cancer. However, the expression and clinical significance of CD3D in gastric cancer are not clear. In this study, we collected 488 gastric cancer tissues and 430 paired adjacent tissues to perform tissue microarrays (TMAs). Then, immunohistochemical staining of CD3D, CD3, CD4, CD8 and PD-L1 was conducted to investigate the expression of CD3D in gastric cancer and the correlation between the expression of CD3D and tumor infiltrating lymphocytes (TILs) and PD-L1. The results showed that CD3D was highly expressed in gastric cancer tissues compared with paracancerous tissues (P<0.000). Univariate and multivariate analyses showed that CD3D was an independent good prognostic factor for gastric cancer (P=0.004, HR=0.677, 95%CI: 0.510-0.898 for univariate analyses; P=0.046, HR=0.687, 95%CI: 0.474-0.994 for multivariate analyses). In addition, CD3D was negatively correlated with the tumor location, Borrmann type and distant metastasis (P=0.012 for tumor location; P=0.007 for Borrmann type; P=0.027 for distant metastasis). In addition, the expression of CD3D was highly positively correlated with the expression of CD3, CD4, CD8, and PD-L1, and the combination of CD3D with CD3, CD4, CD8 and PD-L1 predicted the best prognosis (P=0.043). In summary, CD3D may play an important regulatory role in the tumor immune microenvironment of gastric cancer and may serve as a potential indicator of prognosis and immunotherapy response.