Tumor Microenvironment Mediators CD8+- and FOXP3+-Labeled T Lymphocytes Are Prospective Prognosticators in Curatively Treated Rectal Cancer Patients

Tumour-infiltrating Lymphocytes and Radiation Therapy in Rectal Cancer: Systematic Review and Meta-analysis

AIM

Tumour-infiltrating lymphocytes (TILs) represent a promising cancer biomarker. Different TILs, including CD8+, CD4+, CD3+, and FOXP3+, have been associated with clinical outcomes. However, data are lacking regarding the value of TILs for patients receiving radiation therapy (RT). We conducted a systemic review and meta-analysis of available data evaluating TILs for patients receiving curative-intent therapy including RT.

MATERIALS AND METHODS

Eligible studies presented a defined cohort of patients who all received curative-intent therapy, including RT, and also reported the relationship between any TIL score and either tumour response or survival outcomes. After comprehensive search of online databases (PubMed, EMBASE, Cochrane, and Web of Science), 2 authors conducted title, abstract, and whole-text review for quality and risk of bias following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Data from publications that met quality criteria were grouped via (1) TIL analysed, (2) pre- or post-RT TIL assessment, and (3) clinical outcome measured.

RESULTS

Initial search yielded 669 unique studies. Thirty-one studies met quality criteria, of which 20 studied rectal cancer (RC), 4 oesophageal, 3 pancreas, 2 lung, cervical/uterine 1 each. We conducted systematic review and meta-analysis of the RC publications. All except 2 were single-institutional cohort studies. After meta-analysis, the pre-RT epithelial CD8+ (p = 0.04) and stromal FOXP3+ (p = 0.01) counts were associated with survival without disease, while pre-RT epithelial (p = 0.02) and stromal (p = 0.001) FOXP3+ TILs were associated with overall survival. On post-RT analysis, epithelial (p = .04) and stromal (p = 0.02) CD8+ TILs were associated with survival without disease and epithelial CD8+ TILs were associated with overall survival (p = 0.01).Preoperative CD8+ and FOXP3+ TILs were generally associated with tumour response to RT, but meta-analysis was not conducted due to heterogeneity of response measurement techniques.

CONCLUSION

TILs represent a useful parameter for tumour response and survival outcomes for patients receiving curative-intent therapy, including RT for RC. Future work should aim to standardise TIL measurement and quantification methods and to develop protocols to clarify clinical application of these findings.

The prognostic value of Forkhead box P3 regulatory T cells in biliary tract cancer: A systematic review and meta-analysis

BACKGROUND

This study aimed to explore the value of tumor-infiltrating Forkhead box P3(FoxP3+) regulatory T cells (Tregs) in evaluating the prognosis of biliary tract cancer.

METHODS

Four electronic databases were searched using 2 computers: PubMed, Embase, Web of Science, and Cochrane Library. The vocabulary and syntax were adapted according to the database. Two researchers independently selected the studies, collected information, and assessed the risk of bias. The Meta-analysis was performed using STATA 17.0, and HR and its corresponding 95% CI were used to evaluate the correlation between FoxP3+ Tregs and the overall survival of patients with biliary tract cancer. In addition, the quality of the included studies was evaluated.

RESULTS

Ten articles were included in this study. The results of the meta-analysis showed that patients with high FoxP3+ Tregs infiltration had worse overall survival (OS) (HR = 1.34,95% CI 1.16 to 1.71; P < .001). Subgroup analysis of gallbladder carcinoma and cholangiocarcinoma showed that the high infiltration of FoxP3+ Tregs was significantly correlated with the OS of the former (HR = 1.55,95% CI 1.11 to 2.00; P < .001), but not with the OS of the latter (HR = 1.00,95% CI 0.62 to 1.38; P > .05).

CONCLUSIONS

Our meta-analysis reveals that high infiltration of FoxP3 + Tregs is significantly associated with reduced overall survival in gallbladder carcinoma, endorsing their use as a prognostic biomarker for this subtype. In contrast, no significant prognostic correlation was identified for FoxP3+ Tregs in cholangiocarcinoma, indicating the need for subtype-specific evaluation of their prognostic relevance in biliary tract cancers.

Immune Response and Immune Checkpoint Molecules in Patients with Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy: A Review

It is well-established that tumor antigens and molecules expressed and secreted by cancer cells trigger innate and adaptive immune responses. These two types of anti-tumor immunity lead to the infiltration of the tumor's microenvironment by immune cells with either regulatory or cytotoxic properties. Whether this response is associated with tumor eradication after radiotherapy and chemotherapy or regrowth has been a matter of extensive research through the years, mainly focusing on tumor-infiltrating lymphocytes and monocytes and their subtypes, and the expression of immune checkpoint and other immune-related molecules by both immune and cancer cells in the tumor microenvironment. A literature search has been conducted on studies dealing with the immune response in patients with rectal cancer treated with neoadjuvant radiotherapy or chemoradiotherapy, assessing its impact on locoregional control and survival and underlying the potential role of immunotherapy in the treatment of this cancer subtype. Here, we provide an overview of the interactions between local/systemic anti-tumor immunity, cancer-related immune checkpoint, and other immunological pathways and radiotherapy, and how these affect the prognosis of rectal cancer patients. Chemoradiotherapy induces critical immunological changes in the tumor microenvironment and cancer cells that can be exploited for therapeutic interventions in rectal cancer.

A type I interferon footprint in pre-operative biopsies is an independent biomarker that in combination with CD8+ T cell quantification can improve the prediction of response to neoadjuvant treatment of rectal adenocarcinoma

Tailored treatment for patients with rectal cancer requires clinically available markers to predict their response to neoadjuvant treatment. The quantity of tumor-infiltrating lymphocytes (TILs) in pre-operative tumor biopsies has been suggested to predict a favorable response, but opposing results exist. A biopsy-adapted Immunoscore (ISB) based on TILs has recently emerged as a promising predictor of tumor regression and prognosis in (colo)rectal cancer. We aimed to refine the ISB for prediction of response using multiplex immunofluorescence (mIF) on pre-operative rectal cancer biopsies. We combined the distribution and density of conventional T cell subsets and γδT cells with a type I Interferon (IFN)-driven response assessed using Myxovirus resistance protein A (MxA) expression. We found that pathological complete response (pCR) following neoadjuvant treatment was associated with type I IFN. Stratification of patients according to the density of CD8+ in the entire tumor tissue and MxA+ cells in tumor stroma, where equal weight was assigned to both parameters, resulted in improved predictive quality compared to the ISB. This novel stratification approach using these two independent parameters in pre-operative biopsies could potentially aid in identifying patients with a good chance of achieving a pCR following neoadjuvant treatment.

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

Simple Summary

This study investigated tumor-infiltrating lymphocytes (TILs) in pretherapeutic biopsies as biomarkers of treatment response and long-term prognosis in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. The results indicate that it is possible to identify a sub-group of patients with improved treatment response and long-term prognosis by assessing the density of CD8⁺ TILs at the time of diagnosis.

Abstract

Neoadjuvant chemoradiotherapy (NCRT) is indicated in locally advanced rectal cancer (LARC) to downstage tumors before surgery. Watchful waiting may be a treatment option to avoid surgery in patients, obtaining a complete clinical response. However, biomarkers predictive of treatment response and long-term prognosis are lacking. Here we investigated tumor-infiltrating lymphocytes (TILs) in pretherapeutic biopsies as predictive and prognostic biomarkers. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. In total, 429 articles were identified, of which 19 studies were included in the systematic review and 14 studies in the meta-analysis. Patients with high pretherapeutic CD8⁺ TILs density had an increased likelihood of achieving a pathological complete response (RR = 2.71; 95% CI: 1.58–4.66) or a complete or near-complete pathological treatment response (RR = 1.86; 95% CI: 1.50–2.29). Furthermore, high CD8⁺ TILs density was a favorable prognostic factor for disease-free survival (HR = 0.57; 95% CI: 0.38–0.86) and overall survival (HR = 0.43; 95% CI: 0.27–0.69). CD3⁺, CD4⁺, and FOXP3⁺ TILs were not identified as predictive or prognostic biomarkers. Thus, assessing pretherapeutic CD8⁺ TILs density may assist in identifying patients with increased sensitivity to NCRT and favorable long-term prognosis.