Programmed death-ligand 1 expression in the immune compartment of colon carcinoma

Adoption of enhanced multislice spiral computed tomography combined with magnetic resonance imaging in staging and preoperative assessment of colon cancer patients

BackgroundColon cancer (CC) refers to malignant tumor of the digestive tract worldwide and is also among the cancers with high mortality rates.ObjectiveThe aim of this work was to evaluate the diagnostic performance of multislice spiral CT (MSCT), magnetic resonance imaging (MRI), and MSCT + MRI in different stages of colon cancer (CC) (T1-T2, T3, T4). This work compared the differences in sensitivity (Sen), specificity (Spe), accuracy (Acc), and area under the curve (AUC) values among these methods and explored the optimal diagnostic strategy.MethodsA total of 120 patients with CC confirmed by pathological biopsy and 30 individuals suspected of CC but without detected tumors (as controls) were selected. All subjects underwent MSCT, MRI, and combined MSCT + MRI examinations. Statistical analyses of Sen, Spe, Acc, and AUC values were performed.ResultsIn the T1-T2 stage, MSCT had a Sen of 85.2%, Acc of 86.8%, and an AUC value of 0.878; MRI had a Spe of 91.0%, Sen of 81.6%, and an AUC value of 0.865; the combined MSCT + MRI examination had a Sen of 90.6% and an AUC of 0.903. In the T3 stage, MRI had a significantly higher Sen (91.7%) than MSCT (80.0%), with an AUC of 0.887, while the combined MSCT + MRI examination had a Sen of 98.3% and an AUC of 0.942. In the T4 stage, the combined MSCT + MRI examination performed the best, with a Sen of 100% and an AUC of 0.933, and compared with MSCT or MRI alone, the differences were statistically significant (P < 0.05).ConclusionMSCT and MRI each have their own advantages in the diagnosis of different stages of CC. MSCT is suitable for initial screening in the T1-T2 stage, while MRI is more effective in assessing tumor invasiveness in the T3 and higher stages. The combined MSCT + MRI examination can provide more comprehensive diagnostic information, especially in the T4 stage, where it shows the highest Sen and Acc. Selecting the appropriate examination method based on the patient's specific condition and staging needs is of great significance in improving the diagnostic Acc of CC.

Prognostic value of CD163+ macrophages in solid tumor malignancies: A scoping review

Tumor-associated macrophages (TAMs) play crucial roles in development and progression of malignant diseases. Notably, CD163+ TAMs likely perform specific pro-tumorigenic functions, suggesting that this subset may serve as both prognostic biomarkers and targets for future anti-cancer therapy. We conducted a scoping review to map the current knowledge on the prognostic role of CD163+ TAMs in the five most lethal cancers worldwide: Lung, colorectal, gastric, liver, and breast cancer. For all cancer types, most studies showed that high tumoral presence of CD163+ cells was associated with poor patient outcome, and this association was more frequently observed when CD163+ cells were measured at the tumor periphery compared to more central parts of the tumor. These results support that CD163+ TAMs represent a biomarker of poor patient outcome across a variety of solid tumors, and highlight the relevance of further investigations of CD163+ TAMs as targets of future immunotherapies.

Tumor infiltrating lymphocytes (TILs) - Pathologia, quo vadis? - A global survey

Tumor-infiltrating lymphocytes (TILs) and the tumor microenvironment have become increasingly important in cancer research, and immunotherapy has achieved major breakthroughs in improving patient outcomes. Despite the significant role of the pathologist in identifying, subtyping and reporting TILs, the implementation and assessment of TILs in pathology routine remains vague. To assess the actual use of TILs in routine clinical practice, a formal standardized questionnaire was disseminated on two social media platforms ("X" and LinkedIn) and by email in June 2024. Based on the results, we conducted a literature review on TILs via Medline/Pubmed in the two most scored and reported entities, namely malignant melanoma and colorectal cancer (CRC). 77 participants from 24 different countries around the world, mostly pathologists (n = 63, 82.0 %), completed the survey. More than half of the participants do not assess or report TILs in their daily (clinical) practice, a trend consistent across the countries included in the study. A variety of methods are used to report TILs, ranging from Artificial Intelligence (AI)-based scoring algorithms to quantification by eyeballing. Despite recognizing the importance of TIL assessment in clinical routine, many participants find it time-consuming and express a strong preference for AI-based quantification. Our survey reflects the perspective of mostly early career pathologists who recognize the importance of TILs in cancer but face challenges in implementation. The development of AI tools and consensus guidelines could alleviate these barriers. In addition, increasing the visibility and understanding of the role of pathologists within the medical community remains critical.

Beta-2-microglobulin positive tumor cells and CD8 positive lymphocytes are associated with outcome in post-neoadjuvant colorectal cancer resections

Locally advanced colorectal cancers are treated with neoadjuvant therapy (NAT), which has been shown to alter the characteristics of the tumor including size, lymph node yield, and histologic grade. We seek to interrogate the effect of NAT on the immune microenvironment. We compared 190 patients with colorectal adenocarcinoma treated with NAT with those without NAT (n = 926). We evaluated clinicopathologic and molecular factors and performed immunohistochemistry and quantification on tissue microarrays for HLA class I/II proteins, beta-2-microglobulin (B2M), CD8, CD163, LAG3, PD-L1, and FoxP3. Patients in the NAT group were younger (60.9 vs 67.9, p < 0.001) and more often male (59.5 vs. 47.9, p = 0.004) than those in the non-NAT group. Tumors in the NAT group were smaller (3.5 vs 4.7 cm, p < 0.001), less often high grade (6.5% vs. 16.2%, p = 0.001), more frequently in the rectum (68.9% vs. 6.6%, p < 0.001) and associated with lower lymph node yields (p = 0.002); however, the incidence of extramural venous invasion, perineural invasion, and AJCC stage 3-4 disease were not different. Immune cells positive for CD8 (p = 0.011) were significantly lower in the NAT group. A high number of CD8+ cells and higher expression of B2M in tumor cells showed a significant survival benefit in both NAT and non-NAT group. NAT is associated with an immune-low tumor environment. CD8+ cells and tumor B2M expression may help identify a subset of immune high-tumors following NAT. This identification could aid in determining patients who may benefit from conservative management of colorectal carcinomas.

β2-microglobulin expression is associated with aggressive histology, activated tumor immune milieu, and outcome in colon carcinoma

OBJECTIVES

We sought to assess the expression of human leukocyte antigen (HLA) proteins and β2-microglobulin (B2M) in tumor cells and the relationship with immune microenvironment and outcome in colorectal cancer (CRC).

METHODS

A total of 953 CRC cases were evaluated by immunohistochemistry for HLA class I, HLA class II, and B2M. The expression level of these biomarkers was correlated with clinicopathologic information, BRAF V600E and mismatch repair (MMR) proteins, and the quantitated expression levels of immune cells (CD8 and CD163) and immune regulatory proteins (FoxP3, programmed cell death 1 ligand 1 [PD-L1], and LAG3).

RESULTS

We found that B2M-low tumors were statistically correlated with aggressive histologic features, including higher stage, higher grade, extramural venous invasion, perineural invasion, and distant metastasis. Expression of B2M was positively correlated (R2 = 0.3) and significantly associated with MMR-deficient tumors (P < .001); B2M-low tumors were also associated with an "immune cold"' microenvironment, including a reduced number of immune cells (CD8 and CD163), reduced expression of immune regulatory proteins by immune cells (PD-L1, FoxP3, and LAG3), and reduced tumor cell expression of PD-L1. These B2M-low tumors correlated with lower disease-specific survival (P = .018), a finding that maintained significance only for the proficient MMR cohort (P = .037).

CONCLUSIONS

Our findings suggest that B2M expression may support predictive models for both outcome and checkpoint inhibitor therapy treatment response for colorectal adenocarcinoma.

A Comprehensive Study on the Prognostic Value and Clinicopathological Significance of Different Immune Checkpoints in Patients With Colorectal Cancer: A Systematic Review and Meta-Analysis

Background

The prognostic significance of immune checkpoint expression in the tumor microenvironment has been widely investigated in colorectal cancers. However, the results of these studies are inconsistent and limited to some immune checkpoints.

Objective

The study aimed to investigate the correlation between different immune checkpoint expression and clinicopathological features and prognostic parameters.

Methods

We conducted a systematic review and meta-analysis of the published literature in PubMed, Web of Science-Core Collection, Scopus, Embase, and Cochrane databases to summarize the association between various immune checkpoints expression on both tumor cells and immune cells with clinicopathological features and prognostic parameters in patients with colorectal cancer.

Results

One hundred four studies incorporating 22,939 patients were included in our meta-analysis. Our results showed that among the B7 family, the high expression of B7H3, B7H4, PD-1, and PD-L1 on tumor cells and tumor tissue was significantly associated with higher T stage, advanced tumor, node, metastasis (TNM) stage, presence of vascular invasion, and lymphatic invasion. In addition, patients with high expression of B7H3, B7H4, PD-1, PD-L1, and PD-L2 were associated with shorter overall survival. High expression of PD-1 and PD-L1 in immune cells correlated with the absence of lymph node metastasis, lower TNM stage, early T stage, poor overall survival, and disease-free survival, respectively. Moreover, we found significant positive correlations between CD70 and Galectin-3 expression with advanced T stage. HLA-II overexpression was correlated with the absence of lymph node metastasis (odds ratio = 0.21, 95% CI = 0.11-0.38, P < 0.001) and early TNM stage (odds ratio = 0.35, 95% CI = 0.26-0.47, P < 0.001).

Conclusions

Overexpression of B7H3, B7H4, PD-1, PD-L1, PD-L2, CD70, and Galectin-3 on tumors is significantly associated with unfavorable clinicopathological characteristics and poor prognostic factors. Hence, these immune checkpoints can serve as predictive biomarkers for prognosis and the clinicopathological features of colorectal cancer because this is essential to identify patients suitable for anticancer therapy with immune checkpoint inhibitors.

Clinical, pathological, genetics and intratumoural immune milieu of micropapillary carcinoma of the colon

AIM

Micropapillary carcinoma (MPC) is a recognised WHO variant of colonic carcinoma (CC), although little is known about its prognosis, immune microenvironment and molecular alterations. We investigated its clinical, pathological and immunological characteristics.

METHODS

We assessed 903 consecutive CCs and used the WHO definition to identify MPC. We recorded serrated and mucinous differentiation and mismatch repair (MMR) status. We performed immunohistochemistry and quantification on tissue microarrays for HLA class I/II proteins, beta-2-microglobulin (B2MG), CD8, CD163, LAG3, PD-L1, FoxP3, PD-L1and BRAF V600E.

RESULTS

We classified 8.6% (N=78) of CC as MPC. Relative to non-MPC, MPC was more often high grade (p=0.03) and showed serrated morphology (p<0.01); however, we found no association with extramural venous invasion (p=0.41) and American Joint Committee on Cancer stage (p=0.95). MPCs showed lower numbers of CD8 positive lymphocytes (p<0.01), lower tumour cell B2MG expression (p=0.04) and lower tumour cell PD-L1 expression (p<0.01). There was no difference in HLA class I/II, LAG3, FOXP3, CD163 and PD-L1 positive histiocytes. There was no association with MMR status or BRAF V600E relative to non-MPC. MPC was not associated with decreased disease-specific survival (p=0.36).

CONCLUSION

MPCs are associated with high-grade differentiation and a less active immune microenvironment than non-MPC. MPC is not associated with inferior disease-specific survival.

PU.1 negatively regulates tumorigenesis in non-small-cell lung cancer

PU.1 is a key transcription factor that modulates hematopoietic cell differentiation and is involved in various physiological and pathological processes. PU.1 has been described to have multiple roles in a diverse range of cancers, but its contribution in non-small-cell lung cancer (NSCLC) has not been clearly elucidated. Fifty pairs of lung adenocarcinoma (LUAD) tissues and paraneoplastic tissues were collected. RT-qPCR assay was used to test PU.1 expression. Expression of PU.1 in LUAD cell lines and control cell lines was detected by RT-qPCR, and the role of PU.1 in LUAD was investigated by in vitro experiment. Levels of the major proteins in the apoptotic pathway were also detected by Western blot. The expression of PU.1 was remarkably downregulated in LUAD. Overexpression of PU.1 impaired the viability of LUAD cells as well as their metastatic function. In addition, PU.1 promoted apoptosis of LUAD cells by decreasing Bcl2 and increasing Bax/Bak1 expression. PU.1 plays an inhibitory role in LUAD, mainly promoting the apoptosis of LUAD cells.