Primary Resistance to Immune Checkpoint Inhibitors in Metastatic Colorectal Cancer-Beyond the Misdiagnosis

Targeting Ubiquitin-like Protein, ISG15, as a Novel Tumor Associated Antigen in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in both men and women in the United States. While immune checkpoint inhibitor (ICI) therapy is demonstrating remarkable clinical responses, the resistance and immune-related toxicities associated with ICIs demonstrate the need to develop additional immunotherapy options for CRC patients. Cancer vaccines represent a safe and promising treatment approach for CRC. As previously developed tumor-associated antigen (TAA)-based cancer vaccines for CRC are not demonstrating promising results, we propose that interferon-stimulated gene 15 (ISG15) is a novel TAA and therapeutic target for CRC. Our work demonstrates the anti-tumor efficacy of a Listeria-based vaccine targeting ISG15, designated Lm-LLO-ISG15, in an immunocompetent CRC murine model. The Lm-LLO-ISG15-mediated anti-tumor response is associated with an increased influx of functional T cells, higher production of multiple intracellular cytokines response, a lower number of regulatory T cells, and a greater ratio of effector to regulatory T cells (Teff/Treg) in the tumor microenvironment.

LncRNA ARST is a Novel Prognostic and Diagnostic Biomarker for Colorectal Cancer

Background

ALDOA-related specific transcript (ARST) is a recently identified long non-coding RNA (lncRNA) that suppresses glioma progression, while its role in other cancers is unclear. This study explored the role of ARST in colorectal cancer (CRC).

Methods

The present study included 60 CRC patients, 60 patients with colon polyps (CP), 60 colitis patients, 60 hemorrhoid patients and 60 healthy controls. All participants were subjected to the collection of plasma, and paired CRC and non-tumor tissues were collected from CRC patients. All samples were subjected to RNA isolation and RT-qPCR to detect the expression of ARST. ROC curve and survival curve analysis were performed to evaluate the diagnostic and prognostic values of plasma ARST for CRC.

Results

The expression levels of ARST were lower in CRC plasma samples compared to that in the patient groups and controls (p < 0.01), while other patient groups and controls showed no significant difference. The expression levels of ARST were also lower in CRC tissues compared to that in non-tumor tissues (p < 0.01). Plasma expression levels of ARST effectively distinguished CRC patients from other patients and controls. The expression levels of ARST were closely correlated with patients' survival. Chi-squared test analysis showed that ARST was closely associated with patients' distant metastasis but not tumor size.

Conclusion

ARST is downregulated in CRC, and it might be applied in the diagnosis and prognosis of CRC.

Research Progress of Preoperative FPR, FAR or AFR in Patients with Colorectal Cancer

Research has confirmed that plasma albumin (Alb), prealbumin (PA) and fibrinogen (Fib) are involved in regulating the occurrence and development of various tumors. Their levels in peripheral blood are related to the survival outcome and treatment response of patients, but the accuracy and specificity of single application have yet to be fully realized. A growing amount of evidence indicates that predictors such as preoperative fibrinogen to prealbumin ratio (FPR), fibrinogen to albumin ratio (FAR) or albumin to fibrinogen ratio (AFR) are emerging as comprehensive indicators. Indeed, their components play a key regulatory role in the progression of colorectal cancer (CRC). Preoperative FPR, FAR or AFR levels, therefore, are expected to become new biomarkers for prognosis evaluation and curative effect prediction for CRC patients and are significant in the guidance they could provide for the development of individualized treatment strategies.

Association between body mass index and survival outcomes for cancer patients treated with immune checkpoint inhibitors: a systematic review and meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs) have been increasingly applied in the treatment of several kinds of malignancies. Some clinical demographic characteristics were reported to be associated with the ICIs efficacy. The purpose of our current meta-analysis was to clearly evaluated the relationship between BMI and ICIs efficacy for cancer patients receiving immunotherapy.

METHODS

A systematic search of Pubmed, EMBASE and conference proceedings was performed to investigate the influence of BMI on ICIs efficacy. Pooled analysis for overall survival (OS), progression-free survival (PFS) and immune-related adverse effects (IRAEs) were analyzed in current study.

RESULTS

A total of 13 eligible studies comprising 5279 cancer patients treated with ICIs were included in the analysis. The pooled analysis showed there is positive association between high BMI and improved OS and PFS among patients with ICIs treatment (OS: HR = 0.62, 95% CI 0.55-0.71, P < 0.0001; I2 = 26.3%, P = 0.202); PFS: HR = 0.71, 95% CI 0.61-0.83, P < 0.0001; I2 = 0%, P = 0.591). There is no significant difference between the incidence of all grade IRAEs between obese, overweight patients and normal patients (Overweight vs Normal: pooled RR = 1.28, 95% CI 0.76- 2.18, P = 0.356; Obese vs Normal: pooled RR = 1.36, 95% CI 0.85- 2.17, P = 0.207).

CONCLUSION

An improved OS and PFS were observed in patients with high BMI after receiving ICIs treatment compared with patients of low BMI. No significant association between BMI and incidence of IRAEs was found in cancer patients after ICIs treatment.