Gut microbiome-derived bacterial extracellular vesicles in patients with solid tumours

INTRODUCTION

Gut microbiome-derived nanoparticles, known as bacterial extracellular vesicles (bEVs), have garnered interest as promising tools for studying the link between the gut microbiome and human health. The diverse composition of bEVs, including their proteins, mRNAs, metabolites, and lipids, makes them useful for investigating diseases such as cancer. However, conventional approaches for studying gut microbiome composition alone may not be accurate in deciphering host-gut microbiome communication. In clinical microbiome research, there is a gap in the knowledge on the role of bEVs in solid tumor patients.

OBJECTIVES

Analyzing the functionality of bEVs using (meta)genomics and proteomics could highlight the unique aspects of host-gut microbiome interactions in solid tumor patients. Therefore, we performed a comparative analysis of the proteome and microbiota composition of gut microbiome-derived bEVs isolated from patients with solid tumors and healthy controls.

METHODS

After isolating bEVs from the feces of solid tumor patients and healthy controls, we performed spectrometry analysis of their proteomes and next-generation sequencing (NGS) of the 16S gene. We also investigated the gut microbiomes of feces from patients and controls using 16S sequencing and used machine learning to classify the samples into patients and controls based on their bEVs and fecal microbiomes.

RESULTS

Solid tumor patients showed decreased microbiota richness and diversity in both the bEVs and feces. However, the bEV proteomes were more diverse in patients than in the controls and were enriched with proteins associated with the metabolism of amino acids and carbohydrates, nucleotide binding, and oxidoreductase activity. Metadata classification of samples was more accurate using fecal bEVs (100%) compared with fecal samples (93%).

CONCLUSION

Our findings suggest that bEVs are unique functional entities. There is a need to explore bEVs together with conventional gut microbiome analysis in functional cancer research to decipher the potential of bEVs as cancer diagnostic or therapeutic biomarkers.

Immunological and prognostic significance of tumour necrosis in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) causes the second most cancer deaths worldwide, but the disease course varies according to tumour characteristics and immunological factors. Our objective was to examine the associations of tumour necrosis with tumour characteristics, immune cell infiltrates, serum cytokine concentrations, as well as prognosis in CRC.

METHODS

Three independent CRC cohorts, including 1413 patients, were analysed. Associations of the areal percentage of tumour necrosis with clinicopathologic parameters, tumour infiltrating immune cells, cytokine concentrations in systemic and mesenteric vein blood, and survival were examined.

RESULTS

Higher tumour necrosis percentage associated with shorter colorectal cancer-specific survival independent of tumour grade, T, N or M-class, mismatch repair status, BRAF status, and other possible confounding factors. In the largest cohort (N = 1100), the HR for high tumour necrosis percentage (≥40% vs. <3%) was 3.22 (95% CI 1.68-6.17, Ptrend < 0.0001). Tumour necrosis percentage positively correlated with peripheral serum levels of CXCL8, a proinflammatory chemokine, and negatively correlated with mesenteric serum levels of CXCL10 and mast cell densities in the invasive margin of the tumour.

CONCLUSIONS

Our results support the value of tumour necrosis as a prognostic factor in colorectal cancer. CXCL8 may have a role in the systemic effects of tumour necrosis.

Perioperative oral nutritional support for patients diagnosed with primary colon adenocarcinoma undergoing radical surgical procedures -Peri-Nutri Trial: study protocol for a randomized controlled trial

Background

Colon cancer is one of the most common cancers in Finland and worldwide. Cancer-related malnutrition is a well-known risk factor for increased morbidity and mortality after surgery, and it is associated with complications and longer hospitalizations. There are no established recommendations on how to improve the nutritional status of colon cancer patients´ during the perioperative phase. Administration of simple oral nutritional supplements has been suggested to reduce complication rates, but evidence to support this practice is scarce.

Methods

The Peri-Nutri trial is a prospective, multicenter, randomized, controlled trial. Its primary endpoint is to evaluate whether perioperative oral nutritional support (ONS) decreases the number of complications during the 30-day follow-up after surgery. Secondary endpoints are to study the effect of ONS on quality of life after surgery, length of stay in institutional care, 90-day mortality rate, five-year disease-free survival and overall survival. The patients with a Nutritional risk screening 2002 (NRS-2002) questionnaire result between 2 and 5 (≥ 3 are classified at risk of malnutrition) will be randomized (1:1 ratio) into either the intervention or control group. The intervention group will receive preoperative ONS two weeks before the operation, and nutritional support will continue 10 days after the operation. The control group will not receive ONS. A total of 318 patients will be randomized into two groups and patients are followed five years.

Discussion

Peri-Nutri study evaluate the impact of ONS to short-term and long-term postoperative morbidity and mortality rates of colon cancer patients undergoing curative surgery. If ONS will decrease patients´ morbidity and mortality, that has a huge impact on patients´ quality of life and also to financial cost.

Trial registration

ClinicalTrials.gov, NCT03863236, Registered 25 February 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-022-00591-y.

The impact of sarcopenia and myosteatosis on postoperative outcomes and 5-year survival in curatively operated colorectal cancer patients - A retrospective register study

BACKGROUND

The aim of this study was to evaluate whether sarcopenia or myosteatosis have an impact on short- and long-term results in patients who were surgically treated for colorectal cancer.

METHODS

During 2007-2011 curatively treated colorectal cancer patients (n = 348) were included in the study. Clinical data was collected retrospectively from patient registers. Skeletal muscle mass was measured at the L3 level via venous-phase computed tomography and patients were divided into sarcopenic and non-sarcopenic and into myosteatotic and non-myosteatotic. Postoperative morbidity and mortality were analysed in these groups.

RESULTS

Sarcopenia was found in 208 patients (59.8%) and myosteatosis was found in 108 patients (31.2%). Sarcopenia was associated with increased risk of postoperative pneumonia (6.7% vs. 1.4%, p = 0.021). Sarcopenic colon cancer patients had higher rate of cardiorespiratory complications than non-sarcopenic (6.3% vs. 0.0%, p = 0.023) and sarcopenic rectum cancer patients had more often pneumonia than non-sarcopenic (8.5% vs. 0.0%, p = 0.041). Discharge to home was less common in myosteatotic patients than in non-myosteatotic patients (47.7% vs. 76.9%, p < 0.001) and also in sarcopenic patients than in non-sarcopenic patients (62.7% vs. 75.5%, p = 0.013). Myosteatotic patients had decreased overall survival according to a Kaplan-Meier analysis (p = 0.002) and in the multivariable-adjusted Cox model (HR = 1.6, p = 0.034).

CONCLUSIONS

Sarcopenia increases the pneumonia and cardiorespiratory complication rates. Sarcopenia and myosteatosis predicts the need for institutional care after colorectal cancer surgery. Sarcopenia and myosteatosis seem to be negative factors for colorectal cancer patients' survival. Myosteatosis is an independent risk factor for poor overall 5-year survival.