The association between pro-vegetarian dietary pattern and risk of colorectal cancer: a matched case-control study

A healthful plant-based diet can reduce the risk of developing colorectal cancer: case-control study

INTRODUCTION

The benefit of adherence to a plant-based diet concerning colorectal cancer (CRC) has not been investigated among Middle Eastern population. This study aimed to investigate how adherence to a plant-based diet influences the risk of CRC in this understudied population.

METHODS

This case-control study was conducted in the CRC surgery departments of general hospitals in Tehran, Iran. A total of 71 individuals with newly diagnosed CRC (cases) and 142 controls subjects free of cancer and acute illness were concurrently recruited from the same hospital. Dietary information was collected using a semi-quantitative 168-item food frequency questionnaire. Dietary patterns were characterized using the plant-based diet index (PDI), unhealthy plant-based diet index (uPDI) and healthy plant-based diet index (hPDI). Multivariate logistic regression was employed to assess the association between these dietary patterns and the risk of CRC.

RESULTS

After adjusting the potential confounders, the risk of CRC was significantly lower in the highest tertile of hPDI compared to the lowest tertile (odds ratio (OR) = 0.21; 95% confidence interval (CI): 0.07-0.56, representing 79% risk reduction). Conversely, the risk of CRC was significantly higher in the highest tertile of uPDI compared to the lowest tertile (OR = 6.76; 95% CI: 2.41-18.94). PDI was no significant associated with the risk of CRC.

CONCLUSIONS

This study found that higher scores on the hPDI was significantly associated with a decrease risk of CRC, while greater adherence to the uPDI contributed to a significantly increase risk.

The diagnostic potential of miR-196a-1 in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a common malignancy worldwide. MicroRNAs (miRNAs) are important epigenetic alterations that notably impact various physiological and pathological processes by acting as negative regulators of gene expression. Furthermore, they have a vital function in different types of cancers, including CRC. In this research, we evaluated, for the very first time, the expression levels of miR-196a-1 in the tissue and plasma of patients with CRC and also homeobox D8 (HOXD8) as the target gene.

MATERIALS AND METHODS

This study included a collection of 220 plasma and tissue samples from 55 patients diagnosed with CRC, as well as 55 healthy individuals matched by age and sex. Total RNA was extracted from plasma and tissue samples, and then polyadenylation and cDNA synthesis were performed. The expression levels of miR-196a-1 and HOXD8 as target gene was evaluated by quantitative RT-PCR (qRT-PCR) assay. We compared the diagnostic value of plasma miR-196a-1 with that of the circulating tumor markers CA19-9 and CEA using a Receiver Operating Characteristics (ROC) analysis. The association of miR-196a-1 with clinicopathological characteristics was assessed in tissue and plasma samples from patients with CRC.

RESULTS

Our data demonstrated that the expression levels of miR-196a-1 in the tissue and plasma samples of CRC patients were 11.426- and 11.655-fold higher, respectively than those in adjacent normal tissue and plasma samples from normal subjects (p < 0.001). Through ROC curve analysis, it was identified that the sensitivity and specificity of miR-196a-1 for tissue samples, with an AUC of 0.925, were 89% and 98%, respectively. In addition, the sensitivity and specificity for plasma samples with an AUC of 0.801 were 70% and 98%, respectively. These findings reveal that miR-196a-1 is a useful biomarker for discriminating cases from controls. Furthermore, the expression of HOXD8 was not significantly altered in tumor tissue samples compared to adjacent normal tissues (P > 0.05).

CONCLUSIONS

These results show that miR-196a-1 has an oncogenic impact and plays a significant role in CRC development. The results also indicate that miR-196a-1 could serve as a novel noninvasive biomarker for the detection of CRC.