Current Trends in Colorectal Cancer Screening

Methylation of FBN1, SPG20, ITF2, RUNX3, SNCA, MLH1, and SEPT9 genes in circulating cell-free DNA as biomarkers of colorectal cancer

BACKGROUND

Investigating aberrant tumor-specific methylation in plasma cell-free DNA provides a promising and noninvasive biomarker for cancer detection.

OBJECTIVE

We aimed to investigate methylation status of some promoter regions in the plasma and tumor tissues to find biomarkers for early detection of colorectal cancer.

METHODS

This case-control study on seventy colorectal cancer patients and fifty matched healthy controls used Methylation-Specific High-Resolution Melting Curve analysis to evaluate the methylation of the selected promoter regions in converted genomic tissue DNA and plasma cfDNA.

RESULTS

The methylation levels in selected regions of SPG20 (+24375 to +24680, +24209 to +24399, and +23625 to +23883), SNCA (+807 to +1013, +7 to +162, and -180 to +7), FBN1 (+223 to +429, +1 to +245, and -18 to -175), ITF2 (+296 to +436 and -180 to +55), SEPT9 (-914412 to -91590 and -99083 to -92264), and MLH1 (-13 to +22) were significantly higher in tumor tissues compared with normal adjacent tissues. The methylation levels of FBN1, ITF2, SNCA, and SPG20 promoters were significantly higher in the patient's plasma compared to patient's normal tissue and plasma of healthy control subjects. FBN1, SPG20, and SEPT9 promoter methylation had a good diagnostic performance for discriminating CRC tissues from normal adjacent tissues (AUC > 0.8). A panel of SPG20, FBN1, and SEPT9 methylation had a higher diagnostic value than that of any single biomarker and other panels in tissue-based assay (AUC > 0.9). The methylation of FBN1(a) and SPG20(a) regions, as the closest region to the first coding sequence (CDS), had a good diagnostic performance in plasma cfDNA (AUC > 0.8) while a panel consisted of FBN1(a) and SPG20(a) regions showed excellent diagnostic performance for CRC detection in plasma cfDNA (AUC > 0.9).

CONCLUSION

Methylation of FBN1(a) and SPG20(a) promoter regions in the plasma cfDNA can be an excellent simple, non-invasive blood-based test for early detection of CRC.

Knowledge, attitude and practice towards early screening of colorectal cancer in Riyadh

Background and Aims:

Colorectal cancer (CRC) is a common cause of mortality worldwide. It is preventable, treatable when detected early. The aim of this study is to assess knowledge, attitude and practice (KAP) of the participants toward CRC and its early screening, and identify the sources of information on the subjects.

Methods:

We conducted a cross-sectional study on the people 40y old and above at the primary care clinics at King Saud university medical city (KSUMC) in Riyadh. The estimated sample size was 245 subjects whom we requested to complete a self-administered Arabic questionnaire, which consisted of three parts. These were: 1. Demographic data, 2. KAP toward CRC, its early detection. 3 sources of information of the public about colorectal cancer.

Results:

A total of 231 subjects participated; (54.5%) were male (mean age = 50.7 ± 9.8). About 47% of the participants heard about cancer screening, and 45% knew that colonoscopy is used for such purposes. Another 24.2% were aware that occult blood in the stool test is a method of early detection of colon cancer. About 40% to 50% of the subjects were knowledgeable about hazardous factors and cautioning symptoms for CRC. Only 6.5% of the subjects did an early screening for CRC, but 82.9% would do it if their doctor advised them to do so.

Conclusion:

The participant's knowledge and early checkups of CRC are inadequate. They would undergo early screening if their doctors advised them to do so. It is time to develop a national policy for CRC screening involving primary care doctors and utilizing social media to improve people's information.