International Journal of Molecular Medical Science, 2024, Vol.14, No.5, 274-292 http://medscipublisher.com/index.php/ijmms 276 that the 5-year survival rate for patients with early-diagnosed CRC is greater than 90% (Berger and Mardis, 2018). However, the majority of cases are diagnosed at advanced stages, where the prognosis is poor and treatment options are limited. In metastatic cases, the 5-year survival rate is much lower, approximately 13% (Siegel et al., 2017). Although the incidence of this disease has been decreasing in Western countries, mainly due to the widespread use of colonoscopy, the incidence is rising among younger people, making early detection of colorectal cancer critically important (Stoffel and Murphy, 2020). Early detection allows for the identification and removal of precancerous polyps before they progress to invasive cancer. This can be achieved through regular screening programs, which have been shown to reduce the incidence and mortality of colon cancer. Colorectal cancer screening can be performed using various methods. Screening initiation and follow-up guidelines vary among different organizations (Smith et al., 2019). The diagnosis of colorectal cancer requires a tissue biopsy, typically obtained through a colonoscopy. All newly diagnosed colorectal cancers should undergo screening for common genetic mutations, complete colonoscopy, and baseline carcinoembryonic antigen (CEA) testing. Most patients with invasive cancer require baseline chest and abdominopelvic computed tomography (CT) scans (Benson et al., 2021). Moreover, early detection facilitates the implementation of personalized treatment strategies, improving patient outcomes. 2.3 Current diagnostic methods and their limitations Current diagnostic methods for colon cancer include colonoscopy, fecal occult blood tests (FOBT), and imaging techniques such as CT colonography. The initial diagnosis may involve a barium enema or CT colonography. Ultimately, a colonoscopy is required for tissue diagnosis (Dawson et al., 2019; Grimm and McGill, 2019; Manjunath et al., 2019). Colonoscopy is considered the gold standard for detecting and removing polyps and early-stage cancers. However, it is an invasive procedure that requires bowel preparation and sedation, which can be uncomfortable for patients. FOBT is a non-invasive test that detects hidden blood in the stool, which can be an early sign of colon cancer. Randomized controlled trials and large cohort studies have confirmed that overall survival (OS) is improved in patients whose cancer was detected through FOBT screening compared to those whose cancer was not detected through screening (Hardcastle et al., 1996; Mandel et al., 2000; Lindholm et al., 2008; Scholefield et al., 2012; Shaukat et al., 2013; Ananda et al., 2016). While it is less invasive than colonoscopy, FOBT has lower sensitivity and specificity, leading to false positives and negatives. CT colonography, also known as virtual colonoscopy, is a less invasive imaging technique that provides detailed images of the colon. However, it may miss small polyps and still requires bowel preparation. Despite these available methods, there are significant limitations in the early detection of colon cancer. Many cases are diagnosed at advanced stages due to the lack of symptoms in the early stages and the limitations of current screening methods. Therefore, there is a critical need for the development of more sensitive and specific diagnostic tools, such as those based on multi-omics data integration, to improve early detection and patient outcomes. 3 Multi-Omics Data in Cancer Research 3.1 Definition and types of omics data Multi-omics data integration involves the comprehensive analysis of various types of omics data to gain a holistic understanding of biological systems and disease mechanisms. The primary types of omics data include genomics, transcriptomics, epigenomics, proteomics, and metabolomics. 3.1.1 Genomics Genomics is the study of the complete set of DNA within an organism, including all of its genes. It involves the sequencing and analysis of genomes to identify genetic variations and mutations that may contribute to cancer development. Genomic data provides insights into the genetic basis of cancer and helps in identifying potential driver mutations (Zhao et al., 2020; Menyhárt and Győrffy et al., 2021). The sequencing of the human genome has rapidly advanced. In recent years, numerous publications have described a large number of newly sequenced human genomes, including specific population cohorts from Iceland (Jónsson et al., 2017; Kehr et al., 2017) ,
RkJQdWJsaXNoZXIy MjQ4ODYzNQ==