MicroRNA expression in colorectal cancer

摘要

Colorectal cancer is a common disease entity with anmulti-factorial aetiology which remains poorly understood.nIt is estimated that in 2008, colorectal cancerwasnresponsible for 8% of all cancer deaths, making it thenfourth most common cause of death from cancer [10].nPrognosis is heavily linked to stage at diagnosis. Thenmajor cause of death is development of metastasis innliver, abdominal lymph nodes,and lung, forwhich therenis no cure [21]. According to the most recently definednAmerican Joint Committee on Cancer (AJCC) systemnfor colonic adenocarcinoma, 5-year stage-specific survivalsnwere 93.2% for stage I disease compared withn8.1% for stage IV [34], highlighting a need for novelnearly detection strategies. Colorectal cancer, at leastntheoretically, is a disease entity which is amenable tonearly detection, since it exhibits a stepwise progressionnof carcinogenesis from benign polyps to adenocarcinoma,nover a period of time. The majority of nationalnscreening programmes currently centre on the usenof colonoscopy or faecal immunohistochemistry/occultnblood testing. Colonoscopy is an expensive, invasivenprocedure which carries a significant risk of intestinalnperforation (1:700). Faecal testing ismore cost effectivenand less invasive but sacrifices sensitivity and specificity.nCarcinoembryonic antigen, the only blood test currentlynavailable, exhibits low sensitivity and specificity.nHence, there is great need for new biomarkers for earlyndetection of CRC.