Table 3. Studies highlighting risk factors of colonic inflammation leading to CRC.

UC: ulcerative colitis; CRC: colorectal cancer; IBD: inflammatory bowel disease; CRN: colorectal neoplasia; PSC: primary sclerosing cholangitis

References	Design	No. of Cases	Study Parameters	Conclusion
Lakatos L et al. [18]	Cohort	723	Calculated the incidence and standardized incidence and mortality rate ratios of CRC among adult individuals with intact colons using Kaiser Permanente of Northern California's database of members with IBD and general membership data for the period of 1998 to June 2010 and evaluated trends in medication use and rates of cancer detection over time.	Our UC patients had a high cumulative risk of CRC, although it was lower than that reported in Western European and North American research. When compared to random CRC patients, CRC developed around fifteen years sooner. Long illness duration, severe colitis, iron shortage or chronic anemia, dysplasia, and PSC appear to be key risk factors for CRC in UC patients.
Jess T et al. [19]	Cohort	43	Conducted a nested case-control study of such factors in two well-described IBD cohorts from Copenhagen County, Denmark, and Olmsted County, Minnesota.	CRN was more common in IBD patients with PSC, severe long-standing illness, and x-ray exposure. The preventive impact of careful monitoring, colonoscopy, and 5-amino salicylate therapy appeared uncertain.
Gupta RB et al. [20]	Cohort	418	Determine whether the severity of microscopic inflammation over time is an independent risk factor for neoplastic progression in UC.	In individuals with long-standing UC, the degree of microscopic inflammation over time is an independent risk factor for developing advanced CRN.
Nieminen U et al. [21]	Cohort	183	Investigated the role of histological inflammation as a risk factor for colorectal dysplasia or CRC to better target dysplasia surveillance in IBD.	In conclusion, the degree of inflammation and the length of the condition both raise the risk of dysplasia and CRC. The presence of PSC was not recognized as a risk factor. We found that using thiopurines significantly reduces the risk of CRC. These findings can be used to improve target dysplasia monitoring in IBD patients.
Rutter M et al. [22]	Cohort	68	To determine if the severity of colonic inflammation is an important determinant of the risk of CRN.	The intensity of colonic inflammation is a key predictor of the risk of CRN in patients with long-standing severe UC. Endoscopic and histological grading of inflammation may allow for more accurate risk classification in monitoring systems.