ABSTRACT
BACKGROUND & AIMS: Familial predisposition as a risk for colorectal cancer in ulcerative colitis has not been rigorously explored. The aim of this study was to compare colorectal cancer frequency among kindreds of patients who had ulcerative colitis and colorectal cancer with that of control patients who had ulcerative colitis but no cancer. METHODS: Questionnaires were mailed to subjects to assess cancer occurrence among relatives. Eligible cases included 174 ulcerative colitis patients with colorectal cancer seen at Mayo Clinic in 1976-1994; 174 contemporaneous ulcerative colitis controls without cancer were matched on birth year, sex, and extent and duration of colitis. RESULTS: The responding 147 case and 150 control subjects reported on 1044 and 1090 first-degree relatives, respectively. Colorectal cancer occurred in 14.3% case kindreds and 6.7% control kindreds (P = 0.03). By logistic regression, a family history of sporadic colorectal cancer was an independent risk factor for cancer in ulcerative colitis (odds ratio, 2.33; 95% confidence interval, 1.06-5.14; P = 0.03). CONCLUSIONS: A familial association exists between colorectal cancers occurring with ulcerative colitis and those in the general population. Colorectal cancer in persons with ulcerative colitis represents a risk factor for colorectal cancer in their noncolitic relatives. Likewise, a family history of sporadic colorectal cancer increases the risk of colorectal cancer with ulcerative colitis.
Subject(s)
Colitis, Ulcerative/genetics , Colorectal Neoplasms/genetics , Adult , Aged , Case-Control Studies , Chronic Disease , Colorectal Neoplasms/epidemiology , Female , Genetic Predisposition to Disease/genetics , Humans , Male , Middle Aged , PrevalenceABSTRACT
BACKGROUND: Controversy persists regarding primary sclerosing cholangitis (PSC) as a risk factor for colorectal carcinoma in patients with chronic ulcerative colitis. Small sample size and differing endpoints have contributed to variation among reported studies. This large case-control study was conducted to examine the possible association between PSC and colon carcinoma in patients with ulcerative colitis. METHODS: From Mayo Clinic records spanning 1976-1994, 171 cases with both ulcerative colitis and colorectal carcinoma and 171 contemporaneous controls with ulcerative colitis but no colorectal neoplasia matched with regard to age, gender, extent, and duration of colitis were identified. The diagnosis of PSC required cholangiographic confirmation. Analysis employed a multivariate logistic regression model. RESULTS: The prevalence of PSC was similar in cases (18%) and controls (15%) (P = 0.54). The adjusted odds ratio for colorectal carcinoma with PSC was 1.23 (95% confidence interval, 0.62-2.42). CONCLUSIONS: Based on this large case-control study, there was no association between PSC and colorectal carcinoma in patients with ulcerative colitis.
