Ulcerative colitis: a first-degree relative with colorectal cancer increased the risk of colorectal cancer

Clinical bottom line (level 3b)

Patients with chronic ulcerative colitis who had a first-degree relative who had suffered colorectal cancer were themselves at increased risk of developing colorectal cancer (NNT = 13 at unknown) .

Nuako et al: Gastroenterology 1998; 115: 1079-1083

Expires May 2003

The study

Case-control study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, USA

380 patients (aged mean 47, 70% male) with chronic ulcerative colitis

Excluded if

no histological diagnosis of colorectal cancer in cases

Cases: 206 patients (70% male, mean age 52): with colorectal cancer diagnosed after 1976
Controls: 174 patients (69% male, mean age .): no colorectal cancer; matched for birthdate, sex and extent and duration of ulcerative colitis

Factors studied:

colorectal cancer risk factors

Factors summarised:

colorectal cancer in a first-degree relative

Multivariate regression analysis used to adjust for confounding factors

Outcomes studied:

colorectal cancer confirmed on histology

The evidence

Patient expected event rate for colorectal cancer: 6.7%

risk factor for colorectal cancer	adjusted OR (95% CI)	NNH (95% CI)
colorectal cancer in a first-degree relative	2.31 (1.03 to 5.18)	13 (5 to 270)

A further analysis of the medical records for stroke in the families of cases and controls revealed no difference in occurrence rates.

Citation

Nuako KW, Ahlquist , Mahoney DW, et al: Familial predisposition for colorectal cancer in chronic ulcerative colitis: a case-control study. Gastroenterology 1998; 115: 1079-1083

Search Terms: ?
Contributor: Chris Ball and Bob Phillips, October 1999
Reviewer:

_{Clinical Question.}

_Patient	_{ulcerative colitis}
_{Intervention or Exposure}	_{first-degree relative with colorectal cancer}
_Outcome	_{colorectal cancer}