Table 2.

Selected risk factors for colorectal cancer in relation to median size of ACF

nMedian number of crypts per ACF within person (%)*
Age (y)
First-degree relative with a history of colorectal cancer
History of adenoma
    ≤65 y old
    >65 y old
Cigarette smoking
    ≤65 y old
        Not current966.722.211.10.47§
        Not current1421.435.742.9
NSAID use at least weekly during the past year
    ≤65 y old
    >65 y old
Frequency of NSAID use during the past year
    ≤65 y old
        0-6 times/wk875.§
        ≥7 times/wk757.142.90.0
    >65 y old
        0-6 times/wk633.333.333.3
        ≥7 times/wk119.136.454.6
  • * Row percentages are presented in the columns below this header.

  • Unadjusted P from Fisher's exact test.

  • History of adenoma: one or more adenomas identified during the study colonoscopy or at a previous colonoscopy.

  • § Age-adjusted P from Cochran-Mantel-Haenszel test, with age categories of ≤65 and >65 years.

  • Includes aspirin.