Table 2.

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

nMedian number of crypts per ACF within person (%)*
P
≤4041-80>80
Age (y)
    50-59966.722.211.10.009
    60-69966.722.211.1
    70-80147.135.757.1
First-degree relative with a history of colorectal cancer
    No2941.427.631.01.0
    Yes333.333.333.3
History of adenoma
    ≤65 y old
        No560.020.020.00.44§
        Yes1070.020.010.0
    >65 y old
        No450.025.025.0
        Yes137.738.553.8
Cigarette smoking
    ≤65 y old
        Not current966.722.211.10.47§
        Current666.716.716.7
    >65
        Not current1421.435.742.9
        Current30.033.366.7
NSAID use at least weekly during the past year
    ≤65 y old
        No666.70.033.30.38§
        Yes966.733.30.0
    >65 y old
        No366.733.30.0
        Yes147.135.757.1
Frequency of NSAID use during the past year
    ≤65 y old
        0-6 times/wk875.00.025.00.50§
        ≥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.