Table 10

Number and prevalence of adenomas and hyperplastic polyps

*Mean (SD).
†One way analysis of variance.
‡χ2 test
HNPCC, hereditary non-polyposis colorectal cancer; HCRC, hereditary colorectal cancer; TCR, two close relatives with colorectal cancer.
No of patients10812764
No of adenomas488751
Mean age at first colonoscopy41.445.649.2
Mean age at last colonoscopy44.349.051.1
Subjects with adenomas263925
No of adenomas (adenomas/individual)*0.44 (0.95)0.69 (1.63)0.80 (1.29)0.200†
Mean No of adenomas/individual with adenoma1.852.232.04
Prevalence: adenoma at first colonoscopy (%)16.0 (n=17)17.3 (n=22)25.0 (n=16)0.618‡
Prevalence: ever having an adenoma (%)24.1 (n=26)31.0 (n=39)39.1 (n=25)0.115‡
No of hyperplastic polyps6413989
Subjects with hyperplastic polyps254429
No of hyperplastic polyps (hyperplastic polyps/individual)*0.59 (1.37)1.09 (2.13)1.39 (2.49)0.027†
Mean No of hyperplastic polyps/individual with hyperplastic polyps2.563.163.07
Prevalence: hyperplastic polyp at first colonoscopy (%)9.3 (n=10)15.7 (n=20)31.3 (n=20)0.001‡
Prevalence: ever having a hyperplastic polyp (%)23.1 (n=25)35.0 (n=44)45.3 (n=29)0.010‡