Ethnic differences in the anatomical location of colorectal adenomatous polyps

Authors

  • G. Johan A. Offerhaus,

    1. Department of Pathology, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD USA
    Search for more papers by this author
  • Francis M. Giardiello,

    Corresponding author
    1. Division of Gastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD USA
    • Division of Gastroenterology, Blalock 935, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD 21205, USA
    Search for more papers by this author
  • Kasper W. F. Tersmette,

    1. Department of Pathology, University Hospital, Leiden, The Netherlands
    Search for more papers by this author
  • Jan-Willem R. Mulder,

    1. Department of Pathology, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD USA
    Search for more papers by this author
  • Anne C. Tersmette,

    1. Dept. of Clinical Epidemiology, University Hospital, Leiden, The Netherlands
    Search for more papers by this author
  • G. William Moore,

    1. Department of Pathology, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD USA
    Search for more papers by this author
  • Stanley R. Hamilton

    1. Department of Pathology, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD USA
    2. Oncology Center, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD USA
    Search for more papers by this author

Abstract

The ratio of right- to left-sided colonic cancer is increasing, but data on the distribution of its usual precursor lesion, the colorectal adenoma, are contradictory. Therefore, we investigated the prevalence of right- and left-sided colorectal adeno-matous polyps from January I, 1970, to September 30, 1989, using the study design of „epidemiologic necropsy” and the autopsy files of The Johns Hopkins Hospital.

Compared with the decade of the 1970's, the 1980's showed a slight decrease in the overall prevalence of right-sided adenomas (6.4 per 1,000, 95% confidence limits 4.7-8.8 vs. 5.1 per 1.000, 95% CL 3.6-6.5), but a marked decrease occurred in left-sided adenomas (11.8 per 1,000,95% CL 9.3-14.3 vs. 6.7 per 1,000, 95% CL 4.8-8.6). As a result, the ratio of right-sided to left-sided adenomas increased from 0.55 in the 1970's to 0.77 in the 1980's. This increased ratio occurred in both sexes, although prevalences were lower in females, and in whites. Unexpectedly, blacks had a ratio of right-sided to left-sided adenomas greater than unity in both the 1970's and 1980's (1.19 vs. 1.79) due to a relatively high prevalence of right-sided adenomas (5.8 per 1,000, 95% CL 3.6-8.0 in 1970's; 5.8 per 1,000, 95% CL 3.3-8.3 in 1980's), but low prevalences of left-sided adenomas (4.9 per 1,000, 95% CL 3.0-6.8 in 1970's; 3.2 per 1,000, 95% CL 1.2-5.2 in 1980's). The overall adenoma prevalence in blacks was lower than in whites.

We conclude that the right-sided predominance of colorectal adenomas in blacks suggests ethnic differences in the pathogenesis of colorectal adenomas. This observation may have important implications for secondary prevention of colorectal cancer.

Ancillary