N-acetylcysteine suppression of the proliferative index in the colon of patients with previous adenomatous colonic polyps

Cancer Lett. 1999 Dec 1;147(1-2):109-14. doi: 10.1016/s0304-3835(99)00281-5.


This investigation is part of an effort to develop chemoprevention for carcinogenesis of the large bowel. The agent investigated is N-acetylcysteine (NAC). We used as a predictive biomarker, the proliferative index (PI), in a short-term human study. Patients with previous adenomatous colonic polyps are a cohort with increased risk for colon cancer and an increased PI of colonic crypts. They were randomly assigned to an experimental group given 800 mg/day of NAC for 12 weeks or a placebo group. Using proliferative cell nuclear antigen immunostaining, the PI of colonic crypts was measured prior to and after the treatments. The PI of the NAC group was decreased significantly (P < 0.02) while the placebo group showed no difference (P > 0.45). Since this decrease in PI may be an indicator of decreased risk of colon cancer, more extensive studies of the potential of NAC as a chemopreventive agent for colon cancer appear warranted.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / administration & dosage*
  • Adenomatous Polyps / pathology
  • Adenomatous Polyps / prevention & control*
  • Administration, Oral
  • Age Factors
  • Biopsy
  • Chemoprevention
  • Cohort Studies
  • Colonic Polyps / pathology
  • Colonic Polyps / prevention & control*
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / prevention & control*
  • Diet
  • Free Radical Scavengers / administration & dosage*
  • Humans
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology
  • Mitotic Index / drug effects*
  • Proliferating Cell Nuclear Antigen / metabolism
  • Sex Factors


  • Free Radical Scavengers
  • Proliferating Cell Nuclear Antigen
  • Acetylcysteine