| Phenolphthalein-containing Laxative Use in Relation to Adenomatous Colorectal Polyps in Three Studies Matthew P. Longnecker,
1
Dale P. Sandler,
1
Robert W. Haile,
2
and Robert S. Sandler
3
1
Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
2
University of Southern California Norris Comprehensive Cancer Center, Los Angeles, CA 90033 USA
3
Division of Digestive Diseases and Nutrition, Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA Abstract
Phenolphthalein, the active ingredient in many laxatives, was recently found to be a carcinogen in animal models. Human data suggest a laxative-colon cancer association, but few data specifically address the effects of phenolthalein-containing laxatives. We examined use of phenolphtalein-containing laxatives in relation to occurrence of adenomatous colorectal polyps in data from three case-control studies. The study conducted in Los Angeles, California (1991-1993) , and the two studies conducted in North Carolina (1988-1990 and 1992-1995) altogether included 866 cases and 1,066 controls. The prevalence of using phenolphthalein-containing laxatives at least once a week in the recent past, however, was less than 5% among these subjects. The multivariate-adjusted odds ratios associated with recent use of phenolphthalein-containing laxatives once a week or more were 1.8 [95% confidence interval (CI) , 0.5-6.2] in Los Angeles, 1.0 (CI, 0.4-2.2) in North Carolina (1988-1990) , and 1.1 (CI, 0.2-5.7) in North Carolina (1992-1995) . For use of other types of laxatives, the corresponding odds ratios were 1.3 (CI, 0.9-1.9) in Los Angeles, 1.0 (CI, 0.5-1.7) in North Carolina (1988-1990) , and 0.9 (CI, 0.4-1.8) in North Carolina (1992-1995) . Although the low prevalence of frequent use made for relatively wide confidence intervals, overall these data suggest that use of phenolphthalein-containing laxatives does not increase risk of adenomatous colorectal polyps. Key words : adenomatous, case-control studies, cathartics, colorectal neoplasms, pharmacoepidemiology, phenolpthaleins, polyps. Environ Health Perspect 105:1210-1212 (1997) .
Address correspondence to M.P. Longnecker, NIEHS, PO Box 12233, MD A3-05, Research Triangle Park, NC 27709 USA. This work was supported in part by grants from the National Institutes of Health (CA66635 and CA44684) . Received 5 May 1997 ; accepted 13 August 1997.
The full version of this article is available for free in HTML format. |
