Published online Mar 15, 1997. doi: 10.3748/wjg.v3.i1.16
Revised: September 29, 1996
Accepted: January 31, 1997
Published online: March 15, 1997
AIM: To investigate the chemopreventive effect of sulindac, a nonsteroidal anti-inflammatory drug (NSAID), on the growth of N-methyl-N-nitrosourea (MNU)-induced mouse colonic tumors.
METHODS: The experimental colonic tumor model induced by intrarectal instillation of MNU in mice was used in the present study. In the first experiment, MNU intrarectal was instilled and sulindac administered concurrently to a group of mice for a period of 18 wk, while a control group of animals received MNU only for the same period. In the second experiment, two groups of mice that had already been treated with MNU for 12 wk received sulindac or not for another 18 wk.
RESULTS: The tumors induced in mice were all located in the distal part of the large intestine. There were no significant differences in the location and the gross appearance of the tumors in the MNU-induced group and control group in both experiments. In the first experiment, sulindac caused a significant reduction in both the number of mice with colonic tumors and the number of tumors per mouse. Sulindac had a significant inhibitory effect on the growth of the MNU-induced tumors. However, in the second experiment, the inhibitory effect of sulindac was less or disappeared.
CONCLUSION: Sulindac has a protective effect against the chemical induction of colonic tumors by MNU in mice. The chemopreventive effect is more significant in the initial stage of the tumor, while in the promotion stage this effect is less or disappeared. Sulindac can not cause the regression of established tumors.