Modulation of methylcholanthrene-induced carcinogenesis in the uterine cervix of mouse by indomethacin.

The present paper reports the chemopreventive action of indomethacin on methylcholanthrene (MCA)-induced carcinogenesis in the uterine cervix of virgin young adult Swiss albino mice. Placement of a sterile cotton thread impregnated with beeswax containing approx. 600 micrograms of MCA produces cervical tumors in 91% mice in 16 weeks. When such carcinogen-containing threads are inserted into the uterine cervix of mice fed diets containing indomethacin at the dose levels of 10 mg/kg, 20 mg/kg and 40 mg/kg diet for two pre-insertion weeks plus 16 post-insertion weeks, the cervical tumor incidences were 83%, 65% and 26% (P less than 0.01), respectively. It is concluded that indomethacin, when given in the diet at sufficiently high concentration, significantly inhibits MCA-induced cervical carcinogenesis.