Lack of effect of indomethacin on the growth of N-nitrosomethylurea-induced rat mammary tumors.

Elevated prostaglandin levels have been previously reported in mammary tumors. This study was designed to determine if treatment with indomethacin, a prostaglandin synthesis inhibitor, influenced the growth of N-nitrosomethylurea-induced mammary tumors in Wistar rats. Indomethacin was given in drinking water to tumor-bearing rats, and rats consumed between 2.5 and 3.0 mg/kg body weight/day. Continuous p.o. administration of indomethacin during 4 weeks did not affect the rate of tumor growth as compared to the control group of untreated rats. It can be concluded that indomethacin lack of effect on N-nitrosomethylurea-induced mammary tumors, and this may be due to a specific prostaglandin profile as compared with previous results using other experimental models.

Risk factors in breast cancer.

The incidence of claimed risk factors for breast cancer was studied in 162 patients suffering this entity and in a control group of women with similar sociocultural level and age. Late menopause and sterility or first child born after age of 30 were the only factors more frequent in breast cancer patients.