Hormonal implication of diet and reproductive activity in the genesis of cervical cancer.

The incidence of cervical cancer is known to decrease with the Westernization of life style. The purpose of this study was to see whether or not the practice of pseudopregnancy conditioning (psp-c) and/or non-Western (rice-rich or rice-and salt-rich) diet conditioning (dt-c) in female mice can reproduce a specific steroidal disorder that is associated with cervical cancer--general depression of androgen and partial depression of corticoid in urine. The effects of psp-c and dt-c were assessed by estimating various steroids in urine and plasma of mice, as collected at the terminal stage of the experiment. Macroscopic and microscopic changes of genital organs were also investigated by dissection. Results obtained are as follows: 1) the practice of psp-c and/or dt-c induced a total of 13 deciduomas in the vagina, the cervix and the corpus of experimental mice. No deciduoma was found in virgin mice fed a standard (Western-style) diet. 2) The combination of 2 reproductive markers (psp-c and non-psp-c) and 3 dietary markers (standard diet, rice-rich diet and rice- and salt-rich diet) produced a variety of changes in the excretions of all androgens, progestins and corticoids in the urine of mice for each of 5 experimental groups. A common steroidal trait was extracted from the urinary steroid data of 5 experimental groups--general depression of androgens, progestins and majority corticoids relative to tetrahydrocortisol. By the collation test, the combination of psp-c and rice- and salt-rich diet conditioning was found to be the best choice for reproducing the urinary steroid changes specific for cervical cancer. 3) The results of plasma steroid analysis, though not incompatible with the urinary steroid data, were fragmentary and not very informative in this study. The observed resistance of mice to carcinogenic insults together with the possible role of deciduoma in cervical carcinogenesis is discussed in the light of relevant information including the anti-carcinogenic action of vitamin C.