"Wide geographical and ethnic differences--sometimes orders of magnitude--exist in the incidences of breast, cervical, uterine, ovarian, prostate and testicular cancer worldwide. The incidences of breast, prostate and testicular cancer have been increasing. Cervical cancer is decreasing, and uterine and ovarian are fairly stable. The incidence of uterine cancer in the U.S. increased temporarily in the 1970s, coinciding with the use of unopposed estrogen as therapy for menopausal symptoms. There is no evident increase in uterine cancer that would correlate with the recent increase in breast cancer. Estrogens are known to inhibit the proliferation of prostatic carcinoma cells, so one would expect that environmental estrogens would actually have a protective effect against cancer of the prostate.

"An increase in both breast and prostate cancer is not consistent with an effect from an environmental estrogen. The increase in the incidences of breast and prostate cancer appear to be, at least in part and perhaps entirely, the result of increased diagnosis. The increase in the incidence of testicular cancer appears to be real, but at present there is no convincing explanation for this rise. The data are inconsistent with exposure to PCBs and DDT, because increases in testicular cancer began in cohorts before the use of PCBs and DDT. The increases in breast and prostate cancer, on the other hand, are occurring after concentrations of these organochlorine compounds declined markedly in body tissues.

"Geographical differences in sperm counts are so large that the currently available statistics do not permit a conclusion that there has been a worldwide decline in semen quality. The data on endometriosis, cryptorchidism and hypospadias are not of sufficient quality and detail to make any strong inferences regarding exposure to an environmental estrogen.

"In summary, the epidemiological data on cancers of hormonally responsive tissues, sperm counts, endometriosis, cryptorchidism and hypospadias when taken together do not provide evidence, at least at the present, for an effect of exposure to an environmental estrogen; the data are actually contradictory to the notion that exposure to environmental organochlorine compounds has had an effect on these conditions."

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