Characteristics of estrogen-treated women. A descriptive epidemiological study of a Swedish population. Part II.

A cohort of 23 233 women who had received estrogen prescriptions was recruited for a prospective study of estrogen therapy and the associated risk of endometrial cancer. For a detailed study, a comprehensive questionnaire was mailed to 735 randomly sampled cohort members, and 89 per cent of them responded. Estrogen exposure and its implications were described in a preceding paper (part I). The present paper reports the distribution in the cohort sample of personal features known to be risk factors for endometrial cancer. A comparison with results from various materials derived from population-based surveys and case-control studies implied that the cohort members might have a lower proportion of nulliparity (infertility) and a somewhat higher prevalence of hypertension. Differences in the distributions of age at menarche or menopause, weight, height and prevalence of diabetes were according to these comparisons slight and probably without clinical significance. It was concluded that the prevalence of risk factors for endometrial cancer other than estrogen exposure was not higher in the cohort than in the background population. Moreover, approximately one-fifth of the estrogen takers had been freed of their risk through hysterectomies.