Incidence of breast cancer in a 22-year study of women receiving estrogen-progestin replacement therapy.

OBJECTIVE: To review the incidence of breast cancer in a continuous 22-year study of conjugated estrogen-medroxyprogesterone acetate hormone replacement therapy. METHODS: Eighty-four pairs of continuously hospitalized postmenopausal women who were matched for age, smoking history, and medical diagnosis were treated with estrogen-progestin hormone replacement therapy or placebo in a prospective and double-blind manner for 10 years. In the subsequent 12 years, the women were offered the choice of starting, stopping, or continuing hormone replacement therapy. RESULTS: After the initial 10 years, the incidence of breast cancer in the placebo group was 4.8%, whereas no cancers were found in the hormone replacement therapy group (P = .12). After an additional 12 years of follow-up, the overall incidence of breast cancer in the women who had never taken hormone replacement therapy was 11.5%, whereas no breast cancers had developed in the women who had ever taken hormone replacement therapy (P < .01). CONCLUSIONS: These data suggest that the 22-year administration of estrogen-progestin hormone replacement therapy did not increase the incidence of breast cancer in a small group of continuously hospitalized postmenopausal women.

Estrogen replacement therapy II: a prospective study in the relationship to carcinoma and cardiovascular and metabolic problems.

A 10-year double-blind prospective study was undertaken to evaluate the effects of estrogen replacement therapy (ERT). The sample population consisted of 84 pairs of randomly chosen postmenopausal in-patients, matched for age and diagnosis. The treatment group received high-dose conjugated estrogens, cyclically with progesterone. The controls recieved placebos. Results revealed no statistically significant difference in that incidence of thrombophlebitis, myocardial infarction (MI), or uterine cancer. There was a lower incidence of breast cancer in the treated group. Estrogen-treated patients showed a higher incidence of cholelithiasis. Those in the treated group who began the study with elevated beta/alpha lipoprotein ratios showed a reduction in that ratio over the course of the study, while the controls either maintained or increased their ratios. The low number of cases precludes drawing any real significance from the data on diseases of low frequency. The study excludes only a high incidence of complications from estrogens.

PIP: A study involving 84 pairs of patients evaluated the effects of estrogen replacement therapy over a 10-year period. The pairs of patients were postmenopausal women matched for age and diagnosis. The treated group received high-dose conjugated estrogen, cyclically with progesterone while the control group received placebos. Thrombophlebitis, myocardial infarction, or uterine cancer incidences showed no significant differences in the 2 groups; however, there was a lower incidence of breast cancer in the treated group as well as reduced beta/alpha lipoprotein ratios. Yet the incidence of cholelithiasis was higher in the estrogen-treated group. Of the 168 in-patients, there were 7 deaths in the control group and 3 in the treated group. The results attributable to either estrogen or progesterone cannot be separated due to their concomitant use and due to the small study population, little significance can be placed on the data of diseases of low frequency.

Estrogen replacement therapy I: a 10-year prospective study in the relationship to osteoporosis.

A 10-year, double-blind prospective study was undertaken to evaluate the effects of estrogen replacement therapy. The sample population consisted of 84 pairs of randomly chosen postmenopausal patients who were matched for age and diagnosis. One half of the patients received conjugated estrogens and cyclic progesterone, while the other half received placebo. Estrogen-treated patients whose therapy started within 3 years of menopause showed improvement or no increase in osteoporosis. Control patients demonstrate an increase in their osteoporosis.