George L. Rubin

Pregnancy, breast feeding, and oral contraceptives and the risk of epithelial ovarian cancer

To quantify the effects of cumulative months of pregnancy, breast feeding, and oral contraceptive use on the risk of developing epithelial ovarian cancer, the authors used data collected for the Cancer and Steroid Hormone Study--a multicenter, population-based, case-control study. Detailed reproductive histories were obtained from 436 women aged 20-54 with epithelial ovarian cancer newly diagnosed between December 1980 and December 1982, and from 3833 women aged 20-54 selected at random from the same geographic areas. Estimated relative risks of epithelial ovarian cancer were 0.6 (95% confidence interval (CI) 0.5-0.8) for women who had ever been pregnant, 0.6 (95% CI 0.5-0.8) for women who had ever breast fed, and 0.5 (95% CI 0.5-0.7) for women who had ever used oral contraceptives. Logistic regression analysis revealed a strong trend in decreasing risk of epithelial ovarian cancer with increasing cumulative months of pregnancy; this effect was less pronounced in women aged 50-54 than in younger women. In contrast, a marked reduction in risk was associated with ever having breast fed or used oral contraceptives, while the decrease in risk from additional months of either of these exposures was less than that for pregnancy.

Nutrient intake and supplementation in the United States (NHANES II).

Data from the second United States Health and Nutrition Examination Survey (NHANES II) suggest that almost 35 per cent of the US population 18 to 74 years of age takes vitamin/mineral supplements regularly. Both higher nutrient intake and use of vitamin supplementation are associated with older ages, higher income, higher education level, and White race. Accounting for differences associated with sex, age, race, income, and education, persons with higher nutrient intakes remain more likely to take vitamin supplements.

Oral contraceptives and pelvic inflammatory disease

To study the association of the use of oral contraceptives and pelvic inflammatory disease (PID), we analyzed data from a large multicenter case-control study of contraceptive use and serious gynecologic disorders. The analysis included data from interviews of 648 women hospitalized with an initial episode of PID and 2,516 hospitalized control subjects. The risk of PID for women using oral contraceptives in the 3 months prior to interview was 0.5 (95% confidence limits, 0.4 to 0.6) relative to women using no contraceptive method during this period. This association was not explained by differences between case subjects and control subjects in demographic variables, level of sexual activity, or medical history. The protective effect of current oral contraceptive use against PID was restricted to women using oral contraceptives for more than 12 months; past use of oral contraceptives did not exert a protective effect against PID. Annually, an estimated 50,000 initial cases of PID are prevented by oral contraceptive use; 12,500 hospitalizations are also averted by oral contraceptive use. Consequently, protection against PID is one of the most important noncontraceptive benefits of oral contraception.

Deaths attributable to tubal sterilization in the United States, 1977 to 1981

In 1979, the Centers for Disease Control began surveillance of deaths attributable to tubal sterilization in order to determine why they occur and what may be done to prevent them. Since that time, 29 such deaths have been identified as occurring in the United States from 1977 through 1981. Of these 29 deaths, 11 followed complications of general anesthesia, seven were due to sepsis, four were due to hemorrhage, three were due to myocardial infarction, and four deaths were related to other causes. Some of these deaths might have been prevented by use of endotracheal intubation for general anesthesia, particularly for laparoscopic sterilization, safer use of unipolar coagulation or use of alternative techniques, careful insertion of the needle and trocar for laparoscopy, and discontinuation of oral contraceptives before sterilization. Further surveillance may help to make tubal sterilization even safer.

Oral-contraceptive use and the risk of breast cancer. The cancer and steroid hormone study of the centers for disease control and the national institute of child health and human development

To investigate the effect of individual formulations of oral contraceptives on the risk of breast cancer in women, we analyzed case-control data from the Cancer and Steroid Hormone Study of the Centers for Disease Control. The cases were 4711 women 20 to 54 years old with newly diagnosed breast cancer who were selected from eight population-based cancer registries. The controls were 4676 women selected by random-digit dialing of the population of each area covered by a registry. As compared with women who had never used oral contraceptives, women who had used them had a relative risk of breast cancer of 1.0. Among women who used only one oral-contraceptive formulation, this estimate of relative risk did not change appreciably according to the formulation used. Neither the type of estrogen nor the type of progestin contained in oral contraceptives used was associated with an increased risk of breast cancer. The duration of oral-contraceptive use and the time since last use did not influence the risk. These findings provide further support for the contention that oral-contraceptive use does not increase the risk of breast cancer in women.

Regret after decision to have a tubal sterilization

To determine characteristics associated with regretting sterilization that can be determined preoperatively, we analyzed data from the Collaborative Review of Sterilization (CREST), a multicenter, prospective, observational study. Of 5022 women, 2.0% regretted having had a tubal sterilization at 1 year after the procedure and 2.7% did so after 2 years. Using a multivariate analysis to identify risk factors for regret, we found that almost all characteristics were more closely associated with regret at 1 year than at 2 years postoperatively. Of the characteristics we examined that could be objectively determined preoperatively, we considered only age less than 30 years and (for whites) a concurrent cesarean section to be risk factors for regret at 2 years after sterilization. However, in absolute terms, less than 10% of women with both those risk factors regretted having the procedure.

Seasonal variation in conception and various pregnancy outcomes.

Abstract U.S. vital registration data on live births and data on abortions and ectopic pregnancies from a national hospital discharge survey were used to examine the seasonality of conceptions and the influence the conception pattern has on the monthly incidence of abortions and ectopic pregnancies. We found that in the United States conceptions follow a consistent seasonal pattern with the peak in November and December. However, when the pattern for conceptions is controlled, the monthly variation for abortions and ectopic pregnancies is not significant. Therefore, we find no monthly excess for any of these outcomes of pregnancy over that expected as a consequence of the seasonality of conception. We suggest the monthly variation for the number of each of these pregnancy outcomes will best be explained when the seasonal variation in conceptions is understood.

Endometrial cancer: How does cigarette smoking influence the risk of women under age 55 years having this tumor?

This analysis of the Cancer and Steroid Hormone Study, a multicenter, population-based case control investigation of hormone use by women of reproductive age and endometrial, breast, and ovarian cancer shows that cigarette smoking is not associated with either an increased or a decreased risk of endometrial cancer. This study included 437 women with endometrial cancer and 3200 control subjects, all of whom were between the ages of 20 and 54 years at the time of interview. The absence of any alteration of the risk of endometrial cancer and smoking was found consistently no matter which variable was used as a measure of smoking--ever or never smoked cigarettes, former or current smoking, light or heavy smoking, or age smoking began.

Estrogen Therapy and the Risk of Breast, Ovarian, and Endometrial Cancer

Millions of women have used estrogens for relief of menopausal symptoms. Theoretical considerations, clinical observations, and epidemiologic information raise concern as to possible associations between use of exogenous estrogens and cancers of the female reproductive tract (Thomas, 1978). Because of the large number of women who have been using or will use estrogens for menopausal symptoms, any risk of or protection from these cancers could have major health impact on women in their postmenopausal years.

The health impact of restricting public funds for abortion. October 10, 1977--June 10, 1978.

The Center for Disease Control (CDC), Atlanta, Georgia implemented an eight-month prospective surveillance system in 24 hospitals distributed among states with and without public funding for abortion. Out of 3,157 visits for abortion-related complications, only 10 women gave a history of non-physician or self-induced abortion and none were Medicaid recipients. The small number of hospitals located in non-funded states and the smaller numbers of women served in these hospitals than in the funded states limited the power of out study. Women living along the Texas-Mexico border appeared more likely to have complications after illegal abortions than women from other areas of the country.