Oral contraceptives and @entity5344 . The @entity5 and XXXX Hormone Study Group, Atlanta Georgia.

@entity1 @entity1204 @entity43 @entity0 @entity5344 @entity5 @entity134 @entity204 @entity1558
The @entity5 and @entity134 Hormone Study was designed to minimize certain problems criticized in some previous case-control studies of oral contraceptives (OCs) and gynecological @entity5 . The largest of its type undertaken thus far, the study included over 4000 @entity1 with @entity0 , over 600 with @entity1204 , and over 500 with @entity43 , along with over 4000 controls. The controls were selected from the population in the geographical areas from which the cases were drawn. The study was limited to @entity1 20-54 years. Study enrollment occurred between December 1980 and December 1982 at 8 regional @entity5 registries participating in the Surveillance, Epidemiology, and End Results Program of the National @entity5 Institute (NCI). Investigators at these centers attempted to identify all @entity1 20-54 years of age with newly diagnosed primary @entity5344 . These @entity1 constituted the case group. Controls were @entity1 20-54 years chosen by an established method of telephoning households at random in the geographical regions covered by the participating centers. All controls were interviewed in @entity1 . To improve the accuracy of reporting OC and other hormone use, 2 memory aids were used: use of a book of photographs of all OC and other female hormone preparations marketed in the US up to 1980; and use of a calendar to record information for each @entity1 about such major life events as marriages, births, divorces, and @entity204 . Information on contraception and other reductive events was then recorded around these usually well-remembered milestones. A panel of pathologists reviewed histological specimens for all cases of @entity43 enrolled in this study and for all cases and controls with a history of @entity1558 for whom a biopsy specimen was available. The major findings with respect to OC use and risk of @entity5 of the breast, endometrium, and ovary largely confirmed those in previous studies. It was found that a history of OC use appeared to protect against @entity43 and had no overall effect on the risk of @entity0 . @entity1 who had used OCs for less than 1 year had the same risk of developing @entity1204 as "never-users." Compared with never-users, @entity1 who used OCs for 1-5 years, or for more than 5 years, had a relative risk of 0.4. @entity1 who have ever used combination OCs had about 1/2 the risk of developing @entity43 compared to @entity1 who have never used them. Compared with @entity1 who never used OCs, @entity1 who had ever used them had a relative risk of @entity0 of 0.9. There was no appreciable trend in the relative risk of @entity0 by duration of use.
