Risk Factors for Uterine Fibroids: A Case Control Study

The proposed study is designed to estimate the proportion of 35-49 year-old women in a large urban health plan who have had fibroids. The membership of the health plan is approximately 45% black, so estimates for black and white women can be compared. Risk factors for the condition will be studied, and uterine tissue from women having hysterectomies or myomectomies will be studied to identify genetic, hormonal, and protein mediators of tumor growth. A randomly selected sample of about 1800 women age 35-49 who are members of the George Washington University Health Plan will be invited to participate. Presence of leiomyomas for premenopausal participants with no prior diagnosis of leiomyoma will be determined by an ultrasound examination. Presence of leiomyomas for premenopausal women who report a prior diagnosis of fibroids will be determined by ultrasound evidence in their medical record when available, and by self-report when not available. History of fibroids in postmenopausal women will be based on pathology records for those with surgical menopause and on radiology records or self-report for the small number of naturally postmenopausal women. Estimates of the proportion who have or have had fibroids will be compared for blacks and whites. To examine risk factors for leiomyoma we will conduct a case-control analysis. Cases will be those women identified with leiomyoma from the random sample, supplemented by women in the same age range who have hysterectomies or myomectomies during the study period and hose excised uteri show evidence of fibroids on standard pathology examination. Women from the random sample with ultrasound or pathology evidence showing no uterine fibroids will constitute the control group. Controls will be compared to cases grouped by size of largest fibroid and grouped by clinical. A telephone interview and self-administered questionnaire will provide information on demographic factors, medical history, dietary intake, reproductive history,