Uterine fibroids are hormonally dependent benign tumors of the uterine muscle that develop in premenopausal women. Currently the primary symptoms (pain and bleeding) are treated, but when those treatments fail major procedures to remove or shrink the fibroids are frequently the only options for women. Fibroids are the leading indication for hysterectomy in the United States. African-American women develop fibroids an average of 10 years earlier than white women in the U.S., and they are approximately three times more likely to have a hysterectomy for fibroids. The known risk factors for fibroids do not explain this disparity.
The goal of the Study of Environment, Lifestyle & Fibroids (SELF) is to identify risk factors for uterine fibroid development. It is the first study to identify incident cases based on ultrasound screening. We enrolled a cohort of 1693 women who self-identified as Black or African American, ages 23-35, from the Detroit, Michigan area (SELF participant website). Women with a prior diagnosis of fibroids were not eligible. Participants were screened for fibroids with ultrasound at enrollment and follow-up ultrasounds occurred approximately every 20 months to identify new fibroids. Fibroids that were detected at enrollment and those that arose during follow-up were monitored at subsequent visits for fibroid growth. We collected risk factor and symptom data, physical measurements, as well as blood, urine, and vaginal swab specimens at enrollment and follow-up visits.
The study was designed to test three primary hypotheses:
- Vitamin D deficiency is a risk factor for fibroid incidence and/or growth.
- Reproductive tract infections can increase risk of fibroid development.
- Genotypic variation in African ancestry may influence fibroid development directly or through interaction with life-course risk factors.
In addition, we collected extensive information to examine other exposures of interest, and our extra specimens can be used to test new hypotheses in the future.
With this first prospective study of fibroid development we aim to identify new preventative factors that could directly benefit women. We anticipate that the detailed data on fibroid development can be used to help design new interval treatment strategies to limit fibroid growth and thus reduce the need for the invasive treatments that remain the standard of care when first-line treatments fail.