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Fibroid Growth Study (FGS)

Epidemiology Branch

The Fibroid Growth Study examines the variation in fibroid growth, the biological differences between growing and non-growing fibroids, and the relationship between fibroid growth and symptom severity.  Uterine fibroids are very common, but often asymptomatic. Large tumors are more likely to cause health problems than small tumors, but there are few data on fibroid growth.

The purpose of this study is to better understand fibroid growth among women with clinically relevant tumors. The specific aims are to:

  • Describe variation (between tumors, between women) in fibroid growth
  • Examine biological differences between growing and non-growing fibroids
  • Examine the relationship between fibroid growth and symptom severity

The research team enrolled about 120 women with clinically relevant fibroids, those greater than five centimeters in diameter or a uterine size equivalent to 12 weeks gestation. Approximately 40 participants were followed until surgery or for one year if there was no surgical treatment. Magnetic resonance images (MRIs) were taken at baseline, 3 months, 6 months, 12 months or presurgery. A subgroup of those having myomectomies was also followed with MRIs post-myomectomy. Blood and urine were collected at each MRI examination. For those having surgery, tissue samples were collected from each fibroid and from normal myometrium.

The researchers will compare characteristics of growing versus non-growing tumors using several analyses, including microarray, RT-PCR, and histological staining of fixed tissue specimens to assess proliferation, apoptosis, vascularity, and fibrosis. Participants were interviewed by telephone monthly to collect data on symptom change during participation. These data will be used to investigate the relationship between tumor growth and changes in disease severity as measured by change in symptomatology.

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Last Reviewed: August 02, 2007