Objective
To describe the short-term changes in growth of uterine leiomyomata (fibroids).
Design
Prospective observational study
Setting
University Research Center
Patients
Premenopausal women with fibroids (n = 18 blacks and 18 whites) recruited through a physician network and community outreach.
Intervention(s)
Not applicable.
Main Outcome Measures
The volumes of 101 fibroids were measured at enrollment, 3, 6, and 12 months with magnetic resonance imaging (MRI), resulting in three interval-specific growth rates. Growth spurts were defined by interval growth rates â„ 30% per 3 months and substantially greater than during other intervals of observation. An overall measure of short-term change in fibroid growth was calculated as the variance of the three interval-specific growth rates.
Results
Growth spurts were observed in 37 of the 101 fibroids, a prevalence nearly 10 times higher than that attributable to potential measurement error. Fibroids from the same women did not have similar short-term growth (p=0.27), nor were woman-specific factors (age, race/ethnicity, parity, body mass) or the fibroid position in the uterus important. However, large fibroids (>5 cm diameter) had less short-term change than smaller fibroids (p<0.001).
Conclusions
Short spurts of growth are common for fibroids, suggesting that tumor biology may change rapidly.