Journal: Procedings of the National Acadamy of Science U S A. 2008 Dec 16;105(50):19887-92.

Authors: Peddada SD, Laughlin SK, Miner K, Guyon JP, Haneke K, Vahdat HL, Semelka RC, Kowalik A, Armao D, Davis B, Baird DD.

Study from: National Institute of Environmental Health Sciences, NC

Problem: Fibroids are the leading cause of hysterectomy in the United States. Black women have a greater fibroid burden than whites, yet no study has systematically evaluated the growth of fibroids in blacks and whites.

Study: The authors tracked growth of 262 fibroids (size range: 1-13 cm in diameter) from 72 premenopausal participants (38 black and 34 white women). Fibroid volume was measured by computerized analysis of up to four MRI scans over 12 months.

Results: The average growth rate over 12 months was 9%, but the difference among women was very large: from -89% to +138%.  Seven percent of fibroids got smaller (>20% shrinkage). Fibroids from the same woman grew at different rates.

Black and white women younger than 35 had similar fibroid growth rates. However, growth rates declined with age for white, but not for black women.  Growth rates were not dependant on initial fibroid size, location in the uterus, women’s weight, or number of children.

Most fibroids did not grow (0% change), but other fibroids either grew or got smaller.

Authors’ Conclusions: 1) fibroids can get smaller; 2) fibroids from the same woman grow at different rates, despite exposure to the same hormones in the blood; 3) initial fibroid size does not predict its growth rate; 4) as black women age, they do not experience slower fibroid growth which may explain why black women have more fibroid-related symptoms.

Dr. Parker’s Comments: This is the first study to accurately track fibroid growth, both in different women and different fibroids in the same woman. I (and other gynecologists) have been telling women for 30 years that fibroids do not get smaller until after menopause – this study proves that idea wrong.  I have also been telling women that fibroid growth is unpredictable, some fibroids grow slowly, others fast and others go through growth spurts and then slow down (see next study below).  This idea turns out to be correct.  We do not understand what makes fibroids grow (or shrink), but it is clearly NOT estrogen excess.  If this were the case, as specifically addressed in this article, all fibroids in the same women, and thus exposed to the same hormone levels, would either grow or not grow.  And, that clearly does not happen.  Unfortunately, we still have a lot to learn about fibroid growth.

Short-term change in growth of uterine leiomyoma: tumor growth spurts.

Journal: Fertility & Sterility. 2011 Jan;95(1):242-6.

Authors: Baird DD, Garrett TA, Laughlin SK, Davis B, Semelka RC, Peddada SD.

Study from: National Institute of Environmental Health Sciences, North Carolina

Problem: No one has ever followed fibroid growth closely enough to see what happens over 3 month periods.

Study: 18 black and 18 white premenopausal women had 101 fibroids measured with MRI at the study beginning and again at 3, 6, and 12 months. Growth spurts were defined by growth rates greater than 30% in 3 months.

Results: Growth spurts were seen in 37 of the 101 fibroids. Fibroids from the same woman did not have similar growth, nor were age, race/ethnicity, number of children or a woman’s weight related to growth spurts.  However,fibroids smaller than 5 cm went through growth spurts more often than larger fibroids.

Authors’ Conclusions: Short spurts of growth are common for fibroids.

Dr. Parker’s Comments: As noted above, we do not understand what causes fibroids to grow, but these two studies show that fibroid growth is unpredictable and that small fibroids are likely to grow more quickly than larger (>5 cm) fibroids.

Authors: Sharan C, Halder SK, Thota C, Jaleel T, Nair S, Al-Hendy A.

Study From: Meharry Medical College, Nashville, Tennessee

Journal: Fertility and Sterility, 2010, Aug 23. E-pub

Problem: Women are looking for something they can do to control fibroid growth. Dietary changes and vitamin supplements would be one possible thing they can easily modify.

Laboratory Study: Human fibroid cell cultures were treated with vitamin D and the effect of vitamin D on fibroid genes and proteins was measured.

Results: Vitamin D interfered with the way human fibroid cells make enzymes that either use or block estrogen and inhibited the growth of fibroid cells by 47%.

Authors’ Conclusions: Since Vitamin D inhibits growth of human fibroid cells a deficiency of vitamin D might allow fibroids to grow. The authors reference another article that found that while 45% of African-American women have vitamin D deficiency, only 4% of white women have this deficiency.

Dr. Parker’s Comments: While it is always good to be cautious when interpreting laboratory studies, vitamin D has also been shown to regulate cell growth and inhibit cancer cells. It also helps the body absorb calcium. And, when taken in recommended doses (800-1,000 units per day), the side-effects and risks appear to be almost non-existent. So, even though these results are very preliminary, vitamin D might be worth a try

Dr. Bill Catherino, head of a fibroid research group at the NIH, presented new findings about what causes fibroids to grow and what possible treatments, diets, environmental changes might be used to reduce the health impact of fibroids.  The less-than-good-news is that none of the following research was performed in humans, so the results are very preliminary.

Hormonal Influences

Women with fibroids have normal blood levels of estrogen and progesterone.  Estrogen dominance does not cause fibroids.

Fibroid cells can make their own estrogen, so the level of estrogen inside fibroids is higher than in blood or other tissues.

Estrogen and progesterone receptors, parts of the fibroid cells that cause them to respond to estrogen and progesterone, are more prevalent in fibroid cells than normal uterine muscle cells.

Fibroids have more collagen than normal uterine muscle cells and more glycosaminoglycans (GAG).  GAGs draw water into the cells and make them swell.  Lupron causes a decrease in GAGs, which dehydrates the fibroid cells and causes shrinking of the fibroids.  When Lupron is stopped, the cells take on water again and swell again.

Dietary Factors

Vitamin D – decreases fibroid cell size and disrupt the formation of fibroid muscle cells.

Resveratrol (found in grapes) – decreases growth and increases death of fibroid cells in a test tube.

Curcumin (spice) – decreases growth and increases death of fibroid cells in a test tube.

Licorice (isoliquiritigenin) – decreases growth and increases death of fibroid cells in a test tube.

Green Tea (epigallocatechin gallate) – decreases growth of fibroid cells in a test tube.