From the Guidelines
Uterine fibroids rarely develop into cancer, with an estimated less than 0.1% progression to their presumed malignant counterpart, uterine leiomyosarcoma, as reported in the study by 1. This type of cancer is extremely uncommon, and the vast majority of fibroids are benign growths that do not increase a woman's risk of developing uterine cancer. The key points to consider are:
- Uterine leiomyomata are the most common pelvic tumor in women, occurring in a minimum of 20-25% of women of reproductive age 1.
- These tumors are benign, with an estimate of less than 0.1% progression to their presumed malignant counterpart, uterine leiomyosarcoma 1.
- The risk of malignant transformation is so low that it typically isn't a primary concern when managing fibroids.
- However, rapid growth of fibroids, especially after menopause, or sudden onset of symptoms in previously asymptomatic fibroids may warrant further investigation to rule out the rare possibility of malignancy.
- Regular monitoring through ultrasounds or other imaging studies is usually sufficient to track any concerning changes in existing fibroids. Some important considerations in the management of uterine fibroids include:
- Clinical problems associated with myomas, such as abnormal uterine bleeding, pelvic pain, urinary frequency, and constipation, that greatly decrease the quality of life for women 1.
- The biological role of myomas in impaired fertility and spontaneous abortion, which remains to be elucidated 1.
- The high prevalence of these tumors among women of reproductive age, with some studies indicating that they may be as prevalent as 70% of women in this age range 1.
From the Research
Uterine Fibroids and Cancer Development
- The exact percentage of uterine fibroids that develop into cancer is not specified in the provided studies 2, 3, 4, 5, 6.
- However, it is mentioned that uterine sarcomas, which include leiomyosarcoma, account for less than 1% of gynecological malignancies and 2-5% of all uterine malignancies 5.
- Uterine leiomyosarcoma is a rare and aggressive malignancy that can be difficult to diagnose preoperatively, and its symptoms may mimic those of benign uterine conditions 2.
- The studies discuss the diagnosis, treatment, and management of uterine fibroids and leiomyosarcoma, but do not provide a direct answer to the question of what percentage of uterine fibroids develop into cancer.
Prevalence and Incidence of Uterine Fibroids
- A study found that the overall age-adjusted estimated incidence rates of uterine fibroid diagnoses declined during a 10-year study interval, from 139.4 per 10,000 woman-years in 2005 to 101.4 in 2014 6.
- The same study found that the overall prevalence of uterine fibroids in 2014 was 9.6%, and was highest among women aged 50-54 years (15.9%) 6.
- Uterine fibroids are common, affecting almost 80-90% of all women by age 50 years, and can cause symptoms such as pain, excessive menstrual bleeding, or infertility 3.