Can Fibroids Be Cancerous?

If you have been diagnosed with uterine fibroid tumors, you may have some anxiety and concerns. Hearing the word ‘tumor’ is understandably worrisome because it can be associated with cancer. You may be wondering if fibroids are cancerous and fortunately, fibroid tumors are benign (non-cancerous). In very rare instances, fibroids may contain cancerous cells so if you have a family history or are at high risk for uterine cancer your doctor may perform a biopsy before any surgical decisions are made.

Uterine fibroids are growths created from fibrous tissues and smooth muscle cells that form and grow in various locations within or around the uterus. The size, shape, location, and number of fibroids vary with every woman. An individual may have only one myoma or many, varying in size from a small pearl to a huge pumpkin. Although benign, uterine fibroids can cause significant symptoms including, heavy and prolonged bleeding, pelvic pain & pressure, enlarged uterus, anemia, etc. Some women with fibroids experience no noticeable symptoms and do not require any medical treatment.

Types of uterine fibroids: submucosal, subserosal, intramural, and cervical
Types of uterine fibroids: submucosal, subserosal, intramural, and cervical

Can Uterine Fibroids Lead to Cancer?

Uterine fibroids are benign tumors and do not increase a woman’s chance of developing uterine or other gynecological cancers. That being said, in rare instances cancerous cells (sarcoma) can be hiding inside the substance of a myoma (occurring in approximately 1 out of every 2,000 fibroid patients). To put this small number into perspective, the chance that a woman undergoing a hysterectomy and dying during the surgery is about 1 in 1,500.

If the fibroid is large and is cut apart into smaller pieces during removal (a technique called morcellation), there is a risk of spreading the cancer cells contained in the chopped-up fibroid pieces throughout the pelvis. In 2014, the FDA issued an advisory discouraging the use of morcellation. Johnson & Johnson, one of the leading manufacturers of morcellators stopped production and sales of their power morcellator due to numerous lawsuits involving morcellators. Some morcellator device manufacturers have added a containment bag to prevent the spread of the chopped-up leiomyomas pieces throughout the pelvis.

The take-away on this is that there is a very small risk of spreading hidden cancer if undergoing a laparoscopic myomectomy or hysterectomy to treat fibroids with cancer cells. Anything that needs to be dissected before it is removed could potentially pose a risk. If cancer is suspected, an abdominal hysterectomy is the recommended treatment.

How Do I Know If a Uterine Fibroid Is Not a Sarcoma?

A uterine sarcoma or leiomyosarcoma is a cancerous tumor that arises from the same smooth muscle cells as fibroids, and in very rare instances, cancer cells can hide within fibroids and are very hard to detect using any type of imaging tests. Cancerous tumors are more often discovered during procedures being performed to remove myomas. The removed specimens are studied under a microscope and examined for identifying characteristics of sarcoma.

If cancer is suspected or “to rule it out” a biopsy may be performed on the tumor in question. There are two ways to collect a sample of a tumor: fine-needle aspiration (FNA) or a surgical biopsy. During FNA, a thin needle is inserted into the mass and a sample of tissue is withdrawn and studied under a microscope. If doctors are unable to collect a sample of tissue using FNA they will use surgical methods to remove a sample of tissue through a small incision.

Examination of the suspected tissue under a microscope is the most accurate way to distinguish a benign fibroid from a malignant sarcoma.

Are Fibroid and Sarcoma Symptoms the Same?

The symptoms of uterine sarcoma and uterine fibroids are essentially the same, but fortunately, sarcoma is very rare and fibroids are very common. In addition, the peak age of women with myomas is 35-40 years, while the peak age for uterine sarcoma is 75-80 years.

Many women will be asymptomatic, while others will experience abnormal bleeding from the vagina and uterus as well as pressure or pain in the pelvis, abnormal vaginal discharge, or changes in urination or constipation. Other symptoms related to cancer are fatigue, unexplained weight loss, and fever.

Uterine fibroids often cause heavy and prolonged bleeding that leads to anemia which also causes fatigue and other symptoms that can closely resemble those of sarcoma.

Bleeding after menopause should always prompt an immediate evaluation by the Gynecologist, as it can be a symptom of uterine cancer.

Researchers have found that women under 50 are less likely to experience sarcoma containing tumors but factors such as leiomyomas that are large in size, anemia, inherited conditions, immune deficiency syndromes, radiation or chemical exposure, and certain medications increase the risk of the presence of cancerous cells.

Can Cancer Be Mistaken For Fibroids?

Because the cells originate from the same place and the symptoms are virtually the same, it is possible that cancer could be hidden or mistaken for benign fibroids. After an initial imaging test reveals an unusual mass, the only way to confirm the presence or nonexistence of cancerous cells is through pathology tests on a sample of the actual tissue.

What Can I Do To Protect My Uterus From Sarcoma?

Unfortunately, since experts do not know exactly what causes certain cells to mutate and form cancer there is no “set in stone” formula to prevent cancer, but based on clinical data collected we do know there are correlations between cancer and certain lifestyle aspects.

  • Obesity introduces a significant risk for uterine cancer as well as other types of cancer. Research has proven that excess fat produces extra estrogen and can increase the risk for fibroids and certain types of cancer.
  • Smoking also increases the risk of uterine cancer as well as other cancers. If you use oral contraceptives and also smoke, you are at higher risk of blot clots and stroke as well.
  • Maintaining a BMI balanced weight, exercising, eating a healthy diet full of fruit, veggies, and legumes, and avoiding unhealthy processed foods, red meat, and excessive alcohol consumption can help protect you against many types of women’s health issues.