Fibroids and uterine cancer can both cause growths to form in the uterus. Certain symptoms can also overlap. A doctor can determine whether you have fibroids or uterine cancer.

Fibroids are benign (noncancerous) growths that can occur in the uterus. They’re incredibly common. In fact, it’s estimated that 26 million females between 15 and 50 years old have uterine fibroids in the United States.

Another condition that causes growths to develop in the uterus is uterine cancer. While uterine cancer is much less common, the American Cancer Society estimates that 67,880 new diagnoses will be made in the United States in 2024.

Fibroids and uterine cancer have some symptoms overlap. This article explores the similarities and differences in symptoms between these two conditions.

Uterine cancer is cancer that develops in the uterus. It’s the most common cancer affecting the female reproductive organs in the United States. There are two types of uterine cancer: endometrial cancer and uterine sarcoma.

Endometrial cancer starts in the endometrium, which is the inner lining of the uterus. Uterine sarcoma starts in the muscles of the uterus or in connective tissue supporting the uterus.

Most diagnoses of uterine cancer are endometrial cancer.

Primary symptoms

One of the main symptoms of uterine cancer is abnormal uterine bleeding. This may include bleeding that:

Other symptoms

Other potential symptoms of uterine cancer are:

Risk factors for uterine cancer

The risk factors for endometrial cancer and uterine sarcoma differ. Risk factors for endometrial cancer include:

The risk factors for uterine sarcoma are having previous radiation therapy to your pelvis or taking tamoxifen to treat or prevent breast cancer.

Fibroids are noncancerous tumors that form in the muscles of the uterus. They’re the most common noncancerous tumors affecting females of reproductive age. Researchers estimate fibroids affect more than 70% of females worldwide.

The location and number of fibroids can vary. Additionally, fibroids can be of different sizes. For example, some may be the size of a pea, while others can grow to be several inches wide.

Many times, fibroids do not cause symptoms. When symptoms do happen, they can include:

  • periods that are heavier or longer than is typical for you
  • bleeding between periods
  • painful periods
  • abdominal, pelvic, or lower back pain
  • a feeling of fullness or pressure in your pelvis
  • enlarged abdomen
  • pain during sex
  • changes to your bowel and bladder habits, such as constipation or urination that’s frequent or difficult

Risk factors for fibroids

Most people who develop fibroids are in their 30s or 40s. Fibroids typically begin to shrink after you start menopause.

Fibroids are more common in Black women. Fibroids may also grow more quickly and develop at an earlier age in this group. The exact reason is unknown but may be due to social inequalities and disparities in healthcare access.

Other risk factors for fibroids include:

  • a family history of fibroids
  • obesity
  • reproductive factors associated with higher estrogen exposure, like:
    • never having children
    • starting your period at an early age
    • beginning menopause at a later age
  • a diet high in red meat and lower in green vegetables
  • vitamin D deficiency

The table below compares and contrasts the potential symptoms of uterine cancer and fibroids:

SymptomUterine cancerFibroids
bleeding after menopause
bleeding between periods
heavy or irregular periods
painful periods
pain during sex
abdominal or pelvic pain✓ (can also include lower back pain)
unusual vaginal discharge
a mass you can feel
a feeling of fullness or pressure in your pelvis✓ (with uterine sarcoma)
enlarged abdomen
changes in bowel or bladder habits
unintended weight loss
reduced appetite

Because uterine cancer and fibroids share some symptoms, many of the tests doctors use to help diagnose them are the same.

To begin the diagnostic process, a doctor first gets a thorough personal and family medical history. They’ll also do a general physical exam and pelvic exam.

Imaging can help your doctor see in and around your uterus. Some imaging tests they may order are:

If your doctor suspects uterine cancer, they can collect a biopsy sample from the endometrium or the uterine muscle. This sample can be tested in a lab to see whether cancer cells are present.

If cancer cells are found, further tests on the sample can further characterize the cancer. This can inform a doctor on the type of cancer, its grade, and its molecular markers, which all help a doctor determine the best treatment.

Can uterine cancer be misdiagnosed as fibroids?

Yes, it’s possible that uterine cancer, particularly uterine sarcoma, to be misdiagnosed as fibroids.

What happens if uterine fibroids are left untreated?

Not all fibroids need to be treated immediately, especially if they’re not causing symptoms. When left untreated, some fibroids may grow larger and begin to cause symptoms and problems like pain, anemia, and fertility issues.

Can fibroids turn into cancer?

The vast majority of fibroids are benign. However, there’s a less than 1 in 1,000 chance that a fibroid can turn out to be a type of uterine sarcoma called leiomyosarcoma.

Can you feel fibroids with your finger?

Although some fibroids, particularly larger ones, can cause your abdomen to enlarge, you’re unlikely to be able to feel fibroids externally with just your finger. However, your doctor can potentially feel fibroids during a pelvic exam.

What are the symptoms of a fibroid flare-up?

During a fibroid flare-up, your fibroid symptoms can get worse. As such, you may experience increased pain or heavier bleeding during a flare.

Fibroids and uterine cancer both cause growths to form in the uterus. However, uterine fibroids are almost always benign. They’re also a lot more common than uterine cancer.

Fibroids and uterine cancer can cause similar symptoms. Because of this, it’s important to talk with a doctor if you notice concerning symptoms, like heavier periods, pelvic pain, and urinary or bowel problems.

A doctor can order many tests to determine what is causing your symptoms. Once a diagnosis is made, they can recommend a treatment plan that’s appropriate for you.