Uterine Sarcoma

Uterine sarcoma is a type of uterine cancer that typically forms in the muscle layer of your uterus (myometrium). It’s rare, making up 2% to 5% of all uterine cancers.

Sarcomas are cancers (tumors) that start from tissues like muscle, bone and connective tissue. Cancers that start in epithelial cells, which line most organs, are called carcinomas. Most uterine cancer cases are carcinomas, not sarcomas.

Types

Types of uterine sarcomas include:

• Uterine leiomyosarcoma (LMS): LMS starts in the muscle layer of your uterus. It’s the most common type of uterine sarcoma. LMS can grow and spread quickly (it’s aggressive).
• Endometrial stromal sarcoma (ESS): ESS starts in the connective tissue (stroma) of your endometrium (uterine lining). Low-grade ESSs are easier to treat than high-grade ESSs.
• Undifferentiated uterine sarcoma (UUS): UUS starts in your endometrium or myometrium. It grows and spreads quickly.
• Uterine adenosarcoma: This sarcoma has normal gland cells mixed in with cancer cells of the stroma. It’s usually a low-grade cancer and is the least common uterine sarcoma.

Stages

In general, stages of uterine sarcoma include:

• Stage I: Cancer is in your uterus only.
• Stage II: Cancer has spread in your pelvis beyond your uterus.
• Stage III: Cancer has spread to areas in your abdomen outside your pelvis.
• Stage IV: Cancer has spread to distant areas outside your abdomen or has spread to your bladder or rectum.

Cancer staging is complex. Healthcare providers use more specific stages, like stage IB or IIIA, for uterine sarcoma. Your team will explain the cancer stage in detail and what it means for you.

Symptoms of uterine sarcoma

Symptoms of uterine sarcoma may include:

• Abnormal vaginal bleeding
• Abnormal vaginal discharge
• A feeling of fullness in your abdomen
• A mass (lump or growth) in your pelvic region
• Pelvic pain
• Frequent urination
• Constipation

The main symptoms of uterine sarcoma are similar to uterine carcinoma and noncancerous growths, like fibroids. That’s why it’s important to see a provider if you notice any of these signs. The sooner you get a diagnosis, the better.

You may not notice symptoms until the uterine sarcoma has progressed to a more advanced stage. In rare cases, you may not have any symptoms (be asymptomatic).

Uterine sarcoma cause

Uterine sarcoma develops when immature uterine muscle or connective tissue cells have genetic mutations. The mutations cause the cells to develop into cancer cells that grow out of control.

Scientists don’t know exactly what triggers the DNA changes that lead to uterine sarcomas. They continue to research how to diagnose, treat and prevent them.

Risk factors

Factors that may increase your risk of developing uterine sarcoma include:

• Genetics: Having the gene that causes retinoblastoma increases your risk of developing some types of uterine sarcoma. A rare family cancer syndrome called hereditary leiomyomatosis and renal cell cancer (HLRCC) is also linked to uterine sarcomas.
• Pelvic radiation therapy: Sarcomas rarely form after pelvic radiation. But when they do, they usually appear five to 25 years after the therapy.
• Tamoxifen: Long-term use of tamoxifen to treat breast cancer slightly increases your risk.

Black women are twice as likely as white women to develop uterine sarcomas. Researchers aren’t sure why race is a risk factor for this cancer.

How doctors diagnose this condition

Your healthcare provider will ask about your symptoms and medical history. They’ll also do a physical exam and pelvic exam.

They may recommend the following procedures:

• Transvaginal ultrasound: Your provider inserts a specialized transducer into your vaginal canal to examine your uterus and ovaries.
• Pelvic MRI: This imaging test uses a machine with powerful magnets and radio waves to create detailed pictures of your pelvic area.
• Endometrial biopsy: Your provider removes a tissue sample from the lining of your uterus for examination.

A pathologist can confirm a diagnosis by examining cells with a microscope after a biopsy.

You may need additional tests to stage the cancer once you have a diagnosis. Imaging tests can reveal if the cancer has spread to other parts of your body (metastasized).

Your provider may refer you to a gynecologist who specializes in cancer (gynecological oncologist) to help with both diagnosis and treatment.

Questions to ask your healthcare team

Receiving a cancer diagnosis can be overwhelming. It may be helpful to ask your healthcare team:

• How often will I need follow-up tests and imaging procedures?
• What will follow-up tests and exams check for?
• What everyday habits would you recommend to stay healthy?
• How will my care team stay in contact about my treatment plan?
• How will the type of uterine sarcoma I have affect my treatment options and prognosis?

What is the treatment for uterine sarcoma?

Surgery is the standard treatment regardless of the cancer grade. Types of surgeries include:

• Hysterectomy: This removes your uterus and cervix (sometimes called a total hysterectomy).
• Total hysterectomy with salpingo-oophorectomy: This removes your uterus, one or both ovaries, and one or both fallopian tubes.
• Radical hysterectomy: This removes your uterus, cervix and both fallopian tubes. It also removes some surrounding tissue, including a portion of your vagina.
• Lymphadenectomy: This removes lymph nodes where the cancer has spread.

Your healthcare team may recommend other therapies to help treat uterine sarcoma, like:

• Chemotherapy
• Hormone therapy
• Radiation therapy
• Targeted therapy

Each type of therapy has potential risks and side effects. Your healthcare team will go over all of your options and what to expect. Together, you’ll decide on a plan that’s best for you.

Is uterine sarcoma cancer curable?

Uterine sarcoma can be curable if it’s low-grade (mildly abnormal cells) and hasn’t spread beyond your uterus.

What is the prognosis (outlook) following treatment?

Uterine sarcoma is more difficult to treat than other uterine cancers. Still, the prognosis for uterine sarcoma depends on:

• The type
• The grade (how aggressive the cancer cells look under the microscope)
• How much it has spread throughout your body
• Your overall health

Talk to your healthcare team about your prognosis based on your unique case.

Survival rate

There’s no way to know for sure how long a person with uterine sarcoma will live. Each person’s outcome depends on several factors.

According to the National Cancer Institute, the survival rate for uterine sarcomas five years post-diagnosis ranges from 12% to 99.5%, depending on the type, grade and how much it’s spread. Talk to your healthcare team for more information.

How aggressive is uterine sarcoma?

Uterine sarcoma typically grows faster and spreads more quickly than more common uterine cancers. Still, not all uterine sarcomas are equally aggressive. Your provider will consider its location and type to determine how aggressive it is.

Your provider can also stage the cancer to see if it has spread.