What is Uterine Sarcoma?

Uterine sarcoma is a rare and aggressive cancer that originates in the muscles or supporting tissues of the uterus. Unlike more common uterine cancers, such as endometrial cancer, uterine sarcomas arise from different cell types within the uterus. The most common subtypes are leiomyosarcoma, endometrial stromal sarcoma, and undifferentiated uterine sarcoma. Symptoms often include abnormal vaginal bleeding and pelvic pain. Treatment typically involves surgery to remove the cancerous tissue and possible radiation therapy, chemotherapy, or targeted therapies. Uterine sarcoma has a poorer prognosis compared to other uterine cancers, emphasizing the importance of early diagnosis and treatment.

Types of uterine sarcoma

Most uterine sarcomas are grouped by the cell type in which they begin.

Uterine leiomyosarcoma (LMS)

These tumors start from the muscle layer of the uterus. They are the most common type. These tumors can grow and spread quickly.

Endometrial stromal sarcoma (ESS)

Endometrial stromal sarcoma tumors start in the supporting connective tissue (stroma) of the inner lining of the uterus (endometrium). ESS tumors are often given a grade to help understand how quickly they are likely to grow and spread.

If the tumor is low-grade, the cancer cells look slightly different from normal cells, and the tumor grows slowly. Women with low-grade ESS tumors have a better prognosis than women with other types of uterine sarcoma.

Most low-grade ESS tumors, like some breast cancers, have proteins called estrogen receptors or progesterone receptors. Having these proteins often means that certain hormonal drugs can help treat these uterine sarcomas.

A high-grade Endometrial stromal sarcoma tumor means that the cancer cells look very different from normal cells and that the tumor is growing rapidly. This type of ESS tumor is often found when the tumor is already large or has spread. These tumors are often more difficult to treat.

Undifferentiated sarcoma

These cancers start from the endometrium or myometrium. They grow and spread quickly and tend to have poor visibility.

Adenosarcoma

This type of sarcoma has normal gland cells mixed with stromal cancer cells. These are usually low-grade cancers and usually have a good prognosis.

Is uterine sarcoma aggressive?

Uterine sarcoma is generally considered an aggressive type of cancer. It tends to grow and spread more rapidly than the more common uterine cancer, endometrial cancer. The aggressiveness of uterine sarcoma varies depending on the subtype and stage at the time of diagnosis, but it is often associated with a poorer prognosis than other uterine cancers.

Early diagnosis and prompt treatment are essential for improving outcomes, as uterine sarcoma can be challenging to treat once it has advanced. Treatment typically involves surgery, radiation therapy, chemotherapy, or targeted therapies, depending on the specific subtype and individual patient factors.

Signs and symptoms

The main symptoms of uterine sarcoma are similar to endometrial cancer and non-cancerous growths such as fibroids. It is important to see your doctor if you notice any of these symptoms:

Unusual vaginal bleeding that is not related to menstrual periods or occurs after menopause
A mass in the vagina or pelvis
Vaginal bleeding with a smelly discharge
The feeling of fullness in your abdomen
Pelvic pain
Having to pee often
Constipation

You may not notice symptoms until uterine sarcoma is more advanced. In rare cases, people with uterine sarcoma are asymptomatic.

What are the stages of uterine sarcoma?

Like many other cancers, Uterine sarcoma is often staged to determine the extent of its spread. The American Joint Committee on Cancer (AJCC) staging system is commonly used for uterine sarcoma. The stages of uterine sarcoma typically range from Stage I (early stage with limited spread) to Stage IV (advanced stage with distant metastasis). Here is an overview of the stages:

Stage I: The cancer is confined to the uterus and has not spread to nearby lymph nodes or distant organs.
Stage II: In Stage II, the cancer has spread beyond the uterus to the cervix but has not yet spread to nearby lymph nodes or distant organs.
Stage III: At this stage, the cancer has invaded nearby structures, such as the vagina, fallopian tubes, or ovaries, and may have spread to nearby lymph nodes. It has not spread to distant organs.
Stage IV: This is the most advanced stage. Cancer at Stage IV has spread to distant organs, such as the lungs, liver, or bones, and may also involve the lymph nodes and structures near the uterus.

The specific staging of uterine sarcoma can vary depending on the subtype of sarcoma and its characteristics. Staging helps healthcare providers determine the appropriate treatment plan and prognosis for an individual with uterine sarcoma. Patients must work closely with their healthcare team to understand their stage and treatment options.

Who gets uterine sarcoma?

Most people with uterine sarcoma are over 40, but those as young as 20 have been diagnosed with uterine sarcoma. The average age of diagnosis is approximately 60 years.

Who is at risk for having uterine sarcoma?

Uterine sarcoma is a relatively rare type of cancer. While the exact cause is often unknown, some risk factors may increase the likelihood of developing this disease. Risk factors for uterine sarcoma include:

Age: Uterine sarcoma is more common in postmenopausal women, although it can occur at any age.
Previous pelvic radiation therapy: Women who have received pelvic radiation therapy as part of the treatment for another cancer, such as cervical cancer, may have an increased risk of developing uterine sarcoma.
Genetic conditions: Certain genetic syndromes, such as Li-Fraumeni syndrome, may increase the risk of uterine sarcoma.
Race: Uterine sarcoma is more common in African-American women than women of other racial backgrounds.
Obesity: Some evidence suggests that obesity may be a risk factor for uterine sarcoma, particularly leiomyosarcoma.
Tamoxifen use: Tamoxifen, a medication used to treat breast cancer, has been associated with a slightly increased risk of developing uterine sarcoma, particularly in postmenopausal women.
Hormonal factors: Some hormonal factors, such as estrogen exposure, may play a role in the development of uterine sarcoma. This is more relevant for certain subtypes like endometrial stromal sarcoma.

It’s important to note that uterine sarcoma is still relatively rare, even among individuals with these risk factors. Most women with these risk factors do not develop uterine sarcoma. Additionally, most uterine sarcomas occur in women with no known risk factors. Suppose you have concerns about your risk for uterine sarcoma. In that case, it’s advisable to discuss them with a healthcare provider who can provide personalized guidance and recommend appropriate screening or preventive measures, if necessary. Regular gynecological check-ups and awareness of unusual symptoms are important for early detection.

How is uterine sarcoma diagnosed?

If your provider thinks you might have uterine sarcoma, they will perform a physical examination and take your medical history. Your provider will also conduct a pelvic examination of your vagina, cervix, uterus, fallopian tubes, ovaries, and rectum. To examine these organs, your provider inserts a gloved finger into your vagina and rectum to feel for anything unusual. They may also use a speculum to look inside your vagina. Your doctor may also perform the following procedures:

Transvaginal ultrasound: Ultrasound creates images of soft tissue structures, including your reproductive organs. A specialized transducer is inserted in your vaginal canal about 2 to 3 inches to examine your uterus and ovaries. Sometimes, uterine sarcoma and fibroids appear similar on an ultrasound.
Endometrial biopsy: Your provider removes a tissue sample from the lining of your uterus for examination. Your provider can confirm a uterine sarcoma by examining its cells underneath a microscope after a biopsy or a hysterectomy.

Once diagnosed with uterine sarcoma, you may need additional tests to stage your cancer. Magnetic resonance imaging (MRI), CT scans, PET scans, and chest X-rays can reveal whether your cancer has spread throughout your body. Your provider may refer you to a gynecologist specializing in cancer to help diagnose and treat uterine sarcoma.

How is uterine sarcoma treated?

The provider may use one or more treatments to treat uterine sarcoma.

Surgery

Surgery to remove the cancer is the most common treatment for uterine sarcoma. The surgeon may just remove the lump. Or they may perform one of these methods to remove the damaged tissue and organ:

Hysterectomy: Removal of the uterus and cervix. Using minimally invasive surgery, the doctor may use a laparoscope to remove the uterus.
Total hysterectomy with salpingo-oophorectomy: Removal of the uterus, one or both ovaries and fallopian tubes.
Radical hysterectomy: Removal of the uterus, cervix, fallopian tubes, and some surrounding tissues, including part of the vagina.
Lymphadenectomy: Removal of lymph nodes to check for cancer.
Laparotomy: An incision is made in the abdomen to be checked for cancer. In some cases, the provider may remove other organs with cancer.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy X-rays to kill cancer cells while minimizing damage to healthy cells. It can be internal or external. Both internal and external radiation therapy may be performed for uterine sarcoma. Side effects of radiation therapy include:

Fatigue
Diarrhea
Nausea and vomiting
Changes in skin
Irritations in bladder
Edema in legs

Chemotherapy

Chemotherapy uses medications to kill or slow the growth of rapidly multiplying cancer cells. These medications are often given intravenously and can have major side effects. Radiation therapy and chemotherapy may be done together. Side effects of chemotherapy include:

Nausea and vomiting
Hair loss
Loss of appetite
Low blood count
Fatigue

Hormone therapy

Hormones are substances that the body produces to regulate certain functions. Examples include testosterone and estrogen. In some cases, hormones may contribute to the growth of cancer.

Hormone therapy stops the growth of cancer by blocking the action of hormones. Hormones such as progestins, gonadotropin-releasing hormone agonists, and aromatase inhibitors are used to treat uterine sarcoma.

Prevent uterine sarcoma

Uterine sarcoma is a rare and often aggressive form of cancer, and while there is no surefire way to prevent it entirely, there are some steps you can take to reduce your risk or detect it at an early stage.

Regular check-ups

Visit your gynecologist or healthcare provider for regular check-ups and screenings, especially if you have risk factors such as a history of pelvic radiation therapy, certain genetic syndromes, or other factors that may increase your risk. Early detection can lead to better outcomes.

Healthy lifestyle

Maintaining a healthy lifestyle can help reduce your overall cancer risk. This includes maintaining a healthy weight through diet and exercise, as obesity is sometimes linked to uterine sarcoma.

Hormone therapy

Discuss the risks and benefits with your healthcare provider if you take hormone therapy, such as tamoxifen. They can help you weigh the potential risks of hormone therapy against the benefits of treating another condition, such as breast cancer.

Genetic counseling

Consider genetic counseling if you have a family history of cancer or known genetic syndromes associated with uterine sarcoma. This can help you understand your genetic risk and make informed decisions about screening and preventive measures.

Awareness

Be aware of the symptoms of uterine sarcoma, such as abnormal vaginal bleeding or pelvic pain. If you experience any unusual symptoms, especially if you have risk factors, seek medical attention promptly.

Screening

While there are no specific screening tests for uterine sarcoma, regular gynecological exams and discussions with your healthcare provider can help identify any suspicious symptoms or changes that may warrant further evaluation.

It’s important to note that uterine sarcoma is still relatively rare, and many cases occur in women with no known risk factors. Therefore, early detection through regular check-ups and awareness of symptoms is key to improving outcomes.

The bottom line

Cancer begins when cells in the body begin to grow out of control. Uterine sarcoma is a cancer that starts in the muscles and supporting tissues of the uterus. Compared to other types of uterine cancer, uterine sarcoma is rare. Early detection helps in faster and more effective treatment.

Dr. Arjang Naim can help you in this field.

Additional questions

What is the prognosis for uterine sarcoma?

The prognosis for uterine sarcoma varies depending on factors like the stage at diagnosis, subtype, age, overall health, and response to treatment. Early-stage cases often have better outcomes when the cancer is confined to the uterus, whereas advanced-stage sarcomas may pose greater challenges.

What is endometrium?

The endometrium is the lining that sheds during menstruation. It is also the tissue in which the fetus grows during pregnancy. In some women and people assigned female at birth (AFAB), endometrial hyperplasia can lead to endometrial cancer, a type of uterine cancer.

What is the cause of lymphadenectomy?

A lymph node dissection, also known as a lymphadenectomy, is a surgical procedure in which the lymph nodes are dissected, and a tissue sample is examined under a microscope for malignancy. This procedure is usually performed as part of the surgical management of malignant tumors.

What does tamoxifen do to the body?

By sitting on estrogen receptors on cells, tamoxifen blocks the effects of estrogen on hormone receptor-positive breast cancer cells. If tamoxifen is in the receptor, estrogen cannot attach to the cancer cell, and the cell does not receive estrogen signals to grow and multiply.