What are uterine sarcomas?
Uterine sarcomas are forms of soft tissue sarcoma that develop in the uterus, or womb. The most common types of uterine sarcoma grow in the muscle of the uterus, also called the myometrium. Other types of these cancerous tumors form in the endometrium, the tissue that lines the uterus wall.
Uterine sarcomas tend to grow and metastasize (spread) more quickly than other, more common types of uterine cancer and endometrial cancer. They can also return after treatment. When that happens, some affect nearby pelvic lymph nodes and pelvic organs such as the vagina, bladder, rectum, ovaries, and fallopian tubes. Others affect more distant locations such as the liver or lungs.
Uterine sarcomas account for just 2 to 5 percent of uterine cancers, affecting two people per 100,000. They most often occur in women between 50 and 70. Black women tend to be diagnosed with uterine sarcoma more often.
These rare and complex tumors require prompt care from a knowledgeable team with experience in uterine sarcomas. At Penn Medicine’s Abramson Cancer Center, uterine sarcomas are treated by some of the nation’s most experienced providers, from our Sarcoma Program and the Gynecologic Oncology team. These experts work together to develop the best possible treatment plan for you.
Types of uterine sarcoma cancer
Uterine sarcoma includes several distinct types of cancer:
- Uterine leiomyosarcoma: Uterine leiomyosarcoma is the most common type of uterine sarcoma. It forms in the myometrium, or muscle layer, of the uterus and can grow and spread quickly. Black women get this form of uterine sarcoma twice as often as white women. The average age at diagnosis is 50.
- Endometrial stromal sarcoma: These tumors grow in the endometrium (uterine lining) in supportive tissue called stroma. They may be low-grade, meaning they are more likely to grow slowly. These low-grade tumors frequently need the hormones estrogen or progesterone to continue growing. Other endometrial stromal sarcomas are high-grade, meaning they tend to grow quickly and pose more of a challenge.
- Undifferentiated sarcoma: These less common tumors can develop in the myometrium or the endometrium. They grow and spread quickly.
- Adenosarcoma: Another uncommon uterine sarcoma, these tumors tend to grow slowly. They represent just 5 percent of uterine sarcomas.
Uterine sarcoma symptoms
Uterine sarcomas can cause a range of symptoms that can vary from one person to the next. These symptoms are similar to those of many non-cancerous conditions, so you should seek medical guidance if you experience:
- Feeling of fullness in the belly
- Irregular periods
- Pelvic pressure or pain
- More frequent urination
- Vaginal bleeding that’s not part of your normal period or that happens after menopause
What causes uterine sarcoma?
Doctors often don’t know what causes uterine sarcoma to form. However, some factors may increase the risk of developing one.
Previous radiation therapy to the pelvis for another medical condition may make it more likely to eventually develop uterine sarcoma. Taking the hormone therapy tamoxifen to treat breast cancer can as well.
Some people also inherit genetic changes that raise their risk for developing uterine sarcoma, which include:
- Hereditary retinoblastoma: In addition to raising the risk for the eye cancer retinoblastoma, this syndrome increases the chances that certain soft tissue sarcomas may form, including uterine sarcoma.
- Li-Fraumeni syndrome (LFS): While LFS is mainly tied to rhabdomyosarcoma, it raises the risk for other soft tissue cancers, such as uterine sarcoma.
How we diagnose uterine sarcoma
To diagnose a uterine sarcoma, our doctors perform a thorough exam and talk to you about your symptoms. Part of the evaluation includes a pelvic exam of the reproductive organs and a rectal exam.
To evaluate unusual bleeding, your doctor will often take a tissue sample from the lining of the uterus (endometrium). This may be done by scraping some cells during a procedure called dilation and curettage (D and C) or with a minimally invasive biopsy.
These tests can’t usually reach uterine leiomyosarcoma unless the cancer has grown into the uterine lining. If imaging shows a suspicious tumor within the wall of the uterus, removing the uterus may be the only way to confirm a diagnosis. A specialized pathologist then examines the tissue to determine whether cancer is present.
If uterine sarcoma is confirmed, your provider will recommend additional imaging tests to check whether the cancer has spread and determine its stage.
Your uterine sarcoma treatment plan
Uterine sarcoma treatment at Penn Medicine usually begins with removing the tumor. Doing so often requires a surgical procedure to remove the uterus and cervix. We may do this with a minimally invasive approach or an open procedure. In some cases, our surgeons may also recommend removing the ovaries, depending on the type of uterine sarcoma and other factors like age.
Next steps depend on the type of uterine sarcoma. For some cancers, our team may follow you closely to watch for signs of cancer recurrence. This is often the case with sarcomas that didn’t grow outside the uterus.
For other uterine sarcomas, our team may recommend therapies that target the area where cancer developed, treatments that work throughout the body to slow or stop cancer cell growth, or hormone-blocking medications.
Researchers also continue to evaluate promising new approaches through sarcoma clinical trials.
Expert care for a rare uterine cancer
Treating uterine sarcoma often requires specialized surgical expertise. Whenever appropriate, Penn Medicine offers minimally invasive approaches, including laparoscopic and robotic-assisted surgery, which may help shorten recovery while achieving the best possible surgical outcome.
We’re also helping advance care for uterine sarcoma through research and clinical trials. Our involvement in national research efforts helps bring promising new treatment approaches to people with these rare cancers.
Rated “exceptional” by The National Cancer Institute
Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.