Table of ContentsView AllTable of ContentsHow It FormsSymptoms and DiagnosisStagesTreatmentSurvivalSupport
Table of ContentsView All
View All
Table of Contents
How It Forms
Symptoms and Diagnosis
Stages
Treatment
Survival
Support
Leiomyosarcoma(LMS) is a very rare, abnormal growth in the smooth muscles of many organs—most often the stomach, intestines, anduterus. Leiomyosarcoma tumors usually spread to other tissues and distant organs. They can be unpredictable—growing and spreading very quickly, making them deadly.
Often, leiomyosarcoma doesn’t respond well to traditional cancer treatments like radiation and chemotherapy.While leiomyosarcoma can be deadly, many factors impact a person’s prognosis. In the early stages, leiomyosarcoma is even curable.
This article will cover leiomyosarcoma’s prognosis, why leiomyosarcoma is life-threatening, and what symptoms to watch for. It will cover treatment options and stages of leiomyosarcoma.
Luis Alvarez / Getty Images
Leiomyosarcoma Formation: Cancer in Smooth Muscles
The gastrointestinal (GI) tract (stomach and intestines) and the uterus are the two most common places where leiomyosarcoma develops.Less commonly, leiomyosarcomas appears in the blood vessels, heart, liver,pancreas, areas of the abdominal cavity, skin, bladder, and urinary tract.
What Is a Sarcoma?Leiomyosarcoma is a type of soft tissue sarcoma.This type of cancer starts in smooth and skeletal muscles, tendons, fat,lymphand blood vessels, and nerves (the body’s soft tissues and connective tissues).At least 15,000 new cases of soft tissue sarcoma are diagnosed in the United States annually, accounting for about 1% of all adult cancers. Leiomyosarcoma accounts for about 10% of them.
What Is a Sarcoma?
Leiomyosarcoma is a type of soft tissue sarcoma.This type of cancer starts in smooth and skeletal muscles, tendons, fat,lymphand blood vessels, and nerves (the body’s soft tissues and connective tissues).At least 15,000 new cases of soft tissue sarcoma are diagnosed in the United States annually, accounting for about 1% of all adult cancers. Leiomyosarcoma accounts for about 10% of them.
Leiomyosarcoma is a type of soft tissue sarcoma.This type of cancer starts in smooth and skeletal muscles, tendons, fat,lymphand blood vessels, and nerves (the body’s soft tissues and connective tissues).
At least 15,000 new cases of soft tissue sarcoma are diagnosed in the United States annually, accounting for about 1% of all adult cancers. Leiomyosarcoma accounts for about 10% of them.
Leiomyosarcom a is rare. It affects people of all sexes but is slightly more common in people assigned female at birth. Middle-aged and older adults are more likely to get leiomyosarcoma than children.
Studies have estimated that 3 people out of every 200,000 will develop these tumors per year in Western countries.About 6 out of every 1 million people get a leiomyosarcoma tumor in the uterus annually in the United States.
Leiomyosarcomas that develop in the stomach and intestines are often classified asgastrointestinal stromal tumors (GIST)because of their unique characteristics. They are typically slower growing than other leiomyosarcomas.Between 5,000 and 6,000 of these tumors are diagnosed annually in the United States.
Getting a Leiomyosarcoma Diagnosis
These smooth muscle cancers are very rare. But they’re aggressive and deadly, especially when not caught early. The only way to detect a leiomyosarcoma, other than through imaging tests, is to watch for signs and symptoms of a tumor.
Symptoms
Depending on the tumor’s location, you may feel it as a lump under the skin.There may be some pain or swelling in the area, too.
Other leiomyosarcoma symptoms depend on the size and location of the cancer and if it has spread to other body parts. As these tumors get bigger, they can interfere with how organs function, causing symptoms related to that. For example:
Benign Leiomyoma vs. Malignant LeiomyosarcomaWhen healthcare providers diagnose leiomyosarcoma, they first need to ensure it’s not a similar, benign (non-cancerous) leiomyoma. These are smooth muscle tumors that are not cancerous. Leiomyomas are often calledfibroids, especially when they develop in the uterus.If afibroid grows after menopause, it should be checked for cancer.
Benign Leiomyoma vs. Malignant Leiomyosarcoma
When healthcare providers diagnose leiomyosarcoma, they first need to ensure it’s not a similar, benign (non-cancerous) leiomyoma. These are smooth muscle tumors that are not cancerous. Leiomyomas are often calledfibroids, especially when they develop in the uterus.If afibroid grows after menopause, it should be checked for cancer.
As a leiomyosarcoma gets large and spreads to other organs, it can cause symptoms of metastatic cancer (cancer that has spread to other areas of the body). These include:
Diagnosis
To diagnose leiomyosarcoma, your healthcare provider will ask about your symptoms and medical history and examine your body.
They’ll order imaging tests, such asmagnetic resonance imaging (MRI),computed tomography (CT),angiography, andpositron-emission tomography (PET). The images will give your care team an idea of where and how big the tumor is. They can also help rule out other tumor types and see if it has spread to other organs.
They’ll also order blood tests to look for signs of cancer. They’ll take a small tissue sample called a biopsy to check that a tumor is a leiomyosarcoma.
It’s also possible they’ll go ahead and remove the tumor completely. Surgical resection is the most effective treatment for leiomyosarcoma. After taking the tumor out, the surgeon can remove samples to examine the cancer cells. These can show how aggressive the cancer is and, therefore, if further treatment is necessary.
Stages of Leiomyosarcoma
Staging is how healthcare providers compare cancers in different people. It gives them an idea of what treatments may work best and what a person’s prognosis may be. Sarcoma staging is based on the size of the tumor, how far it has spread, and how the cancer cells look under the microscope.
Sarcomas are staged from 1 to 4 based on how much they’ve grown and spread. The higher the stage, the more advanced the cancer.
The tumor’s grade is determined between 1 and 3; the higher numbers mean the cancer cells look wilder and divide a lot, meaning the tumor is more aggressive.
The American Joint Committee on Cancer’s Version 7 Staging System for Soft Tissue Sarcoma defines sarcoma stages based on tumor size and grade, as outlined below:
The International Federation of Gynecology and Obstetrics (FIGO) also has a staging system specifically for uterine sarcomas. There is less evidence that the tumor’s grade is relevant to the prognosis of people with uterine sarcomas, so these stages do not consider the tumor’s grade.These stages are defined as follows:
Metastatic Leiomyosarcoma
Generally, stage 4 tumors are called metastatic leiomyosarcomas. These cancers have spread (metastasized) to other areas of the body. The most common sites for leiomyosarcomas to spread are the lungs or liver. New tumors in these locations can cause potentially life-threatening complications.
A study of uterine leiomyosarcomas found that they spread most frequently to the:
Recurrent Leiomyosarcoma
Because it’s aggressive and spreads quickly, leiomyosarcoma has a high risk of returning after initial treatment rounds. Even a successfully treated leiomyosarcoma can come back. This is called recurrent leiomyosarcoma.This cancer can be dormant for years, sometimes returning long after initial treatment.
Uterine leiomyosarcomas recur in up to 70% of cases. Leiomyosarcomas in other parts of the body seem to come back in about 40% of cases.
After Diagnosis: Leiomyosarcoma Treatment Plan
It is possible to cure leiomyosarcoma if the tumor is caught early, before it spreads. The tumor can often be removed using surgery. Cells left behind during surgery or already spread to other body parts can be destroyed using other systemic treatments, though this is less likely to lead to a cure.
The treatments needed depend on your general health, age, and information about your cancer, including where the tumor is located, its size, grade, stage, and if it has spread to other parts of the body.
Surgery
Surgery is the best treatment for leiomyosarcoma.Surgery can cure leiomyosarcoma if it’s caught early, hasn’t spread, and can be removed entirely.
Your options for surgery to remove the leiomyosarcoma tumor depend on where it is, how big it is, and if it has spread to other tissues and organs. In some cases of advanced leiomyosarcoma, surgery may not be the best option or an option at all.
If surgery doesn’t altogether remove the tumor and some cancer cells are left behind—either at the surgery site or that have already spread to other parts of the body—the cancer may come back. Other cases may need additional surgeries to reconstruct the area.
Radiation Therapy
If leiomyosarcoma has spread to other tissues, lymph nodes, or organs, you’ll need additional treatments to help prevent it from coming back. One of these isradiation therapy. It’s often used during or right after surgical removal of the tumor. Radiation therapy uses high-energy beams to break apart the genetic material of the cancer cells, killing them.
If your tumor is not a candidate for surgery, you may get radiation therapy alone.
Chemotherapy
Chemotherapydrugs kill dividing cells. Cancer cells, especially aggressive ones, grow and divide often. In leiomyosarcoma, it’s used when the primary tumor is large or if the cancer has spread and grown in other parts of the body. It’s used in combination with surgery.
Chemotherapy drugs kill fast-growing cells, which can damage some of the healthy cells in the body,causing side effectssuch as fatigue and nausea. These side effects may be too much for people who are very old or have other health issues.
Experimental Treatments and Clinical Trials
Due to the lack of treatment options, new drugs are being developed or tested to treat leiomyosarcoma. These include drugs toprevent the formation of new blood vessels to the tumorand those thatprime the immune system to fight cancer.
You can find out more about clinical trials for leiomyosarcoma atclinicaltrials.gov.
Leiomyosarcoma Survival and Determining Factors
Oncologists (cancer specialists) consider leiomyosarcoma aggressive cancer. It grows quickly and spreads easily. Leiomyosarcoma prognosis depends on factors such as:
If found early, leiomyosarcoma can be cured. A person’s prognosis is good and full recovery is likely if surgery removes the tumor entirely.
The prognosis is poor when the tumor has grown large or spread to other body parts. This makes treatment more difficult, especially since chemotherapy and radiation are not very effective at stopping these tumors.
According to the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program database, the survival rate of leiomyosarcoma is not well known, as this is a rare cancer. However, leiomyosarcomas are more aggressive than other sarcomas, so they generally have a worse prognosis.
Soft tissue cancers, in general, have five-year relative survival rates of:
GIST leiomyosarcoma tumors in the gastrointestinal tract are typically less aggressive. According to the National Cancer Institute, the five-year relative survival rates for GIST from 2012 to 2018 were:
According to the the American Cancer Society, uterine leiomyosarcomas have five-year survival estimates of:
Leiomyosarcoma Patient Support
If you’re dealing with a leiomyosarcoma diagnosis and treatment, you’ll need support. These rare and aggressive cancers will challenge you emotionally and physically during your treatment journey.
Lean on your loved ones, friends, and care team for support. Look for in-person or onlinesupport groupsto connect with others dealing with cancer.
While getting treatment, talk to your care team about any side effects you’re dealing with. You may be coping with pain, fatigue, or changes in appetite or body image.
When possible, try to get some physical activity. Eat well. Talk to aregistered dietitianto make sure you’re eating the right foods.
Tryrelaxation techniquessuch asmeditation,deep breathing exercises, or yoga. These can help reduce stress and improve your well-being.
Additional support and resources are available to you. These include counseling services, financial assistance programs, and online communities. Ask your care team about local resources. Work with a counselor or therapist to develop healthy coping mechanisms. They can help you deal with the fears and worries that may develop during treatment.
If you’rediagnosed with a terminal form of leiomyosarcoma, talk to your care team about palliative care options. These can help ease your symptoms without the major side effects that traditional treatment might cause.
Summary
Leiomyosarcoma is a rare and aggressive form of cancer. It develops in the body’s smooth muscles, most often in the stomach, intestines, and uterus. It grows quickly and spreads to other tissues and distant organs, making it deadly. Traditional cancer treatments like radiation and chemotherapy are less effective against leiomyosarcoma.
Leiomyosarcoma primarily affects adults. Detecting leiomyosarcoma can be challenging. Getting an early diagnosis is crucial for a good outcome.
Symptoms vary depending on the location and size of the tumor. They may include pain, swelling, menstrual changes, weight loss, digestive issues, fatigue, and feeling sick. Healthcare workers use imaging, biopsies, and blood tests to diagnose leiomyosarcoma.
Healthcare providers stage leiomyosarcoma using the tumor’s size, spread, and grade. Stages range from 1 to 4, with higher stages indicating more advanced cancer.
Many people with leiomyosarcoma have their cancer come back. Uterine leiomyosarcomas come back in up to 70% of cases. Leiomyosarcomas in other body parts come back about 40% of the time. Metastasis, particularly in the lungs or liver, is a frequent complication.
Treatment for leiomyosarcoma involves surgery to remove as much cancer as possible. Additional treatment with radiation and chemotherapy can cancer cells or is an option when surgery is not. These treatments are not very effective against leiomyosarcoma but may extend lifespan.
Leiomyosarcoma can be challenging to treat, particularly when it has spread to other organs. The prognosis for leiomyosarcoma depends on factors such as tumor location, spread, and the success of surgery. Early detection, proper staging, and comprehensive treatment are crucial for improving outcomes.
12 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Cancer Institute.Leiomyosarcoma.National Organization for Rare Disorders.Leiomyosarcoma - symptoms, causes, treatment.National Cancer Institute.Soft tissue sarcoma—patient version.Kerrison WGJ, Thway K, Jones RL, Huang PH.The biology and treatment of leiomyosarcomas.Critical Reviews in Oncology/Hematology. 2023;184:103955. doi:10.1016/j.critrevonc.2023.103955Singh Z.Leiomyosarcoma: a rare soft tissue cancer arising from multiple organs.Journal of Cancer Research and Practice. 2018;5(1):1-8. doi:10.1016/j.jcrpr.2017.10.002National Cancer Institute.Definition of leiomyoma.George S, Serrano C, Hensley ML, Ray-Coquard I.Soft tissue and uterine leiomyosarcoma.J Clin Oncol. 2018;36(2):144-150. doi:10.1200/JCO.2017.75.9845National Cancer Institute.Tumor grade.National Cancer Institute.Cancer stat facts: soft tissue including heart cancer.American Cancer Society.Survival rates for gastrointestinal stromal tumors.American Cancer Society.Uterine sarcoma survival rates.American Society of Clinical Oncology.Sarcomas, soft tissue: coping with treatment.Additional Reading
12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Cancer Institute.Leiomyosarcoma.National Organization for Rare Disorders.Leiomyosarcoma - symptoms, causes, treatment.National Cancer Institute.Soft tissue sarcoma—patient version.Kerrison WGJ, Thway K, Jones RL, Huang PH.The biology and treatment of leiomyosarcomas.Critical Reviews in Oncology/Hematology. 2023;184:103955. doi:10.1016/j.critrevonc.2023.103955Singh Z.Leiomyosarcoma: a rare soft tissue cancer arising from multiple organs.Journal of Cancer Research and Practice. 2018;5(1):1-8. doi:10.1016/j.jcrpr.2017.10.002National Cancer Institute.Definition of leiomyoma.George S, Serrano C, Hensley ML, Ray-Coquard I.Soft tissue and uterine leiomyosarcoma.J Clin Oncol. 2018;36(2):144-150. doi:10.1200/JCO.2017.75.9845National Cancer Institute.Tumor grade.National Cancer Institute.Cancer stat facts: soft tissue including heart cancer.American Cancer Society.Survival rates for gastrointestinal stromal tumors.American Cancer Society.Uterine sarcoma survival rates.American Society of Clinical Oncology.Sarcomas, soft tissue: coping with treatment.Additional Reading
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Cancer Institute.Leiomyosarcoma.National Organization for Rare Disorders.Leiomyosarcoma - symptoms, causes, treatment.National Cancer Institute.Soft tissue sarcoma—patient version.Kerrison WGJ, Thway K, Jones RL, Huang PH.The biology and treatment of leiomyosarcomas.Critical Reviews in Oncology/Hematology. 2023;184:103955. doi:10.1016/j.critrevonc.2023.103955Singh Z.Leiomyosarcoma: a rare soft tissue cancer arising from multiple organs.Journal of Cancer Research and Practice. 2018;5(1):1-8. doi:10.1016/j.jcrpr.2017.10.002National Cancer Institute.Definition of leiomyoma.George S, Serrano C, Hensley ML, Ray-Coquard I.Soft tissue and uterine leiomyosarcoma.J Clin Oncol. 2018;36(2):144-150. doi:10.1200/JCO.2017.75.9845National Cancer Institute.Tumor grade.National Cancer Institute.Cancer stat facts: soft tissue including heart cancer.American Cancer Society.Survival rates for gastrointestinal stromal tumors.American Cancer Society.Uterine sarcoma survival rates.American Society of Clinical Oncology.Sarcomas, soft tissue: coping with treatment.
National Cancer Institute.Leiomyosarcoma.
National Organization for Rare Disorders.Leiomyosarcoma - symptoms, causes, treatment.
National Cancer Institute.Soft tissue sarcoma—patient version.
Kerrison WGJ, Thway K, Jones RL, Huang PH.The biology and treatment of leiomyosarcomas.Critical Reviews in Oncology/Hematology. 2023;184:103955. doi:10.1016/j.critrevonc.2023.103955
Singh Z.Leiomyosarcoma: a rare soft tissue cancer arising from multiple organs.Journal of Cancer Research and Practice. 2018;5(1):1-8. doi:10.1016/j.jcrpr.2017.10.002
National Cancer Institute.Definition of leiomyoma.
George S, Serrano C, Hensley ML, Ray-Coquard I.Soft tissue and uterine leiomyosarcoma.J Clin Oncol. 2018;36(2):144-150. doi:10.1200/JCO.2017.75.9845
National Cancer Institute.Tumor grade.
National Cancer Institute.Cancer stat facts: soft tissue including heart cancer.
American Cancer Society.Survival rates for gastrointestinal stromal tumors.
American Cancer Society.Uterine sarcoma survival rates.
American Society of Clinical Oncology.Sarcomas, soft tissue: coping with treatment.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
