Leiomyosarcoma

Leiomyosarcoma (LMS) is a rare cancer that grows in smooth muscle. Smooth muscle is found in the hollow organs of the body, including the intestines, stomach, and bladder, as well as in blood vessels. In females, smooth muscle is also found in the uterus.

Because smooth muscle exists in many parts of the body, leiomyosarcoma can start in different places. Like other soft tissue sarcomas, it can grow into nearby tissue and, in some cases, spread to other parts of the body.

Types & Stages

Leiomyosarcoma is a soft tissue sarcoma that begins in smooth muscle cells. It can arise in several areas, including the uterus, the abdomen, the blood vessels, or other soft tissues throughout the body. Where the tumor starts can affect symptoms and treatment, but these cancers share many features.

Leiomyosarcoma is often described in simple terms based on how far it has spread:

• Localized. The cancer is found only where it started and has not spread to other parts of the body.
   
• Regional spread. The cancer has grown into nearby tissues or lymph nodes.
   
• Distant spread (metastatic). The cancer has spread to distant parts of the body, such as the lungs or liver.

Your care team will use the tumor's size, grade, location, and whether it has spread to plan treatment.

Signs & Symptoms

Leiomyosarcoma often causes few symptoms early on. When symptoms do appear, they can depend on where the tumor is located.

Visit a doctor if you are experiencing any of these symptoms:

• A lump or mass that is growing
• Pain in the area of the tumor
• Abdominal swelling or discomfort
• Bleeding, depending on where the tumor is located, such as abnormal vaginal bleeding or blood in the stool
• Pressure symptoms caused by the tumor pushing on nearby organs or structures

Many of these symptoms can be caused by conditions that are not cancer. Still, it is important to pay attention to your body. If symptoms are new, last more than a few weeks, or are unusual for you, talk with a healthcare provider.

Diagnosis

Tests and procedures used to diagnose leiomyosarcoma may include:

• Physical exam and history. Your doctor checks your overall health and asks about your symptoms, how long they have lasted, and your health history.
   
• Imaging tests. A CT scan or MRI can show the size, depth, and location of the tumor and whether it has spread. These tests help guide the biopsy and surgery.
   
• Chest imaging. When needed, imaging of the chest may be used to check whether the cancer has spread to the lungs.
   
• Biopsy. A biopsy removes a small sample of the tumor so it can be examined under a microscope by a pathologist. This is the only way to confirm leiomyosarcoma and learn more about it.

Treatment

Treatment for leiomyosarcoma depends on the tumor's size, grade, and location, whether it has spread, and your overall health. Your care team can help explain the benefits and risks of each option.

Treatment may include:

• Surgery. When the tumor can be safely removed, surgery is the main treatment. The surgeon removes the tumor along with a margin of healthy tissue around it. Removing the cancer completely offers the best chance for cure.
   
• Radiation therapy. Radiation may be used before or after surgery in select cases to help lower the chance that the cancer comes back.
   
• Chemotherapy. Chemotherapy uses medicines to kill cancer cells or slow their growth. It may be considered in select cases, depending on the tumor's grade, size, and whether it has spread.
   
• Targeted or newer systemic therapies. In advanced or recurrent disease, targeted medicines or other newer systemic treatments may be used to help control the cancer.

Clinical trials may also be an option. These studies test new treatments or new ways to use current ones. Ask your care team whether a clinical trial may be right for you.

Causes & Risk Factors

The exact cause of leiomyosarcoma is usually not known. It begins when smooth muscle cells develop changes in their DNA that cause them to grow out of control.

Some cases have been linked to certain factors, including:

• Inherited cancer syndromes. Some genetic conditions passed down in families can raise the risk of developing soft tissue sarcomas.
   
• Prior radiation exposure. Rarely, a sarcoma can develop in an area of the body that received radiation therapy in the past.
   
• Conditions affecting immune function. Some leiomyosarcomas have been linked to conditions that weaken the immune system.

Having a risk factor does not mean you will develop leiomyosarcoma, and many people with the disease have no known risk factors. Talk with your healthcare provider about your personal risk.

Screening

There is no routine screening test for leiomyosarcoma for people at average risk.

Because this cancer is rare, it is most often found when a person has symptoms or during tests done for another reason. There is no recommended test to look for leiomyosarcoma in people who feel well and have no symptoms.

People with a known inherited cancer syndrome or a strong family history of cancer should talk with a healthcare provider, who may suggest closer monitoring in certain cases.

If you have symptoms that are new, persistent, or unusual for you, do not wait. Talk with a healthcare provider about your symptoms and whether further evaluation is needed.

This information is for general education only and is not a substitute for medical advice. Please consult a qualified healthcare provider for diagnosis, treatment recommendations, and guidance based on your personal health history.