Leiomyosarcoma, or LMS, is a type of rare cancer that grows in the smooth muscles. The smooth muscles are in the hollow organs of the body, including the intestines, stomach, bladder, and blood vessels. In females, there is also smooth muscle in the uterus. These smooth muscle tissues help move blood, food, and other material through the body and work without you being aware.
LMS is an aggressive cancer, which means it can grow quickly. LMS is found most often in the abdomen or in the uterus.
It is not known what causes LMS to form. Scientists are always working to understand how cancer forms, but it can be hard to prove. We do know that some genetic conditions are associated with LMS. These genetic conditions include hereditary retinoblastoma, Li-Fraumeni syndrome, neurofibromatosis type 1, tuberous sclerosis, nevoid basal cell carcinoma syndrome, Gardner syndrome, and Werner syndrome.
No. LMS without an underlying genetic condition is not known to run in families.
Symptoms depend on where the tumor is and how big it is. Some people with LMS do not have symptoms when the cancer first starts. Later, when the tumor gets larger, symptoms can include:
- Unintentional weight loss
- Nausea and vomiting
- Lump under the skin.
Imaging: If you have symptoms of LMS, your doctor will use imaging scans such as MRI, CT scan, angiography, and PET to look at where the tumor is and how big it is. They will also check for signs that the tumor has spread to other parts of the body.
Biopsy: To check if the tumor is LMS, your doctor will do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope to see what kind of tumor it is.
Sometimes, LMS may be mistaken for a different type of tumor or condition using imaging scans. A biopsy will confirm the tumor is LMS. Getting the correct diagnosis is very important in order to get the right treatment.
Treatment for each patient will be unique and depends on the size and location of the tumor. You should go to an expert in LMS treatment to decide the best approach for treating your tumor. Surgery: The best option for LMS treatment is surgery. If all of the tumor is removed, there is a good chance of LMS being cured. If some cancer cells are left behind, there is a greater chance of the cancer coming back in the same spot, or a different part of the body.
Radiation therapy: Radiation therapy can be used around the time of surgery. The radiation is aimed at the tumor area to prevent it from growing back after it is removed.
Chemotherapy: When the LMS tumors are large, or the cancer cells have spread to other parts of the body, then chemotherapy is used in combination with surgery.
The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.
- Trabectedin (Brand name: Yondelis) For the treatment of patients with unresectable or metastatic liposarcoma or leiomyosarcoma who received a prior anthracycline-containing regimen.
The outlook for people with leiomyosarcoma depends on various factors, including tumor location, size, and type, as well as the extent of spread. Some patients with low grade tumors or with tumors that have not spread beyond Stage I have had excellent prognoses. There are numerous long term survivors from this group. In general, high-grade tumors that have spread widely throughout the body have less favorable survival rates.