Leiomyosarcomas can start in any organ that contains smooth muscle, but can be found in the walls of the stomach, large and small intestines, esophagus, uterus, or deep within the abdomen (retroperitoneal). But for perspective, smooth muscle cancers are quite rare: Less than 1% of all cancers are leiomyosarcomas. Very rarely, leiomyosarcomas begin in blood vessels or in the skin.
Most leiomyosarcomas are in the stomach. The second most common site is the small bowel, followed by the colon, rectum, and esophagus.
Leiomyosarcomas do occur in the breast and uterus, but they are very rare. Uterine sarcomas comprise less than 1% of gynecological malignancies and 2% to 5% of all uterine malignancies. Of these numbers, leiomyosarcomas are found in only 0.1% of women of childbearing age who have tumors of the uterus. Less than 2% of tumors in women over age 60 who are undergoing hysterectomy are leiomyosarcomas.
Causes and symptoms
The exact causes of leiomyosarcoma are not known, but there are genetic and environmental risk factors associated with it. Certain inherited conditions that run in families may increase the risk of developing leiomyosarcoma. High-dose radiation exposure, such as radiotherapy used to treat other types of cancer, has also been linked to leiomyosarcoma. It is possible that exposure to certain chemical herbicides may increase the risk of developing sarcomas, but this association has not been proven.
Since leiomyosarcoma can occur in any location, the symptoms are different and depend on the site of the tumor. When leiomyosarcoma begins in an organ in the abdomen, such as the stomach or small bowel, the physician may be able to feel a large lump or mass when he examines the abdomen. When leiomyosarcoma affects a blood vessel, it may block the flow of blood to the body part supplied by the artery. Commonly occurring symptoms include:
- painless lump or mass
- painful swelling
- abdominal pain
- weight loss
- nausea and vomiting
Some patients who have leiomyosarcomas may be visiting the doctor because they have discovered a lump or mass or swelling on a body part. Others have symptoms related to the internal organ that is affected by the leiomyosarcoma. For example, a tumor in the stomach may cause nausea, feelings of fullness, internal bleeding, and weight loss. The patient's doctor will take a detailed medical history to find out about the symptoms. The history is followed by a complete physical examination with special attention to the suspicious symptom or body part.
Depending on the location of the tumor, the doctor may order imaging studies such as x ray, computed tomography (CT) scan, and magnetic resonance imaging (MRI) to help determine the size, shape, and exact location of the tumor. A biopsy of the tumor is necessary to make the definitive diagnosis of leiomyosarcoma. The tissue sample is examined by a pathologist (specialist in the study of diseased tissue).
Types of biopsy
The type of biopsy done depends on the location of the tumor. For some small tumors, the doctor may perform an excisional biopsy, removing the entire tumor and a margin of surrounding normal tissue. Most often, the doctor will perform an incisional biopsy, a procedure that involves cutting out only a piece of the tumor that is used to determine its type and grade.
Patients with leiomyosarcoma are usually cared for by a multidisciplinary team of health professionals. The patient's family or primary care doctor may refer the patient to other specialists, such as surgeons and oncologists (specialists in cancer medicine), radiologic technicians, nurses, and laboratory technicians. Depending on the tumor location and treatment plan, patients may benefit from rehabilitation therapy with physical therapists and nutritional counseling from dieticians.
Clinical staging, treatments, and prognosis
The purpose of staging a tumor is to determine how far it has advanced. This is important because treatment varies depending on the stage. Stage is determined by the size of the tumor, whether the tumor has spread to nearby lymph nodes, whether the tumor has spread elsewhere in the body, and what the cells look like under the microscope.
Examining the tissue sample under the microscope, using special chemical stains, the pathologist is able to classify tumors as high grade or low grade. High-grade tumors have the more rapidly growing cells and so are considered more serious.
Tumors are staged using numbers I through IV. The higher the number, the more the tumor has advanced. Stage IV leiomyosarcomas have involved either lymph nodes or have spread to distant parts of the body.
Treatment for leiomyosarcoma varies depending on the location of the tumor, its size and grade, and the extent of its spread. Treatment planning also takes into account the patient's age, medical history, and general health.
Leiomyosarcomas on the arms and legs may be treated by amputation (removal of the affected limb) or by limb-sparing surgery to remove the tumor. These tumors may also be treated with radiation therapy, chemotherapy, or a combination of both.
Generally, tumors inside the abdomen are surgically removed. The site, size, and extent of the tumor determine the type of surgery performed. Leiomyosarcomas of organs in the abdomen may also be treated with radiation and chemotherapy.
The surgical treatment of leiomyosarcoma carries risks related to the surgical site, such as loss of function resulting from amputation or from nerve and/or muscle loss. There also are risks associated with any surgical procedure, such as reactions to general anesthesia or infection after surgery.
The side effects of radiation therapy depend on the site being radiated. Radiation therapy can produce side effects such as fatigue, skin rashes, nausea, and diarrhea. Most of the side effects lessen or disappear completely after the radiation therapy has been completed.
The side effects of chemotherapy vary depending on the medication, or combination of anticancer drugs, used. Nausea, vomiting, anemia, lower resistance to infection, and hair loss (alopecia) are common side effects. Medication may be given to reduce the unpleasant side effects of chemotherapy.
Alternative and complementary therapies
Many patients explore alternative and complementary therapies to help to reduce the stress associated with illness, improve immune function, and feel better. While there is no evidence that these therapies specifically combat disease, activities such as biofeedback, relaxation, therapeutic touch, massage therapy, and guided imagery have been reported to enhance well-being.
The outlook for patients with leiomyosarcoma varies. It depends on the location and size of the tumor and its type and extent of spread. Some patients, such as those who have had small tumors located in or near the skin surgically removed, have excellent prognoses. Their 5-year survival is greater than 90%. Among patients with leiomyosarcomas in organs in the abdomen, survival is best when the tumor has been completely removed. In general, high-grade tumors that have spread widely throughout the body are not associated with favorable survival rates.
Coping with cancer treatment
Fatigue is one of the most common complaints during cancer treatment and recovery. Many patients benefit from learning energy-conserving approaches to accomplish their daily activities. They should be encouraged to rest when tired and take breaks from strenuous activities. Planning activities around times of day when energy is highest is often helpful. Mild exercise, small, frequent nutritious snacks, and limiting physical and emotional stress also help to combat fatigue.
Depression, emotional distress, and anxiety associated with the disease and its treatment may respond to counseling from a mental health professional. Many cancer patients and their families find participation in mutual aid and group support programs helps to relieve feelings of isolation and loneliness. By sharing problems with others who have lived through similar difficulties, patients and families can exchange ideas and coping strategies.
Several clinical studies were underway as of 2001. For example, doctors at Memorial Sloan-Kettering Cancer Center were using specific chemotherapeutic drugs to treat patients with leiomyosarcoma that cannot be removed by surgery or has recurred. These drugs, gemcitabine, docetaxel, and filgrastim (G-CSF), work by stopping tumor cells from dividing, so they cannot grow. To learn more about this clinical trial and the availability of others, patients and families may wish to contact Memorial Sloan-Kettering Cancer Center at (212) 639-6555, or visit the National Cancer Institute (NCI) web-site at <http://cancertrials.nci.nih.gov>.
Since the causes of leiomyosarcoma are not known, there are no recommendations about how to prevent its development. It is linked to radiation exposure; however, much of this excess radiation exposure is the result of therapy to treat other forms of cancer. Among families with an inherited tendency to develop soft tissue sarcomas, careful monitoring may help to ensure early diagnosis and treatment of the disease.
Leiomyosarcoma, like other cancer diagnoses, may produce a range of emotional responses. Education, counseling, and participation in support group programs may help to reduce feelings of fear, anxiety and hopelessness. For many patients suffering from spiritual distress, visits with clergy members and participation in organized prayer may offer comfort.
Murphy, Gerald P. et al. American Cancer Society Textbook of Clinical Oncology Second Edition. Atlanta, GA: The American Cancer Society, Inc., 1995.
Otto, Shirley E. Oncology Nursing. St. Louis, MO: Mosby, 1997.
Pelletier, Kenneth R. The Best of Alternative Medicine. New York, NY: Simon & Schuster, 2000.
Schwartz, L. B. et al. "Leiomyosarcoma: Clinical Presentation." American Journal of Obstetrics and Gynecology168 (1)(January 1993):180-183.
Ishida, J. et al. "Primary Leiomyosarcoma of the Greater Omentum." Journal Of Clinical Gastroenterology 28 (2)(March 1999): 167-170.
Antonescru, C. R. et al. "Primary Leiomyosarcoma of Bone: AClinicopathologic, Immunohistochemical, and Ultrastructural Study of 33 Patients and a Literature Review." Amer ican Journal of Surgical Pathology 21 (11) (November 1997): 1281-1294.
American Cancer Society. 1599 Clifton Road, N.E., Atlanta, GA 30329. (800) 227-2345.
Cancer Research Institute. 681 Fifth Avenue, New York, NY10022. (800) 992-2623.
National Cancer Institute (National Institutes of Health). 9000Rockville Pike, Bethesda, MD 20892. (800) 422-6237.
National Cancer Institute Clinical Cancer Trials <http://cancertrials.nci.nih.gov>.
Barbara Wexler, M.P.H.
QUESTIONS TO ASK THE DOCTOR
- What stage is the leiomyosarcoma?
- What are the recommended treatments?
- What are the side effects of the recommended treatment?
- Is treatment expected to cure the disease or only to prolong life?
—The surgical removal and microscopic examination of living tissue for diagnostic purposes.
—Treatment of cancer with synthetic drugs that destroy the tumor either by inhibiting the growth of cancerous cells or by killing them.
—A doctor who specializes in cancer medicine.
—A doctor who specializes in the diagnosis of disease by studying cells and tissues under a microscope.
—Treatment using high energy radiation from x-ray machines, cobalt, radium, or other sources.
—A term used to describe the size and extent of spread of cancer.