1. What are soft tissue sarcomas?

Sarcomas are malignant (cancerous) tumors that develop in tissues which connect, support, or surround other structures and organs of the body. Muscles, tendons (bands of fiber that connect muscles to bones), fibrous tissues, fat, blood vessels, nerves, and synovial tissues are types of soft tissue. Soft tissue sarcomas are grouped together because they share certain microscopic characteristics, have similar symptoms, and are generally treated in similar ways (1). They are usually named for the type of tissue in which they begin.

Examples of soft tissue sarcomas and the type of tissue in which they begin include the following (2):

• Fibrous tissue (tissue that holds bones, muscles, and organs in place)—fibrosarcoma, malignant fibrous histiocytoma
• Fatty tissue—liposarcoma
• Smooth muscle (e.g., uterus)—leiomyosarcoma
• Skeletal muscle—rhabdomyosarcoma
• Blood and lymph vessels—epithelioid hemangioendothelioma, angiosarcoma, lymphangiosarcoma, Kaposi sarcoma
• Perivascular tissue (near or around blood vessels)—glomangiosarcoma, malignant hemangiopericytoma
• Synovial tissue (tissue that lines joints, tendon sheaths, and fluid-filled sacs between tendons and bones)—synovial sarcoma
• Peripheral nerves—malignant granular cell tumor, malignant peripheral nerve sheath tumor (also called malignant schwannoma or neurofibrosarcoma)
• Mesenchymal cells (cells that develop into connective tissue, blood vessels, and lymphatic tissue)—gastrointestinal stromal tumor (GIST), malignant mesenchymoma

Other types of soft tissue sarcomas include alveolar soft part sarcoma, epithelioid sarcoma, desmoplastic small cell tumor, and clear cell sarcoma. At this time, scientists do not know the types of tissue in which these sarcomas begin (2). Many sarcomas have specific chromosomal alterations, which are used to help classify the tumors (2).

Sarcomas that develop in the bone and cartilage (osteosarcoma, Ewing sarcoma, and chondrosarcoma) are not classified as soft tissue sarcomas and are not described in this resource. (More information about these types of cancer is available in the National Cancer Institute (NCI) fact sheet Bone Cancer: Questions and Answers at http://www.cancer.gov/cancertopics/factsheet/Sites-Types/bone on the Internet.)

2. Where in the body are soft tissue sarcomas more likely to develop?

Soft tissue sarcomas can arise almost anywhere in the body. About 43 percent occur in the extremities (e.g., arms, legs); 34 percent occur in and around the internal organs (e.g., uterus, heart); 10 percent occur in the trunk (e.g., chest, back); and 13 percent occur in other locations (2). In very rare cases, these tumors develop in the gastrointestinal tract. A small percentage of these are GISTs. Malignant GISTs occur most commonly in the stomach and small intestine.

3. What are the possible causes of soft tissue sarcomas?

Although most soft tissue sarcomas do not have a clearly defined cause, researchers have identified several factors that increase the likelihood of developing these tumors (2). External radiation therapy is the most well-established risk factor for soft tissue sarcomas. Patients treated with radiation therapy for cancers of the retina, breast, cervix, ovary, testes, or lymphatic system have a much higher chance of developing soft tissue sarcomas than the general population (1). The risk appears to be related to the dose of radiation. To limit this risk, radiation treatment for cancer is planned to ensure that the greatest amount of radiation is delivered to diseased tissue while surrounding healthy tissue is protected as much as possible.

Another risk factor for soft tissue sarcomas is exposure to certain chemicals in the workplace, including vinyl chloride, arsenic, herbicides such as phenoxyacetic acids, and wood preservatives that contain chlorophenols (2). Chronic lymphedema (a condition in which excess fluid collects in the tissue and causes swelling) following radiation to, or surgical removal of, lymph nodes is also a risk factor.

Certain inherited diseases are associated with an increased risk of developing soft tissue sarcomas. Studies have focused on genetic changes that may lead to the development of soft tissue sarcomas. For example, people with Li-Fraumeni syndrome (associated with alterations in the p53 tumor suppressor gene), von Recklinghausen disease (also called neurofibromatosis type 1 and associated with alterations in the NF1 gene), hereditary leiomyomatosis and renal cell cancer syndrome (with alterations in the FH gene), and hereditary retinoblastoma (with alterations in the RB1 gene) are at increased risk of developing soft tissue sarcomas.

Kaposi sarcoma is a soft tissue sarcoma that sometimes develops in people with human immunodeficiency virus (HIV) infection. The primary cause of Kaposi sarcoma is infection with Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8. However, people infected with KSHV, but not HIV, rarely develop Kaposi sarcoma (3).

4. How often do soft tissue sarcomas occur?

Soft tissue sarcomas are rare. About 9,500 new cases were diagnosed in the United States in 2006 (4), which is less than 1 percent of all new cancer cases. However, sarcomas occur more often in children and young adults. For example, soft tissue sarcomas account for about 7 percent of all childhood cancers. The most common soft tissue sarcomas are leiomyosarcoma, malignant fibrous histiocytoma, and liposarcoma. By site of origin, leiomyosarcoma is the most common sarcoma of the organs, while liposarcoma and malignant fibrous histiocytoma are the most common sarcomas of the extremities (5). Rhabdomyosarcoma is the most common soft tissue sarcoma in children.

5. What are the symptoms of soft tissue sarcomas?

Soft tissue sarcomas usually appear as a lump or mass, but they rarely cause pain, swelling, or other symptoms (1). A lump or mass might not be a sarcoma; it could be benign (noncancerous), a different type of cancer, or another problem. It is important to see a doctor about any physical change, such as a lump or mass, because only a doctor can make a diagnosis.

6. How are soft tissue sarcomas diagnosed?

The doctor performs a physical exam and may use the following procedures and tests to diagnose soft tissue sarcoma:

• X-rays create images of areas inside the body on film.
  
  
• Computed tomography (CT), a procedure that uses special x-ray equipment to obtain cross-sectional pictures of the body, can determine whether a soft tissue tumor has metastasized (spread) to the lung or abdomen (1). CT scans, also called CAT scans, can also be helpful in determining the size of the tumor and whether the tumor can be accessed through surgery.
  
  
• Magnetic resonance imaging (MRI) uses a powerful magnet linked to a computer to create detailed pictures of areas inside the body. MRI scans can aid in diagnosis, particularly in helping to distinguish soft tissue sarcomas from benign tumors, as well as showing the extent of the tumor. MRIs are also used to monitor the patient after treatment to see if the tumor has recurred (come back) (1).
  
  
• A biopsy is the removal of cells or tissue for examination by a pathologist. The pathologist studies tissue samples under a microscope or performs other tests on the cells or tissue. A biopsy is the only sure way to tell whether a person has cancer.

Specialized testing of the tumor cells for chromosomal alterations may also be conducted to aid in diagnosis (5).

7. How are soft tissue sarcomas treated?

Treatment for soft tissue sarcomas is determined mainly by the stage of the disease. The stage depends on the size of the tumor, the grade, and whether the cancer has spread to the lymph nodes or other parts of the body. The most important component of the stage is the tumor grade (how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread). Treatment options for soft tissue sarcomas include surgery, radiation therapy, and chemotherapy. A multidisciplinary team of cancer specialists can help plan the best treatment for patients with soft tissue sarcomas.

• Surgery is the usual treatment for soft tissue sarcomas. For surgery to be effective, the surgeon must remove the entire tumor with negative margins (no cancer cells are found at the edge or border of the tissue removed during surgery). The surgeon may use special surgical techniques to minimize the amount of healthy tissue removed with the tumor. Some patients need reconstructive surgery.
  
  
• Radiation therapy, also called radiotherapy, involves the use of high-energy x-rays to kill cancer cells. This therapy may be used before surgery to shrink the tumor, after surgery to kill any cancer cells that may remain in the body, or both before and after surgery. Radiation may come from a machine outside the body (external radiation therapy). It can also come from radioactive materials placed directly into or near the area where the cancer cells are found (internal radiation therapy or radiation implant) (1).
  
  
• Chemotherapy is the use of anticancer drugs to kill cancer cells. Chemotherapy may be used before or after surgery, and with or without radiation therapy. The effectiveness of current anticancer drugs depends on the type of sarcoma. Some sarcomas are very responsive to chemotherapy, while others do not respond to current anticancer drugs (1). Some sarcomas with specific chromosomal alterations can be treated with therapies targeted to the alteration. For example, imatinib mesylate (Gleevec^®) is a targeted therapy used to treat GIST that has metastasized (1).

8. Are clinical trials (research studies) available? Where can people get more information about clinical trials?

Yes. Participation in clinical trials is an important treatment option for many people with soft tissue sarcomas. To develop new treatments, and better ways to use current treatments, the NCI, a component of the National Institutes of Health, is sponsoring clinical trials in many hospitals and cancer centers around the country. Clinical trials are a critical step in the development of new methods of treatment. Before any new treatment can be recommended for general use, doctors conduct clinical trials to find out whether the treatment is safe for patients and effective against the disease.

People interested in taking part in a clinical trial should talk with their doctor. Information about clinical trials is available from the NCI's Cancer Information Service (CIS) (see below) at 1–800–4–CANCER and in the NCI booklet Taking Part in Cancer Treatment Research Studies, which can be found at http://www.cancer.gov/publications on the Internet . This booklet describes how research studies are carried out and explains their possible benefits and risks. Further information about clinical trials is available at http://www.cancer.gov/clinicaltrials on the NCI's Web site. The Web site offers detailed information about specific ongoing studies by linking to PDQ^®, the NCI's comprehensive cancer information database. The CIS also provides information from PDQ.

Selected References

1. Cormier JN, Pollock RE. Soft tissue sarcomas. CA: A Cancer Journal for Clinicians 2004; 54(2):94–109.
   
   
2. Brennan M, Singer S, Maki R, O’Sullivan B. Sarcomas of the soft tissue and bone. In: DeVita VT Jr., Hellman S, Rosenberg SA, editors. Cancer: Principles and Practice of Oncology. Vol. 2. 7^th ed. Philadelphia: Lippincott Williams and Wilkins, 2004.
   
   
3. Yarchoan R, Little R. Immunosuppression-related malignancies. In: DeVita VT Jr., Hellman S, Rosenberg SA, editors. Cancer: Principles and Practice of Oncology. Vol. 2. 7^th ed. Philadelphia: Lippincott Williams and Wilkins, 2004.
   
   
4. Ries LAG, Harkins D, Krapcho M, et al. SEER Cancer Statistics Review, 1975–2003. Bethesda , MD: National Cancer Institute, 2006.
   
   
5. Brennan MF. Soft tissue sarcoma: Advances in understanding and management. Surgeon 2005; 3(3):216–223.
   
   

# # #

• National Cancer Institute Fact Sheet 5.9, Tumor Grade: Questions and Answers ¹
  (http://www.cancer.gov/cancertopics/factsheet/Detection/tumor-grade)
• National Cancer Institute Fact Sheet 5.32, Staging: Questions and Answers ²
  (http://www.cancer.gov/cancertopics/factsheet/Detection/staging)
• National Cancer Institute Fact Sheet 6.1, Synovial Sarcoma: Questions and Answers ³
  (http://www.cancer.gov/cancertopics/factsheet/Sites-Types/synovial)
• National Cancer Institute Fact Sheet 6.20, Metastatic Cancer: Questions and Answers ⁴
  (http://www.cancer.gov/cancertopics/factsheet/Sites-Types/metastatic)
• National Cancer Institute Fact Sheet 6.26, Bone Cancer: Questions and Answers ⁵
  (http://www.cancer.gov/cancertopics/factsheet/Sites-Types/bone)
• National Cancer Institute Fact Sheet 7.49, Targeted Cancer Therapies: Questions and Answers ⁶
  (http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted)
• Chemotherapy and You: Support for People With Cancer ⁷ (http://www.cancer.gov/cancertopics/chemotherapy-and-you)
• Radiation Therapy and You: Support for People With Cancer ⁸ (http://www.cancer.gov/cancertopics/radiation-therapy-and-you)
• Taking Part in Cancer Treatment Research Studies ⁹ (http://www.cancer.gov/clinicaltrials/Taking-Part-in-Cancer-Treatment-Research-Studies)

For more help, contact:

NCI's Cancer Information Service
Telephone (toll-free): 1–800–4–CANCER (1–800–422–6237)
TTY (toll-free): 1–800–332–8615
LiveHelp^® online chat: https://cissecure.nci.nih.gov/livehelp/welcome.asp

Glossary Terms

The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

A change resulting in something that is different from the original.

A type of cancer that begins in the cells that line blood vessels or lymph vessels. Cancer that begins in blood vessels is called hemangiosarcoma. Cancer that begins in lymph vessels is called lymphangiosarcoma.

A poisonous chemical used to kill weeds and pests. Also used in cancer therapy.

Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body. Also called nonmalignant.

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

Primary bone cancer is cancer that forms in cells of the bone. Some types of primary bone cancer are osteosarcoma, Ewing sarcoma, malignant fibrous histiocytoma, and chondrosarcoma. Secondary bone cancer is cancer that spreads to the bone from another part of the body (such as the prostate, breast, or lung).

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

The Cancer Information Service is the National Cancer Institute's link to the public, interpreting and explaining research findings in a clear and understandable manner, and providing personalized responses to specific questions about cancer. Access the CIS by calling 1-800-4-CANCER (1-800-422-6237), or by using the LiveHelp instant-messaging service at https://cissecure.nci.nih.gov/livehelp/welcome.asp. Also called CIS.

A tough, flexible tissue that lines joints and gives structure to the nose, ears, larynx, and other parts of the body.

The lower, narrow end of the uterus that forms a canal between the uterus and vagina.

Treatment with drugs that kill cancer cells.

A type of cancer that forms in bone cartilage. It usually starts in the pelvis (between the hip bones), the shoulder, the ribs, or at the ends of the long bones of the arms and legs. A rare type of chondrosarcoma called extraskeletal chondrosarcoma does not form in bone cartilage. Instead, it forms in the soft tissues of the upper part of the arms and legs. Chondrosarcoma can occur at any age but is more common in people older than 40 years. It is a type of bone cancer.

A disease or condition that persists or progresses over a long period of time.

A type of cell that looks clear inside when viewed under a microscope.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

Supporting tissue that surrounds other tissues and organs. Specialized connective tissue includes bone, cartilage, blood, and fat.

Causing or forming adhesions or fibrous connective tissue within a tumor.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The amount of medicine taken, or radiation given, at one time.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

A type of cancer that forms in bone or soft tissue. Also called peripheral primitive neuroectodermal tumor and pPNET.

A type of soft tissue sarcoma that begins in fibrous tissue, which holds bones, muscles, and other organs in place.

Containing or resembling fibers.

A substance that flows smoothly and takes the shape of its container. Liquids and gases are fluids.

A type of tumor that usually begins in cells in the wall of the gastrointestinal tract. It can be benign or malignant. Also called GIST.

The stomach and intestines. The gastrointestinal tract is part of the digestive system, which also includes the salivary glands, mouth, esophagus, liver, pancreas, gallbladder, and rectum.

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

A drug used to treat different types of leukemia and other cancers of the blood, gastrointestinal stromal tumors, skin tumors called dermatofibrosarcoma protuberans, and a rare condition called systemic mastocytosis. It is also being studied in the treatment of other types of cancer. Gleevec blocks the protein made by the bcr/abl oncogene. It is a type of tyrosine kinase inhibitor. Also called imatinib mesylate and STI571.

A description of a tumor based on how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Grading systems are different for each type of cancer.

A type of cancer involving blood vessels and soft tissue.

A chemical that kills plants.

Transmitted from parent to child by information contained in the genes.

A rare inherited disorder that increases the risk of developing benign (not cancer) tumors of the skin and the uterus (leiomyomas) and malignant (cancer) tumors of the uterus (leiomyosarcoma) and the kidney. Also called HLRCC.

A type of herpesvirus that may cause Kaposi sarcoma (a rare cancer that can cause skin lesions) and a type of lymphoma (cancer that begins in the lymph system), especially in patients who have a weak immune system. Also called HHV8, Kaposi sarcoma-associated herpesvirus, and KSHV.

The cause of acquired immunodeficiency syndrome (AIDS). Also called HIV.

A drug used to treat different types of leukemia and other cancers of the blood, gastrointestinal stromal tumors, skin tumors called dermatofibrosarcoma protuberans, and a rare condition called systemic mastocytosis. It is also being studied in the treatment of other types of cancer. Imatinib mesylate blocks the protein made by the bcr/abl oncogene. It is a type of tyrosine kinase inhibitor. Also called Gleevec and STI571.

A substance or object that is put in the body as a prosthesis, or for treatment or diagnosis.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Transmitted through genes that have been passed from parents to their offspring (children).

A type of cancer characterized by the abnormal growth of blood vessels that develop into skin lesions or occur internally.

A type of herpesvirus that may cause Kaposi sarcoma (a rare cancer that can cause skin lesions) and a type of lymphoma (cancer that begins in the lymph system), especially in patients who have a weak immune system. Also called HHV8, human herpesvirus 8, and KSHV.

A malignant (cancer) tumor of smooth muscle cells that can arise almost anywhere in the body, but is most common in the uterus, abdomen, or pelvis.

A rare, inherited predisposition to multiple cancers, caused by an alteration in the p53 tumor suppressor gene.

A rare cancer of the fat cells.

One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.

A type of cancer that begins in the cells that line lymph vessels.

The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the bone marrow, spleen, thymus, lymph nodes, and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body.

A condition in which extra lymph fluid builds up in tissues and causes swelling. It may occur in an arm or leg if lymph vessels are blocked, damaged, or removed by surgery.

A procedure in which radio waves and a powerful magnet linked to a computer is used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. Magnetic resonance imaging makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. Magnetic resonance imaging is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called MRI, NMRI, and nuclear magnetic resonance imaging.

Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.

A soft tissue sarcoma that usually occurs in the limbs, most commonly the legs, and may also occur in the abdomen. Also called malignant fibrous cytoma.

A type of soft tissue sarcoma that develops in cells that form a protective sheath (covering) around peripheral nerves, which are nerves that are outside of the central nervous system (brain and spinal cord). Also called MPNST.

Refers to cells that develop into connective tissue, blood vessels, and lymphatic tissue.

To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.

Too small to be seen without a microscope.

In medicine, a term used to describe a treatment planning approach or team that includes a number of doctors and other health care professionals who are experts in different specialties (disciplines). In cancer treatment, the primary disciplines are medical oncology (treatment with drugs), surgical oncology (treatment with surgery), and radiation oncology (treatment with radiation).

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

A federal agency in the U.S. that conducts biomedical research in its own laboratories; supports the research of non-Federal scientists in universities, medical schools, hospitals, and research institutions throughout the country and abroad; helps in the training of research investigators; and fosters communication of medical information. Access the National Institutes of Health Web site at http://www.nih.gov. Also called NIH.

A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.

A rare genetic condition that causes brown spots and tumors on the skin, freckling in skin areas not exposed to the sun, tumors on the nerves, and developmental changes in the nervous system, muscles, bone, and skin. Also called NF1.

A part of the body that performs a specific function. For example, the heart is an organ.

A cancer of the bone that usually affects the large bones of the arm or leg. It occurs most commonly in young people and affects more males than females. Also called osteogenic sarcoma.

One of a pair of female reproductive glands in which the ova, or eggs, are formed. The ovaries are located in the pelvis, one on each side of the uterus.

A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.

A doctor who identifies diseases by studying cells and tissues under a microscope.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

An exam of the body to check for general signs of disease.

Energy released in the form of particle or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, medical x-rays, and energy given off by a radioisotope (unstable form of a chemical element that releases radiation as it breaks down and becomes more stable).

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

Giving off radiation.

Surgery that is done to reshape or rebuild (reconstruct) a part of the body changed by previous surgery.

To come back or to return.

The light-sensitive layers of nerve tissue at the back of the eye that receive images and sends them as electric signals through the optic nerve to the brain.

Cancer that forms in the tissues of the retina (the light-sensitive layers of nerve tissue at the back of the eye). Retinoblastoma usually occurs in children younger than 5 years. It may be hereditary or nonhereditary (sporadic).

Cancer that forms in the soft tissues in a type of muscle called striated muscle. Rhabdomyosarcoma can occur anywhere in the body.

Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.

A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

A tumor of the peripheral nervous system that arises in the nerve sheath (protective covering). It is almost always benign, but rare malignant schwannomas have been reported.

Having to do with the skeleton (bones of the body).

The part of the digestive tract that is located between the stomach and the large intestine.

A cancer that begins in the muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

An organ that is part of the digestive system. The stomach helps digest food by mixing it with digestive juices and churning it into a thin liquid.

A doctor who removes or repairs a part of the body by operating on the patient.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A malignant tumor that develops in the synovial membrane of the joints.

A type of treatment that uses drugs or other substances, such as monoclonal antibodies, to identify and attack specific cancer cells. Targeted therapy may have fewer side effects than other types of cancer treatments.

One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testicle.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

A type of gene that makes a protein called a tumor suppressor protein that helps control cell growth. Mutations (changes in DNA) in tumor suppressor genes may lead to cancer. Also called antioncogene.

The small, hollow, pear-shaped organ in a woman's pelvis. This is the organ in which a fetus develops. Also called womb.

A substance used to make plastics. Exposure to vinyl chloride may increase the risk of developing liver, brain, and lung cancers; lymphoma; and leukemia.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.