Sarcomas are rare cancers of the bones and soft tissues including fat, muscles, blood vessels, nerves, tendons and joints. They affect approximately 12,000 people each year in the United States. Bone sarcomas are more common among children, and soft tissue sarcomas are more common in adults. Soft tissue tumors can occur in children and adults.
Dr. David Loeb with patient
In children, one of the most common soft tissue tumors is rhabdomyosarcoma -- a cancer occurring in the muscles. It can occur anywhere in the body, but most commonly originates in the head and neck region. Only about 15 percent of rhabdomysosarcomas occur in the extremities (arms, elbow, legs, knee, thigh, foot, or shoulder). Rhabdomyosarcoma accounts for approximately five percent of all childhood cancers and more than half of the soft tissue sarcomas diagnosed in children. The disease can occur anytime throughout childhood but is most commonly diagnosed in children under age six.
There is a slightly higher incidence of rhabdomyosarcoma among boys. In addition, there is a higher incidence of the disease among children exposed to chemicals and chemical pollution, and in those whose fathers are cigarette smokers.
Rhabdomyosarcomas are typically classified into four types:
- Embryonal - most frequently seen in head and neck and genitourinary tumors.
- Botryoid - a variation of the embryonal type that can arise as polyp or grape-like lesions in the genitourinary tract.
- Alveolar - a more aggressive form of the disease most often found in the extremities or trunk.
- Pleomorphic – the rarest form of the disease, typically occurring in the extremities or trunk.
In adults, sarcomas can occur in the soft tissues throughout the body but most commonly are found in the arms and legs. Some soft tissue sarcomas such as synovial sarcoma, rhabdomyosarcoma, clear cell sarcoma, and epithelioid sarcoma can spread to the lymph nodes, usually in the same extremity where the tumor started.
There is much debate surrounding whether adult soft-tissue sarcoma patients should receive chemotherapy. Our medical oncologists will meet with patients to provide an individualized approach assessing whether chemotherapy is appropriate. To find new drugs that target these specific cancers, researchers are collecting sarcoma tissues and comparing the cancer's genetic qualities that may lend themselves to emerging targeted therapies.
A treatment plan and recovery will depend on a variety of factors, including the type of sarcoma; the location, grade and size of the tumor; the age of the patient; and whether the cancer is new or has returned.
Types of Soft Tissue Sarcomas
Experts with the Johns Hopkins Sarcoma Program are experienced in managing all types of soft tissue sarcomas, including:
- Malignant fibrous histiocytoma
- Rhabdomyosarcomas (Types: Embryonal, Embryonal botryoid, Embryonal alveolar, pleomorphic or anaplastic)
- Synovial Cell Sarcomas
- Malignant schwannomas
- Alveolar soft-part sarcoma
- Kaposi's Sarcoma
- Gastrointestinal Stromal Tumor (GIST)
- Extraskeletal Ewing 's Sarcoma
- Extraskeletal chondrosarcoma
- Extraskeletal osteosarcoma
- Clear cell sarcoma
- Desmoplastic small round cell tumor
- Undifferentiated pleomorphic high grade sarcoma
- Malignant peripheral nerve sheath tumor
- Desmoid sarcoma
Bone tumors also may occur in both children and adults.
Osteosarcoma is the most common. Classic osteosarcomas are high grade and begin to grow within the bone. They often start in the ends of the bones, where new bone tissue forms as a young person grows. While bones in the thigh, upper arm and shin are the most common site, osteosarcoma can occur anywhere in the body. It often develops during the period of rapid growth during adolescence, when a teenager matures into an adult. The average age at diagnosis is 15 years. Boys and girls have a similar incidence of this tumor until late adolescence, at which time boys are more commonly affected. Osteosarcoma cells can be many different shapes and sizes. Only rarely does osteosarcoma run in families. A defective tumor suppressor gene (which allows tumors to grow) has been linked to an increased risk of this disease and is also associated with familial retinoblastoma, a childhood cancer of the eye. Children with familial retinoblastoma have a high risk for osteosarcoma in adolescence.
Osteosarcomas have less than a five percent chance of recurring in the original location of the disease after surgical resection. It is most common for an osteosarcoma to metastasize (spread) to the lungs. Less commonly, osteosarcoma can spread to other bones.
There are several subtypes of osteosarcomas that vary in appearance under the microscope or in their rate of growth or likelihood of metastasis. Surface osteosarcomas include parosteal, periosteal, and high grade surface osteosarcomas. Parosteal osteosarcomas are low grade and grow on the surface of the bone. These tumors are easily removed by surgery but it is important to be sure the entire tumor is removed as these cancers have a high chance of recurrence if not removed properly. Periosteal osteosarcomas are very rare and also occur on the surface of the bone.
A telangiectatic osteosarcoma is a high grade osteosarcoma that is filled with large blood-filled spaces and has a different appearance on X-rays and under the microscope.
Ewing's sarcoma is the second-most common cancerous bone tumor affecting children and young adults. It was first described by Dr. James Ewing in the 1920s. Ewing's sarcoma may arise anywhere in the body but usually originate in the long bones of arms and legs, the pelvis or the chest. Though more rare, it may also develop in the skull or flat bones of the trunk. While it is most often a bone tumor, Ewing's sarcoma can develop in the soft tissue near bones as well. Under the microscope, Ewing's sarcoma is characterized by small, round, blue cells. Primitive neuroectodermal tumors (PNET) are very rare molecularly-related tumors that often arise outside of the bone and are treated the same as Ewing's sarcoma. While Ewing's sarcoma can occur anytime during childhood, it most commonly develops during puberty when bones are growing rapidly.
Chondrosarcoma is the most common bone tumor in adults. It occurs most often in the pelvis but can grow in any bone, usually in people ages 50 and older.
Types of Bone Tumors
Experts with the Johns Hopkins Sarcoma Program are experienced in managing all types of bone tumors, including:
- Clear Cell Chondrosarcoma
- Classic Osteosarcoma
- Ewing's sarcoma of bone
- Giant cell tumor of bone
- High-Grade Surface Osteosarcoma
- Intraosseous Osteosarcoma
- Malignant fibrous histiocytoma
- Mesenchymal Chondrosarcoma
- Neurofibroma of bone (schwannoma)
- Paget's disease / Pagetoid osteosarcoma
- Periosteal Osteosarcoma
- Periosteal Chondroma
- Periosteal Osteosarcoma
- Peripheral neuroectodermal tumor (PNET)
- Primitive neuroectodermal tumor of bone
- Small Cell Osteosarcoma
- Telangiectatic Osteosarcoma