Sarcoma at a glance
- Sarcoma is a relatively rare type of cancer, which is the uncontrollable growth of cells that develop in bones or soft tissues, including cartilage, fat, muscle, blood vessels, fibrous tissue, or other connective or supportive tissue.
- The two main types of sarcoma are soft tissue sarcomas, accounting for about 1% of all adult cancers, and bone sarcomas, which are more common in children and represent about 15% of all childhood cancers.
- In most cases, there are no known causes of sarcomas, although there are several factors that could increase an individual’s risk of developing a sarcoma.
- Soft tissue sarcomas often present no symptoms in the early stages but symptoms can be pain or a lump; the primary symptom of bone sarcomas is pain, possibly with a lump.
- Testing for a sarcoma can involve an exam, imaging like X-rays or MRI, and lab tests.
- Sarcoma is most commonly treated with surgery, radiation and chemotherapy.
What is sarcoma?
A sarcoma is a rare cancer that develops in the mesenchymal cells of the body, which are in the bones and soft tissues. Sarcomas are essentially tumors, and they can be benign (noncancerous) or malignant (cancerous).
Soft tissues include fat, muscles, blood vessels, nerves, deep skin tissues, and fibrous tissue such as ligaments and tendons. The two main types of sarcoma are soft tissue sarcomas, which are more common in adults, and bone sarcomas, which are more common among children.
Sarcomas can develop in any part of the body because bones and soft tissues are located everywhere. The American Cancer Society estimates that about 13,460 new soft tissue sarcomas will be diagnosed (7,720 in males and 5,740 in females) in 2021. Bone sarcomas account for less than 0.2% of all cancers, and it’s estimated that 3,610 cases will occur in the United States in 2021.
Within the bone sarcoma and soft tissue sarcoma groups are over 75 specific subtypes.
Rewriting The Cancer Story
Soft tissue sarcomas
Soft tissue sarcomas begin in the soft tissues of the body and are most commonly found in the abdomen, chest, legs or arms, but can occur anywhere in the body. Soft tissue tumors can develop in children and adults but are more common in adults. There are many types of soft tissue sarcomas. The three most common types follow.
Undifferentiated pleomorphic sarcoma
This can begin in the bone as well as soft tissue and usually occurs in the arms, legs or at the back of the abdomen.
This sarcoma occurs in fatty tissue anywhere in the body, but most commonly in the thigh, abdomen and the back of the knee.
This type grows in the smooth muscles of hollow organs like the stomach, bladder, blood vessels, intestines and uterus.
Primary bone sarcoma is cancer that begins in the bone, and most commonly occurs in children. Cancer that is spread to bone is not referred to by oncologists as bone cancer. Rather, the bone may be the site of metastasis (spread) for a cancer that began in another organ. Bone sarcomas most commonly occur in children, but anyone can get this cancer. There are many types of bone sarcomas.
This is the most common type of bone sarcoma, occurring more commonly in children, teens and young adults. In these younger people, osteosarcoma usually begins in bones growing quickly, which are the ends of the arm bones and leg bones, with the knee being the most common area. Osteosarcoma also affects older people, more often in the shoulder, hips and jaw.
Chondrosarcomas are the second most common type of bone sarcomas and occur in cartilage cells, most commonly in the hips, legs and arms. This is relatively rare in people under age 20, and the risk for it in adults increases with age. Chondrosarcomas are graded from level I to level III; most are levels I or II, which are less likely to spread.
Also called Ewing tumor, this bone sarcoma occurs most often in children through young adults. Cases after age 30 are rare. Common sites are the hips, bones in the chest wall, the long leg bones and bones in the spine. Though primarily beginning in the bones, Ewing sarcoma can also begin in organs and other tissues.
Sarcoma causes & risk factors
In most cases, sarcomas do not have a known cause. Sarcomas tend to occur infrequently, for no apparent reason and with little or no family history. There are several factors that could increase a person’s risk of developing a sarcoma. The most common soft tissue sarcoma risk factors according to the American Cancer Society include the following:
- High amounts of radiation
- Chemical exposure
- Genetic disorders
- Lymphedema, swelling caused by lymph fluid build-up after cancer or its treatment
Risk factors for osteosarcoma are being age 10-30, being tall as a child, being a male, radiation to bones and bone diseases. Ewing sarcoma risk factors are being male, being white, and being an older child or a teen. Risk factors for other forms of bone sarcoma are inherited, benign bone tumors and previous radiation.
Currently, there’s no known way to prevent sarcomas, and injury and lifestyle factors such as smoking, diet and exercise are not related to the risk for soft tissue sarcoma. The best way to prevent some sarcomas is to avoid exposure to radiation and chemicals.
Some sarcomas may not cause any symptoms until they grow and press on nearby nerves, organs or muscles. Symptoms of soft tissue sarcomas can include a painless lump or swelling.
If a tumor does develop that affects local tissues, nerves or muscles, an individual may notice pain in that area. Specific symptoms can also depend on the location of the sarcoma. For example, a sarcoma tumor in the uterus can cause uterine bleeding or a growth in the size of the uterus; tumors that start in the heart or a lung may cause pain in the chest or breathing problems.
The first symptom of bone sarcoma can be pain, sometimes with a lump present. Symptoms often occur in the arms, legs or pelvis, with symptoms in the pelvis often not showing until the later stages of the cancer.
Testing for sarcoma can include a medical history to understand any risk factors and a physical exam in order for the doctor to look for clues indicating sarcoma and evaluate any symptoms. Imaging tests can also be done such as X-rays, CT scans or MRIs to help locate the cancer, conclude how far it has spread and to check on effectiveness of treatment.
Lab tests may also be done if sarcoma is the consensus after exams and imaging tests. Biopsies are the primary procedure, in which a piece of tissue from the tumor is removed so that it can be looked at under a microscope for cancer cells, as well as identification of the type of sarcoma.
Treatment can vary depending on where the sarcoma is located, the size, grade and stage of the tumor, along with how fast the cancer cells are growing. The patient’s age, preferences and overall health are also factors in treatment options.
Treatments can involve various types of oncologists including medical, radiation, pediatric and surgical. Orthopedic surgeons and other members of a multidisciplinary team may also be involved in the patient’s treatment plan.
The primary method of treatment for sarcoma is surgery, which aims to remove the tumor and often the surrounding tissue. A biopsy to identify the exact type of sarcoma generally takes place at the time of surgery.
Radiation therapy uses high-energy rays or particles to kill cancer cells. Radiation therapy may be done before surgery to diminish the tumor so that it may be more easily removed. Often radiation is given after surgery to kill any cancer cells that remain. It’s an essential part of soft tissue sarcoma treatment.
Chemotherapy for sarcomas is the use of medications to destroy or to slow the growth of rapidly multiplying cancer cells that are left behind after surgery. This type of medication is given through the bloodstream to reach cancer cells all over the body. Chemotherapy maybe given with radiation before surgery or following surgery, depending on the risk of recurrence.
Targeted drug therapy
Targeted therapy drugs invade the parts of cancer cells that make them different from normal, healthy cells. Although these drugs work differently from standard chemotherapy drugs, all of them are similar in that they affect the way a cancer cell grows, divides, repairs itself or connects with other cells. Targeted therapy is based on analysis of an individual tumor. Targeted therapy is initiated by the medical oncologist if a molecular target is identified and if such a treatment is appropriate.
Side effects vary according to the treatment. The oncologist and treatment team will discuss potential side effects specific to the treatment that is proposed.
Living with sarcoma cancers
According to the American Cancer Society, with soft tissue sarcomas, the chance of surviving at least five more years after diagnosis is 81% if the cancer is localized. For bone sarcomas, the average five-year survival rate for localized cancer is 77%.