The world knows Terry Fox. But few know that the disease which claimed Fox’s life was osteosarcoma, a form of sarcoma cancer. Since Fox's heroic battle with cancer in 1981, much progress has been made in treating and curing this insidious disease.
A sarcoma is a malignant tumor that develops from particular tissues, such as muscle or bone. There are two types of sarcoma: osteosarcoma and soft tissue sarcoma.
Soft tissue sarcoma affects nerves, muscles, joints, fat and blood vessels - the body’s “connective tissues.” There are more than 50 kinds of soft tissue sarcomas, but more than half start in the arms or legs.
Due to the fact that the tissues affected can be found anywhere on the body, soft tissue sarcoma does not target one particular area of the body. Depending on the type of tissue from where it originated, the sarcoma has a different name. For instance, leiomyosarcoma develops in smooth muscle, osteosarcoma originates in the bone, and liposarcoma originates in fat cells.
Bone cancers can be divided into the following three groups:
Osteosarcoma - often seen in children and young adults (ages 10-25). Treatment usually involves chemotherapy and surgery. Chemotherapy is given in the sarcoma unit on an inpatient basis. Surgery usually involves a limb salvage/sparing procedure. Occasionally amputation is required but this is very rare nowadays, approximately 5% of the time.
Chondrosarcoma - most frequently seen in adults over the age of 50. This type of tumor arises in the cartilage. Treatment usually involves surgical removal.
Ewings Sarcoma - most often found in the middle part of the bones such as the pelvis and lower extremities. Seen primarily in children and young adults (age 10-25). Treatment usually involves chemotherapy and surgery. Occasionally radiation may be included in the treatment.
About 43 percent of sarcoma cancers 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); 13 percent occur in other locations. In very rare cases, these tumors develop in the gastrointestinal tract.
Smooth muscle, deep soft tissue – Lungs, brain, lower & upper extremities
Blood or lymph vessels – Skin, breast, liver, spleen, and deep tissue
Bones and joints – Arms, legs, pelvis
Fibrous tissue (tendons and ligaments) in the limbs – Feet, hands, and gastrointestinal tract
Cells that wrap and grow into fat, muscle, and bone – Trunk
No obvious related normal tissue – Arms, legs, trunk
Localized round tumor of cells – Abdomen
Deep soft tissue – Hands, forearms
No obvious related normal tissue; may be a tumor of stem cells – Pelvis & large, long bones; thigh, knee, shoulder
Smooth muscle, deep soft tissue – Arms, legs
Smooth muscle, deep soft tissue – Gastrointestinal tract
Smooth muscle, deep soft tissue – Skin, mouth
Smooth muscle, deep soft tissue – Uterus, stomach, small intestine
Smooth muscle, deep soft tissue – Arms, legs, trunk
Smooth muscle, deep soft tissue – Arms, legs
Smooth muscle, deep soft tissue – Lungs, brain, lower & upper extremities
Smooth muscle, deep soft tissue – Thigh, knee, shoulder
Smooth muscle, deep soft tissue – Arms, legs, trunk, neck
Smooth muscle, deep soft tissue – Arms, legs
Smooth muscle, deep soft tissue – Legs
*Desmoid tumors are not considered sarcomas; however, they have been classified as aggressive fibromatosis, and the optimal treatment plan usually requires multidisciplinary teams only found in sarcoma centers.
The list above is not complete, but several of the most common types are listed. Experts have found many types and subtypes of sarcomas. Pathologists (doctors who specialize in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease) are now trying to find new ways to quickly determine a tumor's subtype, as this helps determine treatment. Looking at a tumor's abnormal genetics may help determine its characteristics and predict which treatments will be most effective.
Sarcomas are rare and account for less than 1% of all new cancer cases. Sarcomas affect people of all ages, although they are most often observed in children and young adults. In addition, certain types of sarcomas are most common for specific age groups. For example, soft-tissue sarcomas account for about 7% of all cancers in children, and liposarcomas are most often found in adults between 30 and 60 years old.
In their early stages, soft tissue and bone sarcomas rarely display any symptoms. Because soft tissue is very elastic, tumors can grow quite large before they are felt. Common symptoms include:
Lump or mass: The first symptom is usually a lump or mass. The lump will form in the area in which the tumor is growing, and there may be some pain if it is pressing on a nerve or muscle. Even if the lump isn’t painful, if it continues to grow in size, or if it is located deep within an extremity or body cavity, consult your doctor.
Uncomfortable swelling: This is another sign of a sarcoma, especially when it is located in the arms and legs. Some tumors can restrict motion, such as those found in the hip, knee, shoulder or hands. Some sarcomas, such as osteosarcoma, may first present itself as joint pain that gets noticeably worse.
Skin lesions: can occur when a sarcoma tumor breaks through the skin.
Due to the nature of sarcoma and its ability to form almost anywhere in the body, other symptoms may be a sign, and can therefore affect a variety of organs. For example, sarcomas in the abdomen may cause abdominal pain, vomiting or constipation, while sarcomas in the uterus may cause vaginal bleeding and/or abdominal pain. With gastrointestinal stromal tumors (GISTs), you may feel full after eating only very small meals, or you may vomit blood or have dark bowel movements.
Most sarcomas develop in people with no known risk factors, however identified risk factors include genetic conditions such as absence of the retinoblastoma. Other risk factors include chromosomal alterations and, rarely, radiation exposure, especially in childhood. According to the American Cancer Society, radiation exposure accounts for less than 5% of sarcomas. Exposure to vinyl chloride and arsenic are linked to development of liver sarcoma.
There are currently no screening tests for sarcoma, so it is important to know if you have a family history of sarcoma or any of the conditions listed above. If so, you may want to ask your healthcare provider about genetic testing.
If you have symptoms or other reasons that suggest you may have a sarcoma, your doctor will use one or more methods to find out if the disease is present, including reviewing your complete medical history to check for risk factors, and to ask you about symptoms, as well as any other medical conditions. They will also examine you for signs of sarcomas and other health problems.
A biopsy is a sample of tissue removed from a tumor and tested in order to determine if cancer is present. A physical exam may suggest that a tumor is a sarcoma, but a biopsy is the only way to be certain that it is a sarcoma and not another type of cancer or a benign disease. Several types of biopsies are used to diagnose sarcomas. Doctors with experience in these tumors will choose one, based on the size and location of the tumor. Most experts prefer a fine needle aspiration or a core needle biopsy as the first step.
This test may be done to determine if the sarcoma has spread to your lungs.
CT Scans and MRIs
The computed tomography (CT) scan is an x-ray procedure that produces detailed, cross-sectional images of your body. Instead of taking one picture like a conventional x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body. The machine will create multiple images of the part of your body that is being studied. A CT scan is often done if the doctor suspects a soft tissue sarcoma in the chest, abdomen, or the retroperitoneum. This test is also used to see if the sarcoma has spread into the liver or other organs.
MRI scans are often part of the work-up of any tumor that could be a sarcoma. They are often better than CT scans in evaluating sarcomas in the arms or legs. They provide a good picture of the extent of the tumor. They can tell your health care team many things about the tumor, including location, size, and sometimes even the type of tissue it comes from (like fat or muscle). This makes MRI scans useful in planning a biopsy.
Ultrasound uses sound waves and their echoes to produce pictures of parts of the body. A small instrument called a transducer emits sound waves and picks up the echoes as they bounce off the organs. The sound wave echoes are converted by a computer into an image that is displayed on a computer screen. This test may be done before a biopsy to see if the lump is a cyst, meaning it contains fluid and is likely benign, or if it is solid and more likely a tumor. This test is often not needed if an MRI was done.
Here are some questions you may want to ask your doctor:
- How can this disease be treated?
- What are my treatment choices?
- Which treatment do you recommend? Why?
- How successful is the treatment likely to be?
- Would a clinical trial be appropriate for me?
- What are the expected benefits of treatment?
- What are the risks and possible side effects of treatment?
- What can be done to help manage side effects?
- Who will do the treatment?
- When will the treatment begin? Is there a waiting list for treatment?
- Where will the treatment be given? Does this treatment require a hospital stay?
- How is the treatment given?
- What will I have to do to prepare for treatment?
- What might happen without treatment?
- Will I have to change my normal activities?
- Can I keep working during treatment?
- How often will I need checkups?
Your doctor is the best person to give advice about your ability to work or to answer questions about other activities. Many patients find it also helps to talk with others who are facing similar problems. This kind of help is available through cancer-related support groups. Social services, clergy, nursing personnel or your doctor can offer suggestions as to where to seek assistance with emotional support.
Because sarcomas are rare, it is important to find physicians and multidisciplinary treatment centers that have experience with this disease.
You will hear a lot about the risk factors for survival from sarcoma. These are mainly:
- The location of the tumor.
- The size of the tumor.
- Whether it has spread to other parts of the body.
- The special characteristics of the tumor that can only be determined after biopsy.
- The “grade,” which is an important term you will hear about during the pathological analysis.
Your doctors will plan your treatment taking into account:
- The type of sarcoma you have
- How far your cancer has grown or spread (the ' stage')
- Your general health and fitness
- Your age
- What you prefer or want
Cancer treatments can be divided into local and systemic treatments. Surgery and radiotherapy are local treatments. They treat just one area of the body. Systemic treatments are carried in the bloodstream and can reach cancer cells wherever they are in the body, not just at the original tumour site. Chemotherapy and biological therapies are systemic treatments.
The care and treatment is often done by a healthcare team that is experienced in dealing with sarcomas. Most cases need to be managed by many specialists, including a radiologist, surgeon, medical oncologist, and radiation oncologist.
Surgery is the main treatment for most sarcomas. The surgeon's goal is to remove the tumor and enough normal tissue around it to leave behind what is called a “clean margin” (meaning there are no tumor cells left in the area where the tumor was removed). Small sarcomas can usually be effectively eliminated by surgery alone. Those larger than 5 cm are often treated with a combination of surgery and radiation therapy. Radiation therapy or chemotherapy may be used before surgery (to shrink the tumor and make removal easier), or during and after surgery (to kill any remaining cancer cells). Depending on the size and location of the tumour, you may have one or more of the following types of surgery:
Wide local excision - removes the cancer along with some normal tissue around it. It is used to treat soft tissue sarcoma that is only in the area where it started (localized). It may also be used for soft tissue sarcoma that has come back in the area where it started (local recurrence).
Limb-sparing surgery - removes a tumour from an arm or a leg (a limb) without removing the whole arm or leg. It is used to treat soft tissue sarcoma that is only in an arm or a leg and hasn't spread anywhere else in the body.
Moahs surgery - removes the cancer in layers, little by little, until no cancer remains. It may be used for soft tissue sarcoma that can be seen near the surface of the skin.
Reconstructive surgery - repairs the skin and nearby area after the tumour is removed. When a large area has been removed to make sure the cancer is completely gone, the doctor rebuilds the area using a piece of tissue from another part of the body.
Amputation - removes all or part of a limb. It is not usually done for soft tissue sarcoma. Amputation may be necessary is the cancer has grown into certain nerves, blood vessels and muscles so the limb won't work properly or if there will be many long-term problems after surgery.
Lymph node dissection - removes a group of lymph nodes from the body. It may be done for soft tissue sarcoma that has spread to nearby lymph nodes.
Surgery for long metastases - may be done to remove the metastatic soft tissue sarcoma that has spread to only one area or a few areas in the lungs.
Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy. A radiation therapy regimen (schedule) usually consists of a specific number of treatments given over a set period of time.
Radiation therapy may be done before surgery to shrink the tumor so it is more easily removed. Or, it may be done after surgery to remove any cancer cells left behind. Radiation treatment may make it possible to do less surgery, often preserving the arm or leg if that is where the sarcoma is located. Radiation therapy can also damage normal cells, but because it is focused around the tumor, side effects are usually limited to those areas.
In the short term, radiation can cause injury to the skin that looks like a sunburn and is usually treated with creams that keep the skin soft and helps relieve pain. In the long term, radiation can cause scarring that limits the function of an arm or a leg. In rare cases, radiation can cause a sarcoma or other cancer. Each person is encouraged to talk with his or her doctor about the possible risks and benefits of a specific treatment such as radiation therapy.
Most radiation therapy side effects go away soon after treatment ends. Newer radiation techniques, including intensity modulated radiation therapy, stereotactic body radiation, and proton beam radiation may help control sarcoma and cause fewer short-term and long-term side effects.
Chemotherapy is the use of drugs to kill cancer cells, usually by stopping the cancer cells’ ability to grow and divide. Systemic chemotherapy is delivered through the bloodstream to reach cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. A chemotherapy regimen usually consists of a specific number of cycles given over a set period of time. Most chemotherapy drugs are given by injection into a vein (called intravenous or IV injection). A patient may receive one drug at a time or combinations of different drugs at the same time. Different drugs are used to treat different types and subtypes of sarcoma. Chemotherapy for sarcoma can usually be given as an outpatient treatment.
Chemotherapy is often used when a sarcoma has already spread. In addition, certain types of sarcoma might be treated with chemotherapy before surgery to more easily remove the tumor with surgery. Chemotherapy may be given alone or in combination with surgery and/or radiation therapy. Chemotherapy given before surgery may be called by different names, including preoperative chemotherapy, neoadjuvant chemotherapy, or induction chemotherapy.
If a patient has not received chemotherapy before surgery, chemotherapy may be given to destroy any microscopic tumor cells that remain after a patient has recovered from surgery. Chemotherapy given after surgery is called adjuvant chemotherapy or postoperative chemotherapy.
Side effects vary depending on the drug and the dose. Talk with your doctor about the potential side effects, how long they may last, and how they can be relieved. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications.
Targeted therapy is a treatment that targets the cancer’s specific proteins or the tissue environment that contributes to cancer growth and survival, usually by blocking the action of proteins in cells called kinases. This type of treatment blocks the growth and spread of cancer cells while limiting damage to normal cells.
Recent studies show that not all tumors have the same targets (kinases). To find the most effective
treatment, your doctor may run tests to identify the genes, proteins, and other factors in your tumor. As
a result, doctors can better match each patient with the most effective treatment whenever possible. In
addition, many research studies are taking place now to find out more about specific molecular targets
and new treatments directed at them.