(Osteosarcoma; Chondrosarcoma; Ewing’s Sarcoma; Fibrosarcoma; Malignant Fibrous Histiocytoma; Primary Lymphoma of Bone; Giant Cell Tumor; Chordoma)
Bone cancer – Definition
Bone cancer is a relatively rare disease in which cancer cells grow in the bone tissue. Cancer occurs when cells in the body (in this case bone cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and spread to other parts of the body. A benign tumor does not invade or spread.
Cancer may form in the bone or spread to the bone from another site in the body. When cancer starts in bone tissue, it is called primary bone cancer. When cancer cells travel to the bone from elsewhere, it is called secondary or metastatic cancer to the bone. Types of bone cancer include:
- Osteosarcoma — a cancerous tumor of the bone, usually of the arms, legs, or pelvis; the most common primary cancer.
- Chondrosarcoma — cancer of the cartilage; the second most common primary cancer.
- Ewing’s sarcoma — tumors that usually develop in the cavity of the leg and arm bones
- Fibrosarcoma and malignant fibrous histiocytoma — cancers that develop in soft tissues (eg, tendons, ligaments, fat, muscle) and move to the bones of the legs, arms, and jaw
- Giant cell tumor — a primary bone tumor that is malignant (cancerous) only about 10% of the time; most common in the arm or leg bones
- Chordoma — primary bone tumor that usually occurs in the skull or spine
The sooner bone cancer is treated, the more favorable the outcome. If you suspect you have this condition, contact your doctor immediately.
Bone cancer – Causes
The cause of primary bone cancer is unknown. Genetics play a major role in most cases. Conditions that cause increased bone breakdown and regeneration over an extended period of time increase the risk of tumor development. This explains why osteosarcoma in children is most common during the adolescent growth spurt.
Bone cancer – Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
The following factors increase your chance of developing bone cancer:
- Paget’s disease (a noncancerous bone condition)
- Exposure to radiation
- Injury to a bone (not yet been confirmed as a risk factor)
- Family history of bone cancer
In addition, the following are risk factors specific to certain types of bone cancer:
- Age: 10-30 years old
- Sex: male
- Inherited cancer syndromes, including Li-Fraumani and Rothmund-Thompson syndromes
- Retinoblastoma (a rare eye cancer)
- Bone marrow transplantation
- Age: older than 20
- Multiple exostoses (an inherited condition that results in bumps on bones)
- Ewing’s sarcoma:
- Age: younger than 30
- Fibrosarcoma and malignant fibrous histiocytoma:
- Age: middle-aged and elderly
- Giant cell tumor:
- Age: young and middle-aged
Bone cancer – Symptoms
Symptoms of bone cancer vary, depending on the location and size of the tumor.
Symptoms may include:
- Pain at the tumor location
- Swelling or a lump at the location of the tumor
- Deep bone pain severe enough to wake you up
- Bone fractures (rarely)
- Unexplained weight loss
- Trouble breathing
- Fever or night sweats
These symptoms may also be caused by other, less serious health conditions. Anyone experiencing these symptoms should see a doctor.
Bone cancer – Diagnosis
The doctor will ask about symptoms and medical history. A physical exam will be performed.
Tests may include the following:
- Blood test — to check the level of the enzyme alkaline phosphatase; An increased amount of this enzyme is released in patients with bone tumors and when healthy children are growing.
- X-ray — a test that uses radiation to take a picture of structures inside the body, especially bones
- Bone scan — a test that looks for evidence of bone tumors. A radioactive substance injected into the bloodstream is absorbed by bone tissue, and is then tracked by the bone scan.
- CT scan — a type of x-ray that uses a computer to make pictures of structures inside of the body
- MRI scan — a test that uses magnetic waves to make pictures of structures inside of the body
- Biopsy — removal of a sample of bone tissue to test for cancer cells. Excisional (removing the tumor) biopsy for bone tumors may mean excision of a considerable portion of the involved bone or limb, and occasionally, partial or complete amputation of the extremity depending on the location and type of tumor.
Bone cancer – Treatment
Once cancer is found, staging tests are performed to find out if the cancer has spread and, if so, to what extent. Treatment depends on the type, stage, and location of the cancer, and your overall health. Talk with your doctor about the best treatment plan for you. Treatment options include:
Radiation therapy for bone cancer uses radiation to kill cancer cells and shrink tumors. Radiation may be:
- External radiation therapy — radiation directed at the tumor from a source outside the body
- Internal radiation therapy — radioactive materials placed into the body near the cancer cells
Bone cancer – Chemotherapy
Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be given in many forms, including: pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body, killing mostly cancer cells, but also some healthy cells. The most common chemotherapy drugs used to treat bone cancer include:
- Methotrexate with calcium
Surgery for bone cancer involves the removal of a cancerous tumor, nearby tissues, and possible nearby lymph nodes. Surgery may require amputation of the limb with cancer. Whenever possible, doctors try to remove the cancerous part of the bone without amputating. In this case, metal plates or a bone graft replace the cancerous tissue that has been removed.
Sometimes, adding radiation therapy or chemotherapy can help avoid the need for amputation. If the tumor is large or aggressive, or the risk of spread is high, chemotherapy and radiation therapy may be added to help prevent a recurrence at the site of surgery. This is also done to prevent spread to distant organs.
Myeloablative Therapy With Stem Cell Support
For cancer that has spread, intense chemotherapy is sometimes given to kill cancer cells. This therapy also destroys the bone marrow. Stem cells, which have the ability to develop into other types of cells, are then given to replace the lost bone marrow.
Special Treatment Considerations for Certain Cancer Types
- Osteosarcoma — Chemotherapy given before and after surgery will often cure osteosarcoma and can allow for limb-sparing surgery in people who might have otherwise required amputation.
- Ewing’s sarcoma — Since Ewing’s sarcoma is very responsive to chemotherapy, its treatment often involves several weeks of chemotherapy followed by surgical removal or radiation therapy, then several more months of chemotherapy.
- Fibrosarcoma and malignant fibrous histiocytoma — These conditions are usually treated with surgery to remove the cancerous tumor and a one-inch margin of healthy tissue surrounding it.
Bone cancer – Prevention
There are no guidelines for preventing primary bone cancer. Early diagnosis and treatment improve your chance of successful treatment.