Bone cancer

 Definition

 

Bone cancer is a tumor that originates in the bone, thus destroying the normal bone tissue. Bone cancers account for less than 0.2% of all cancers. Depending on the bone tissue affected, bone cancer can be of the following types:

1. Osteosarcoma -- arises from the bony tissue

2. Chondrosarcoma -- arises from the cartilaginous tissue

3. Ewing’s tumor or Ewing’s sarcoma -- arises from bone tissue but can begin in other tissues and organs.

The most common sites are the pelvis, the chest wall, and the long bones of the legs or arms.

 

 

The exact cause of most of the bone cancers is not known. Following are the factors that can increase the risk:

1. Genetic disorder: Having inherited genetic syndromes like Li-Fraumeni syndrome, hereditary retinoblastoma, and Rothmund-Thomson syndrome which can increase the risk of suffering from bone cancer

2. Paget’s disease: This is a benign (non-cancerous), but precancerous condition affecting one or many bones

3. Radiation: Exposure to large doses of radiation (like those given as therapy for cancer), increases the risk of developing bone cancer later in life.

 

 

Early symptoms include: 

Pain in the affected bone is the commonest symptom of bone cancer. In the beginning pain is not constant, may be worse at night or when that part of the body is being used, but as the disease progresses the pain becomes constant.

Late symptoms include:

1. Swelling: Swelling in the area of the pain can be seen after few weeks.

2. Fractures: Bone cancer weakens the affected bone causing easy fractures of affected bones despite minimal and sometimes no force or injury.

3. Fatigue

4. Unexplained weight loss

 

 

After performing the physical examination and taking into consideration the history provided by the patient, the doctor may get the following tests done:

1. Blood tests: Serum alkaline phosphatase levels are raised in case of bone cancer.

2. Imaging studies: Imaging tests like x-ray, bone scan, MRI (magnetic resonance imaging), CT (computed tomography) scans, and PET (positron emission tomography) are done to determine the extent of bone cancer.

3. Biopsy: A tissue sample is obtained from the affected bone to look for cancer cells.

 

 

Treatment options vary according to the type, size, site, and stage of cancer; the person’s age and general health also play an important role. Following are the treatment options:

1. Surgery: Surgical removal of the entire bone tumor is the main line of treatment for bone cancer.

2. Chemotherapy: A combination of anticancer drugs like cyclophosphamide is used to kill malignant cells.

3. Radiation therapy: High-energy x-rays are used during this therapy to destroy malignant cells. This therapy can be used along with surgery for better results.

4. Cryosurgery: This technique uses liquid nitrogen to freeze and kill cancer cells and can be used sometimes to destroy the tumor instead of conventional surgical removal.

 

 

Bone cancer may lead to:

1. Increased blood calcium (hypercalcemia): Symptoms include constipation, psychotic episodes, and kidney stones.

2. Osteomyelitis: Patients undergoing treatment for bone cancer are at increased risk of contracting bone infection, thus causing fever, chills, and pain.

3. Metastasis: cancer can spread to other parts of patient’s body.

A doctor should be consulted in case of following cases:

1. Continuous bone pain

2. Swelling around the area of pain

3. Fatigue with unexplained weight loss

 

 

Prognosis depends on age, sex, the overall health of the patient, extent of cancer, and its spread to other parts of the body. With proper treatment, about 70% of patients suffering from any type of bone cancer survive up to 5 years after the diagnosis is made. Till date, there is no known way to prevent bone cancer.