• What is bone cancer?
• What are the symptoms of bone cancer?
• How is bone cancer diagnosed?
• How is bone cancer treated?
• What are the side effects of treatment for bone cancer?
• What does the future hold for patients with bone cancer?

What is bone cancer?

Cancer begins in cells, the building blocks that form tissues. Tissues make up theorgans of the body.
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place.
Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor. The cells also become abnormal and have altered functions in patients with cancer.
Bone cancer is caused by a problem with the cells that make bone. More than 9,500 people are diagnosed in the India each year with a bone tumor. Bone tumors occur most commonly in children and adolescents and are less common in older adults. Cancer involving the bone in older adults is most commonly the result of metastatic spread from another tumor.

Common types of bone cancer
There are many different types of bone cancer. The most common bone tumors include

• Osteosarcoma is the most common primary malignant bone cancer. It most commonly affects males between 10 and 25 years old, but can less commonly affect older adults. It often occurs in the long bones of the arms and legs at areas of rapid growth around the knees and shoulders of children. This type of cancer is often very aggressive with risk of spread to the lungs.
• Ewing's sarcoma is the most aggressive bone tumor and affects younger people between 4-15 years of age. It is more common in males and is very rare in people over 30 years old. It most commonly occurs in the middle of the long bones of the arms and legs.
• Chondrosarcoma is the second most common bone tumor and accounts for about 25% of all malignant bone tumors. These tumors arise from the cartilage cells and can either be very aggressive or relatively slow-growing. Unlike many other bone tumors, chondrosarcoma is most common in people over 40 years old. It is slightly more common in males and can potentially spread to the lungs and lymph nodes. Chondrosracoma most commonly affects the bones of the pelvis and hips.
• Malignant fibrous histiocytoma (MFH) affects the soft tissues including muscle, ligaments, tendons, and fat. It is the most common soft-tissue malignancy in later adult life, usually occurring in people 50-60 years of age. It most commonly affects the extremities and is about twice as common in males as females. MFH also has a wide range of severity.
• Fibrosarcoma is much more rare than the other bone tumors. It is most common in people 35-55 years of age. It most commonly affects the soft tissues of the leg behind the knee. It is slightly more common in males than females.
• Chordoma is a very rare tumor with an average survival of about six years after diagnosis. It occurs in adults over 30 years of age and is about twice as common in males as females. It most commonly affects either the lower or upper end of the spinal column.

There are many types of benign bone tumors. The more common types include

• Non-ossifying fibroma unicameral (simple) bone cyst
• Osteochondroma
• Giant cell tumor
• Enchondroma
• Fibrous dysplasia

What are the symptoms of bone cancer?

The most common symptom of bone tumors is pain. In most cases, the symptoms become gradually more severe with time. Initially, the pain may only be present either at night or with activity. Depending on the growth of the tumor, those affected may have symptoms for weeks, months, or years before seeking medical advice. In some cases, a mass or lump may be felt either on the bone or in the tissues surrounding the bone. The bones can become weakened by the tumor and lead to a fracture after little or no trauma. Fever, chills, night sweats, and weight loss can occur but are less common. These symptoms are more common after spread of the tumor to other tissues in the body.

How is bone cancer diagnosed?

The first thing your doctor will do is to take a complete medical history. This will give your doctor clues as to your diagnosis.. A description of your symptoms can help your doctor identify the possibility of bone cancer from other possible causes. Next, a complete physical examination can help find the cause of your symptoms. This may include testing your muscle strength, sensation to touch, and reflexes. Certain blood tests can be ordered that can help to identify a possible cancer.
Next, your doctor will order some imaging studies. Plain x-rays are often ordered first. In some cases, if the cancer is identified very early it may not show up on plain x-rays. The appearance of a tumor on the x-ray can help determine the type of cancer and whether or not it is benign or malignant..
A CT scan (CAT scan or computed tomography) is a more advanced test that can give a cross sectional picture of your bones. This test gives very good detail of your bones and is better able to identify a possible tumor. It also gives additional information on the size and location of the tumor.
An MRI (magnetic resonance imaging) is another advanced test that can also provide cross sectional imaging of your body. The MRI provides better detail of the soft tissues including muscles, tendons, ligaments, nerves, and blood vessels than a CT scan. This test can give better detail on whether or not the bone tumor has broken through the bone and involved the surrounding soft tissues.
A bone scan is a test that identifies areas of rapidly growing or remodeling bone. The bone scan is often taken of the entire body. This test may be ordered to see if there are any other areas of bone involvement throughout the body.
If a tumor is identified, your doctor will use all of the information from the history and physical examination along with the laboratory and imaging studies to put together a list of possible causes (differential diagnosis).

Tests

Blood tests and/or urine tests may be done. A biopsy is another test. A biopsy removes a sample of tissue from the tumor. The tissue sample is examined under a microscope.
There are two basic methods of doing a biopsy.

Needle Biopsy

The doctor inserts a needle into the tumor to remove some tissue. This may be done in the doctor's office using local anesthesia. A radiologist may do a needle biopsy, using some type of imaging, such as an X-ray, CT, or MRI to help direct the needle to the tumor.

Open Biopsy

The doctor surgically removes tissue. This is generally done in an operating room. The patient is given general anesthesia and a small incision is made and the tissue is removed

How is bone cancer treated?

There are many different methods available for your doctor to treat bone cancer. The best treatment is based on the type of bone cancer, the location of the cancer, how aggressive the cancer is, and whether or not the cancer has invaded surrounding or distant tissues (metastasized).
There are three main types of treatment for bone cancer:

• surgery,
• chemotherapy, and
• radiation therapy.

These can be used either individually or combined with each other.
Surgery is often used to treat bone cancer. The goal of surgery is usually to remove the entire tumor and a surrounding area of normal bone. After the tumor has been removed, a pathologist examines it to determine if there is normal bone completely surrounding the tumor.. Historically, amputations were frequently used to remove bone cancer. Newer techniques have decreased the need for amputation.

Limb Salvage Surgery

This surgery removes the cancerous section of bone but keeps nearby muscles, tendons, nerves, and blood vessels. If possible, the surgeon will take out the tumor and a margin of healthy tissue around it. The excised bone is replaced with a metallic implant (prosthesis) or bone transplant.

Amputation

Amputation removes all or part of an arm or leg when the tumor is large and/or nerves and blood vessels are involved.

You may be referred to a medical oncologist for chemotherapy. This is the use of various medications used to try to stop the growth of the cancer cells. Chemotherapy can be used prior to surgery to try to shrink the bone tumor to make surgery easier. It can also be used after surgery to try to kill any remaining cancer cells left following surgery.
You could also be referred to a radiation oncologist for radiation therapy. The radiation therapy uses high-energy x-ray aimed at the site of the cancer to try to kill the cancer cells. This treatment is given in small doses daily over a period of days to months.

What is osteosarcoma?
Osteosarcoma  is a disease in which cancer (malignant) cells are found in the bone. It is the most common type of bone cancer. Osteosarcoma most often occurs in adolescents and young adults. In children and adolescents, tumors appear most often in the bones around the knee. The symptoms and chance for recovery in children and adolescents appear to be the same.
If a patient has symptoms (such as pain and swelling of a bone or a bone region), a doctor may order x-rays and blood tests. The orthopedic oncologist may cut out a piece of tissue from the affected area. This is called a biopsy. The tissue will be looked at under a microscope to see if there are any cancer cells. This test may be done in the hospital.
The prognosis (chance of recovery) is affected by certain factors before and after treatment.
The prognosis of untreated osteosarcoma depends on the following:

• The location of the tumor.
• The size of the tumor.
• The stage of the cancer(whether it spread from where it started to other places in the body).
• The age of the patient.
• The results of blood tests and other tests.
• The type of tumor (based on how the cancer cells look under a microscope).

After osteosarcoma is treated, prognosis also depends on the following:

• How much of the cancer was killed by chemotherapy; and/or
• How much of the tumor was taken out by surgery.

Treatment options depend on the following:

• The location of the tumor.
• The stage of the cancer.

Whether the cancer has recurred (come back) after treatment.

Stages of osteosarcoma
Once osteosarcoma has been found, more tests may be done to find out if cancer cells have spread to other parts of the body. This is called staging.Most patients are grouped depending on whether cancer is found in only one part of the body (localized disease) or whether the cancer has spread from one part of the body to another (metastatic disease). Your doctor needs to know where the cancer is located and how far the disease has spread to plan treatment.

The following groups are used for osteosarcoma:

Localized osteosarcoma
The cancer cells have not spread beyond the bone or nearby tissue in which the cancer began.

Metastatic osteosarcoma
The cancer cells have spread from the bone in which the cancer began to other parts of the body. The cancer most often spreads to the lungs. It may also spread to other bones. About one in five patients with osteosarcoma has cancer that has metastasized by the time it is diagnosed.

Recurrent Osteosarcoma
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the tissues where it first started or it may come back in another part of the body. Osteosarcoma most often recurs in the lung. When osteosarcoma recurs, it is usually within 2 to 3 years after treatment is completed. Later recurrence is possible, but rare.

• Surgery(taking out the cancer in an operation).
• Chemotherapy (using drugs to kill cancer cells).
• Radiation therapy (using high- dose x-rays to kill cancer cells).

All patients with localized osteosarcoma should have surgery to remove the tumor, if possible. The doctor will remove only the cancer and some of the healthy tissue around the cancer (limb-sparing surgery). When the tumor is in a weight-bearing bone, the bone should be protected during activity to avoid fractures that could prevent limb-sparing surgery. Sometimes all or part of an arm or leg may have to be removed (amputated) to make sure that all of the cancer is taken out
In patients with osteosarcoma that has not spread beyond the bone, researchers have found no difference in overall survival whether patients have limb-sparing surgery or whether they have surgery with amputation. When the cancer can be taken out without amputation, artificial devices or bones from other places in the body can be used to replace the bone that was removed. The process of rebuilding (reconstructing) a part of the body changed by previous surgery is called reconstructive surgery. Options for reconstructive surgery in patients with osteosarcoma depend on many factors, including where the tumor is, how large it is, the age of the patient, and how much the patient will continue to grow.
Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill or put into the body by a needle in a vein . Chemotherapy is called systemic treatment because the drug enters the blood stream, travels through the body, and can kill cancer cells throughout the body. Chemotherapy with more than one drug is called combination chemotherapy.
In Osteosarcoma, surgery is often used to remove the local tumor and chemotherapy is then given to kill any cancer cells that remain in the body. Chemotherapy given after surgery has removed the cancer is called adjuvant chemotherapy. Chemotherapy can also be given before surgery to shrink the cancer so that it can be removed during surgery; this is called neoadjuvant chemotherapy.