Bone cancer

READ IN HINDI

• Types
• Causes
• Symptoms
• Diagnosis
• Treatment

 
 

Bone cancer can arise in any of the bones of the body but it is most commonly seen in the long bones of the arms and legs. It has the ability to attack the body within the first 20 years of life when maximum growth in the musculoskeletal system takes place.

Primary bone cancers originate in the bone tissue. Common types are osteosarcoma, chondrosarcoma and Ewing sarcoma. Other rare bone cancers include fibrosarcoma, leiomyosarcoma, malignant fibrous histiocytoma, angiosarcoma and chordoma. Secondary bone cancer occurs when cancer cells from other parts of the body migrate to the bone tissue. High dose radiotherapy, Paget’s disease, rare inherited genetic disorders such as Li-Fraumeni syndrome, hereditary multiple exostoses (HME) and hereditary retinoblastoma increase the chances of developing primary bone cancers.

Types

There are different types of cancers identified by the organ or tissue that it originates from. As the name suggests, bone cancer simply means cancer that originates in the bone. Bone cancer can arise in any of the bones of the body but it is most commonly seen in the long bones of the arms and legs. They are broadly classified into

• Primary bone cancers: Bone cancer that originates in the bone tissue is categorized as primary bone cancer. Primary bone cancers may spread to other parts of the body (malignant) or may develop as localized tumors (benign).
• Secondary bone cancers: Bone cancer resulting from cancer cells that migrate to the bone tissue from other parts of the body through the blood stream is called as secondary bone cancer. Almost any type of cancer can migrate to the bone. However, most commonly cancer cells from the breast, prostate, lung, thyroid and kidney form secondary bone tumors.

Primary bone cancer is further categorized into:

• Osteosarcoma: This is the most common type of malignant bone cancer. It occurs majorly in the long bones of the leg, knee and the upper arm. It is mainly seen in males between 10-25 years of age. Osteosarcoma is known to be very aggressive with increased risk of spreading to the lungs.

• Chondrosarcoma: It is the 2nd most common primary bone cancer which originates in the cartilaginous tissue present at the end of the bones. It mainly occurs in the pelvis region, positioned between the hip bones, shoulder region, ribs and in the upper leg. Chondrosarcoma may sometimes be cancerous. Most cases of chondrosarcoma are seen in people above the age of 40 years.

• Ewing Sarcoma Family of Tumors (ESFTs): Ewing’s sarcoma is named after James Ewing who first established an aggressive bone tumor distinct from other cancers known during that time. It usually occurs in the soft tissues and mainly affects the backbone, pelvis region and legs and arms. It affects children under 19 years of age with higher incidences seen in boys than girls.

Apart from the above three types, other rare bone tumors include –

• Fibrosarcoma (affecting the knee or hip region)
• Leiomyosarcoma (cancer of smooth muscles)
• Malignant fibrous histiocytoma (benign tumor of the histiocytes, cells that play a role in the immune system)
• Angiosarcoma (malignant cancer affecting endothelial-type cells lining walls of blood or lymph vessels)
• Chordoma (tumor found in the skull base or lower spine)

Causes

Although the exact cause of bone cancer is not yet known, it is thought to be related to changes taking place in the bones during their growing phase. Cancer develops due to an abnormal cell that either has some genetic alterations or is damaged due to external factors. The abnormal cell multiplies out of control to form a tumor or may migrate to other parts of the body. Here are a few factors that increase the risk of developing primary bone cancers:

• External factors like radiation increases the chances of bone cancers. Therefore, individuals taking high dose radiotherapy for other problems have higher risk of developing bone cancer.
• Certain benign tumors like Osteochondroma (chondroma) can progress to become chondrosarcoma.
• Adults who suffer from Paget’s disease, characterized by weak and disorganized bone structure, may develop a primary bone cancer.
• Rare inherited genetic disorders such as Li-Fraumeni syndrome (increased risk of cancer), HME-hereditary multiple exostoses (causes lumps on the bones) and hereditary retinoblastoma (cancer of the retina) increase the chances of primary bone cancers.

Symptoms

There is an evident lack of awareness and understanding about bone cancers in the public domain, which is often the main reason for its delayed diagnosis. Because people hardly know about bone cancers, the initial signs and symptoms are often neglected. Plus, bone cancers markedly differ from other cancers in their nature, distribution and prognosis. Therefore, the associated signs of cancer are not totally the same as seen in other cancers. The first sign of bone cancer in children is painful bones and joints, which is easily mistaken for minor sporting injury or growing teenager pain. If this sign goes unnoticed it may worsen with time and significantly reduce survival rates.

So, if you or your child experiences the following symptoms persistently, do not ignore. Seek medical help immediately.

• Intermittent pain in the bones and occasional swelling. The pain may worsen at nights and is usually not relieved by over-the-counter pain killers
• Presence of a mass or lump on the bone
• Decreased range of motion: Trouble in moving a particular joint due to a nearby tumor
• Pressure on nerves near the tumor may cause a tingling sensation, pain or numbness in that area of skin
• Dizziness and fatigue
• High body temperature, chills
• Unexplained bone fractures due to slight injury or trauma
• Weight loss
• Anemia

These signs may also develop due to other conditions. It is advisable to consult a physician for confirmed diagnosis.

Diagnosis

Diagnostic tests include blood test to determine alkaline phosphatase level, Magnetic Resonance Imaging (MRI) and biopsy.

Alkaline phosphatase test:

Initially, the doctor may suggest a few laboratory tests. In India, alkaline phosphatase test is a key test for detecting bone cancers. Alkaline phosphastase is chemical substance that is particularly present in higher concentrations in the blood in the presence of highly active bone-forming cells. A positive test indicates abnormal bone tissue.

Imaging test

• X Ray: A distinguished appearance of cancer, such as abnormal bone growth, can be seen on an X-ray.
• A bone scan is taken by injecting a small dose of radioactive material into a vein. Cancerous bone tissues that take up the radioactive material shows are seen as ‘hot spot’ on a CT scanner.
• Magnetic Resonance Imaging (MRI) scan may be suggested to determine the exact location and size of the tumor.

Biopsy:

Biopsy of the suspected tissue is crucial for definite diagnosis. A small sample of the tissue is removed from the body and is examined under the microscope to detect abnormal cells. Biopsy is also used to confirm the stage and grade of cancer by analyzing the features of abnormal cells.

Treatment

In the past, the only available option to treat bone cancer was to surgically remove the affected limb. With growing technological advances and development in health care, bone cancer surgeries are carried out in 90% of patients worldwide without the need to amputate the limb.

Since bone cancers mainly affect children, pediatric oncologists face several challenges in the treatment of bone cancers. This is because bone cancer treatment involves radiation therapy, surgery and chemotherapy that can have an adverse effect on the growth and development of children.

The treatment is decided depending on various factors such as the type of primary bone cancer, its exact location, the stage and grade of cancer, the extent of reach and the size of tumor, and the overall general health of the patient. Also read Latest advances in cancer treatments

• Radiotherapy

Radiotherapy is a treatment which involves the use of high-energy radiation beams targeting cancerous tissue or tumor. The high radiation beam damages the DNA of abnormal cells rendering them incapable to multiply. The only disadvantage is that radiation also harms surrounding healthy cells. However, healthy cells are resilient and can recover fully whereas cancer cells are sensitive to radiation and get killed rapidly. Read more about radiotherapy. In the treatment of bone cancer, radiation therapy is used:

• To destroy the tumor completely
• To reduce pain in advanced stages of cancer
• Before a surgery to shrink the tumor in size, making it easier to remove surgically
• After the surgery to eliminate cancer cells that may have left behind.
• In combination with chemotherapy (chemoradiation)

• Chemotherapy

Chemotherapy involves use of chemical drugs/anti-cancer drugs targeted to kill rapidly growing cancer cells. Usually a combination of drugs is administered. Since anti-cancer drugs target only fast growing cells, without distinguishing between normal and abnormal cells, other rapidly growing healthy cells of the body, such as hair follicle cells, are also attacked which results in side-effects. Read more about chemotherapy side-effects. Chemotherapy may be used in bone cancer treatment the following reasons:

• To completely eliminate cancer cells
• In combination with surgery or radiotherapy for better results. Read more about combination therapy
• To prevent the recurrence of cancer after surgical removal of tumor

• Surgery

Bone cancer surgery is aimed at removing the entire tumor and probably some affected bone tissues surrounding the tumor. It is extremely challenging because if some cancer cells or a part of tumor is left behind after the surgery, it may grow and spread eventually. A limb sparing surgery means surgical intervention without amputating the limb. In severe cases, amputation may be necessary.

Bone cancer treatment in India

In India, bone cancer surgery is very common because of the increased success rate. Today India has emerged as one of the crucial centers for bone cancer surgery. The availability of good treatment facilities and experienced cancer surgeons has even attracted international patients for surgical treatment.

Here’s a list of leading hospitals in India that provide bone cancer treatment:

• Tata Memorial Hospital, Mumbai: It is the pioneer of cancer research in India and provides free care to about 70 percent of its cancer patients.
• Kidwai Memorial Institute of Oncology, Banglore: It is the regional center for affordable cancer treatment in the country. Moreover, it offers cancer drugs at about 40 to 60% cheaper than other markets.
• Apollo Hospital, Chennai: It specializes in bone cancer and offers effective and affordable cancer treatment