(osteosarcoma, chondrosarcoma, Ewing's sarcoma, fibrosarcoma, malignant fibrous histiocytoma, primary bone lymphoma, giant cell tumor, chordoma)

What is Cancer of the Bones

Bone cancer is a relatively rare disease in which cancer cells grow in bone tissue. The cancer can form in the bone or expand to the bone from another place in the body. When cancer begins in the bone tissue, it is called primary bone cancer. When cancer cells are directed to the bone from another location, it is called secondary or metastatic bone cancer.

Types of bone cancer:

1. Osteosarcoma: a cancerous tumor of the bone, usually in the arms, legs or pelvis. Osteosarcoma is the most common primary cancer.
2. Chondrosarcoma: cancer of the cartilage. Chondrosarcoma is the second most common type of primary cancer.
3. Ewing's sarcoma: tumors that usually develop in the cavity of the bones of the arms and legs.
   Fibrosarcoma and malignant fibrous histiocytoma: cancers that develop in the soft tissues (eg, tendons, ligaments, fat, muscle) and move to the bones of the legs, arms, and jaw.
4. Giant cell tumor: primary bone tumor that is malignant (cancerous) in only 10% of cases. It often appears on the bones of the legs or arms.
5. Cordoma: primary bone tumor that usually appears in the skull or spine.

Cancer occurs when the cells of the body (in this case, the cells of the bones) reproduce without control or order. Generally, the cells are divided in a regulated manner. If cells continue to divide uncontrollably when new cells are not needed, a mass of tissue called neoplasia or tumor is formed. The term cancer refers to malignant tumors, which can invade nearby tissues and spread to other parts of the body. A benign tumor is not invasive or spreads.

The sooner bone cancer is treated, the more favorable the result will be. If you suspect you have this condition, consult your doctor immediately.

Causes of Cancer of the Bones

The cause of primary bone cancer is not known. Genetics plays a very important role in most cases. The conditions that cause greater deterioration in the bones and their regeneration over a long period of time increase the risk of tumor development. This explains why osteosarcoma in children is more common during the late stage of growth in adolescence.

Risk factors Cancer of the Bones

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 non-cancerous bone condition)
• Being exposed to radiation
• Bone injury (not yet proven to be a risk factor)
• Family history of bone cancer

In addition, the following factors are specific for certain types of bone cancer:

Osteosarcoma

• Age: between 10 and 30 years
• Male sex
• Syndromes of hereditary cancer, such as Li-Fraumeni syndrome and Rothmund-Thompson syndrome
• Retinoblastoma (a rare type of eye cancer)
• Bone marrow transplant

Chondrosarcoma

• Age: over 20 years
• Multiple exostosis (hereditary condition that causes bulges in the bones)
• Ewing's sarcoma
• Age: under 30 years

Fibrosarcoma and malignant fibrous histiocytoma

• Age: middle-aged and elderly adults

Giant cell tumor

Age: young and middle-aged adults

Symptoms of Cancer of the Bones

Symptoms vary depending on the location and size of the tumor. These symptoms may be caused by other less serious health conditions. If you experience these symptoms, you should consult your doctor.

• Pain in the place of the tumor
• Swelling or swelling where the tumor is
• Acute pain in the bones, severe enough to wake him up
• Bone fractures (rare)
• Unexplained weight loss
• Fatigue
• Trouble breathing
• Fever or night sweats

These symptoms may be caused by other less serious conditions. If you experience these symptoms, you should consult your doctor.

Diagnosis of Cancer of the Bones

The doctor will ask about your symptoms and medical history, and perform a physical exam.

Tests may include:

• Blood tests: to control the levels of the enzyme alkaline phosphatase. Patients who have bone tumors and healthy children during the stage of their development release large amounts of this enzyme.
  X-rays-a test that uses radiation to make pictures of structures inside the body, especially bones
• Bone scan: a study that looks for evidence of bone tumors. A radioactive substance is injected into the bloodstream that is absorbed by the bone tissue and then detected by the bone scanner.
• Computed tomography scan -a type of x-ray that uses a computer to make pictures of structures inside the body
• MRI scan -a test that uses magnetic waves to make pictures of structures inside the body
• Biopsy: removal of a sample of bone tissue to examine it for cancer cells. An excisional biopsy (removal of the tumor) for bone tumors may involve the removal of a significant portion of the affected bone or limb and, in some cases, total or partial amputation of the extremity, depending on the location of the tumor and the type.

Treatment of Cancer of the Bones

Once the cancer is found, stage tests are done to find out if the cancer has spread and, if so, to what extent. Treatment depends on the stage of the cancer and your general health. Ask your doctor about the best treatment plan for you. Treatment options include:

Radiation therapy (radiotherapy)

Radiation therapy to treat bone cancer uses radiation to kill cancer cells and decrease the size of tumors. Types of radiation:

• External radiotherapy: radiation is applied to the tumor from an external source to the body
• Internal radiotherapy: radioactive materials are placed inside the body, near the cancer cells

Chemotherapy

Chemotherapy is the administration of drugs to kill cancer cells. It can be administered in several ways, for example, in the form of pills, injection or through a catheter. The drug enters the bloodstream and travels through the body, mainly eliminating cancer cells, but also some healthy cells. Some common chemotherapy drugs used to treat bone cancer include calcium methotrexate, leucovorin, doxorubicin, and cisplatin. Ifosfamide and etoposide can also be used.

Surgery

Surgery to treat bone cancer involves removal of the cancerous tumor and surrounding tissue and, sometimes, nearby lymph nodes. Surgery may require amputation of a limb with cancer. Whenever possible, doctors will try to remove the malignant part of the bone, without amputating it. Metal plates or bone grafts replace the extracted cancer tissue.

In some cases, adding radiotherapy or chemotherapy to treatment can help prevent amputation. If the tumor is large and aggressive or if the risk of spreading is high, radiotherapy and chemotherapy may be added to help prevent recurrence at the site of surgery and to prevent it from spreading to distant organs.

Myeloablative therapy with stem cell support

When the cancer has spread, intense chemotherapy can be used to kill the cancer cells. This therapy also destroys the bone marrow. Stem cells, which have the ability to convert to another type of cells, are administered to replace the loss of bone marrow.

Special considerations for the treatment of certain types of cancer

• Osteosarcoma: Chemotherapy given before and after surgery usually cures osteosarcoma and may enable surgery to keep the limb in people who otherwise would have required an amputation.
• Ewing sarcoma: because it responds very successfully to chemotherapy, the treatment usually includes several weeks of chemotherapy followed by surgical removal or radiotherapy and then several more months of chemotherapy.
• Fibrosarcoma and malignant fibrous histiocytoma: usually treated with surgery to remove the cancerous tumor and a margin of 2.5 cm or 1 inch of surrounding healthy tissue.

How to Prevent Cancer of the Bones

There are no guidelines for the prevention of primary bone cancer. Diagnosis and early treatment improve your chances of treatment success.