When cells in the bone begin to divide uncontrollably, they are called bone cancer. It can affect any bone in the body, but it is common in the thigh bone, knee bone, and other long bones in the body. It mostly affects children and young adults. The nature of cancer can be suspected based on the type of destruction seen on an X-ray.

Bone cancer may be primary or secondary. The former arise in the cells of the bone while the latter spread from elsewhere. Some quick facts of bone cancers are:

1. Benign bone tumors are more common than malignant bone tumors.

2. There are several different bone cancer types.

3. Early symptoms might include pain in the affected area.

4. A range of diagnostic tests can help diagnose bone cancer.

5. Radiotherapy, chemotherapy, and surgery can all be used to treat bone cancer.

What are the types of bone cancer?

Bone cancers classified into primary and secondary. Primary bone cancer is the cancer that forms in the cells of bone. Secondary bone cancer is that cancer which spreads to bone from another part of the body (example cancers from lung, prostate, breast, kidney etc.). The most common cancers of bone are secondary bone cancer.

There are five main types of primary bone cancer.

1.  Chondrosarcoma

A malignant bone tumor that arises from cells of the cartilage either from the normal bone (primary chondrosarcoma) or in a pre-existing cartilaginous tumor-like enchondroma (secondary chondrosarcoma). It may arise from any bone but is common in flat bones such as ribs, scapula, and ribs.

2.  Ewing Sarcoma (pronounced you-ing)

This is a highly malignant tumor that is more common in teenagers and young adults but can occur in any age.

Listed below are the features of Ewing Sarcoma

• Bones affected: It commonly occurs in long bones like the femur and tibia, and less commonly in flat bones like the pelvis and the calcaneus. Occasionally, it is known to have a multicentric origin.
• Site: It may begin anywhere but diaphysis of the long bone is most common.

3.  Osteosarcoma (Osteogenic Sarcoma)

It is the second most common and a highly malignant primary bone tumor.

It is defined as a malignant tumor of the mesenchymal cells, characterized by the formation of osteoid or bone by the tumor cells.

a) Primary Osteosarcoma

Most primary osteosarcomas have the following important features:

• Age at onset: These tumors occur between the ages of 15-25 year, constituting the commonest musculoskeletal tumor at that age.
• Common sites of origin: In decreasing order of frequency these are: the lower-end of the femur; the upper end of the tibia; and the upper end of the humerus. However, any bone in the body may be affected.

b) Secondary Osteosarcoma

When osteosarcoma develops in a bone affected by a premalignant disease (like Piaget’s or Enchondromatosis) it is known as secondary osteosarcoma. It is less malignant and affects people older than 45 years of age. Treatment is similar to mainstream osteosarcoma.

c) Parosteal Osteosarcoma

This arises from the region of the periosteum. It occurs mostly in adults and is a slower growing tumor. Treatment is similar to osteosarcoma but the prognosis is preferable.

4. Fibrosarcoma

Fibrosarcoma is a rare type of cancer that affects cells known as fibroblasts. Fibroblasts are responsible for creating fibrous tissue throughout the body like in tendons which connect muscle to bone and other soft tissue like ligaments, fat or muscle.

Listed below are the features of Fibrosarcoma:

• Fibrosarcoma, after onset multiplies and creates extra tissue that affects the region surrounding it.
• Site: It may begin anywhere in soft tissue around the bones like tendons, ligaments and fat.

Diagnosis:

The American Cancer Society enlists a variety of tests to be carried out regularly for the diagnosis of soft tissue sarcomas. Diagnosis is confirmed by the following means:

• Biopsy
• X-ray
• Computer tomography (CAT or CT) scan
• Magnetic resonance imaging (MRI)
• Positron emission tomography (PET) scan

Treatment:

Treatment for fibrosarcoma depends on the stage of cancer. It may vary from surgery to remove cancer to radiation and chemotherapy to treat it. There may also be a requirement for surgery to remove lymph nodes or cancer which has spread to lungs.

5. Chordoma

Chordoma is a very rare variety of bone cancer which is slow growing and slow spreading. Chordomas develop from the notochord which forms early spinal tissue in a fetus. The six-month fetus develops a bone which replaces the tissue but in some cases, the notochord may remain. 2 out of 5 chordomas grow in the skull or the bones of the middle face while the rest grows in the spinal cord.

Listed below are the features of Chordoma

• Chordoma in the skull may cause the patient to have double vision, headaches, weaknesses, and paralysis in the face; while those in the spine cause pain, difficulty in passing of urine and weakness in legs; those in the upper back may cause difficulty in swallowing food.
• Site: They are found within the tissue of the spinal canal and are sometimes classified as bone tumors or central nervous system tumors.

Diagnosis:

The doctor may advise multiple blood tests to inspect overall general health. Other tissues may include:

• CT scan
• MRI scan
• Biopsy

Treatment:

Treatment depends on the location and the severity of the chordoma. It is important that it is diagnosed as soon as possible to prevent recurrence of cancer. Surgery to remove as much of the tumor as is possible and radiation therapy to remove any remaining cells is important to prevent other symptoms from relapsing.

A symptom is a physical feature apparent to an individual that indicates a condition of the disease. The signs and symptoms of bone cancer are:

Pain in the affected bone

One of the earliest signs is a pain in the affected area. It may progress to a severe condition during metastasis.

Swelling

The affected area may develop swelling and lumps, indicating the gene defects and cancer cell spreading.

Fractures

Brittleness of bones on account of other medical conditions needs to be screened and investigated by a doctor as it may be a sign of bone cancer.

Cancer in spinal bones can cause numbness or a tingling sensation

Neural tracts in the spine may cause discomfort due to unexplained sensations along the affected area.

It may cause weight loss and fatigue

Lack of bone health can cause deterioration in weight and fatigue.

Problems during movement

Bone cancer around the joints may especially cause difficulty in movement.

Other symptoms

Spreading to the lungs may cause difficulty in breathing and may develop as other cancers if it has spread to other organs.

What are the risk factors of bone cancer?

A risk factor is that which influences an individual’s chance of getting a disease. The causes of bone cancer may be due to lifestyle, environment, and genetic changes. Read on to find out which risks you might need to be alert. Regular screening can help early detection and consequently, aid more effective treatment. In case of doubt, contact your health care team for more information.

1. Age

Cancers usually appear with age. But in some types of cancers, younger people have a higher risk of developing them.

Osteosarcoma is common in teenagers and young adults and is associated with the growth of bones during puberty. It may also appear in older people.
Spindle cell sarcomas and chondrosarcomas tend to occur in adults between ages 35 and 40 while chondromas occur in adults over 60 years of age.

2. Radiation therapy or chemotherapy:

People who have received radiation or chemotherapy previously run the risk of developing bone cancer, even though it is negligible. If it does occur, it is usually 10-20 years after having radiotherapy. People previously treated with certain chemotherapy drugs, including alkylating agents and anthracyclines, might have an increased risk of developing secondary cancer like osteosarcoma. Majority of radiation-induced sarcomas like angiosarcoma and undifferentiated pleomorphic sarcoma of the soft tissue. Others may be like osteosarcoma.

3. Individuals with non-cancerous (benign) bone tumors:

Paget’s disease of the bone is a benign condition that causes painful and deformed bones. It mostly occurs in people older than 60 years of age, which results in the formation of abnormal bone tissue. The bones affected are usually dense, thick, brittle and weak. They may be susceptible to a fracture. While Paget’s disease is not fatal, it increases the risk of developing osteosarcoma. Osteosarcoma develops in 1% of cases when the tumor affects many bones. A non-cancerous bone tumor-like osteochondroma (or chondroma) can sometimes develop into chondrosarcoma.
Also, people with multiple hereditary exostoses (HME) have an increased risk of developing chondrosarcoma. It causes lumps to grow most commonly in the limb bones. This condition mostly shows appearance in childhood but not in all cases. It is inherited by people who have a close relative who has bone cancer.
Ollier’s disease, also known as enchondromatosis, causes several benign tumors in the cartilage. This disease increases the risk of developing chondroblastostoma. Furthermore, Maffucci’s syndrome is a benign condition that causes abnormally shaped bones. Approximately 20 – 40 % of people

4. Genetic disorders:

People who have inherited a gene that is maladaptive to the bones may run the risk of developing bone cancers. Hereditary retinoblastoma is a rare eye cancer affecting children. They are more susceptible to develop bone cancer (osteosarcoma), soft tissue sarcomas and other cancers. Radiation therapy used as a treatment for retinoblastoma also increases the risk of osteosarcoma. Despite this, there are examples of non-inherited genes whose defects need more research.
Li-Fraumeni is an inherited syndrome caused due to gene fault. It increases the risk of several cancers, including bone cancer.

5. Bone Marrow Transplant:

Bone marrow transplant is a procedure that replaces bone marrow that is malignant due to infection or chemotherapy. In such cases, there has been an increased risk for developing bone cancers.

How is Bone Cancer Diagnosed?

Accurate diagnosis of bone cancer include the combination of information on the bone affected, then part of the bone involved, X-rays, and a biopsy. While other diseases like bone infections can cause symptoms and imaging results for them can cause misdiagnosis.

Screening And Imaging tests used for diagnosis:

1. X-ray:

A diagnostic test that uses invisible electromagnetic energy beams( X-ray) to make images of internal tissues, bones, and organs onto film. The bone at the affected area may look disorganized and ragged instead of solid. It is also possible that the tumor spread to nearing muscle, fat, or organs.

An experienced radiologist may be able to diagnose the condition by looking at the X-ray images, but a biopsy is mandatory to confirm.

2. Computed tomography scan (also called a CT or CAT scan):

It is an imaging test that uses X-rays and a computer to make detailed images of the body. A CT scan shows details of the bones, muscles, fat, and organs.

It is also used to guide a biopsy needle into a tumor which is known as a needle biopsy. For this, the individual is inspected on the CT scanning table while the radiologist moves the biopsy needle towards the tumor, and CT scans shots repeat until the needle is inside the tumor.

3. Magnetic resonance imaging (MRI):

A diagnostic procedure that uses a combination of large magnets, radio frequencies, and a computer to make detailed images of organs and structures within the body. It is a powerful magnet link to a computer to take detailed pictures of the tumor without using X-rays. It is most useful in gauging tumors near the brain or the spinal cord.

4. Positron emission tomography (PET) scan:

An imaging test in which radioactive-tagged glucose (sugar) enters the bloodstream. A scanning machine can detect tissues that use glucose more than healthy tissues (such as tumors). As cancer cells use more glucose than healthy cells, the images spot cancer cells in the body.

5. Biopsy:

A procedure in which tissue samples are removed with a needle or during surgery from the body for examination under a microscope. It is done to determine if cancer or other abnormal cells are present. Also, an experienced surgeon/physician must do a biopsy.

a. Needle Biopsy

A needle biopsy is of two types (fine aspiration), and core, both of which happen after the affected area is numbed.

In fine needle aspiration (FNA), the surgeon uses a thin needle and a syringe to extract some fluid and some cancer cells. If the tumor lies close to the surface of the individual’s skin, the surgeon may aim the needle by feeling the region. However, if it is deep, the doctor may guide the needle by looking at the CT scan pictures. An X-ray specialist or an interventional radiologist conducts a CT guided biopsy.

In a core needle biopsy, the doctor uses a larger needle which is about 1/16 inches in diameter and ½ inches long to remove a small cylinder of tissue. Experts recommend core needle biopsy over fine needle biopsy to diagnose primary bone cancer.

b. Surgical Biopsy

There are two types of surgical biopsy. One, an incisional biopsy and two, an excisional biopsy. While the former cuts through the skin to more a small piece of tissue, the latter removes the entire tumor.

What are the stages of bone cancer?

After diagnosis, doctors will set about to determine the stage of bone cancer. Staging is the process of trying to find out the severity and spread of cancer. It further helps in understanding how serious it is and what treatment one must follow.

There are four cancer stages from I (1) through IV (4). By rule, the lower the number, the lower the spread of cancer. Although each patient has individual differences, approaches to a particular stage of cancer are by and large similar and usually receive similar treatment.

How do you determine the stage of cancer?

Doctors use diagnostic tests to determine the stage and metastasis of cancer. Knowing the stage helps them best predict the prognosis, treatment, and determining the chance for recovery.

The staging system the American Joint Committee on Cancer (AJCC) uses mostly is the TNM method. There are four primary pieces of information in this method:

1. The extent (size) of the tumor (T):

It indicates how extensive the cancer is and if it has affected more bones than one.

2. The spread of nearby lymph nodes (N):

It determines if cancer has spread to the lymph nodes.

3.The metastasis or the spread of cancer to the distant site (M):

It indicates if cancer has spread to either the lungs alone or distant sites such as the liver.

4.The grade of cancer (G):

It determines how abnormal the cells appear when viewed under a microscope. The grading scale for bone cancer is from 1 to 3. Low-grade (G1) cancers grow and spread slower than high-grade (G2 or G3) cancers.

Numbers or letters after initials T, N, and M help understand the factors that determine the stage of cancer.

Tumor:

The ‘T’ in the TNM system indicates the size and the location of cancer. Some stages have sub-stages as in the following:

Skeleton, trunk, skull, and facial bones have the following groups:

TX: the primary tumor cannot be evaluated

T0: there still is no evidence of the primary tumor

T1: the tumor is 8 cm or smaller

T2: the tumor is more significant than 8 cm

T3: there are more than one separate tumors in the primary site

Spine:

TX: the primary tumor cannot be evaluated

T0: There is no evidence of primary tumor

T1: the tumor is only found on one part of the vertebra, called the vertebral segment, or on two adjacent portions of the vertebrae

T2: the tumor is found only on three adjacent parts of the vertebrae

T3: the tumor is located on four or more nearing parts of the vertebrae, or in parts of the vertebrae that are not next to each other

T4: the tumor has grown into the spinal canal (T4a) or great vessels (T4b)

Pelvis:

TX: the primary tumor cannot be evaluated

T0: there is no evidence of primary tumor with no extraosseous extension

T1: the tumor is only in one part of the pelvis; where the tumor is 8 cm or smaller (T1a) or tumor is more significant than 8 cm (T1b)

T2:  the tumor is found only on 1 part of the pelvis with extraosseous extension or on two parts of the pelvis with extraosseous extension; where the tumor is 8 cm or smaller (T2a) or tumor is larger than 8 cm (T2b)

T3: the tumor is found on two parts of the pelvis, with extraosseous extension; where the tumor is 8 cm or smaller (T3a), or tumor is more prominent than 8 cm (T3b)

T4: tumor is found on 3 parts of the pelvis or has crossed the sacroiliac joint, which connects the bottom of the spine with the pelvis; where the tumor involves the sacroiliac joint and has grown into the neural foramen (T4a) or the tumor has grown around blood vessels or affects blood flow (T4b)

Node:

The ‘N’ in the TNM system expands to lymph nodes. These are tiny; bean-shaped organs that help fight infection and help in immunity. The lymph nodes near the cancer are regional lymph nodes, while those away from the site are distant lymph nodes. The following are sub-stages of N grades:

NX: the regional lymph nodes cannot be evaluated

N0: cancer has not spread to regional lymph nodes

N1: cancer has spread to regional lymph nodes, and this is rare for primary bone cancer

Metastasis:

The ‘M’ in the TNM system indicates the spread of cancer to other body parts, that are distant.

M0: cancer is in early stages

M1: cancer has metastasized to other body parts; where when it has metastasized to the lungs it is M1a, or to other bones and organs it is M1b

Grade

Doctors also describe bone cancer by its grade (G), which indicates their health when viewed under a microscope. Doctors compare the cancer tissue to healthy tissue. The lower the tumor grade, the better the prognosis. The following are the sub-stages:

GX: tumor grade cannot be identified

G1: the cancer cells are well differentiated (low-grade)

G2: the cancer cells are moderately differentiated (high-grade)

G3: the cancer cells are poorly differentiated (high-grade)

The Number Stages

The tumor, node, and metastasis along with number stages.

In situ tumors are at stage 0. Detections in this early stage, show that it is small, low-grade and has not spread.

In stage 1A, the tumor is at low-grade not larger than 8 cm.

At stage 1B the tumor is longer than 8 cm. It is in more than one region of the bone.

Stage 2A is a high-grade tumor that is less than 8 cm across without having affected lymph nodes and without metastasis.

At stage 2B the tumor is a high-grade in more than one place in the same bone.

Stage 3 is a high-grade tumor in more than one place on the same bone.

In stage 4A, the tumor that has spread to the lung.

At stage 4B, the tumor has spread to the lymph nodes or other distant parts of the body.

How is bone cancer treated?

Surgery to remove the cancer is the first resort for bone cancers. More importantly, surgical techniques can eliminate the tumor without the need for amputation of the limb involved. But when affected muscles and other tissues that surround the region need to be removed, reconstructive surgery along with cancer resection brings back the limb to optimum functioning.

Cancer types like Ewing Sarcoma and osteosarcoma may require both surgery and chemotherapy. However, radiation therapy also treats chondrosarcoma.

Chemotherapy in the Treatment of Bone Cancer

Doctors recommend the treatment of Osteosarcoma and Ewing Sarcoma. Nonetheless, it is not sufficient for other types of bone cancers. They are not sensitive to the drugs. Also, read about chemotherapy here.

Primarily, chemotherapy uses the technique of using anti-cytotoxic drugs to kill cancer cells. A few of its primary functions are to starve cancer cells, impede their cell division, and triggering their suicide. While side effects remain, there is an attempt to research drugs that will minimize adverse effects, which are, nausea, weakness, fatigue, bowel-related issues, and blood-related issues, etc.

Conventional drugs for osteosarcoma include:

• Cisplatin (Platinol)
• Doxorubicin (Adriamycin)
• Ifosfamide (Ifex)
• Methotrexate (multiple brand names)

Conventional drugs for Ewing sarcoma include:

• Vincristine (Oncovin, Vincasar)
• Doxorubicin (Adriamycin)
• Cyclophosphamide (Cytoxan, Neosar)
• Ifosfamide (Ifex)
• Etoposide (Toposar, VePesid)
• Dactinomycin (Cosmegen)

Radiation

Radiotherapy is for patients whose tumors are unresectable (they cannot be treated with surgery).

Types of Radiation Therapy

Particular kinds of radiation therapy are most commonly used to treat bone cancer.

1. Intensity-modulated treatment is a sophisticated technique of radiation therapy in which a computer matches radiation beams to the size and the severity of the tumor. In this case, the radiation aims at the tumor from different angles.

2. Proton beam radiation uses beams of positively charged particles of atoms instead of regular X-rays. It is popular in treating skull, spine, rib, or sternum chondrosarcomas and chordomas.

3. Extracorporeal used as part of limb-salvaging surgery which involves taking the infected bone out of the body, treating it with cancer and putting it back. However, side effects like fatigue, nausea, loss of appetite, low blood counts prevail after the radiotherapy.

Surgery

Surgery is another essential part of the treatment. The aim is to obliterate cancer cells. Different types of surgery exist for various types and grades of cancer, depending on its size and severity; namely, limb-salvaging surgery, amputation surgery, reconstructive surgery, and surgery for metastasis.

Side effects include infection around the wound, bleeding, urinary issues, shortness of breath, rehabilitation from physical and emotional distress, etc.

Stem-cell transplants

When Ewing sarcomas are not particularly sensitive to chemotherapy, it may require radiation therapy and perhaps even stem-cell transplants. Stem cell transplants kill bone marrow cells of the affected region, and new cells are induced through the veins to replace destroyed cells through a blood transfusion. Eventually, these new cells adapt to settling down to make healthy bone cells. This process is known as engrafting.

There are two types of stem-cell transplants:

1) Autologous stem-cell transplants

Autologous transplant is primarily used to treat certain leukemias, lymphomas, and multiple myeloma. Also, there are no risks of new cells attacking the body (known as the graft-versus-host cancer effect)

2) Allogeneic stem-cell transplants

In allogeneic stem-cell transplants, there may be two kinds of donors. Firstly, a close family member. And secondly, a donor from the general public called the MUD or matched unrelated donor. MUD type of transplants is usually riskier than those from a relative of the patient’s.

Targeted therapies

Targeted uses drugs to treat cancers but is different from conventional chemotherapy. It works by targeting specific proteins and genes to impede the growth and spread of cancer. The U.S. Food and Drug Administration (FDA) has authorized targeted therapies for many types of cancer. Furthermore, these drugs:

1. disable the growth and division of cancer cells
2. prevent cells from living longer than usual
3. and then, destroy cancer cells

Examples

Denosumab (Xgeva) is a monoclonal antibody that acts to block the activity of osteoclasts. Used in the treatment of giant cell tumors of bone that has relapsed after surgery or that cannot be removed, it has proved effective.

Clinical trials

Clinical trials are research studies that doctors use to find new ways to improve medical techniques and technology. Also, health professionals must talk to the patient and the patient’s family about the nature, extent, and safety of the trial. Clinical trials:

1. find and diagnose cancer
2. then, treat cancer
3. also, prevent cancer
4. and finally, help cope with symptoms of cancer and handle its side effects

What are the different drugs Used In Bone Cancer treatment?

The Food and Drug Administration (FDA) for bone cancer has approved of certain drugs, and here is a list with generic names and brand names for the drugs used in the treatment of bone cancer:

• Cosmogenic (Dactinomycin)
• Dactinomycin
• Denosumab
• Doxorubicin Hydrochloride
• Methotrexate
• Trexall (Methotrexate)
• Xgeva (Denosumab)
• Vincristine
• Cisplatin
• Ifosfamide
• Etoposide
• Cyclophosphamide

Conventional drugs for osteosarcoma include:

• Cisplatin (Platinol)
• Doxorubicin (Adriamycin)
• Ifosfamide (Ifex)
• Methotrexate (multiple brand names)

Conventional drugs for Ewing sarcoma include:

• Vincristine (Oncovin, Vincasar)
• Doxorubicin (Adriamycin)
• Cyclophosphamide (Cytoxan, Neosar)
• Ifosfamide (Ifex)
• Etoposide (Toposar, VePesid)
• Dactinomycin (Cosmegen)

How can bone cancer be prevented?

There are no precise and foolproof ways that have been discovered yet to prevent bone cancer. Experts widely agree upon the following tips to living a healthy life:

Genes

Individuals need to be aware of their genes for any history of cancer and other risks that may influence their medical condition.

Skeletal Fragility

It is essential to be informed about bone health so that a bone disease is avoided to keep further complications at bay. Also, read more about Risk Factors causing Bone Cancer.

Other Diseases

Anybody diagnosed with osteoporosis needs evaluation for secondary causes of the diseases.

Diet and Nutrition

Keeping a healthy and nutritious diet is vital to keep a fit body that is robust enough to combat unnecessary complications.

Exercise

Physical exercise and yoga are effective in curing diseases. It keeps body circulation adequate and helps ward off diseases.

Drugs and Medication

Drugs that prevent bone breakdown for most common bone diseases are antiresorptive. They are effective in reducing the risk of future fractures. These drugs both keep the skeleton from deteriorating and allow for some repair and restoration of bone mass and strength.

Additionally, anabolic therapy helps build new bone and reduce the risk of further fracture. Although it prevents and treats osteoporotic fractures, it applies to other bone diseases.

General Awareness

There must be community programs and campaigns that educate people about bone cancer, its symptoms, causes, risks, and stages. People need to be informed about the drugs that heighten the risk of bone diseases and avoid them.

Keeping tobacco off-limits

A healthy lifestyle is a crucial component in keeping any cancer at bay. Smoking is a no-go to live a happy life free from cancer.

Early diagnosis

Early diagnosis is key for effective treatment before metastasis. Consulting a doctor for screening and detection before the onset of a more damaging stage is essential.