Diagnosis of bone cancer

Children and young adults with symptoms of bone cancer present to their physician with bone pain, swelling, lump or a fracture. Diagnosis is made on the basis of physical examination and detailed imaging studies. 1-6

Diagnosis of bone cancer includes taking a medical history, physical examination and so forth.

Medical history

History of bone pain, radiation exposure, Paget’s disease, retinoblastoma and umbilical hernia at birth is important. Family history of Li-Fraumeni syndrome or HME needs to be evaluated as these may raise the risk of bone cancers.

Physical examination

A physical examination shows the signs of a bone tumor. The long bones (especially at the ends) like the thigh bone (femur), shin bone (tibia), upper arm (humerus), pelvis (hip bone) are commonly affected. However, other bones may also be affected. A complete physical examination reveals swelling, tenderness, joint movement restriction etc.

Routine blood tests

Routine blood tests are advised. If there is affliction of the bone marrow due to spread of the cancer there may be anemia, low white blood cell or platelet counts.

Blood biochemical tests

Blood biochemical tests may show increase in an enzyme called alkaline phosphatise in patients with osteosarcoma

X-ray of the bone

This is the most common and most cost effective investigation advised when a bone condition is suspected. The patient who presents to the physician with a fracture may have an underlying bone cancer that may be suspected on an X ray. If the X ray is suggestive of bone cancer the patient is referred to a specialist for further evaluation and management.

Biopsy

This is the most definite method of detecting bone cancer. Biopsy involves taking a small sample of the affected area of the bone and staining it with suitable dyes on a slide and examining the cells of the sample under a microscope in the laboratory.

Biopsy is used to detect the type of cancer, the stage or grade of the cancer and how aggressive the cancer is. This helps in planning management of the cancer and also helps in predicting the outcome of the cancer.

Biopsy of the bone may be taken by one of the two methods - core needle biopsy or open biopsy. A core needle biopsy is performed after applying local or general anesthesia. A thin needle is inserted into the bone and a sample of tissue is removed.

An open biopsy is usually performed under general anaesthesia. The surgeon makes an incision over the affected bone and removes a larger section of the bone for analysis.

MRI scan

MRI scan is another imaging study that uses a strong magnetic field and radio waves to look at the bones and the organs of the body. This may be advised to detect the size and spread of any cancerous tumour within the bone.

CT scan

A CT scan also involves taking a series of X-rays that look at the size and extent of spread of the cancer. CT scans of the chest may reveal spread of the bone cancer to the lungs.

Bone scan

A bone scan or Bone scintigraphy using technetium99 may be prescribed. This used a small amount of radioactive material (technetium99) that is injected into the veins of the arm.

Abnormal areas of bone will absorb the material at a faster rate than normal bone. A special camera is then used to take pictures of these “hot spots” where the dye is concentrated.

A Positron emission tomography (PET) scan may also be performed.

Staging bone cancer

After diagnosis and confirmation of the cancer the cancer is staged into various stages. Staging helps to decide on the treatment and also helps to determine the outcome of the cancer.

Stage 1 for example is when the cancer is low grade and has not spread beyond the bone.

Stage 2 is when the cancer has still not spread beyond the bone but testing shows that it is high grade cancer and has the potential for spread.

Stage 3 occurs when the cancer has spread into other parts of the body, such as the lungs.