Diagnosis is the process of finding the cause of a health problem. The process of diagnosis may seem long and frustrating, but it is important for the doctor to rule out other reasons for a health problem before making a cancer diagnosis. Diagnostic tests for mesothelioma cancer are usually done when:
Many of the same tests used to initially diagnose cancer are used to determine the stage (how far the cancer has progressed). Your doctor may also order other tests to check your general health and to help plan your treatment. Tests may include the following.
The medical history is a record of present symptoms, risk factors and all the medical events and problems a person has had in the past. The medical history of a person’s family may also help the doctor to diagnose mesothelioma.
In taking a medical history, the doctor will ask questions about:
A physical examination allows the doctor to look for any signs of mesothelioma. During a physical examination, the doctor may:
An x-ray uses small doses of radiation to make an image of the body’s structures on film. It is used to check for abnormalities of the lung or abdomen.
Ultrasound uses high-frequency sound waves to make images of structures in the body. An abdominal ultrasound may be done to check for fluid in the abdomen if the doctor suspects peritoneal mesothelioma.
A CT scan uses special x-ray equipment to make 3-dimensional and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures. It is used to:
MRI uses powerful magnetic forces and radio-frequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3-dimensional pictures. It is used to:
During a biopsy, tissues or cells are removed from the body so they can be tested in a laboratory. The pathology report from the laboratory will confirm whether or not cancer cells are present in the sample. The biopsies that could be used to diagnose mesothelioma are:
An endoscopic procedure may be done to diagnose and stage a mesothelioma. It allows a doctor to look inside body cavities using a flexible tube with a light and lens on the end (an endoscope). Endoscopic procedures that may be done for mesothelioma are:
A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check for problems with platelets and white blood cells. People with mesothelioma can have an abnormally high platelet level (thrombocytosis) and high white blood cell level (leukocytosis).
Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are functioning and can also be used to detect abnormalities.
Doctors may use blood chemistry tests to determine a prognosis for people with mesothelioma. People with mesothelioma may have an increased lactate dehydrogenase (LDH). LDH is an enzyme in the blood that can be increased when there is tissue damage or if cancer cells are present.
Tumour markers are substances – usually proteins – in the blood that may indicate the presence of mesothelioma. Tumour marker tests are used to check a person’s response to cancer treatment. Tumour markers are not used to diagnose mesothelioma, but increased levels may help confirm a diagnosis of malignant mesothelioma.
The tumour markers that may be measured in people with mesothelioma are:
These markers appear to be sensitive for mesothelioma, but studies are being done to better determine their role in diagnosing mesothelioma and assessing response to treatment.
Pulmonary function tests (also called lung function tests) check how well the lungs are working. They measure how much air the lungs can hold and how well the person can let the air out of the lungs. This type of test is important if surgery is being considered as a treatment for mesothelioma.
A PET scan uses radioactive materials (radiopharmaceuticals) to detect changes in the metabolic activity of body tissues. A computer analyzes the radioactive patterns and makes 3-dimensional colour images of the area being scanned. It is used to see if mesothelioma has spread to distant sites in the body, if other imaging tests are not conclusive and if surgery is being considered.
Sometimes a combined PET/CT scan may be done. It joins CT scans and PET scans into one procedure. A PET/CT may provide a more complete picture of a tumour’s location and growth than either test alone. PET scan and PET/CT are not as readily available as other imaging tests and are only available in certain centres in Canada.
Seeing my sister Erin – a young mother – struggle with the emotional blow and then the physical toll of cancer treatment made me want to do something to help women feel confident.
Thousands of Canadian Cancer Society volunteers work in regional cancer centres, lodges and community hospitals to support people receiving treatment.