Blood tests for cancer, cancer screening tests and other laboratory tests can help your doctor determine the diagnosis. Blood tests alone can rarely shows Introduce or absence of cancer. If a patient is suspected of cancer, the doctor or recommend some specific blood tests or other laboratory tests such as urinalysis or a biopsy of a suspicious formation in order to establish the diagnosis of cancer.
In general, blood tests can not tell whether the patient has cancer or other noncancerous condition but may offer clues about what happens physician in the patient’s body. Just because the doctor recommended to perform specific blood tests for cancer and look for signs of that disease does not necessarily mean that the patient has the diagnosis.
Blood samples and other biological products such as urine and other body fluids or tissue for biopsy are analyzed in the laboratory to identify changes characteristic of cancer. These tests can show the presence of cancer cells, proteins and other substances produced by cancer cells. Blood and urine tests can provide clues about the doctor and how well the patient’s organs and whether they have been affected by cancer.
Examples of urine and blood tests used to diagnose cancer are:
This blood test commonly used measures the number of different types of blood cells in a blood sample. Blood cancers can be diagnosed if certain types of cells are abnormal in number (too many or too few). A bone marrow biopsy can help confirm the diagnosis of blood cancer.
Analyzing a sample of urine under a microscope can reveal the presence of cancer cells that may originate from the bladder, ureter or kidney.
Blood protein tests
A test that examines various blood proteins (protein electrophoresis) can help detect certain abnormalities of immune system proteins (immunoglobulins) are often elevated in patients with multiple myeloma. Other tests, such as bone marrow biopsy are used to confirm the suspected diagnosis.
Tests for tumor markers
Tumor markers are substances produced by cancer cells can be detected in the blood. But tumor markers are also produced, and some healthy cells in the body, and levels are elevated in non-cancerous conditions. This limits the potential for tumor markers tests to help diagnose cancer.
The best way to use the tests for tumor markers in cancer diagnosis has not yet been determined. And use of certain tests for tumor markers is controversial. Examples of tumor markers are prostate specific antigen (PSA) for prostate cancer antigen 125 for ovarian cancer, medullary thyroid cancer calcitonin, alpha fetoprotein (AFP) for liver cancer and human chorionic gonadotropin (HCG) for sexual cell tumors such as testicular cancer and ovarian cancer.
What is the result?
Test results should be interpreted with caution because many factors can influence, such as variations in body or diet. In addition, the patient should be aware that there are certain non-cancerous diseases that sometimes cause abnormal results of these tests. And in other cases, the cancer may be present even if the tests are normal.
Usually the doctor uses the test results to determine if they are normal. Or the doctor can compare current results with those of tests performed in the past.
What happens then?
Although blood and urine tests can help your doctor giving clues, other tests are usually required to establish the diagnosis. For most cancers, biopsy – a procedure to obtain a tissue sample from the affected area – is usually required for diagnosis.
In some cases tumor marker levels are monitored over time. Your doctor may schedule tests every few months. Tumor markers are often helpful after cancer diagnosis. These tests may be used to determine response to treatment or if the cancer recurs.