What are the different types of laboratory tests used to diagnose cancer?
Clinical chemistry uses chemical methods to determine the levels in body fluids and tissues of chemical components. Blood and urine are the most important substances used in clinical chemistry.
There are several different methods for detecting and measuring nearly every form of a chemical component in the blood or urine. Blood glucose, electrolytes, enzymes, hormones, lipids (fats), other metabolic substances, and proteins may be components for diagnosing cancer.
Some of the commonest laboratory tests are as follows:
Your evaluation can include conducting different blood tests including (but not limited to) cell counts, assessing various blood chemistries, and inflammation markers. We can calculate several things like salts, blood cell counts and heart-specific protein markers (one is called BNP) in your blood. Additional tests can include blood chemistries, liver and kidney function evaluations, and genetic studies). In certain cases, it may be advised to do genetic testing. We may also ask you to join our ongoing studies by enabling us to collect and store some of your blood for further study.
Types of Blood Count test:
- Antinuclear antibody: An antinuclear antibody is a diagnostic test that tests blood levels of antibodies, frequently found in people with rheumatic disease.
- Blood chemistry: A blood chemistry test is a process in which blood samples are tested to determine the concentrations of certain substances released into the blood from organs and tissues in the body. An excessive quantity of material (higher or lower than normal) may be a sign of disease in the organ or tissue that makes it.
- Blood lipid profile: A blood lipid profile measures the levels of each type of fat in your blood: total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and others.
- BNP testing: B-type natriuretic peptide (BNP) testing is a blood test showing the BNP hormone level. BNP is released from the ventricles (heart pumping chambers) in response to increased stress in the wall that occurs with heart failure.
- Complement: A blood test assessing complement level, a group of proteins in the blood; low blood supplement levels are correlated with immune disorders.
- Complete blood count (CBC): A complete blood count (CBC) measures the size, number, and maturity of the different blood cells in a specific volume of blood. This is one of the most common tests performed.
- Creatinine: A creatinine is a blood test used to determine underlying kidney disease.
- C-reactive protein (CRP): A blood test to help detect the presence of inflammation or an infection.
- Erythrocyte sedimentation rate (ESR): Erythrocytes sedimentation rate (ESR) is an indicator of how fast red blood cells fall to the bottom of a test tube. When swelling and inflammation occur, the proteins in the blood clump together and get heavier than normal. Thus they fall and settle more easily at the bottom of the test tube when weighed. In general, the quicker the cells fall in the blood, the more serious the inflammation.
- Faecal occult blood test (FOBT): A faecal occult blood test (FOBT) is a test that can only be used with a microscope to search stool (solid waste) for blood. Small stool samples are placed on special cards and returned for examination to the doctor or laboratory.
- Genetic studies: Genetic studies are diagnostic tests that evaluate for conditions that have a tendency to run in families.
- Hematocrit: A hematocrit tests the number of red blood cells contained in a blood sample. In humans with inflammatory arthritis and rheumatic diseases, low levels of red blood cells (anaemia) are normal.
- Serum bilirubin test: This test tests bilirubin levels in the blood. The liver produces bilirubin, which is excreted in the bile. Elevated bilirubin levels may suggest an obstruction of bile flow or a liver problem in bile production.
- Serum albumin test: This test is used to measure albumin levels (the protein in the blood) and to help diagnose liver disease.
- Serum alkaline phosphatase test: This test is used to measure the level of alkaline phosphatase (an enzyme) in the blood. Alkaline phosphatase is found in many tissues, with the highest concentrations in the liver, biliary tract, and bone. This test may be performed to assess liver functioning and to detect liver lesions that may cause biliary obstruction, such as tumours or abscesses.
- Serum aminotransferases (transaminases): This enzyme is released from damaged liver cells.
- Prothrombin time (PTT) test: The prothrombin time test measures how long it takes for blood to clot. Blood clotting requires vitamin K and a protein that is made by the liver. Prolonged clotting may indicate liver disease or other deficiencies in specific clotting factors.
- Alanine transaminase (ALT) test: This test measures the level of alanine aminotransferase (an enzyme found predominantly in the liver) that is released into the bloodstream after acute liver cell damage. This test may be performed to assess liver function, and/or to evaluate treatment of acute liver disease, such as hepatitis.
- Aspartate transaminase (AST) test: This test measures the level of aspartate transaminase (an enzyme that is found in the liver, kidneys, pancreas, heart, skeletal muscle, and red blood cells) that is released into the bloodstream after liver or heart problems.
- Gamma-glutamyl transpeptidase test: This test measures the level of gamma-glutamyl transpeptidase (an enzyme that is produced in the liver, pancreas, and biliary tract). This test is often performed to assess liver function, to provide information about liver diseases, and to detect alcohol ingestion.
- Lactic dehydrogenase test: This test can detect tissue damage and aids in the diagnosis of liver disease. Lactic dehydrogenase is a type of protein (also called an isoenzyme) that is involved in the body’s metabolic process.
- 5′-nucleotidase test: This test measures the levels of 5′- nucleotidase (an enzyme specific to the liver). The 5′- nucleotidase level is elevated in persons with liver diseases, especially those diseases associated with cholestasis (disruption in the formation of, or obstruction in the flow of bile).
- Alpha-fetoprotein test: Alpha-fetoprotein (a specific blood protein) is produced by fetal tissue and by tumours. This test may be performed to monitor the effectiveness of therapy in certain cancers, such as hepatomas.
- Mitochondrial antibodies test: The presence of these antibodies can indicate primary biliary cirrhosis, chronic active hepatitis, and certain other autoimmune disorders.
- Peripheral blood smear: Blast cell tests, amount and types of white blood cells, amount of platelets and variations in the form of the blood cells are tested during this process.
- Rheumatoid factor (RF): This blood test measures the presence of rheumatoid factor in the blood, an antibody present in most people with rheumatoid arthritis, and other rheumatic conditions.
Complete blood count (CBC)
A complete blood count (CBC) is a blood test that examines the numbers and features of blood cells. Three types of cells it examines are red blood cells (RBCs), white blood cells (WBCs) and platelets.
A CBC measures the following:
- White blood cell (WBC, leukocyte) count. White blood cells protect the body from infection. White blood cells attack and kill the bacteria, virus, or other organism which causes it when an infection develops. White blood cells are larger than red blood cells but less numerous. When a person has a bacterial infection the number of white cells is very rapidly growing. Often the number of white blood cells is used to detect an infection, or to see if the body is handling cancer.
- White blood cell types (WBC differential). Neutrophils, lymphocytes, monocytes, eosinophils, and basophils are the main forms of white blood cells. Another part of this study are immature neutrophils or band neutrophils. Each cell type plays a different role in safeguarding the body. The numbers of each of these white blood cell types provide essential immune system information. Too many or too few of the various forms of white blood cells may help identify an infection, an allergic or toxic reaction to drugs or chemicals, and other disorders, such as leukaemia.
- Red blood cell (RBC) count. Red blood cells carry oxygen from their lungs to the rest of their bodies. They even bring carbon dioxide back to their lungs so they can exhale it. If the amount of RBCs is small (anaemia), the body may not get the oxygen it needs. If the count is too high (a condition called polycythemia), the red blood cells can clump together and block tiny blood vessels. This also makes the transfer of oxygen to the red blood cells challenging.
- Hematocrit (HCT, packed cell volume, PCV). This check tests the number of red blood cells taking up space (volume) in the blood. The value is given in a blood volume, as a percentage of red blood cells. For example, a hematocrit of 38 means that red blood cells make up 38 per cent of the blood volume. Hematocrit and haemoglobin values are the two major tests which show whether there is anaemia or polycythemia.
- Hemoglobin (Hgb). The red blood cells are filled with the haemoglobin molecule. It carries oxygen and gives its red colour to the blood cell. The haemoglobin test measures the amount of haemoglobin in the blood and is a good measure of the capacity of the blood to carry oxygen across the body.
- Red blood cell indices. There are three measures of the red blood cells: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean concentration of corpuscular haemoglobin (MCHC). They are weighed by a computer, and their values derive from other CBC measurements. The MCV displays the red blood cells in proportion. The MCH value is the haemoglobin content of an average red blood cell. The MCHC tests haemoglobin levels in a typical red blood cell. Such numbers help to detect multiple forms of anaemia. Red cell distribution width (RDW) may also be calculated, showing if the cells are all the same, or different sizes or shapes.
- Platelet (thrombocyte) count. The smallest type of blood cell is the platelets (thrombocytes). They are critical in clotting the blood. The platelets swell when bleeding happens, clump together and form a sticky barrier that helps stop bleeding. Uncontrolled bleeding can be a concern when there are too few platelets. There is a risk of a blood clot forming in a blood vessel if there are too many platelets. Platelets may also be involved in artery hardening (atherosclerosis).
- Mean platelet volume (MPV). Mean number of platelets measures the total sum (length) of platelets. Mean platelet volume is used to identify such diseases, along with platelet count. If the platelet count is usually the mean volume of the platelet might still be too high or too low
Why a CBC is done
A CBC is a common blood test. It is often done as part of a routine checkup but can be done at any time.
A CBC may be done to:
- learn information about your general health
- check how well the bone marrow and spleen are working
- help diagnose diseases and conditions that affect blood cells, such as anaemia, infection, blood disorders or leukaemia
- provide a baseline to compare with future CBCs
- check for bone marrow suppression
- monitor a condition (as a part of follow-up)
How a CBC is done
A CBC is normally performed in a laboratory or hospital.
You may be given specific instructions to obey before getting a CBC completed. Some medicines that influence the outcomes of CBC so you might be told to stop taking some medicines before a CBC. Check with the laboratory to see if any drugs should be stopped, and how long.
Typically the blood is drawn from a vein in the arm. To apply pressure to the wound, an elastic band (tourniquet) is wrapped around your upper arm to make it easier to see the veins. You may be told to make a palm so that the veins would stand out. It cleanses and disinfects the skin. A needle is placed into the vein, thus removes a small amount of blood. You may experience a sensation of pricks or stingings.
The blood is collected in a tube and marked with your name and other details that marks you. Occasionally more than one blood tube is collected. Remove the tourniquet, and remove the needle. When the needle is taken off, you can experience slight pain. The pressure is applied before bleeding ceases in the region where the needle was inserted. You that put a small bandage on the area.
A medical expert (a medical technologist) analyses the extracted blood using microscopes and other special equipment.
What the results mean
The results of CBC are given as numbers and sometimes rely on other factors like sex, age and history of the medication. To have the significance they should be compared with a standard reference range or with previous tests. Normal ranges for CBCs can differ slightly from laboratory to laboratory.
Usually, a CBC contains general information which can provide hints to potential health issues for doctors. Input from a CBC lets doctors determine if a diagnosis needs more testing or procedures. It can also help the doctor to establish or update treatment plans.
The best person to describe your CBC findings and what they mean for you is a doctor familiar with your medical background and general health.
Popular terminology for explaining CBC outcomes are:
- anaemia – not enough healthy RBCs or haemoglobin
- leukopenia –low number of WBCs
- neutropenia – low number of neutrophils
- leukocytosis – increased number of WBCs
- thrombocytopenia – low number of platelets
- thrombocytosis – increased number of platelets
For several factors, the CBC results can be high or low. Below are some examples of irregular cancer-related CBC findings.
Abnormal RBC counts
A low RBC count may be due to:
- anaemia due to prolonged bleeding or blood loss (haemorrhage), a diet lacking iron or certain vitamins, certain types of chemotherapy, blood disorders or chronic disease
- Hodgkin lymphoma and other lymphomas
- cancers of the blood, such as leukaemia and multiple myeloma
- some myeloproliferative disorders
A high RBC count may be due to:
- dehydration, such as from severe diarrhoea
- kidney tumours
- lung diseases
- polycythemia vera (a myeloproliferative disorder)
Abnormal WBC counts
A low WBC count may be due to:
- viral infection
- severe bacterial infection
- bone marrow suppression caused by treatments like chemotherapy or radiation therapy
- bone marrow diseases, such as leukaemia or myelodysplastic syndrome (MDS)
A high WBC count may be due to:
- some myeloproliferative disorders
- some types of cancer, such as bronchogenic carcinoma
- certain drugs, such as colony-stimulating factors
- stress, allergies or tissue injury
Abnormal platelet counts
A low platelet count may be due to:
- some types of cancer, such as leukaemia or lymphoma
- autoimmune diseases
- bacterial infection
- viral infection
- chemotherapy or radiation therapy
- having many blood transfusions
- certain drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs) including acetylsalicylic acid (ASA, Aspirin, salicylate) and ibuprofen (Motrin, Advil, Nuprin)
A high platelet count may be due to:
- prolonged bleeding or blood loss (haemorrhage)
- anaemia from low iron levels
- infection (inflammation)
- surgical removal of the spleen (splenectomy)
- polycythemia vera
- some types of leukaemia
A urinalysis is a group of tests done to examine your urine (pee). It finds and measures substances such as electrolytes, sugar (glucose), proteins, blood, cells and bacteria. It may also be called a urine test.
Why a urinalysis is done
A urinalysis is often done as part of a routine checkup, but it can be done at any time. It may be done to:
- learn about your general health
- check how well organs of the urinary system are working
- check for kidney problems, kidney disease, urinary tract infections or diabetes
- check if a woman is pregnant
- help diagnose certain cancers, such as kidney cancer and bladder cancer
- monitor a condition (as a part of follow-up)
How a urinalysis is done
A urinalysis is usually done in a laboratory or hospital.
You don’t typically need any special preparation for a urinalysis. But in some cases, special instructions will be given to you to obey before a urinalysis is completed. You may be told not to eat or drink anything for several hours (called fasting) or to avoid other foods.
It stores the urine in a clean bottle. For urinalysis, a random sample of urine is most commonly obtained. This ensures it produces a small volume of urine at any time of day. But you may be asked to collect the urine at a particular time of day, like first thing in the morning
The lab will give you directions about how to retrieve the urine and how long it should be stored. You should clean the genital region before collecting the urine sample (between the labia in women or the tip of the penis in men). Start urinating in the toilet (the first bit of urine you do not collect); Then collect any urine (called midstream urine or clean-catch) in the bottle.
A 24-hour sample of urine is often needed to help doctors better understand what is happening in the body. This ensures that all of the urine is collected over a 24-hour period. The urine is stored in a large container which often contains or has to be held cold with special preservatives. The laboratory will give you instructions for collecting the urine.
A research expert (a research technologist) then analyses the urine sample. The urine is analyzed with special paper strips (called dipsticks) and a microscope.
What the results mean
A urinalysis offers general information which may offer clues to potential health issues for doctors. Urinalysis information lets physicians determine whether more testing or procedures are needed to make a diagnosis. The details will also assist the doctor in designing or revising treatment plans.
To have value, the findings of the urinalysis should be contrasted with a standard reference set. A doctor understanding your medical background and general health is the best source to clarify the findings of your urinalysis and what they mean for you.
A urinalysis and its results are usually divided into 3 parts:
- what the urine looks like (visual exam)
- levels of certain chemicals or substances (chemical exam)
- cells and bacteria in the sample (microscopic exam)
The following are some examples of urinalysis results and what they may mean.
Visual exam results
Standard urine is light to dark yellow and translucent. Some drugs or foods may cause an irregular colour in the urine. Cloudy urine can mean the sample contains blood cells or bacteria.
Chemical exam results
Urine is usually slightly acidic. Having urine that is very acid or very alkaline may mean you at increased risk of developing kidney stones (hard deposits of minerals such as calcium that start forming in the kidney).
Certain substances are not usually found in urine.
- Protein in the urine (proteinuria) may mean kidney problems, kidney disease, high blood pressure, inflammation of the urinary tract or cancer in the urinary tract.
- Sugar in the urine may mean diabetes or disease of the liver or pancreas.
- Blood in the urine (hematuria) may mean there is bleeding in the urinary tract, which could be caused by cancer.
- Bilirubin in the urine may mean there is cancer in the liver or a bile duct is blocked by a tumour.
Microscopic exam results
Looking at urine through a microscope can find cells, parts of cells and bacteria or other germs.
- An increased number of red blood cells (RBCs) and haemoglobin in the urine means there is blood in the urine.
- An increased number of white blood cells (WBCs) in the urine may mean there is an infection or inflammation in the urinary tract.
- An increased number of epithelial cells in the urine may mean there is an infection, inflammation or cancer.
- Bacteria in the urine may mean there is an infection in the urinary tract or vagina.
Tumour markers are substances either released by cancer cells into the blood or urine or substances created by the body in response to cancer cells. Tumour markers are used to evaluate how well a patient has responded to treatment and to check for tumour recurrence. Research is currently being conducted on the role of tumour markers in detection, diagnosis, and treatment of cancers.
According to the National Cancer Institute (NCI), tumour markers are useful in identifying potential problems, but they must be used with other tests for the following reasons:
- People with benign conditions may also have elevated levels of these substances in their blood.
- Not every person with a tumour has tumour markers.
- Some tumour markers are not specific to any one type of tumour.
Some common tumour markers:
Prostate-Specific Antigen (PSA)
Prostate-specific antigen (PSA) is always present in low concentrations in the blood of adult males. An elevated PSA level in the blood may indicate prostate cancer, but other conditions such as benign prostatic hyperplasia (BPH) and prostatitis can also raise PSA levels. PSA levels are used to evaluate how a patient has responded to treatment and to check for tumour recurrence.
Prostatic Acid Phosphatase (PAP)
Prostatic acid phosphatase (PAP) originates in the prostate and is normally present in small amounts in the blood. In addition to prostate cancer, elevated levels of PAP may indicate testicular cancer, leukaemia, and non-Hodgkin’s lymphoma, as well as some noncancerous conditions.
Ovarian cancer is the most common cause of elevated CA 125, but cancers of the uterus, cervix, pancreas, liver, colon, breast, lung, and digestive tract can also raise CA 125 levels. Several noncancerous conditions can also elevate CA 125. CA 125 is mainly used to monitor the treatment of ovarian cancer.
Carcinoembryonic Antigen (CEA)
Carcinoembryonic antigen (CEA) is normally found in small amounts in the blood. Colorectal cancer is the most common cancer that raises this tumour marker. Several other cancers can also raise levels of carcinoembryonic antigen.
Alpha-fetoprotein (AFP) is normally elevated in pregnant women since it is produced by the fetus. However, AFP is not usually found in the blood of adults. In men, and in women who are not pregnant, an elevated level of AFP may indicate liver cancer or cancer of the ovary or testicle. Noncancerous conditions may also cause elevated AFP levels.
Human Chorionic Gonadotropin (HCG)
Human chorionic gonadotrophin (HCG) is another substance that normally appears in pregnancy and is produced by the placenta. If pregnancy is ruled out, HCG may indicate cancer in the testis, ovary, liver, stomach, pancreas, and lung. Marijuana use can also raise HCG levels.
The CA 19-9 marker is associated with cancers in the colon, stomach, and bile duct. Elevated levels of CA 19-9 may indicate advanced cancer in the pancreas, but it is also associated with noncancerous conditions, including gallstones, pancreatitis, cirrhosis of the liver, and cholecystitis.
The CA 15-3 marker is most useful in evaluating the effect of treatment for women with advanced breast cancer. Elevated levels of CA 15-3 are also associated with cancers of the ovary, lung, and prostate, as well as noncancerous conditions such as benign breast or ovarian disease, endometriosis, pelvic inflammatory disease, and hepatitis. Pregnancy and lactation also can raise CA 15-3 levels.
The CA 27-29 marker, like CA 15-3, is used to follow the course of treatment in women with advanced breast cancer. Cancers of the colon, stomach, kidney, lung, ovary, pancreas, uterus, and liver may also raise CA 27-29 levels. Noncancerous conditions associated with this substance are first-trimester pregnancy, endometriosis, ovarian cysts, benign breast disease, kidney disease, and liver disease.
Lactate Dehydrogenase (LDH)
Lactate dyhydrogenase (LDH) LDH is a protein that normally appears throughout the body in small amounts. Many cancers can raise LDH levels, so it is not useful in identifying a specific kind of cancer. Measuring LDH levels can be helpful in monitoring treatment for cancer. Noncancerous conditions that can raise LDH levels include heart failure, hypothyroidism, anaemia, and lung or liver disease.
Neuron-Specific Enolase (NSE)
Neuroson-specific enolase (NSE) is associated with several cancers, but it is used most often to monitor treatment in patients with neuroblastoma or small cell lung cancer.
Bladder Tumour Marker Studies
Tests to determine cellular characteristics and markers or substances released by bladder cancer cells into the urine.
Some tumour markers doctors look for when diagnosing and treating cancer include:
|Alpha-fetoprotein (AFP)||Liver cancer||Blood test||Tests may help diagnose and stage cancer, determine treatment options and measure response to treatment.|
|Beta-2-microglobulin (B2M)||Multiple myeloma, chronic lymphocytic leukemia, and some lymphomas||Blood, urine, spinal fluid||Tests may help determine response to treatment and prognosis.|
|Beta-human chorionic gonadotropin (Beta-hCG)||Choriocarcinoma and germ cell tumours||Urine or blood||Tests may help diagnose and stage cancer, determine treatment options and measure response to treatment.|
|CA15-3/CA27.29||Breast cancer||Blood||Tests may help diagnose cancer recurrence and measure response to treatment.|
|CA19-9||Pancreatic cancer, gallbladder cancer, bile duct cancer, and gastric cancer||Blood||Tests may help measure response to treatment.|
|Calcitonin||Thyroid cancer||Blood||Tests may help diagnose cancer and measure response to treatment.|
|Carcinoembryonic antigen (CEA)||Colorectal cancer||Blood||Tests may help diagnose cancer recurrence and measure treatment response.|
|Chromogranin A (CgA)||Neuroendocrine tumours||Blood||Tests may help diagnose cancer recurrence and measure response to treatment.|
|HE4||Ovarian cancer||Blood||Tests may help determine treatment options, monitor for recurrence and measure response to treatment.|
|Immunoglobulins||Multiple myeloma and non-Hodgkin lymphoma||Blood and urine||Tests may help diagnose disease, monitor recurrence and measure response to treatment.|
|Neuron-specific enolase (NSE)||Lung cancer||Blood||Tests may help diagnose disease and measure response to treatment.|
|Nuclear matrix protein 22||Bladder cancer||Urine||Tests may help measure response to treatment.|
|Thyroglobulin||Thyroid cancer||Blood||Tests may help monitor response to treatment and diagnose recurrence.|