Can Blood Tests Detect Cancer?

In 2012, over 14.1 million people worldwide drowned in a sea of cancer, with just 5.9 million managing to swim back to land. About 2.5 million Indians are fighting for their lives against cancer every year. These statistics raise questions about how to combat such a disease, how is cancer detected, is there a simple test like a blood test that detects cancer, what if it is diagnosed too late, can it be cured, how it is cured, etc. Many people have this concern that they followed a risk-reducing lifestyle like avoiding tobacco, good dietary habits, protection from the sun, immunisation, and safe sex but still developed cancer. Of course, these healthy habits reduce the probability of cancer but do not guarantee the prevention of cancer. In such cases, as well as in all the other instances, an early diagnosis can be of tremendous help in your battle against cancer. The first diagnostic step for most diseases is made simple with just one test, the blood test.

Blood Tests for Cancer:

Let us have a look at which blood tests can help in the detection of cancer, and how?

Complete blood count (CBC): It is the most common type of blood test that detects the number of various blood cells. It may be useful in the detection of blood cancers if the count is hugely lesser or higher than the standard value. In leukaemia, the CBC indicates abnormally high or low white blood cell (WBC) counts, and abnormalities of the red blood cells or platelets are observed. In a few cases, immature WBCs may also be seen. In multiple myeloma, low red blood cell (RBC), WBC, and platelet counts may be seen. These little variations in the CBC are frequently overlooked or misconstrued as symptoms of another disease, and cancer is not considered an option. This major mistake delays the early diagnosis of cancer. A bone marrow biopsy can be used as a confirmatory test for blood cancer.
Blood protein testing: This test examines the proteins in your blood and aids in the detection of particular abnormal proteins called immunoglobulins that are sometimes elevated in people with multiple myeloma. Immunoglobulin levels may be elevated in some other conditions as well, hence additional tests and bone marrow biopsy will help in diagnosing the condition and prevent delay in the detection of cancer.
Tumour marker tests: Tumour markers are the chemicals produced by tumour cells in your blood. Cancer antigen-125 (CA-125), cancer antigen-19-9 (CA-19-9), and cancer antigen-15-3 (CA-15-3) are a few tumour markers that are elevated in various types of cancers. The CA-125 level in blood is measured for early diagnosis of ovarian cancer in high-risk patients such as patients with a strong family history of ovarian cancer or patients with a gene mutation. Certain types of cancers release CA 19-9 into the blood. A high level of CA 19-9 is often seen in pancreatic cancer, but other cancers or infections of the liver, gallbladder, and pancreas may also cause it. CA-15-3 is a protein produced by normal breast cells, but its level rises in the case of breast cancer. The level of prostate-specific antigen, which is a tumour marker derived from the prostate gland, may rise in the presence of prostate cancer. Thus, measuring the level of various tumour markers in the blood is very helpful for the early diagnosis of cancer. This very basic blood test will prevent the advancement of cancer, and you will be able to fight back against the enemy when it is in the early stages. Tumour markers may also be produced by some normal cells in your body, resulting in elevated levels of markers. This restricts the effectiveness of the tumour marker tests in cancer detection.
Circulating tumour cells tests: This is a group of recently developed tests that are used to detect cells that have moved from an original site where cancer has begun and are floating in the bloodstream. The presence of these floating cells indicates cancer, and you can start with your cancer therapy in the very initial stages when your body is strong enough to deal with it. One of the circulating tumour cell tests is approved by the Food and Drug Administration.
Ploidy analysis: This blood test determines the amount of DNA in the cells. Most cancer cells contain an abnormal amount of DNA.

Early detection of cancer is now possible with simple blood tests, and you can fight easily against the disease.