Cancer is one of the top 10 causes of death globally, and in the US, the disease is ranked second, just behind heart disease in overall fatalities. Cancer develops when cells start dividing unnaturally, to the point that they form big masses or tumors. These clumps of out-of-control cells are adept at redirecting blood supply and nutrients to themselves and increasing their growth.
When tumor cells break away from the main site and spread to other parts of the body, the condition is called metastasis, as the wandering cells start forming tumors all over the body. As tumors compete with organs for nutrients, the organs eventually lose the battle and start to shut down. This is how cancer kills.
But metastasis does not happen until the later stages in the disease, except in rare cases of fast-spreading cancers. If cancer is diagnosed in the early stages, tumors can be contained and removed before they spread to the rest of the body. A course of radiation or chemotherapy can kill off any traces of cancer cells and the patient goes into remission.
The problem lies in the early detection of cancer. Often, by the time symptoms like extreme weight loss, blood in urine, swollen lymph nodes, lumps in the breast, and so on are detected, the cancer has already advanced. This is why a comprehensive cancer screening test is vital even before the symptoms are noticed.
Cancer Blood Test before Symptoms Arise
The problem with cancer lies in its early detection. Often, by the time symptoms like extreme weight loss, blood in urine, swollen lymph nodes, lumps in the breast, and other possible signs are detected, the cancer has already advanced. This is why a comprehensive cancer blood test is vital even before the symptoms are noticed.
Blood testing for cancer is especially important for people who have a history of the disease in the family. Patients who are in remission are given a schedule by their doctor of how often they need to get screened to check for a recurrence of the disease. But people who have never had cancer usually don’t think of getting a check-up. And with so many types of cancer, it can be difficult to know what to look for and how many tests to get done.
Luckily, eight types of cancer can be detected using a single sample of blood, as they have markers that show up relatively early and are present in the bloodstream. One sample of blood can be used to test for all eight of these cancers and either rule out their presence or detect those that have developed. A cancer blood test is a good place to start for people who want to undergo annual cancer screening.
How Does Cancer Blood Testing Work?
The proliferation of cancer cells is brought about by mutated DNA. Fragments of the erroneous DNA and certain proteins get released into the bloodstream as the tumors start to grow. Some of these proteins include antigens released by the tumor. A total of 16 gene mutations and a number of proteins related to cancer can be identified from the blood. Each of these proteins corresponds to a different type of cancer, making it possible to identify all eight types of cancer using just one blood sample.
Cancer blood tests can also be performed to detect circulating tumor cells (CTCs), which are another indicator of malignant cells in the body. The cells that are identified in the blood can be used to trace back to where they originated from and find the part of the body where the tumor might be.
Which Cancers Does Blood Testing Show?
These are the eight cancers that have specific protein markers in the blood that help in a diagnosis using a cancer blood test:
- Lung cancer: Two protein biomarkers — LG3BP and C163A — can be used to detect whether a patient might be suffering from lung cancer. Any indication by the blood test that the patient might have lung cancer can be followed up with a chest X-ray to look for nodules in the lungs. However, higher concentrations of these proteins in the blood have been found to be 98% accurate at diagnosing lung cancer, and blood testing is less invasive than methods like a biopsy.
The blood test for lung cancer can be done on its own or as a follow-up to a scan or X-ray that shows nodules in the lungs. There is a less than 50% chance that the nodules are malignant if the tests for these biomarkers are negative.
- Breast cancer: The biomarkers that can be tested for in the blood to diagnose breast cancer are CA 15.3, TRU-QUANT, and CA 27.29. If the marker that’s evaluated is present in the blood, the results might need to be followed up with other tests to confirm a malignant breast tumor. These are also done to check how a patient is responding to treatment like chemotherapy and whether the cancer has recurred.
If a woman finds a lump in her breast, it’s advisable to have a breast cancer blood test. But it’s recommended that you consult with your doctor if you find any abnormal growth or test results that are not within the normal range.
- Colorectal cancer: Carcinoembryonic antigen, or CEA, is an indicator of colorectal cancer. Malignant cells in the colon have been found to release antigens into the bloodstream. CEA levels in the blood are also monitored during the treatment of colorectal cancer to check how effective it is, as an increase in levels might lead to a change in treatment.
If there’s a suspicion of colorectal cancer, the patient might be required to undergo a colonoscopy to remove any polyps. By comparison, a colon cancer blood test is a lot less invasive and can help prevent unnecessary procedures, if possible.
- Liver cancer: Protein alpha-fetoprotein (AFP) in the blood serum is a biomarker for liver cancer. An increase in AFP levels in the blood might result in the test being repeated after a couple of weeks. If the concentrations have increased further, it’s a strong indicator of hepatocellular carcinoma (HCC).
Rising AFP levels are also an indicator of a person who’s at high risk of developing HCC. A person suffering from cirrhosis of the liver also shows high AFP levels in the blood. If monitored and treated on time, HCC can be prevented altogether. Rising AFP levels in the blood are usually followed up by imaging tests like a CT scan or an MRI.
- Stomach cancer: Stomach cancer, or gastrointestinal cancer, can be diagnosed by looking for three biomarkers: CEA, cancer antigen (CA) 19.9, and CA 72.4. CTCs can also be checked in a blood sample to diagnose gastrointestinal cancer.
If there are indications that there might be a malignant tumor in the gastrointestinal tract, more tests can then be conducted to locate the tumor and start treatment. A cancer blood test can be used as an early detection tool that can greatly help in a positive prognosis of the disease.
- Ovarian cancer: Ovarian cancer originates in the ovaries and affects about 21,000 women in the US annually. Ovarian cancer is treatable and has a high survival chance when detected early. Most cases are seen in women over the age of 63. An annual cancer blood test to screen for ovarian cancer for women over 60 could help control the disease.
CA125 is the biomarker in the blood used to diagnose ovarian cancer. A high level of CA125 in the blood is a strong indicator of this type of cancer and should be followed up by other tests.
- Pancreatic cancer: Pancreatic cancer is a fast-spreading cancer, and patients can benefit greatly from an early detection. Some symptoms of pancreatic cancer include a loss of appetite, weight loss, and diabetes. These symptoms, along with a cancer blood test that shows elevated levels of CEA and CA19.9, could warrant further investigation.
Pancreatic cancer can be confirmed with the help of imaging technology and a biopsy. The earlier the disease is caught, the better the patient’s chances of healing and going into remission.
- Esophageal cancer: Esophageal cancer is one of the most common cancers in the world. It’s usually detected by carrying out an endoscopy and taking a tissue sample of the tumor to do a biopsy. These invasive methods can be put off until necessary if a cancer blood test can first be done to check for certain biomarkers that are indicative of a malignant tumor.
The blood test for esophageal cancer looks for antibodies against tumor-associated antigen (TAA), immunohistochemical (IHC) biomarkers or m-RNA-based biomarkers.
Personalabs Cancer Blood Testing
At Personalabs, we have highly sophisticated and accurate blood tests to screen for cancers. If you’re concerned that you might be at high risk, you can order a cancer blood test from us to put your mind at ease. We don’t need a doctor’s order and you can rest assured that your results are 100% confidential.
We also provide online medical assistance if you need help in interpreting the results or wish to consult with a doctor. What you do with your results once we’ve delivered them is completely at your discretion. Contact us to learn more about our lab testing services.