What is screening?
Screening is a test that looks for signs of cancer before any symptoms appear. Screening can help detect cancer early. If abnormal tissue or cancer is found at an early stage, it is more likely to be treated. If you wait until symptoms are associated to find out, the cancer may have already spread by then.
Scientists are learning more about which people are more likely to develop specific types of cancer. They are also looking at people’s behaviors and environmental factors to see if they are predisposed to cancer. The information from the study could help doctors recommend who should be screened for cancer, which screenings to take, and how often to do them.
It’s important to note that if your doctor recommends screening, it doesn’t necessarily mean you have cancer. Screening is a test that is done when people do not have symptoms of cancer.
If a screening test reveals abnormal results, more tests may be needed to find out for sure if you have cancer, and these tests are called diagnostic tests.
What are the screening tests for liver cancer?
There are many different screening methods for different cancers. Some screening methods can help detect cancer early and reduce cancer mortality; other screening methods can detect cancer in specific populations, but whether they reduce cancer mortality has not yet been proven in clinical trials.
Scientists hope that research will lead to screening methods that have the lowest risk and greatest benefit. Cancer screening trials are also designed to see if early detection (finding cancer before symptoms appear) reduces its mortality. Certain types of cancer have a better chance of being cured if they are detected and treated early.
There is no standard or routine way to screen for liver cancer, but the following tests can be used to screen for liver cancer:
Ultrasound examination
In this test, high-energy sound waves (ultrasound) are bounced off the liver, creating echoes. The image of the liver formed by the echoes is called a sonogram.
CT scan
A CT scan is a test that gives a series of detailed images of the liver from different angles, generated by a computer connected to an X-ray instrument. A contrast agent is given intravenously or swallowed to help show the liver more clearly, and this test is also known as a CAT scan or computed tomography.
Tumor markers
Tumor markers, also known as biomarkers, are certain substances produced by tumors that can be detected in blood, other body fluids, or tissues. High levels of specific tumor markers may indicate the presence of a specific type of cancer in the body.
alpha fetoprotein (AFP) is the most widely used tumor marker for liver cancer. However, other cancers and specific conditions, including pregnancy, hepatitis, and other types of cancer, may also cause AFP to be elevated. Scientists are investigating specific tumor markers that can detect liver cancer early.
Is there a risk associated with screening for liver cancer?
There are some risks associated with cancer screening. Not all screening tests are beneficial, most have some risk, and sometimes decisions about screening methods are difficult. Before starting screening, it is important for patients to discuss the screening test with their doctor to understand the risks of screening and whether the test will reduce the risk of death from cancer.
The following is a list of possible risks associated with liver cancer screening.
Possible false-negative results
A patient may have a normal screening result even if liver cancer was already present, which is called a “false negative.
Patients who get a false-negative result (a result that shows no cancer even though they actually have cancer) may delay going to the doctor even though they have symptoms.
Possible false-positive results
A screening test may show an abnormal result even if there is no cancer, and this is called a “false positive.
A false-positive result (a result that shows cancer when there is no cancer) can cause anxiety and is often followed by risky diagnostic tests and procedures, such as a liver biopsy.
What are the side effects of diagnostic tests for liver cancer?
When screening test results are abnormal, patients may need a liver biopsy to diagnose liver cancer. Liver biopsy may cause the following rare but serious side effects:
- bleeding;
- Hypopnea;
- Bile leakage, which can lead to peritoneal infection;
- perforation of abdominal organs;
- Proliferation of cancer cells along the needle tract may result during biopsy needle insertion and extraction.
The doctor will make recommendations regarding the patient’s risk of developing liver cancer and whether screening is needed.