Researchers find new biomarker that can detect a dangerous type of liver cancer

A team of researchers at the Medical University of South Carolina has discovered a way to easily detect a dangerous type of liver cancer in the human body. They were able to identify a biomarker specific to intrahepatic cholangiocarcinoma (iCCA), one of the most lethal subtypes of liver cancer.

What are CCA and ICCA?

Cholangiocarcinoma (CCA), also known as bile duct cancer, is the second most common type of liver cancer. It grows in small tubes called bile ducts that carry bile, a fluid that helps with digestion. Bile ducts, in turn, connect the liver to the gall bladder and small intestine.

This rare cancer generally affects individuals over the age of sixty-five and is slightly more common in men than women.

"In general, the incidence and mortality rates of cholangiocarcinoma appear to be increasing globally and across all age groups, including younger people, but current data show this increase varies between the different subtypes," the Global Cholangiocarcinoma Alliance reports.

There are three subtypes of CCA, each named after where they grow in the bile ducts. One of them is intrahepatic cholangiocarcinoma (iCCA), the least common form of CCA which accounts for only 10 per cent of all cases. iCCA is a type of cancer that grows in parts of the bile ducts that can be found in the liver.

According to statistics from the National Cancer Institute, for people with intrahepatic cholangiocarcinoma that has been found at an early stage, 24 per cent are alive five years after diagnosis, but if not found early, 8 per cent are alive five years after diagnosis.

"Early detection saves lives. If you identify patients who have early-stage cancers, no matter what cancer, they tend to have much longer survival time," Mehta stated.

However, CCA is hard to diagnose. Symptoms can only be seen once the cancer has progressed and the tumours have grown larger, with some being yellow skin and eyes (jaundice), itching, weight loss, and abdominal pain. Then again, the main symptoms of this disease are also common among other types of liver cancer.

"It is impossible to tell if people experiencing these symptoms have liver cancer or some other liver issue," said Ochoa-Rios. In situations like these, a specific and reliable biomarker is ideal.

What are biomarkers?

Biomarkers are molecules that indicate normal or abnormal processes taking place in the human body, and may also be a sign of an underlying condition or disease. Cancer biomarkers can include a variety of different anatomical parts and processes. These can vary from proteins to gene mutations, gene rearrangements, extra copies of genes, and missing genes, My Cancer reports.

CA 19-9, the current biomarker being used to identify CCA, is not very specific, Ochoa-Rios explained. "That same marker is also used to diagnose other types of liver conditions and even other types of cancers as well," she said.

Since a positive CA 19-9 test does not automatically point to an iCCA diagnosis, the patient still has to undergo general imaging tests. This tedious process could delay diagnosis and treatment, potentially further worsening the individual's condition.

To solve this problem, the team has found a biomarker specific to CCA. Mehta boasted that they believe they have found a "novel serum biomarker of CCA". In tissue samples from patients with CCA, the researchers found certain changes to a type of sugar called N-glycan, which is found in proteins. Though the reason for these N-glycan changes is not yet known, they occur consistently in tissue with CCA, but not in healthy tissue or tissue with other types of liver cancer.

The team further found that these changes could be identified in blood samples, allowing them to function as a biomarker and removing the need for invasive tissue biopsy. Another positive thing about it is, unlike CA 19-9, this new biomarker could help rule out other diseases.