Better test developed to detect liver cancer

Scientists in China have identified DNA markers specific to liver cancer, which is expected to greatly improve accuracy in diagnosis of one of the most common cancers in China.

Using the new technology, doctors can provide a diagnosis and prognosis to patients with liver cancer through simple blood tests. That could decrease the chances of a misdiagnosis by more than half, according to Xu Ruihua, director of the Sun Yat-sen University Cancer Center in Guangzhou, Guangdong province, who has led the research.

After five years of research, involving over 100 researchers from different institutes, the scientists identified methylation in DNA circulating in the blood that is related to liver cancer. Methylation, like genetic mutation, is an abnormal genetic change that can cause cancer, Xu said.

Using samples of circulatory system DNA from a large group of 1,098 liver cancer patients and 835 healthy people for comparison, they constructed a diagnostic prediction model that showed high diagnostic specificity and sensitivity, Xu said in the study, which was published in Nature Materials, a science journal, on Monday.

Liver cancer is one of the most common cancers in China. The number of new cases reached 466,000 in 2015, and the cancer caused 422,000 deaths that year, according to the center, accounting for more than half of the world's liver cancer cases and deaths.

Currently, a method that is often used for diagnosis of early-stage liver cancer is to check the level of alpha fetoprotein, which normally remains at very low level in the blood but increases significantly in many liver cancer patients.

But the method is ineffective for 40 percent of those who have liver cancer, and 20 percent of patients with no liver cancer are diagnosed as having the disease because rising alpha fetoprotein levels can also be caused by factors such as pregnancy and hepatitis, Xu said.

But using the new method, about 85 percent of cancer patients can be diagnosed and only about 7 percent of patients are misdiagnosed, he said.

The new method is more accurate and much simpler and does not require other tests such as a liver biopsy, Xu said.

The center has developed tests for liver cancer based on the research, and they will be used on people with a high risk of the disease at Sun Yat-sen University's Cancer Hospital, he said.

The tests are expected to be widely available for clinical use by the end of the year, he said.

Zhu Jiye, a professor of liver diseases at Peking University, said the new findings represent progress in the early diagnosis of liver cancer, but he thinks more research is needed before it significantly improves diagnosis of liver cancer in clinical practice.

"We recommend that people with a higher risk of liver cancers go to the hospital for screening regularly for early diagnosis and treatment," he said.

A doctor at Beijing Friendship Hospital who specializes in liver disease treatment, who asked to remain anonymous, said that worldwide, several methods are used in testing and screening for liver cancer, including blood tests, ultrasound and computed tomography scans.

"Most liver cancer patients are diagnosed only when at late stages in China, and the major reason is they ignore their condition and fail to come to hospitals for regular tests," he said. "We suggest patients with a high risk to go to hospitals every six months for early diagnosis and treatment."