Chinese scientists have discovered a way to detect cancer up to four years earlier than through conventional diagnosis, paving the way for quicker intervention and treatment and a better prognosis for patients.

A paper about the study was published on the website of the United Kingdom-based journal Nature Communication on Tuesday.

The research found a signal for early-stage cancer that can be found in DNA in blood samples for five types of malignant tumors-rectal, esophagus, liver, lung and stomach-before they can be diagnosed by current clinical diagnosis methods, said the research team from Shanghai-based Fudan University.

Through blood screening tests for circulating tumor DNA, the scientists found that the signal could be detected as early as four years before a current clinical diagnosis.

The research was conducted using a biobank from Fudan University's Taizhou Institute of Health Sciences in Taizhou, Jiangsu province. The biobank collected plasma samples from over 120,000 healthy individuals who were cancer-free when recruited into the study.

"When someone was diagnosed with cancer in a hospital, we could trace his or her blood samples collected years before the diagnosis to verify how much time in advance we could have found traces of tumors with our method," said Chen Xingdong, a leading researcher on the team.

Both sensitivity and specificity of the noninvasive test, of which individuals can obtain a result within four hours, were around 90 percent, Chen said.

Compared with early-stage tumors, which have a five-year survival rate of 91 percent, the rate for terminal-stage tumors stands at only 26 percent. Effective approaches to help realize early discovery of cancers are of great significance to individuals and society, doctors said.

Chen said a multi-center study spanning many parts of the country has been designed and will be launched within this year. It will function as a follow-up study before the research results can be potentially promoted for clinical use.