New research has revealed how it is possible to detect cancer with a blood test even before the symptoms start showing.

Oncologists at the Johns Hopkins University have taken a big step towards developing the test that can detect a majority of cancer types including breast, lung, ovarian and colon. 

The study titled "Direct detection of early-stage cancers using circulating tumor DNA" was published in the journal Science Translational Medicine.

According to the study, the test is still developing and is far from being used to detect cancer, but is a step toward it.

Dr. Victor Velculescu, professor of oncology and pathology at the University's  Sydney Kimmel Comprehensive Cancer Center and who led the study, said, “There is a lot of excitement about liquid biopsies, but most of that has been in late-stage cancer or in individuals where you already know what to look for. The surprising result of this study is that we can find a high fraction of early-stage patients having alterations in their blood.” 

According to reports, the test was able to determine tumour DNA in almost half the patients tested, all of whom had been diagnosed with stage one cancer. The test was more accurate in later-stage cancers. 

There already are a lot of liquid biopsies available in the medical field to determine cancer, if the test comes to fruition it would be the first of its kind to actually be able to spot the disease before the first symptoms start to show. 

In the abstract of the study, Dr. Velculescu said the team developed an approach called a targeted error correction sequencing (TEC-Seq) that "allows ultrasensitive direct evaluation of sequence changes in circulating cell-free DNA using massively parallel sequencing."

“We have used this approach to examine 58 cancer-related genes,” the team wrote in their report.

The method involved sequencing DNA over 30,000 times to look for alterations in DNA from tumor cells that float in the blood. 

The study of 194 patients found that people who had cancer had more of this DNA in their blood. 

The doctors identified more than three-quarters of colorectal cancer patients, two-thirds of ovarian cancer patients, and most of the lung and breast cancer patients, who exhibited detectable alterations in driver genes.  

Driver genes are the mutations within a gene that confers a selective growth advantage (thus promoting cancer development). 

Despite great results, the test still missed out on a large percentage of cancers and needs further research, according to a report.

The downside to the whole test is the prohibitive cost attached to it. Genetic sequencing is an expensive affair, however, Dr. Velculescu assured the costs were steadily coming down.

However, Dr. Velculescu is positive that these tests would prove to be monumental in the field of science as it could help save many lives as cancer stands as a second killer overall in the United States.

"The survival difference between late stage and early stage disease in these cancers would account for more than a million lives each year worldwide," he said.

As of now, John Hopkins has patented the developing test.