Detecting cancer as early as possible is key to successful treatment and researchers at the Stanford University School of Medicine have created a new test that could make early detection easier and more accurate. Unlike other cancer discovery methods that require a biopsy or other visible signs of the disease, the Stanford method uses a simple blood test that searches for cancer DNA in a patient's blood.

The new test is called cancer personalized profiling by deep sequencing (CAPP-Seq) and it searches for stray cancer molecules that are floating in a person's bloodstream.

It is so sensitive that it can spot a single cancerous molecule of cancer DNA even when it is located among 10,000 healthy molecules. The test only works on solid or liquid types of cancer, the kind that create tumors, but since these types account for 80 percent of all known cancers the test could prove immensely beneficial.

"We set out to develop a method that overcomes two major hurdles in the circulating tumor DNA field. We are trying to develop a general method to detect and measure disease burden," said Dr. Maximilian Diehn, an assistant professor of radiation oncology at Stanford University's School of Medicine. 

The initial test results had the procedure finding the cancer in 50 percent of the test subjects who had stage 1 lung cancer. The procedure is even more effective with those unfortunate enough to have more advanced cancer, spotting it 100 percent of the time.

"The initial impetus was having something I could use in my own patients ... as a blood test that would let us both detect the presence of cancer as well as monitor how a patient's cancer responds to various treatments," he said.

In addition to detecting cancer in new patients, the test will enable doctors to track whether people believed in remission or cured are suffering a recurrence. Currently, the standard procedure is to just wait and see if the cancer returns.

"If there is cancer DNA in the body left, that suggests there are still cancer cells left, so that patient is probably not cured," he says, "whereas if the cancer DNA is gone, that suggests the patient is likely to be cured."

Diehn did not say when the new procedure would leave the test phase and become a standard cancer detection tool.