A new blood test that screens for colorectal cancer has been found to be nearly as effective as colonoscopy and better than some standard methods at diagnosing the life-threatening condition.

A new study of the test, unveiled at the recent 2018 Gastrointestinal Cancers Symposium in San Francisco, found that it can identify signs of colorectal cancer at its earliest — or even in precancerous — stages, when it can be most effectively treated.

The blood test — a type of “liquid biopsy” — can be administered by a healthcare professional, who collects a routine sample of blood that is then analyzed to see if there are circulating colorectal tumor cells.

The new study involved 620 patients at a hospital in Taoyuan, Taiwan, who were seeking either a routine colonoscopy test or had been previously diagnosed with colorectal cancer, the cancer.net Website reports.

Researchers tested the patients’ blood tested for cancer cells. The results showed that it accurately identified people who had precancerous polyps — a sign of colorectal cancer that colonoscopies are designed to find — or any stage of cancer.

In fact, the accuracy of the blood test was calculated to be 84-88 percent, which is higher than that of a standard colorectal cancer screening test called a fecal occult blood test (FOBT). The odds of a “false positive” result — in which a patient without cancer was incorrectly identified as having it — were less than 3 percent.

Currently, colorectal cancer is found through such tests as the FOBT, colonoscopy, sigmoidoscopy, barium enema, or stool test. But studies show that many people find such tests uncomfortable or inconvenient — particularly colonoscopy, which requires a day of fasting and prep to clear the bowel.

A simple and accurate blood test could be an easier and more affordable screening option and might increase the number of people who undergo screening, experts say.

“Our study is important because there is still some reticence among patients to use stool-based tests or have an invasive exam like colonoscopy to detect colorectal cancer,” said lead researcher Dr. Wen-Sy Tsai, with the Linkou Chang Gung Memorial Hospital in Taipei, Taiwan. “Our results may point to a solution.”

Researchers now plan to test the liquid biopsy technique in additional studies in Taiwan and in the United States.

According to the researchers, this blood test could eventually be used to screen for other types of cancer, such as breast, lung, and prostate cancers.

Colorectal cancer is the fourth most common cancer diagnosed in both men and women in the United States, according to the American Cancer Society. Each year doctors diagnose 97,220 new cases of colon cancer and 43,030 new cases of rectal cancer.