Results from a study by Guardant Health (NASDAQ:GH), presented at the American Association for Cancer Research Virtual Annual Meeting II, showed the company's Lunar-2 blood test can detect early-stage colon cancer.

Lunar-2 uses blood to detect cell-free DNA from tumor cells using three different types of changes seen in tumor DNA compared to normal DNA. After training the test on known samples, the study tested blood blinded samples from 113 patients who were known to have colon cancer and 88 patients who were deemed negative for colon cancer by colonoscopy.

In the study, Lunar-2 had a sensitivity of 90%, meaning it detected 90% of patients who actually had colon cancer. The test had a specificity of 96.6%, meaning it correctly identified 96.6% of patients who didn't have the cancer.

The results compare well to Exact Sciences' (NASDAQ:EXAS) stool-sample test Cologuard, which had a sensitivity of 92% to 94% depending on the stage of colon cancer and a specificity of 90% in patients with negative colonoscopy results.

Doctor talking to a patient in his office

Image source: Getty Images.

Shares of Guardant Health were up 5% at 3:22 p.m. EDT on the news, while Exact Sciences had slipped 2%.

Guardant Health is currently running a prospective clinical trial of 10,000 patients at average risk for colon cancer to validate the Lunar-2 test. The healthcare company was shooting for enrolling the study by November 2021, but COVID-19 has thrown a wrench in the enrollment process, with patients delaying non-emergency doctor visits.