What happened

Shares of Exact Sciences (EXAS -0.46%) were soaring 9.8% higher as of 3:38 p.m. EDT on Thursday. The company announced on Wednesday that new data for its Oncotype DX tests will be showcased at the upcoming American Society of Clinical Oncology (ASCO) annual meeting in June. However, the primary catalyst was Guardant Health's (GH 4.38%) announcement on Wednesday of results for its blood test for early-stage colorectal cancer.

So what

It's not that Guardant Health's results for its Lunar-2 assay were bad; they weren't. The company reported an overall sensitivity of 91% in the detection of early-stage colorectal cancer with a specificity of 94%. Sensitivity is the ability of a test to correctly identify the presence of the disease, while specificity is the ability of a test to correctly identify people without the disease.

Scientist wearing a mask holding a vial with a blood sample

Image source: Getty Images.

Those results appear to put Guardant Health in a good position to obtain reimbursement from the U.S. Centers for Medicare and Medicaid Services (CMS). However, Exact Sciences' Cologuard stool-based colorectal cancer screening test should still be the market leader. That news was enough to provide a nice boost for the healthcare stock

Now what

The main thing to watch with Exact Sciences over the near term is how the COVID-19 pandemic impacts its business. The company stated in its Q1 conference call that in-person visits in March were roughly half of what they were before the pandemic, with patient wellness visits down between 10% and 20%. As COVID-19 concerns ease with more Americans receiving vaccines, more patients could go back to visiting their doctors -- which would likely boost the company's sales.