The updated American Cancer Society guidelines that recommend average risk colorectal cancer screening begin at age 45 years, as opposed to 50 years old, is a "significant incremental positive" for Exact Sciences, Jefferies analyst Brandon Couillard tells investors in a research note. The new guidance could potentially add 10M-13M to the screening population and over $1.5B to Exact's total addressable market, Couillard predicts. Support from the American Cancer Society is an "important first step," but it will take time for payors and U.S. Preventive Services Task Force to update their own policies, the analyst adds. He keeps a Buy rating on Exact Sciences with a $60 price target. The stock in afternoon trading is up 10%, or $5.17, to $57.88.