Exact Sciences falls after disappointing colorectal cancer test results

** Exact Sciences EXAS.O falls 10% to $42.20 after blood colorectal cancer (CRC) test did not meet expectations in trial

** Brokerage BTIG calls it a "worst case scenario"

** This also overshadowed a strong beat and raise Q2

** EXAS on Weds inked deal for exclusive rights to Freenome's blood-based screening CRC test, but analysts noted this excluded multi-cancer tests, which disappointed investors

** At least six brokerages cut price targets

** Shares of rival Guardant Health GH.O gain nearly 17%

** Canaccord Genuity says GH's Shield test performance is a touch better than Freenome's test

** EXAS stock down 27% YTD while GH has surged nearly 70%