Medicare issued a draft local coverage determination rescinding Medicare's coverage of Vectra DA, Piper Jaffray analyst William Quirk tells investors in a research note. The draft LCD cites Vectra DA is not in treatment guidelines and a recent study found there was no association between Vectra DA and disease activity, the analyst notes. He finds the news surprising as he believes the test is well validated. He estimates that cutting Vectra DA's Medicare coverage would impact Myriad's revenue by $35M-$40M annually and "impede one of the company's growth drivers." On the positive side, Quirk notes Medicare also issued a draft LCD covering Prolaris for intermediate-risk patients, a market he estimates at $65M. The analyst keeps a Neutral rating on Myriad with a $21 price target.