** Shares of cancer test maker Exact Sciences EXAS.O rise 17.6% to $101.38 premarket
** Medical device maker Abbott ABT.N says it will acquire EXAS for about $21 billion, to tap into the fast-growing cancer diagnostics segment
** Under terms of the deal, ABT will acquire all outstanding shares of EXAS for $105 per share, a premium of 21.8% to EXAS' last close price
** Deal expected to close in the second quarter of 2026
** Up to last close, EXAS up 53.4%, ABT up 11.5% YTD
(Reporting by Sneha S K)
((Sneha.SK@thomsonreuters.com;))