Turrini O, Schmidt CM, Moreno J, Parikh P, Matos JM, House MG, Zyromski NJ, Nakeeb A, Pitt HA, Lillemoe KD. Very high serum CA 19-9 levels: a contraindication to pancreaticoduodenectomy? J Gastrointest Surg. 2009 Oct; 13(10):1791-7.