My wife had subtotal gastrectomy on 9/26/2006 because of signet ring stomach cancer (stage I). She recovered fine after that. Last month (10/23/2007) she had a blood test and the level of the cancer marker CA 19-9 rised to 86U/ml. Normal value is less than 37U/ml. CT scan found nothing unusual. Last week, she did another blood test and the value is 82U/ml. Do I have to worry about? What should I do? Thanks.