I am sure you have done some research by now and know that CA19-9 is possibly elevated in conditions related to the stomach, liver, intestines (small and large) and commonly, the pancreas and biliary system (gallbladder and it's related structures).
The common scenario nowadays is that most health screening packages would include cancer markers and abnormal results in these markers naturally lead to alarm and worry.
I would however like to reassure you that based on one blood test result alone, we do not know whether you have cancer or not until we have done the necessary tests. This is because an elevated reading can be from non-cancer causes too e.g. pancreatitis.
What you need, and I would highly advise you to consider, is to undergo a detailed consultation and the necessary investigations to exclude cancers in the organs mentioned above, as well as identify any other non-cancerous conditions that can be serious in their own right.
This would reassure you of the significance of the raised CA19-9 results, and if so needed, undergo the necessary treatment of the reason for the abnormal result as soon as possible.