My tumor maker: ca 19-9 is 10 is it cancer?

WHY WAS IT CHECKED? Tumor markers are not used to diagnose cancer. A biopsy for tissue diagnosis is the gold standard. Ca 19-9 normal range is 0 - 37 depending on your reference lab. Can someone with cancer have a normal level? Yes. When there is a diagnosis of cancer and ca 19-9 is elevated it can be used to indirectly monitor response to therapy. Ca 19-9 can be elevated with pacreatobiliary cancers.
Not likely. Ca 19-9 is not a good marker for cancer diagnosis and a level of 10 is barely above the average normal value.