CA 19-9

CA 19-9 is a serum antigen (monosialoganglioside) that has increased diagnostic use in management of several (mainlymalignancies, mainly of hepato-pancreatico-biliary) malignancies origin. It is nonspecific, however, and can rise in both malignant and nonmalignant conditions.

Elevation of serum CA 19-9 has been associated with many conditions including the following

• hepato-pancreatico-biliary malignancies
  • cholangiocarcinoma
    • a CA 19-9 of > 100 U/ml may have a sensitivity of 50% in diagnosing cholangiocarcinoma ³
    • when it is elevated with proven malignancy, larger unresectable tumours are generally thought to have higher levels of elevation 
  • pancreatic adenocarcinoma
    • with an upper limit of normal at 37 U/ml, the assays overall sensitivity is approximately 80% and its specificity is 90% for pancreatic adenocarcinoma ¹
    • when it is elevated with proven malignancy, larger unresectable tumours are generally thought to have higher levels of elevation ⁵
• other malignancies
  • colorectal carcinoma
  • gastric carcinoma ^{ref required}
• nonmalignant conditions ⁴: the increase in generally considered to be small
  • nonmalignant obstructive jaundice: usually should go down after relief of obstruction unless there is an associated malignancy ⁷
  • heavy tea consumption ⁶
  • idiopathic with no definite cause found ⁴

History and etymology

It was initially discovered by H Koprowski and co-workers in 1980 in associated with colon and pancreatic cancer ⁹.