Discussion
Clinical Significance and Limitations of CA 19-9
CA 19-9 is a tumor-associated antigen that was first
described in the early 1980s.5,6 A large literature review of
24 pancreatic cancer studies in 1990 by Steinberg and associates
showed that when using 37 kU/L as a cutoff point,
CA 19-9 was reported to have a median sensitivity of 81%
and specificity of 90%, whereas increasing the cutoff point
to 100 kU/L improved specificity to 98% but reduced
sensitivity to 68%