CA 19-9 and pancreatic cancer: What do the numbers mean?

Having an adenocarcinoma and not being a secretor of CA19-9 is known and documented. Approximately 10% of the Caucasian population of North America are non secretors. The cause is related to the Lewis antigen which determines blood group factor. Those with the genetics of the gene that codes for the antigen having Le-a-, Le-b- are non-secretors. Their CA19-9 value will range between -3U/mL and +3U/mL. The reason it is possible to have a negative value is that the inherent error of measurement is +/-3.

My husband was also a stage 1B. Had Whipple in Feb and currently received treatment #9. His CEA numbers were in normal range and CA-19 fluctuates. Was wondering how you are doing and if your Oncologist had any thoughts to reliability of these numbers during Chemo. Thank you.

Hi,
I am still ( since April 2023) on Gemzar/Abraxane (second reduced dose), after Folferinox failed in its six months trying to chase down cancer cells floating around in my bloodstream. Now, they set up camp on my liver. My oncologist looks at trends with CA numbers. I trended up when I started Gemzar, but next test went down. Doctor thought the trend up was attributable to new regimen after a break in treatment. Lots of variables, it seems, affect CA results. Best wishes, and I hope this helps a little.

My body doesn’t make CEA or CA 19-9; totally non-existent even with biopsied cancer present. Mayo said your body doesn’t make them - can’t be used. We watch CT scans. It’s frustrating because others can do blood work once a month and get an idea. I’ll ask if there is any other way on my next visit.

@lvtexas , Did they get enough malignant tissue from the biopsy to "build" a Signatera test?

This is a test that extracts DNA tissue from your original tumor, builds a special "filter" to exactly match its DNA, and then checks later blood samples for evidence of ctDNA (Circulating Tumor DNA) with exactly that pattern. It provides a numerical result in tumor molecules per milliliter, and the trend over time can indicate the response you're having to the chemo.

Ideally it detects the presence of cancer before standard imaging does, but it's not a perfect test (twice returned zero-point-zero while my recurrent tumor was growing) and didn't return a positive (0.14) until after imaging did and my CA19-9 was near 300 (after that post-Whipple low of 12). Since my chemo resumed, the CA19-9 levels have dropped, and the Signatera numbers have all gone back down to 0.00 (which they note doesn't mean no cancer, just below their ability to detect). My PA said if it's > 0.00, you do have cancer, but if it's negative (0.00) it doesn't mean you don't.

We had lots of tissue from my Whipple procedure, and we re-run this Signatera test every 2-3 months to get data that supplements my biweekly CA19-9 tests. I hope they can do this or something like it for you.

I occasionally get static from my insurance company about the Signatera test "not being medically necessary," but always find a way to get it covered. Since you don't produce CA19-9, I think it would be easy to justify as medically necessary along with scans.

I agree. Signatera test is another data point, of which we have very few, without scans every 3months

Mine was at 0 after I was declared NED but rose to .04 in June, in tandem with my CA19-9 rising. Sure enough, a 1 cm tumor reared in my liver. So VERY GLAD all of these screening tools are there. I have the KRAS G12D mutation and am lucky that CA19-9 seems to trend with my disease. There is no immunotherapy or treatment options matched with this mutation as yet. BUT-both fulfurinox and now Gemzar are working! 22 months and thriving!!