Pancreatic cancer and CA19-9

I can't answer the CA 19 question, but thank you for posting encouraging news for yourself. It will help me stay positive. Prayers for you , and all, for more positive outcomes in treatments.

I have done 14 rounds of same chemo, then y90 and last month a pancreadectomy. My CA-19-9 got to normal range but after the Y90 it jumped up . It’s now trending down again. I know your fears as I am sitting on them as well, but 2 points could even be a different lab processing results. My experience so far says 2 points not a worry; but I would be excited for the next labs. I’m told it’s about the trend more than anything. Sounds like you are doing great-the F drugs are no nonsense!!

Going up only two points is insignificant. I hope they told you that it is NOT a reliable indicator of whether you have pancreatic cancer. It is only one part of making a diagnosis. Many things can make it fluctuate. What my oncologist told me was she looks for a pattern of it increasing over time. I have mine checked every month. 67 is a very low number. Stay strong and positive.

TY

What is Y90??

Having initially trained as a medical technologist performing assays in clinical hospital labs using similar immunoassay techniques like is done for determining the value of CA19-9, one had to be versed in the limitations of the assay, interfering substances, intra and inter variability of a particular test method. There are a number of manufacturers of the CA19-9 assay (Roche, Abbott, Siemans) and many reference laboratories and large medical centers where there is a high volume of patients to justify doing the test in-house. Each manufacturer has determined by statistical analysis what the variability and error of measurement is for their test kit.

A variation of +/- 2 is insignificant. During my clinical research careeer, I worked on developing a number of assays of blood and urine analytes and remember all to well having to do a substantial amount of statistical analysis to determine variation in results called standard error of the mean. Samples were run in triplicate….something that is not likely done in clinical testing vs when a test is being developed and optimized.

During the pandemic I had to have my CA19-9 done at a large nation testing lab instead of the medical center I go to for exams and surveillance. The value was 5 points higher. When I went back to the hospital lab for testing, my value was what it always measured at. Ever ask a nurse to recheck your blood pressure measurement when the first result seemed higher or lower than what you normally run? I have and usually the second measurement falls more in line with what I normally run. That is the problem when a test value of n=1 is used.

A rise of 2U/nL of CA19-9 is within the margin of error of the CA19-9 assay. It would be interesting to see what the values would be had your sample been run in triplicate and whether two of the three matched with one outlier or they all matched. The change in value is also not statistically significant to indicate a change in disease treatment status. There are also benign conditions that can cause variations…from inflammation to the use of the vitamin B-7 commonly known as Biotin contained in both pharmaceutical and cosmetic products. The next test point is the one that will give an answer and there needs to be a significant increase to indicate concern is warranted.

This link to Quest Diagnostics indicates a margin of error of 3U/nL.

Thank you for this response. Mine has been processed in two different labs and I have always wondered if that could be an underlying factor. Appropriate or not, we live to see these numbers trend <35!

Y90 is done by an Interventional Radiologist. They embolize the tumor (s)with a precision method to cut off blood flow to the area. So far it has shrunk my liver tumors and they “believe”they are necrotic. I’m still asking for proof. Next up is a PET scan

There was a study done by an Italian group on the CA19-9 assay and one of the recommendations in the paper is using the same lab for consistency in reporting results. This is why I always go to the same medical center to have the test done. And as I noted in the previous reply, the one time I was directed to have it done by a National Reference Laboratory due to Covid concerns, the value reported out was double- 10 instead of 5. So to try and reduce the amount of variables in testing, I use the same lab. The same holds true for when I have imaging done. I continue to do to the hospital where I was treated rather than a more convenient neighborhood imaging center. Going to the medical center maintains consistency in the instrumentation and the radiologists doing the interpretation of the image. There is a familiarity between my case history and the same radiologists reviewing the images.

Stay STRONG and Thrive!!! 🙂