N.E.D. And other things that go bump in the night

In that brief 3.5-month period after the Whipple during which pathology, MRI, Signatera, Galleri, and CA19-9 said I was NED, CA19-9 was:

12 one month after Whipple
33 two months after Whipple
77 three months after Whipple; MRI spotted recurrent tumor on pancreas head, but biopsy was still negative

Seven weeks later, CA19-9 hit 277, MRI showed more tumor, and Signatera went positive.

Now that I am "ED" and metastatic after 12 rounds of chemo, CA19-9 has decreased to 56, approaching the ULN (Upper Limit of Normal 33-36). It's somewhat reassuring, but I still don't like the trends we're seeing on MRI. Next test, chemo, and MRI this Friday.

Lesson: Low CA19-9 can be deceiving, but not always. High CA19-9 may not mean anything, but should definitely be checked out. In my case, increasing level was the earliest and cheapest indicator of recurrence, beating out two high-priced DNA tests.

The other note I've posted a few times here is that high levels of Biotin (Vitamin B-7) can cause artificially low CA19-9 readings, depending on the test. Screenshot indicating the testing method and equipment is attached below. Per my pharmacy expert, regarding the CA19-9 test: "Impacts on these results are seen with doses of biotin greater than 5 mg taken within 12 hours of the test."

Blue dot on the CA19-9 graph was one month after Whipple; others left of it were before Whipple. The peak of 677 was right after I started chemo. One treatment of Gemcitabine plus cisplatin done at that point. Abraxane was added later that day and corresponds to the decreasing values.

I was 59 at my high before surgery. I was 5 after surgery and 7 months later I am at 3. Not sure that helps as I realize how Blessed I am.

When my tumor was first discovered, CA19-9 was only 20 (normal range from my lab is 3-32). Since surgery it has remained at 7 / 8. Apparently, gall stones can elevate CA19-9 numbers and I saw gall stones mentioned in one radiology report. There are a lot of people where the CA19-9 measurement doesn't seem to be a helpful marker.

CAUSES OF CA19-9 ELEVATION IN NON-CANCEROUS AND MALIGNANT

CONDITIONS

The most common diseases why the CA 19-9 (Carbohydrate Antigen) can be higher than normal are:
* Pancreatic cancer
* Gastric cancer
* Gallbladder cancer
* Colorectal cancer
* Liver cancer
* Rectal cancer
* Pancreatitis
* Cholangitis
* Cholestasis
* Cholecystitis
* Cirrhosis
* Primary biliary cirrhosis
* Hepatitis
* Cystic fibrosis
* Ovarian cancer
* Small-cell lung cancer
* Gallstones
* Asbestosis
* Tuberculosis
* Pulmonary fibrosis

ELEVATED/FALSE VALUES IN CA19-9
https://gut.bmj.com/content/52/6/913
Effects of Biotin (Vitamin B7)
https://www.clancyclark.com/fda-warns-biotin-may-interfere-with-pancreatic-cancer-lab/
Sucontral D for treating diabetes contains Biotin

Thanks …

Sitting at 43.7 and a little nervous (guess that can raise it too!!).

@bobsrdoch , sitting at 43.7 would cause me a little nervousness too, but the real issue is the trend. How often are you getting retested? It's a fairly cheep test, and the more data you have, the more you know what YOUR normal is.

I was disappointed that my hometown pre-Whipple oncologist was only testing my CA19-9 every 4 weeks (every other infusion of Folfirinox) instead of every time (despite drawing blood for CBC/CMP every 2 weeks), so we got 6 CA19-9 readings out of 12 possible, but there was a bit of noise and low confidence in the trend.

I actually had my primary care doc write me an Rx for serial testing at a different lab, which was cheap enough for a self-pay ($27 every two weeks). Despite a "vertical" offset from my other labs, linear regression showed a similar slope between the two labs, but the extra data points added confidence to the trendline.

The biweekly CA19-9 testing with my new chemo has helped produce the smooth, consistent trend in the graph attached to my original post. Friday's bloodwork brought he level down from 55 to 49, and another negative Signatera -- continued encouragement. MRI continuous to show numerous tumors (no new ones), with stable or slight shrinkage in the existing ones. So, low CA19-9 but definite evidence of disease (just stunted for the time being).