Why CA-19-9 Test not included in annual lab tests

I'm certainly no expert, but I suspect no tumor markers are routinely drawn at annual checkups. Tumor markers are usually described as lousy for definitive diagnosis, but good for tracking treatment progress. Years ago, when I was diagnosed with ovarian cancer, I didn't have the CA-125 tumor marker drawn until after they'd done the ultrasound imaging and I was in the gyn onc's office. This year, my CA 19-9 wasn't drawn until after I was determined to have the ATM mutation. Could you convince your PCP to draw those labs? Maybe, but I wonder whether insurance would pay for them.

I'm sorry for your situation and hope you can get good results from treatment.

Thank you for your reply. I have an appointment with my primary care doctor tomorrow and will ask him…. will respond with his answer.

The gastrointestinal doctors I’ve spoken with say CA 19-9 is not a diagnostic test for PC absent other symptoms. Certainly, insurance won’t pay absent other symptoms; however, it’s an inexpensive test--$50.00 or so-- if lab self-referral is permitted in your state. (Walk-In-Lab is one of many online ordering sites, https://www.walkinlab.com/?gclid=CjwKCAjw38SoBhB6EiwA8EQVLksrl24yZc0t_DG_vMqrjMtzLU1aYDpyguCW6--EXfYvWh6pf0tkOBoC4t0QAvD_BwE).

As to the issue of lab self-referrals, see this Medscape article and the associated comments (often the most interesting part): “Laboratory Testing: No Doctor Required?” https://www.medscape.com/viewarticle/996528. You can register for free with Medscape to view this and many other interesting medical articles, written for health professionals but nonetheless revealing for the layperson (like me). Also, the Medscape website provides detailed “work-up” regimes (written for docs) for most every medical condition.

My gyn-oncologist said that test isn't very useful alone, only as part of a bigger picture. I can't remember why. She ordered it for me because of my genetics and family history.
Based on the replies posted here, it seems like "not very useful alone" is a reasonable thing for a doctor to say, not unusual or irresponsible on the doctor's part.

I think the test measures a waste product in the blood, not the actual tumor. So, even healthy people can have some measurable amount of the waste product in their blood. People with active tumors have more of it. Maybe the docs don't want the blood test to scare people unnecessarily.

Good luck and let us know what your doc says : )

Some researchers are getting a little bit more interested in expanded screening for early detection, but it's really something the patient often has to advocate for.

If you're known to be high-risk, you might get the advanced screening. But unless you've had another close blood relative with pancreatic cancer, or had genetic testing for yourself that identifies mutations associated with higher risk, you probably won't even know you're at risk.

I'm a huge believer in using the open-access walk-in labs for everything. https://www.mdsave.com/ is an affordable option.

A few resources related to screening and detection:
https://www.mdanderson.org/content/dam/mdanderson/documents/for-physicians/algorithms/screening/screening-pancreatic-web-algorithm.pdf
https://letswinpc.org/treatments/screening-programs-save-high-risk-people/
https://letswinpc.org/treatments/screening-pancreatic-cancer/

There are a number of reasons why CA19-9 is not part of a routine screening for the general population. First, it is not specific for pancreatic cancer. It can be elevated in a number of benign conditions related to inflammation. Some examples of benign, non-cancerous conditions that can have high CA19-9 levels are:
* Gallstones
* Biliary infection (cholangitis)
* Blockage of the bile duct (jaundice)
* Pancreatitis (swelling of the pancreas)
* Cystic fibrosis
* Liver disease
* Pulmonary Fibrosis
* Tuberculosis

Every test method can yield a false positive or a false negative result. False positives can cause anxiety in a patient until the result is ruled out/in.

Only the PDAC form of pancreatic cancer secretes CA19-9 except in approximately 10% of the Caucasian population who are non-secretors. They lack the genetic coding for the Lewis antigen associated with blood group factor also associated with the secretion of CA19-9. This makes it possible to have several other rare forms of pancreatic cancer go undetected.

There is the issue of cost to benefit of doing an annual mass screening for a cancer that in the US in 2023 will be diagnosed in approximately 64,050 cases out of an adult population of age 55 and older of 96,799,000 according to the 2020 US Census data (https://www2.census.gov/programs-surveys/demo/tables/age-and-sex/2020/older-population/2020older_table1.xlsx). Testing would have to be justified based on testing benefit over financial burden for taxpayer funding. An individual has the right to make the request for screening and if their private insurance doesn’t cover, can be paid out-of pocket.

For someone that has or had pancreatic cancer such as myself, the CA19-9 test is done multiple times a year even though I am 11 years out from initial diagnosis. For an individual that is deemed high risk as a result of having a genetic mutation associated with pancreatic cancer or a blood relative having been diagnosed, it makes sense to request early detection screening. In high risk individuals, a GI specialist may suggest other methods of surveillance that may include a scan or EUS.

Also, abdominal exercises such as sit ups or a recent colonoscopy will elevate CA 19-9.

Your list of other disorders that can elevate CA 19-9 is interesting. I was diagnosed in July with a bile duct blockage caused by a gallstone (which apparently removed itself, since it wasn't there when I had surgery). Turns out my gallbladder was full of gallstones, and it was removed in early August. I'm now wondering whether this might have the effect of lowering my CA 19-9 reading. It has steadily gone down since we began treatment in April, although to a lesser degree now than earlier. Hope springs eternal! 🙂

The decrease in CA19-9 likely decreased as a result of the clearance of the blockage that was preventing the free flow of bile to your intestine and causing inflammation. With removal of your gall bladder and no other GI tract co-morbidities, your CA19-9 should be in the normal range of 0-37 U or 0-35U depending on the specific test kit assay that is used.

As I've noted before, you can get false positives, false negatives, and abnormal range results from almost any test. (And, specifically false low CA19-9 readings if you're taking large doses of vitamin B-7 (Biotin)).

If you know what your normal values are, it's easier to not freak out over a single result, but use that knowledge to begin closer examination and search for supporting data.

Given the huge number of possible cancer markers (CA19-9 being just one of many), it doesn't make sense for every person to get every test at every physical. CEA might be one exception that is common to more cancers. It's not a sole diagnostic marker for or against any cancer, but might have more bang for the buck than others. And it can still be artificially high or low for many reasons.

More sensible now (in my humble opinion) is to get one of germline (hereditary) DNA tests to identify any mutations you may have that increase your risk of certain cancers. Combine that with any known family history and any environmental risk factors you've been exposed to (smoking, sunlight, herbicides / pesticides, asbestos, etc) and focus your tests on the cancers most likely to be caused by those combinations.

The nice thing about most of the basic cancer marker blood tests is that they can be done inexpensively and frequently (cheaper and more often than your annual doctor visit; much cheaper than CT/MRI/PET), to help you identify your own normal range and trends. But misinterpretation or misuse can put an undue burden on the medical system, in a manner similar to one study about the impact of the Apple Watch EKG feature on cardiologists. https://www.theverge.com/2020/10/1/21496813/apple-watch-heart-monitor-ekg-false-positive

For those interested, some of the most common, affordable cancer marker tests are:
https://cancer.ca/en/treatments/tests-and-procedures/tumour-markers
alpha-fetoprotein (AFP)
cancer antigen 125 (CA125)
cancer antigen 15-3 (CA15-3)
carbohydrate antigen 19-9 (CA19-9)
carcinoembryonic antigen (CEA)
human chorionic gonadotropin (hCG or beta-hCG)
prostate-specific antigen (PSA)

A more lengthy and detailed list of not-so-affordable tests can be found here:
https://www.cancer.gov/about-cancer/diagnosis-staging/diagnosis/tumor-markers-list
I'd rather have a false positive to investigate than the ignorant bliss of an assumed negative that comes from not testing at all, but that's just me, and it's based on a bad family history of cancer.