If your pre-surgery CEA was 16 ng/mL and if it had been stable at that level for some time, then you would fall in the category "10 ng/mL -19 ng/mL" in the rule-of-thumb chart below. In the chart it says, "low threshold for mets (probably indicates a met, will require further testing)".
The implication is this: This high a level probably indicates lymph node metastasis in the local lymph nodes (the ones close to the tumor removed during primary surgery). If this is the case, then a post-surgery CEA test is required to see if the CEA level returns to normal after the primary surgery. If it does return to normal, then it means that the elevated CEA was most probably due to the local (regional) lymph nodes that had just been removed by surgery. It then suggests that a regimen of adjuvant chemotherapy is required in order to "mop up" any stray cancer cells that may have escaped earlier from the infected lymph node area and possibly traveled to other parts of the body.
If CEA stabilizes at an elevated level over a period of months, then there are some rule-of-thumb guidelines for interpreting the elevated stable levels. For example:
CEA levels (stable trend)
o Normal range, non-smokers: < 3.5 ng/mL
o Normal range, smokers: < 5 ng/mL
o 5 ng/mL – 9 ng/mL : slighty above normal – most likely a benign inflammation
o 10 ng/mL – 19 ng/mL - low threshold for mets (probably indicates a met; will require further testing)
o 20 ng/mL - 35 ng/mL - most likely metastatic; moderate tumor burden
o > 35 ng/mL – most certainly metastatic; large tumor burden
If the CEA level does
not return to normal after the primary surgery, then this suggests that the problem rests elsewhere and may be a false positive generated by one or more of the following benign conditions.
Here is a list of possible false positives for elevated CEA:
Carcino Embryonic Antigen (CEA) - False Positives•Inflammatory Bowel Disease.
•Pancreatitis.
•Liver disease.
•Tobacco use can lead to elevated CEA levels. (CEA is elevated in 19% of smokers and only 3% of the non-smoking healthy population.)
•Diverticulitis.
•Hepatitis.
•Peptic ulcers.
•Hypothyroidism.
•Cirrhosis of the liver.
•COPD.
•Lung infection.
•Pleural effusions.
•Biliary obstruction.
•Treatment with oral 5-FU.
•High serum glutamic-pyruvic transaminase (sGPT) levels.
Reference:
http://www.kantrowitz.com/cancerpoints/tumormarkerfalsepositives.html
Since you mentioned gall bladder problems earlier, the elevated CEA may be due in part to "biliary obstruction" or in part to smoking, or in part to any combination of the various potential causes listed above. This means that you may have to undergo a series of tests of various sorts to try to pin down what is causing the elevation.
In any event, these are the kinds of issues that an oncologist would normally deal with when troubleshooting a patient's prognosis for recurrence.
You need to have an oncologist. When are they going to assign an oncologist to your case?
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I think your next major intervention would be comprehensive bloodwork to establish a good post-surgery baseline of all the blood-based biomarkers that will be important to monitor over the next few months. This needs to be done before starting any kind of chemo regimen.
It is important for this baseline to be
comprehensive and not just a set of generic physical exam panels. Since you seem to have hepato-biliary problems, I think your comprehensive baseline should include extra tests in the systemic inflammation and liver function area, even if you have to pay extra for them. For example, ESR (erythrocyte sedimentation rate), hCRP(c-reactive protein), LDH (lactate dehydrogenase), etc. See links below for a recommended expanded list "immediately after surgery".
Comprehensive Baseline Blood Testinghttps://coloncancersupport.colonclub.com/viewtopic.php?f=1&t=56306&p=447864#p447864https://coloncancersupport.colonclub.com/viewtopic.php?f=1&t=61741&p=487962#p487962==== CEA overview:
What is the CEA biomarker?
Carcinoembryonic Antigen, also called CEA, is a protein that may be elevated in many colorectal cancer patients and is detected in the blood. CEA levels are expected to go down in patients who have had surgery to remove their tumor. An elevated CEA may indicate a recurrence of your cancer. CEA is not a biomarker in all colorectal cancer patients.
When and how should I have CEA biomarker testing?
Your doctor will test your blood for CEA levels after you are diagnosed with colorectal cancer, during treatment, and during follow-up visits.
If you were diagnosed at an early stage and are having surgery, your doctor will test your CEA levels before and after surgery and during your follow-up visits: every 3-6 months during the first 2 years, every 6 months during the following 3 years, and every year afterwards to make sure your cancer is not coming back for a total of 5 years.
If you were diagnosed with locally advanced cancer and are treated with chemotherapy before or after your surgery, your doctor will test your CEA levels during the course of treatment to make sure the treatment is effective, and killing the cancer cells.
If you were diagnosed with metastatic disease, your doctor will test your CEA levels during treatment to make sure your treatments are effective at killing the cancer cells.
What do I do with this information?
If your CEA level does not go down after surgery, it could mean that you may have residual or leftover cancer in your body. It could be metastatic (usually in the liver or in the lungs) or not completely removed after surgery. If this is the case, you will have imaging to determine where the cancer may be and determine next steps with your doctor.
If your CEA levels went down after surgery but then went up during your follow-up visits, it could mean that your cancer came back. To confirm that cancer returned (recurrence), it is important to repeat the test and also use imaging, such as a chest X-ray, abdominal ultrasound, abdominal, chest and pelvic CT. You may also have a colonoscopy.
If your CEA levels do not go down during chemotherapy, it could mean that the cancer is not responding to your current treatment. You and your doctor may have to decide on a new course of treatment.
Limitations of CEA testing:
While CEA biomarker testing is a very common procedure for detecting colorectal cancer growth and division, it has some limitations because the results are not always 100% correct.
If CEA is negative, it does not guarantee that the cancer has not come back.
If CEA is positive, it does not mean that the cancer has come back. Test results may need to
be repeated or confirmed by additional tests.
Reference:
https://go.ccalliance.org/l/105332/2020-05-02/bv6xcl/105332/165219/Colorectal_Cancer_Alliance_CEA_Biomarker.pdf