Eileen M. O'Reilly, MD: Importance of CA19-9 and Albumin Markers

What is the importance of markers such as CA19-9 and albumin for diagnosis and response prediction in pancreatic cancer?

CA19-9 has been studied forever. It’s a glycosylated carbohydrate and protein that’s both free floating and tissue-expressed in pancreas cancer. About 85% of people will have detectable levels of CA19-9, and for some it’s a reproducibly reliable biomarker that corresponds to the course of the disease. So, if their cancer is responding, their CA19-9 is typically declining, and declining significantly. However, there are other times when it does not correspond with what’s happening with their disease and sometimes, frankly, it’s misleading in terms of the direction. So we always have to keep an open mind and I would say that making a decision on CA19-9 in isolation is really not something that we recommend, but interpreting it in terms of the totality of the evidence—in terms of the clinical picture, radiology, and the CA19-9 trend—I think that collective interpretation allows us to best understand how to use that information and what it means for that particular patient. We also have to remember that CA19-9 can be confounded by benign processes such as pancreatitis and obstructive jaundice. Or, a patient’s stent getting clogged is a classic way that the CA19-9 can go up and can sometimes go up 10-fold over where it was. So, again, we have to be careful about the interpretation of what it means in those settings.

Moving on to albumin, serum albumin is an important biomarker that we look at. It’s one that we follow. In people who are sick and symptomatic from their disease we tend to see their albumin falling, and not just as a reflection of the nutritional issues, but as a reflection of the totality of the impact of this disease in terms of its metabolic implications. A low serum albumin generally, not exclusively, means a lower performance status, a higher burden of disease, and a more symptomatic patient. In terms of clinical trial eligibility, albumin restrictions are sometimes present because we want to make sure we give the treatment an adequate test and select patients who may be on that downhill trajectory where we may not get a chance to fully utilize the benefits of a particular combination. So albumin is useful. I wouldn’t say at the end of the day that it’s a deciding factor in terms of one treatment choice versus another outside of a clinical trial, but it does contribute to the collective thinking as to what may be the best approach for a patient.

Metastatic Pancreatic Cancer: Case 2

Henry R was diagnosed with adenocarcinoma in the body of the pancreas when he was 64 years old, following rapid weight loss, abdominal pains, and the development of venous thrombosis.

• At diagnosis, measurable distant lymph node, liver, and lung metastases were observed
• His CA19-9 level was 2760 U/ml and his concentration of albumin was 28 g/L. His ECOG performance status was 1.

Upfront treatment was administered with nab-paclitaxel and gemcitabine, which lasted for 4months:

• At the time of progression, pain levels had increased interfering with daily activity and raising the ECOG performance status to a 2.
• At this point, second-line therapy was initiated with liposomal irinotecan, fluorouracil, and folinic acid.