Final answer:
An elevated CA 19-9 level in a patient might suggest the presence of cancer, but it is not definitive and does not confirm the location of the tumor. Further diagnostic investigations are often needed, and cancer-specific markers like CA 19-9 can be helpful in monitoring treatment response.
Step-by-step explanation:
When a patient's CA 19-9 levels are significantly elevated, it may suggest the presence of an underlying malignancy, as CA 19-9 is one of the cancer-specific markers that can be elevated in various types of cancer. However, the elevation of CA 19-9 alone does not conclusively indicate that the patient has cancer, nor does it pinpoint the exact location of a tumor if present. Similarly to carcinoembryonic antigen (CEA), CA 19-9 can be elevated in conditions other than cancer, such as pancreatitis or liver disease, and its levels can be used for monitoring the treatment response or recurrence in patients with a known diagnosis. Thus, a nurse should interpret an elevated CA 19-9 cautiously, considering the patient's entire clinical context and potentially utilizing it as a prompt for further diagnostic investigation.
Notably, tumor markers like CA 19-9 can aid in the follow-up of treated cancer patients by indicating the progress or recurrence of the disease. Tissue-specific markers, such as PSA or AFP, are more indicative of particular types of cancer and might be used to guide the search for specific cancer locations when elevated.