The tumor marker test sends an icy chill down my spine. Why? Well, just look at the name. It is as advertised.
My girlfriend who is going through FC (f’ing cancer) treatments right now just had a tumor marker test and after, she called asking what it is. Why aren’t these tests explained more clearly? I remember having my blood drawn one day this fall during an horrendous stomach flu and I asked the phlebotomist what the “black” tube is. She simply said, “Tumor Marker Test” with a, “Pleaaaaaase don’t ask me any questions” look on her face.
After my conversation with my girlfriend, it occurred to me that I hadn’t written about tumor markers. Whoopsie! So, I thought that it’s time to do a little A-B-C on tumor markers with high hopes that it helps you (or a loved one) understand WTF is going on (Silver Lining)!!!
Tumor markers are substances, usually proteins, that are produced by the body in response to cancer growth or by the cancer tissue itself. They may be detected in blood, urine, or tissue samples. Some tumor markers are specific for a particular type of cancer, while others are seen in several cancer types.
There are many uses for the tumor marker test:
- Screen for disease
- Inform prognosis
- Help determine management
- Evaluate response to treatment. If tumor marker levels decrease, that is a major Silver Lining because sign that the cancer is responding to the therapy. An increased level indicates that the cancer is resisting the treatment, and a change may be required.
- Identify disease recurrence
Rising levels on test results can be, but are not always worrisome. Although changes in tumor marker levels may sound the alarm bells (those same bells that are so quick to ring during any kind of FC), other non-cancerous diseases can cause test results to vary. Speaking of which, tumor markers are not the end all, be all. In fact, they are not always reliable for the following reasons:
- Most tumor markers can be made by normal cells, as well as cancer cells.
- Tumor markers can be associated with noncancerous conditions.
- Tumor markers are not always present in early stage cancers.
- People with cancer may never have elevated tumor markers.
- Even when tumor marker levels are high, they are not specific enough.
The bottom line is that it is super important to always talk to your oncologist about they why, how and when of tumor markers test and keep asking questions until you understand how these results will impact your prognosis and treatment plan.
It is also important to know that tumor markers are one part of the whole clinical puzzle. These test results are used together with other data, such as biopsy results, to get a clear picture of the stage of the cancer, what type of treatment will be most effective, and to measure progress during treatment.
The best Silver Lining is that my girlfriend’s numbers are decreasing since starting chemo, which is a great indication that the chemo is working! Hip! Hip! Horray!
To learn more, I recommend the looking at the National Cancer Institute Tumor Marker fact sheet: http://www.cancer.gov/cancertopics/factsheet/Detection/tumor-markers