Tag Archives: cancer marker tests

The Telomerase Test for Monitoring Breast Cancer

Image Source: Dreamstime / Dmitry Sunagatov Image Source: Dreamstime / Dmitry Sunagatov

The Telomerase Test for Monitoring Breast Cancer

One of the things I am frequently asked is whether there are new tests for cancer markers available that help you monitor the level of cancer in your body. One such test is the CA 15-3 cancer antigen test, and you can read more about that in my article: The CA 15-3 Cancer Marker Test and its Accuracy.  Another test that is available to us is the telomerase test, although to my knowledge it is not widely used.

What is Telomerase?

Telomerase is an enzyme involved with your DNA. It is called a reverse transcriptase enzyme. It acts like a template to make more DNA sequences and adds them to the ends of chromosomes. Telomeres are essential for maintaining the stability of those chromosomes. Think of telomeres as the protective cap on the end of a highlighter pen. Telomeres protect the important information-carrying DNA in cells from injury during cell division.

Healthy cells that are lacking the enzyme telomerase have a problem because the telomeres shorten with each cell division. During DNA replication, the two newly formed chromosomes separate and small bits of DNA are trimmed off the end of the chromosomes. Long telomeres allow these cells to keep on dividing for a longer time and restoring the tissue, whereas short telomeres have to give up early because the protective telomere caps are depleted sooner. Short telomeres are associated with aging more rapidly.

Telomerase and Cancer

Scientists have discovered that short telomeres can lead to chromosomal instability and/or rearrangements, and that is related to cancer. One study stated: “Irrespective of its source, damage acts as the basis for the development of dysfunctional tissues, which are a hallmark of age decline as well as the basis for cancer.” [1]

Another study found that short telomeres also promoted metastasis (cancer spread) in the absence of telomerase activity. [2]

Stem cells have the ability to create the enzyme telomerase – and thus telomeres – and so can cancer cells. This makes them immortal. It has been discovered that if there is a high quantity of telomerase in the body, it can be an indicator that there is cancer in the body somewhere. High levels of telomerase have been found to be present in 85-95 percent of malignancies. The telomerase test is, however, a non-specific test, in other words it can’t tell you where the cancer is located.

So is the Telomerase Test Useful? Accurate?

Apparently the telomerase test can be helpful in the assessment of breast cancer risk. In 2011, a joint review of research by both Brazilian researchers and  scientists at Memorial Sloan-Kettering Cancer Center in New York City, entitled “Accuracy of Telomerase in Estimating Breast Cancer Risk: a Systematic Review and Meta-analysis” [3] investigated the accuracy of the telomerase test in predicting breast cancer risk. They thoroughly examined 25 studies that qualified, covering a total of 2,395 breast tumors. They found that 82 percent of breast cancer tumors and 18 percent of benign tumors were positive for telomerase activity. Researchers concluded that “telomerase activity was significantly present in breast cancer when compared with normal breast tissue or benign breast lesions.”

Who is Using the Telomerase Test?

Quite a few alternative and integrative doctors are using the telomerase test to follow the progress of cancer patients they treat. One holistic practitioner in the UK, Dr Patrick Kingsley, has treated cancer patients for over 40 years. Dr Kingsley shared some interesting information about the telomerase test. For the patients diagnosed with cancer with whom he works, he relies on several other tests besides the telomerase test, one which investigates pyruvate kinase levels, and another called the laevorotatory lactic acid test. The combination of these three tests, he felt, were fairly indicative of what was going on in the body. [4] He said that raised telomerase levels in the blood, while often being indicative of the presence of cancer cells, also told him something else. When levels were low, around a few hundred, it made the patient happy because they assumed it meant low levels of cancer in their body. What he found, however, was that raised levels of telomerase in the blood did not necessarily reflect the fact that the cancer was spreading, particularly if they were going through some of the natural treatments he recommends for cancer. Dr Kingsley stated that one actually needed raised levels of telomerase in the blood when fighting cancer, otherwise there was nothing for the immune system to notice and respond to. His experience was that when telomerase levels increased to quite high levels, it was an indication that cancer cells were being killed and releasing that extra telomerase into the blood, that it is a good sign that the immune system is doing its job.

Dr Al Sears of the Sears Institute for Anti-Aging Medicine in South Florida also uses the telomerase test for his patients interested in monitoring their health and for anti-aging concerns. [5]

Of course, there are always nay-sayers, those who feel the test has absolutely no merit. Discuss the telomerase test with your integrative doctor or naturopath and then decide for yourself!

References:

Testing Time for Telomeres – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166469/

[1] Telomerase at the Intersection of Cancer and Aging – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3896987/

[2] Dysfunctional Telomeres Promote Genomic Instability and Metastasis in the Absence of Telomerase Activity in Oncogene Induced Mammary Cancer – https://www.ncbi.nlm.nih.gov/pubmed/22086874

[3] Accuracy of Telomerase in Estimating Breast Cancer Risk: a Systematic Review and Meta-analysis – http://www.academia.edu/25335428/Accuracy_of_telomerase_in_estimating_breast_cancer_risk_A_systematic_review_and_meta-analysis

[4] Dr Patrick Kingsley – Breast Cancer, Your Way Forward

[5] http://alsearsmd.com/2015/12/the-most-important-test-your-doctor-wont-order/

GET MY BEST TIPS on getting through breast cancer and preventing recurrences by signing up for my free e-newsletters and e-books on the right. You can also “like” me on Facebook (Marnie Clark, Breast Health Coach) to get my inspirational snippets, news and updates. I promise to do my utmost to keep you informed and empowered on your healing journey… and beyond.

The CA 15-3 Cancer Marker Test And Its Accuracy

Image Source: rgbstock.com / Littleman

Image Source: rgbstock.com / Littleman

The CA 15-3 Cancer Marker Test And Its Accuracy

Women who have been through treatments for breast cancer are normally followed for five years to monitor their status and one of the tests frequently done by doctors is the CA 15-3 marker test. In this article I will share some information about the CA 15-3 test, discuss the accuracy of the test, and some new research.

What Is The CA 15-3 Cancer Marker Test?

CA 15-3 stands for cancer antigen 15-3 which is a protein produced by normal breast cells.  Some  people – not all – with cancerous breast tumors have an increased production of CA 15-3.  The protein does not cause or promote cancer, rather copies of it are cast off by tumor cells, the copies then enter the bloodstream and can be detected through a blood sample.

CA 15-3 Not That Reliable For Early Stage Breast Cancer

The problem with the CA 15-3 test is that it is not all that reliable, particularly for early breast cancer.  One source indicated that CA 15-3 is elevated in only about 10% of women with early localized breast cancer, while another source indicated the figure was 30%.  CA 15-3 levels can also be completely absent in early-stage breast cancer, making it quite difficult to rely upon this test for early stage cancers or those tumors that do not express the antigen.

A 1999 Italian study comparing the CA 15-3 test with another marker test, the CA 27-29, found that “CA27.29 discriminates primary breast cancer from healthy subjects better than CA15.3, especially in patients with limited disease.” 1

Other Conditions Can Cause Elevated CA 15-3 Levels

CA 15-3 levels can also be elevated in healthy people, as well as in people with other cancers such as lung, pancreas, colon, ovary, or prostate.  Elevated levels are also seen in benign breast disease, cirrhosis, hepatitis, tuberculosis, pelvic inflammatory disease, endometriosis – and this is by no means an exhaustive list.

CA 15-3 More Useful In Metastatic Breast Cancer, Response To Treatment

For those with metastatic breast cancer, the CA 15-3 test does tend to be a bit more reliable an indicator, being elevated in 50-90% of those with breast cancer that has spread to other parts of the body, particularly when metastases to the bones or liver exist.  One French study 2 found that 42% of women with metastases present had normal CA 15-3 levels, however.

The CA 15-3 test tends to be most useful for deciding whether a certain treatment is assisting the patient or not, as a decrease in CA 15-3 levels during treatment such as chemotherapy tells the doctor that the tumor is responding to the treatment, while a stable or increasing marker level may indicate that the tumor has not responded as well (or at all) to the treatment.

While it can be worrisome to the patient to be monitored for CA 15-3 – especially if the marker keeps rising over a period of time and various other tests have not picked up cancer activity – it can be a sign for the patient to be more proactive with their anti-cancer regimen rather than waiting for the development of physical symptoms.  Knowing levels are rising early on can have a huge impact on therapies chosen and survival.

New Study Indicates A Combo Of Marker Tests More Specific

A March 2015 study 3 indicated that a combination of 3 marker tests was more useful.  204 disease-free breast cancer patients who had undergone mastectomy were followed and monitored for an average of 3.7 years with a combination of three marker tests.  Researchers employed the CA 15-3, one called TPA (for tissue polypeptide antigen, more on that below), and one called CEA (for carcinoembryonic antigen, more on that below).  This study indicated that “the sensitivity of the CEA-TPA-CA15.3 tumor marker panel was 93%, the specificity was 97.6% and the rate of false ‘warning signals’ per year of follow-up was 9 per 100 patients.”

In addition to the above study, another smaller but interesting Iraqi study on women with breast cancer indicated that tissue polypeptide antigen (TPA) levels were a good indicator of disease progression, as well as tumor response. 4

The carcinoembryonic antigen test (CEA) was studied in patients with metastatic colorectal cancer treated with chemotherapy.  The researchers reported that low levels of CEA were indicative of progression-free survival. 5

Obviously, new marker tests are being discovered and researched.  A study yet to be published in the Journal of Proteomics 6 reported that there was a necessity for the identification of new markers for breast cancer that could lead to early detection and also provide evidence of effective treatment.  The researchers examined 1,020 polypeptides and discovered 78 that were overexpressed in all cancer lines. This kind of forward-thinking research may help us to discover new and better ways of identifying earlier the existence of breast cancer as well as response to treatments.

In the meantime, and to sum up, please be aware that a CA 15-3 tumor marker test on its own does not provide enough information to screen for the presence of breast cancer.  Normal levels do not ensure the absence of localized or metastatic breast cancer, further tests should be employed.

2017 Update: See also my article The Telomerase Test for Monitoring Breast Cancer.

References:

http://breastcancer.about.com/od/tumormarkers/f/ca_15-3.htm

http://emedicine.medscape.com/article/2087491-overview#aw2aab6b3

1.  Comparison of the Diagnostic Accuracy of CA27.29 and CA15.3 in Primary Breast Cancer – http://www.clinchem.org/content/45/5/630.short

2.  Value of CA 15-3 determination in the initial management of breast cancer patients – http://annonc.oxfordjournals.org/content/20/5/962.2.full

3.  An individual reference limit for ‘early’ diagnosis of metastatic breast cancer during postoperative follow-up – http://www.ncbi.nlm.nih.gov/pubmed/25808435

4. Tissue polypeptide antigen & interleukin-6: Are their serum levels a predictor for response to chemotherapy in breast cancer? – http://www.ncbi.nlm.nih.gov/pubmed/25225536

5.  The Association of Serum Carcinoembryonic Antigen, Carbohydrate Antigen 19-9, Thymidine Kinase, and Tissue Polypeptide Specific Antigen with Outcomes of Patients with Metastatic Colorectal Cancer Treated with Bevacizumab: a Retrospective Study – http://www.ncbi.nlm.nih.gov/pubmed/25875421

6.  Determination of the protein expression profiles of breast cancer cell lines by quantitative proteomics using iTRAQ labelling and tandem mass spectrometry – http://www.ncbi.nlm.nih.gov/pubmed/25918110

GET MY BEST TIPS on getting through breast cancer and preventing recurrences by signing up for my free e-newsletters and e-books on the right.  You can also “like” me on Facebook (Marnie Clark, Breast Health Coach) to get my inspirational snippets, news and updates.  I promise to do my utmost to keep you informed and empowered on your healing journey… and beyond.