Comparing Prognostic Breast Cancer Tests

Back in the late 2000's, I heard about the new Oncotype Dx test that was just coming available for women who had early stage breast cancer and could help in the decision making process - whether to chemotherapy or not. The test was supposed to tell your risk of recurrence. That was great news (of course I was not eligible because of my medical history...) and many women found their risk and made the big chemotherapy decision.

New research has looked at the results of these tests and compared them. They looked at these four tests: Oncotype Dx Recurrence Score, PAM50-based Prosigna Risk of Recurrence Score (ROR), Breast Cancer Index (BCI) and EndoPredict (EPclin).

"The analysis, published in JAMA Oncology, funded by Cancer Research UK and involving co-authors at the Institute of Cancer Research, compares four common prognostic tests for breast cancer, and finds that not all are able to accurately predict whether the cancer will return after five years. This could be limiting clinicians' abilities to advise patients on whether chemotherapy or preventive medication, in the form of endocrine therapy, should be taken.

Lead author Dr Ivana Sestak from Queen Mary's Wolfson Institute of Preventive Medicine said: "This is the first time that anyone has directly compared the prognostic performance of these four common commercially-available tests. This gives clinicians and oncologists the opportunity to review all the results and decide upon the test they want to use for their breast cancer patients.

"If a woman is deemed high risk of recurrence by any test, the benefit of chemotherapy is greatest. In contrast, if a women is deemed low risk then endocrine therapy alone will be sufficient and patients could forego chemotherapy and its side effects."

The FDA approved ROR and the European Society for Medical Oncology recommend Oncotype, ROR, and EPclin. The research found that while the tests provide good information Oncotype was found to lag behind the other three newer tests. And another nice factoid for all of us is:

"However, one important critical time period to consider is years 5-10 after the start of treatment, since over 50 per cent of women with ER+ breast cancer develop a recurrence after five years. BCI, ROR, and EPclin were found to be the most accurate for stratifying women into low or high risk of recurrence after five years in patients with node-negative disease.

For women with node-positive disease2 only those tests (ROR and EPclin) that incorporated clinical information (e.g. tumour size and the number of positive lymph nodes a woman has), as well as gene expression levels, provided substantial prognostic value."

I think to keep those dark thoughts saying 'what if...' at bay, I need to talk to my oncologist about these two tests, ROR and EPclin, and see if I am eligible for either one of these... 

New research can be good but if you can't take advantage of it, it is of no use.