Five, seven or ten? No – it’s not a trendy store for juniors… it is a real-life anti-estrogen treatment dilemma facing oncologists and their post-menopausal, ER+, early-stage, breast cancer patients.
Standard of care is to take anti-estrogen treatment for at least the first 5 years after diagnosis to help prevent hormone-receptor positive breast cancer recurrences. In pre-menopausal women, studies have shown that 10 years of tamoxifen is significantly better than 5. For those women who become post-menopausal during this long course of daily therapy, switching to an aromatase inhibitor (AI) and completing 10 years of treatment has also been proven to be beneficial.
However, most breast cancer is diagnosed in women who are postmenopausal, and for these women, the recommended initial anti-estrogen treatment is an AI for 5 years. Recent studies have evaluated the benefit of adding 5 more years of AI beyond the initial 5 years of treatment (for a total of 10 years of AI), but have had mixed results. While some women benefited from a full 10 years, it was clear that not EVERYONE benefited, and across all studies, 5 more years of an AI had a significant impact on bone health and other health-related issues. Ultimately, the NCCN clinical practice guidelines (used by many physicians who treat cancer) recommend considering extending AI treatment to 10 years.
The Goldie Locks Effect – Researchers thought there may be a better way – could there be a happy medium? In a study completed this past winter, 10 years of AI was compared to 7 years of AI. The results showed that the two treatment arms were very similar – with increased problems in bones in the 10-year treatment arm. For some oncologists, 7 years of treatment offers a good compromise – extending treatment for 2 more years to obtain the benefit … but not out to 10 years where other significant health issues show up.
The dilemma – how do oncologists know what treatment approach is right for a particular patient after 5 years? Clinical study results report the combined data for the population of all patients in the study. Some studies go so far as to evaluate results from subgroups of patients with similar characteristics. But, importantly – these are averages for the group. The average consists of patients who benefited from the treatment, and those who did not benefit from treatment. In the studies where treatment out to 10 years was assessed, 70-80 women needed to be treated to have 1 woman benefit from extension of anti-estrogen therapy to prevent a distant recurrence (metastasis). In the more recent study, up to 100 women needed to be treated in order to benefit 1 woman.
A tool to help predict an individual’s likelihood of benefit. Many oncologists have turned to Breast Cancer Index to help address this dilemma. Breast Cancer Index or BCI is a non-invasive lab test that looks at the tumor specimen removed when you were initially diagnosed with breast cancer. BCI provides information about your risk of cancer recurrence and whether you are likely to benefit from more than 5 years of anti-estrogen therapy. The oncologist uses the information the test provides, along with other information about the tumor and your health to provide the best recommendation possible…to extend or end therapy at year 5.
You are an individual and should be treated like one. Ask your oncologist if Breast Cancer Index is right for you.
- Davies C et al., Lancet. 2013 ;381(9869):805-16
- Gray et al., J Clin Oncol 31, 2013 (suppl; abstr 5)
- Goss PE et al, J Natl Cancer Inst 2005;97:1262–71
- Goss PE et al., N Engl J Med. 2016 Jun 5
- Mamounas EP et al., San Antonio Breast Cancer Symposium 2016
- Gnant M et al., San Antonio Breast Cancer Symposium 2017
Note: The content, products and services discussed in this material are offered to educate healthcare providers and/or consumers on molecular diagnostic testing performed by Biotheranostics, and should not be considered or used as a substitute for medical advice, diagnosis or treatment of specific medical conditions.
– Breast Cancer Index Intended Use and Limitations –
The Breast Cancer Index (BCI) Risk of Recurrence & Extended Endocrine Benefit Test is intended for use in patients diagnosed with estrogen receptor-positive (ER+), lymph node-negative (LN-) or lymph node positive (LN+; with 1-3 positive nodes) early-stage, invasive breast cancer, who are distant recurrence-free. BCI provides: 1) a quantitative assessment of the likelihood of both late (post-5 years) and overall (0-10 year) distant recurrence following an initial 5 years of endocrine therapy (LN- patients) or 5 years of endocrine therapy plus adjuvant chemotherapy (LN+ patients), and 2) prediction of likelihood of benefit from extended (>5 year) endocrine therapy. BCI results are adjunctive to the ordering physician’s workup; treatment decisions require correlation with all other clinical findings.
This test was developed and its performance characteristics determined by Biotheranostics, Inc. lt has not been cleared or approved by the U.S. Food and Drug Administration. This test is used for clinical purposes. lt should not be regarded as investigational or for research. How this information is used to guide patient care is the responsibility of the physician. Biotheranostics is certified under the Clinical Laboratory lmprovement Amendments of 1988 to perform high complexity clinical laboratory testing.
For Breast Cancer Index Intended Use and Limitations, visit www.answersbeyond5.com.