Contrasting Cases: TAILORx- Chemotherapy or no?

Dr. Sparano is Professor of Medicine & Obstetrics, Gynecology, and Women's Health at the Albert Einstein College of Medicine, Associate Chairman for Clinical Research in the Department of Oncology at Montefiore Medical Center, and Associate Director for Clinical Research at the Albert Einstein Cancer Center. He also serves as Vice Chair of the ECOG-ACRIN Research Group and Vice Chair of the AIDS Malignancy Consortium. He is former director of the Hematology-Oncology Fellowship Program at Einstein/Montefiore,  co-directs the ECOG-ACRIN Young Investigator Program, and is a faculty member of the Calabresi K12 Oncology Training Program.  He is co-principal investigator of the Montefiore-Einstein Minority/Underserved National Community Oncology Research Program (NCORP) grant (in conjunction with Dr. Bruce Rapkin), which funds multicenter, NCI-sponsored clinical trials in cancer therapeutics, cancer prevention/control, and cancer care delivery research.  He is also the recipient of funding from the Breast Cancer Research Foundation that is supporting creation of a biospecimen bank designed to identify determinants of late relapse.

Dr. Sparano is a practicing clinician who specializes in medical oncology and clinical and translational cancer research. His research has focused on developmental therapeutic approaches for breast cancer, lymphoma, and HIV-associated cancers, and therapeutic application of molecular profiling in cancer. TRANSCRIPT

Welcome to the ASCO University Weekly Podcast. My name is Joseph Sparano, and I am Associate Director for Clinical Research at the Albert Einstein Cancer Center, and chief of the section of breast medical oncology at Montefiore Medical Center in New York. Today, we contrast two cases on adjuvant treatment of breast cancer. The standard treatment for hormone receptor positive, HER2 negative, early stage breast cancer is surgery, followed by endocrine therapy. Since the early 2000s, adjuvant chemotherapy has also been recommended to the majority of these women, but the added benefit from chemotherapy is modest for most. Many different gene expression assays have been developed to determine prognosis and identify which woman may be more likely to benefit from chemotherapy. One commercial test that is recommended in clinical practice guidelines is a 21 gene recurrence score assay. Based on the recently completed TAILORx study, it was known that woman with low recurrence scores on the 21 gene expression assay do well with adjuvant endocrine therapy alone. Whereas woman with high recurrence scores benefit from adjuvant endocrine therapy and chemotherapy. The TAILORx study clarified the best treatment option for women with an intermediate recurrence score, which was defined as a recurrence score of 11 to 25 in the trial. This is particularly important because the majority of patients fall in this intermediate risk category, up to 70%, in fact. Before we discuss the new evidence reported from this study, let's take a look at two intermediate risk cases. These two cases are very similar, yet the recommended treatments may be very different. Can you identify the key differences between these two cases? We begin with the first case. Case 1 is a 55-year-old postmenopausal woman with a node negative, ER positive, PR positive, HER2 negative breast cancer. The size of the tumor is 1.6 sonometers. The 21-gene recurrence score is 24, which is in the upper range of the intermediate risk category. Which option would you recommend as the best systemic treatment. The choices in this case include endocrine therapy alone or chemotherapy followed by endocrine therapy. The correct answer to this question is, A, endocrine therapy alone. We will discuss the rationale for this recommendation shortly, but first let's move on to the second case. The second case is a 44-year-old premenopausal woman with node negative, ER positive, PR positive, HER2 negative breast cancer. Like case 1, the size of the tumor is 1.6 centimeters and the 21-gene recurrence score is 24. Which option would be the best adjuvant treatment in this case? The choices here include endocrine therapy alone or chemotherapy, followed by endocrine therapy. The correct answer in this case is chemotherapy, followed by endocrine therapy. Both of these cases had nearly identical clinical presentations. That is, they presented with ER, PR positive, HER2 negative breast cancer, associated with negative axillary nodes, a primary tumor size of 1.6 sonometers, and a 21-gene recurrence score of 24. However, the key difference was the age at presentation, with one patient being in her mid 50's and postmenopausal, and the other patient being in her mid 40's and premenopausal. The TAILORx trial found that endocrine therapy was not inferior to chemotherapy plus endocrine therapy in the overall population with a mid-range 21-gene recurrence score of 11 to 25. However, there was an interaction between age, chemotherapy treatment, and recurrence score. About 1/3 of women who participated in the trial were 50 or younger. These women seem to have some chemotherapy benefit if the recurrence score was between 16 and 25. For those who had a recurrence score of 21 to 25, the absolute reduction in the risk of distant recurrence was approximately 7% at 9 years. For a woman who had a recurrence score of 16 to 20, the absolute reduction in distant recurrence by the addition of chemotherapy was about 2%. It remains unclear as to whether the benefit from chemotherapy in younger woman was due to a true cytotoxic effect associated with chemotherapy in eradicating micrometastatic disease, or a castration effect in inducing early menopause. Nevertheless, the findings from the TAILORx trial provide the highest level of evidence supporting the greatest level of precision in using the 21-gene assay to guide the use of adjuvant chemotherapy in early stage breast cancer. Thank you for listening to this week's episode of the ASCO University Weekly Podcast. For more information on the adjuvant treatment of breast cancer, including additional patient cases and opportunities for self-evaluation, visit the comprehensive e-learning center at university.asco.org. Thank you for your attention. The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care, and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.