Meredith Regan, ScD
Sara Hurvitz, MD
In the San Antonio meeting’s closing session, “View From the Trenches: What Will You Do Monday Morning?” Meredith Regan, ScD, and Sara Hurvitz, MD, offered their thoughts on the use of RSClin in the clinic, as described at the San Antonio Breast Cancer Symposium by Joseph Sparano, MD.1
Dr. Regan is Associate Professor of Medicine at Harvard Medical School, Associate Professor in the Division of Biostatistics at Dana-Farber Cancer Institute, Boston, and Director of the Statistical and Data Management Center of the International Breast Cancer Study Group. Dr. Hurvitz is Director of the Breast Cancer Clinical Research Program, Co-Director of the Santa Monica–UCLA Outpatient Hematology/Oncology Practice, and Professor of Medicine at David Geffen School of Medicine at the University of California, Los Angeles.
With TAILORx, Dr. Sparano and colleagues provided estimates of distant recurrence risk at 9 years with endocrine therapy alone and with chemotherapy for patients with early node-negative breast cancer and recurrence scores of 11 to 25.2 The primary analysis did not consider clinical-pathologic features, though exploratory analyses did examine outcomes by recurrence score ranges of 11 to 15, 16 to 20, and 21 to 25, and according to age ≤ 50 or > 50 years. The researchers followed this assessment with another analysis that incorporated features of tumor size and grade and began to formulate clinical-pathologic low- and high-risk subgroups.3 This further analysis provided insight into how distant recurrence risk and chemotherapy benefit may vary according to these features, rather than as “average” benefits for patients with the same recurrence scores, Dr. Hurvitz said.
“Now, we have seen the development of RSClin, which has formally integrated recurrence score with clinical-pathologic features as continuous variables (notably, menopausal status is not part of RSClin),” Dr. Hurvitz said. “The group has updated the output to a 10-year distant recurrence risk, and they did an external validation with a reasonable data source…. The question is how to use this tool in the clinic.”
Dr. Regan offered: “With RSClin, we now have the possibility to integrate recurrence score with clinical and pathologic features for lymph node–negative breast cancers. This provides refined estimates that are specific to the patient’s age, tumor size, and tumor grade. RSClin has the potential to change some of the treatment recommendations, especially around the ‘transition’ recurrence score range of 25 to 26 that has been presented as a clear threshold for decision-making. I like the fact that, with RSClin, the chemotherapy benefit is recognized as a continuum.”
Dr. Regan provided a number of examples where patients varied in age, recurrence score, and clinical-pathologic characteristics, showing how the use of RSClin shifts the absolute chemotherapy benefit, often predicting more chemotherapy benefit—or less benefit—than is estimated for recurrence score alone.
“This is an interesting individualized assessment we can provide patients,” Dr. Hurvitz said. Unfortunately, RSClin is not yet part of the Oncotype DX report, which would make it simpler for a busy clinician to use, she added.
DISCLOSURE: Dr. Regan has received honoraria from Bristol Myers Squibb; has served as a consultant or advisor to Bristol Myers Squibb and Tolmar Pharmaceuticals; has served as an institutional consultant or advisor to Ipsen; has received institutional research funding from Astellas Pharma, AstraZeneca, Bayer, Bristol Myers Squibb, Celgene, Dendreon, Ferring, Ipsen, Janssen, Medivation, Merck, Millennium Pharmaceuticals, Novartis, OncoGenex, Pfizer, Pierre Fabre, Roche, Sanofi, Sotio, TerSera, and Veridex; has been reimbursed for travel, accommodations, or other expenses by Bristol Myers Squibb. Dr. Hurvitz has an immediate family member who holds stock or other ownership interests in Ideal Implant and ROMTech; has received institutional research funding from Ambrx, Amgen, Arvinas, Bayer, BioMarin, Cascadian Therapeutics, Daiichi Sankyo, Dignitana, Genentech/Roche, Gilead, GlaxoSmithKline, Immunomedics, Lilly, MacroGenics, Merrimack, Novartis, OBI Pharma, Pfizer, Phoenix Molecular Designs, Pieris, Puma Biotechnology, Radius, Sanofi, Seattle Genetics, and Zymeworks; has been reimbursed for travel, accommodations, or other expenses by Lilly; and has stock options with NK Max.
REFERENCES
1. Sparano JA, Crager MR, Tang G, et al: Development and validation of a tool integrating the 21-gene recurrence score and clinical-pathological features to individualize prognosis and prediction of chemotherapy benefit in early breast cancer. 2020 San Antonio Breast Cancer Symposium. Abstract GS4-10. Presented December 11, 2020.
2. Sparano JA, Gray RJ, Makower DF, et al: Adjuvant chemotherapy guided by a 21-gene expression assay in breast cancer. N Engl J Med 379:111-121, 2018.
