Reply to J. Hornberger et al

Abstract

We thank Hornberger et al for their letter, and especially for their interesting updated economic analyses based on our study results. They demonstrate that use of the 21-gene recurrence score (RS) assay for estrogen receptor (ER) –positive, lymph node–negative breast cancer results in gains of quality-adjusted years of life and total direct medical savings, even when cost of the assay is included. We agree that their economic analysis may in fact underestimate gains and savings, given the intermediate and late effects of chemotherapy and the costs of treating these events (unmeasured in our study), which could not be factored into their model, as well as work productivity and other issues they mention in their letter. We are now in the early stages of a similar prospective study of treatment decisions in lymph node–positive, ER-positive breast cancer, based on the findings of the Southwest Oncology Group study which showed, like the lymph node–negative data, that patients with very low RS do not appear to benefit from chemotherapy. We would be interested in the findings from a similar economic analysis utilizing the 21-gene RS assay in node-positive, ER-positive breast cancer.