Adoption of Gene Expression Profile Testing and Association With Use of Chemotherapy Among Women With Breast Cancer.

Hassett MJ, Silver SM, Hughes ME, Blayney DW, Edge SB, Herman JG, Hudis CA, Marcom PK, Pettinga JE, Share D, Theriault R, Wong YN, Vandergrift JL, Niland JC, Weeks JC.

Source

Michael J. Hassett, Melissa E. Hughes, and Jane C. Weeks, Dana-Farber Cancer Institute, Boston, MA; Samuel M. Silver, University of Michigan Cancer Center, Ann Arbor; James G. Herman, Sparrow Regional Cancer Center, Lansing; Jane E. Pettinga, Spectrum Health, Grand Rapids; David Share, BlueCross BlueShield of Michigan, Detroit, MI; Douglas W. Blayney, Stanford Cancer Center, Stanford; Joyce C. Niland, City of Hope National Medical Center, Duarte, CA; Stephen B. Edge, Roswell Park Cancer Institute, Buffalo; Clifford A. Hudis, Memorial Sloan-Kettering Cancer Center, New York, NY; P. Kelly Marcom, Duke Comprehensive Cancer Center, Durham, NC; Richard Theriault, MD Anderson Cancer Center, Houston, TX; Yu-Ning Wong, Fox Chase Cancer Center, Philadelphia; and Jonathan L. Vandergrift, National Comprehensive Cancer Network, Fort Washington, PA.

Abstract

PURPOSEGene expression profile (GEP) testing is a relatively new technology that offers the potential of personalized medicine to patients, yet little is known about its adoption into routine practice. One of the first commercially available GEP tests, a 21-gene profile, was developed to estimate the benefit of adjuvant chemotherapy for hormone receptor-positive breast cancer (HR-positive BC). PATIENTS AND METHODSBy using a prospective registry data set outlining the routine care provided to women diagnosed from 2006 to 2008 with HR-positive BC at 17 comprehensive and community-based cancer centers, we assessed GEP test adoption and the association between testing and chemotherapy use.ResultsOf 7,375 women, 20.4% had GEP testing and 50.2% received chemotherapy. Over time, testing increased (14.7% in 2006 to 27.5% in 2008; P < .01) and use of chemotherapy decreased (53.9% in 2006 to 47.0% in 2008; P < .01). Characteristics independently associated with lower odds of testing included African American versus white race (odds ratio [OR], 0.70; 95% CI, 0.54 to 0.92) and high school or less versus more than high school education (OR, 0.63; 95% CI, 0.52 to 0.76). Overall, testing was associated with lower odds of chemotherapy use (OR, 0.70; 95% CI, 0.62 to 0.80). Stratified analyses demonstrated that for small, node-negative cancers, testing was associated with higher odds of chemotherapy use (OR, 11.13; 95% CI, 5.39 to 22.99), whereas for node-positive and large node-negative cancers, testing was associated with lower odds of chemotherapy use (OR, 0.11; 95% CI, 0.07 to 0.17). CONCLUSIONThere has been a progressive increase in use of this GEP test and an associated shift in the characteristics of and overall reduction in the proportion of women with HR-positive BC receiving adjuvant chemotherapy.