Patient and physician factors associated with Oncotype DX and adjuvant chemotherapy utilization for breast cancer patients in New Hampshire, 2010\u20132016

Thomas M Schwedhelm,Erika L Moen,Maria O Celaya,Ronnie J Zipkin,Tracy Onega,Judy R Rees,Andrew Schaefer

doi:10.1186/s12885-020-07355-6

Abstract

BackgroundOncotype DX® (ODX) is used to assess risk of disease recurrence in hormone receptor positive, HER2-negative breast cancer and to guide decisions regarding adjuvant chemotherapy. Little is known about how physician factors impact treatment decisions. The purpose of this study was to examine patient and physician factors associated with ODX testing and adjuvant chemotherapy for breast cancer patients in New Hampshire.MethodsWe examined New Hampshire State Cancer Registry data on 5630 female breast cancer patients diagnosed from 2010 to 2016. We performed unadjusted and adjusted hierarchical logistic regression to identify factors associated with a patient’s receipt of ODX, being recommended and receiving chemotherapy, and refusing chemotherapy. We calculated intraclass correlation coefficients (ICCs) to examine the proportion of variance in clinical decisions explained by between-physician and between-hospital variation.ResultsOver the study period, 1512 breast cancer patients received ODX. After adjustment for patient and tumor characteristics, we found that patients seen by a male medical oncologist were less likely to be recommended chemotherapy following ODX (OR = 0.50 (95% CI = 0.34–0.74), p < 0.01). Medical oncologists with more clinical experience (reference: less than 10 years) were more likely to recommend chemotherapy (20–29 years: OR = 4.05 (95% CI = 1.57–10.43), p < 0.01; > 29 years: OR = 4.48 (95% CI = 1.68–11.95), p < 0.01). A substantial amount of the variation in receiving chemotherapy was due to variation between physicians, particularly among low risk patients (ICC = 0.33).ConclusionsIn addition to patient clinicopathologic characteristics, physician gender and clinical experience were associated with chemotherapy treatment following ODX testing. The significant variation between physicians indicates the potential for interventions to reduce variation in care.

Highlights

Oncotype DX® (ODX) is used to assess risk of disease recurrence in hormone receptor positive, HER2negative breast cancer and to guide decisions regarding adjuvant chemotherapy
Risk stratification of women with Hormone receptor (HR) positive, lymph node (LN) negative Breast cancer (BC) is a priority, because about 85% of these women are at low risk of disease recurrence with endocrinemodulating therapy alone and are unlikely to benefit from adjuvant chemotherapy [8, 9]
Oncotype DX® (Genomic Health Inc., Redwood City, CA) (ODX) is a widely-used prognostic breast cancer test which analyzes gene expression of 16 tumor-specific genes and 5 reference genes [11, 13]. It was commercially introduced in the United States in 2004 and shortly thereafter was recommended in guidelines released by the American Society for Clinical Oncology (ASCO) and the National Comprehensive Cancer Network (NCCN) [14, 15]

Summary

Introduction

Oncotype DX® (ODX) is used to assess risk of disease recurrence in hormone receptor positive, HER2negative breast cancer and to guide decisions regarding adjuvant chemotherapy. Oncotype DX® (Genomic Health Inc., Redwood City, CA) (ODX) is a widely-used prognostic breast cancer test which analyzes gene expression of 16 tumor-specific genes and 5 reference genes [11, 13]. It was commercially introduced in the United States in 2004 and shortly thereafter was recommended in guidelines released by the American Society for Clinical Oncology (ASCO) and the National Comprehensive Cancer Network (NCCN) [14, 15]. Additional studies have validated the usefulness of ODX in patients with LN positive disease [18,19,20]

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