Recent Trends in Chemotherapy Use and Oncologists' Treatment Recommendations for Early-stage Breast Cancer

Allison W. Kurian; Irina Bondarenko; Reshma Jagsi; Christopher R. Friese; M. Chandler McLeod; Sarah T. Hawley; Ann S. Hamilton; Kevin C. Ward; Timothy P. Hofer; Steven J. Katz

Disclosures

J Natl Cancer Inst. 2018;110(5):493-500. 

In This Article

Abstract and Introduction

Abstract

Background There is growing concern about overtreatment of breast cancer as outcomes have improved over time. However, little is known about how chemotherapy use and oncologists' recommendations have changed in recent years.

Methods We surveyed 5080 women (70% response rate) diagnosed with breast cancer between 2013 and 2015 and accrued through two Surveillance, Epidemiology, and End Results registries (Georgia and Los Angeles) about chemotherapy receipt and their oncologists' chemotherapy recommendations. We surveyed 504 attending oncologists (60.3% response rate ) about chemotherapy recommendations in node-negative and node-positive case scenarios. We conducted descriptive statistics of chemotherapy use and patients' report of oncologists' recommendations and used a generalized linear mixed model of chemotherapy use according to time and clinical factors. All statistical tests were two-sided.

Results The analytic sample was 2926 patients with stage I–II, estrogen receptor–positive, human epidermal growth factor receptor 2–negative breast cancer. From 2013 to 2015, keeping other factors constant, chemotherapy use was estimated to decline from 34.5% (95% confidence interval [CI] = 30.8% to 38.3%) to 21.3% (95% CI = 19.0% to 23.7%, P < .001). Estimated decline in chemotherapy use was from 26.6% (95% CI = 23.0% to 30.7%) to 14.1% (95% CI = 12.0% to 16.3%) for node-negative/micrometastasis patients and from 81.1% (95% CI = 76.6% to 85.0%) to 64.2% (95% CI = 58.6% to 69.6%) for node-positive patients. Use of the 21-gene recurrence score (RS) did not change among node-negative/micrometastasis patients, and increasing RS use in node-positive patients accounted for one-third of the chemotherapy decline. Patients' report of oncologists' recommendations for chemotherapy declined from 44.9% (95% CI = 40.2% to 49.7%) to 31.6% (95% CI = 25.9% to 37.9%), controlling for other factors. Oncologists were much more likely to order RS if patient preferences were discordant with their recommendations (67.4%, 95% CI = 61.7% to 73.0%, vs 17.5%, 95% CI = 13.1% to 22.0%, concordant), and they adjusted recommendations based on patient preferences and RS results.

Conclusions For both node-negative/micrometastasis and node-positive patients, chemotherapy receipt and oncologists' recommendations for chemotherapy declined markedly over time, without substantial change in practice guidelines. Results of ongoing trials will be essential to confirm the quality of this approach to breast cancer care.

Introduction

Medical oncologists are leading efforts to reduce the burden of treatment for patients diagnosed with curable breast cancer. Recent advances in test algorithms enable increasingly precise estimates of the benefit of adjuvant chemotherapy for individual patients.[1–3] The growing concern about overtreatment is particularly acute for patients with early-stage disease, for some of whom the benefit of chemotherapy approaches nil in the face of substantial harms. The criteria for chemotherapy decision-making are evolving from being based primarily on anatomy to biology.[2–5] Prior studies have shown decreasing use of adjuvant chemotherapy concomitant with increasing use of tumor genomic profiling in patients diagnosed from 2006 to 2013.[6–9] Despite this progress, questions remain about the causes of this downward trend in chemotherapy receipt and whether it persists. Prior studies have been limited by a lack of granular information from patients' and oncologists' reports of the treatment decision-making context, and by a lack of direct assessment of the impact of clinical factors including changes in the use of 21-gene recurrence score (RS) testing on treatment trends.[10–12]

Treatment decisions are influenced by factors other than clinical information, including patients' fear of recurrence and physicians' reluctance to miss any potential opportunity to improve survival.[13] Yet little is known about the perspectives of patients and their attending oncologists during the most recent period of changing views about adjuvant therapy. Understanding the shifting patterns of systemic therapy decisions is essential to initiatives that aim to advance the individualization and quality of cancer care. We therefore examined trends in chemotherapy receipt and oncologists' recommendations in a large, contemporary, diverse, population-based sample of newly diagnosed breast cancer patients, along with their oncologists' perspectives on chemotherapy decision-making.

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