Assessment of potential process quality indicators for systemic treatment of breast cancer in Belgium: a population-based study

Abstract

Background: Quality indicators (QIs) for the management of breast cancer (BC) have been published in Europe and internationally. In Belgium, a task force was established to select measurable process indicators of systemic treatment for BC, focusing on appropriateness of delivered care. The objective of this study was to evaluate the results of the selected QIs, both nationally and among individual centres.

Patients and methods: Female Belgian residents with unilateral primary invasive BC diagnosed between 2010 and 2014 were selected from the Belgian Cancer Registry database. The national number enabled linkage with the national reimbursement database, which contains information on all reimbursed medical procedures. A total of 12 process indicators were measured on the population and hospital level. Intercentre variability was assessed by median results and interquartile ranges.

Results: A total of 48 872 patients were included in the study. QIs concerning specific BC subtypes only applied to patients diagnosed in 2014 (n = 9855). Clinical stage (cStage) I patients (n = 17 116) were staged with positron emission tomography/computed tomography. Among patients who were pT1aN0 human epidermal growth factor receptor 2 (HER2) positive (n = 47), 25.5% (n = 12) received adjuvant trastuzumab. Among patients with de novo metastatic luminal A/B-like HER2-negative BC (n = 295), 17.3% (n = 51) received upfront chemotherapy. (Neo)adjuvant chemotherapy was administered in 52.4% (n = 12 592) of operated women with cStage I-III, in 37.0% (n = 1270) of operated women with cStage I-III luminal A/B-like HER2-negative BC, and in 19.1% of operated women with cStage I luminal A/B-like HER2-negative BC. In the population of operated patients with cStage I-III, of those younger than 70 years that started adjuvant endocrine therapy (n = 3591), 81.7% (n = 2932) continued treatment for ≥4.5 years. Among patients in cStage I-III older than 70 years (n = 8544), 19.0% (n = 1622) received (neo)adjuvant chemotherapy, whereas among patients with cStage I-III luminal A/B-like HER2-negative BC (n = 1388), 13.0% (n = 181) received (neo)adjuvant chemotherapy. In patients with cStage I-II luminal A/B-like HER2-negative BC older than 70 years (n = 1477), 11.6% (n = 171) were not operated and received upfront endocrine treatment.

Conclusion: Well-considered QIs using population-based data can evaluate quality of care and expose disparities among treatment centres. Their use in daily practice should be implemented in all centres treating BC.

Keywords: breast cancer; national cancer registry; overtreatment; population-based data; quality indicators; quality of care; systemic treatment.

Figure 1

Proportion of patients with clinical stage I breast cancer that received PET/CT during staging. PET/CT, positron emission tomography/computed tomography; PI, prediction interval.

Figure 2

Proportion of patients with breast cancer younger than 70 years that received (neo)adjuvant chemotherapy in (A) cStage I-III, (B) cStage I-III luminal A/B-like HER2-negative, (C) cStage I, and (D) cStage I luminal A/B-like HER2-negative breast cancer. cStage, Clinical Stage; HER2, human epidermal growth factor receptor; LumA/B-like, luminal A- or B-like; PI, prediction interval.

Figure 2

Proportion of patients with breast cancer younger than 70 years that received (neo)adjuvant chemotherapy in (A) cStage I-III, (B) cStage I-III luminal A/B-like HER2-negative, (C) cStage I, and (D) cStage I luminal A/B-like HER2-negative breast cancer. cStage, Clinical Stage; HER2, human epidermal growth factor receptor; LumA/B-like, luminal A- or B-like; PI, prediction interval.

Figure 4

Proportion of patients with cStage I-III breast cancer aged (A) 70 years or older and (B) 75 years or older that received (neo)adjuvant chemotherapy within 4 months after surgery. cStage, clinical stage; PI, prediction interval.

Figure 3

Proportion of patients with cStage I-III breast cancer younger than 70 years who were diagnosed in 2010 and started adjuvant endocrine therapy. (A) Histogram depicting the drop-out among patients receiving adjuvant endocrine therapy after the date of surgery, (B) funnel plot depicting the variability between centres for at least 4.5 years of adjuvant endocrine therapy. cStage, clinical stage; PI, prediction interval.