Adherence to endocrine therapy in patients with hormone receptor-positive early-stage breast cancer: a retrospective study

The persistence and adherence to endocrine therapy (ET) in hormone receptor-positive (HR +) breast cancer patients remain far less than optimal.

This retrospective study aimed to evaluate adherence to ET and to identify influencing factors in early-stage HR + breast cancer patients.

A stratified random sampling method was used to select patients admitted for breast cancer surgery at a university hospital in Shanghai, China. Patients who received ET medications in the hospital information system (HIS) were included. The primary outcomes were early discontinuation of and adherence to ET. Potential factors influencing the discontinuation and adherence were assessed using univariate and multivariate logistic regression analyses.

In total, 706 patients were included, and 161 (22.8%) discontinued ET in less than five years from the first prescription. The discontinuation rates from the one-year to the five-year treatment were 5.38, 16.70, 32.27, 51.52, and 50.00%, respectively (P < 0.001). The rates of adherence (defined as medication possession ratio ≥ 80%) from the first to the fifth year were 85.18, 82.25, 82.18, 72.92, and 73.68%, respectively (P = 0.18). Age, insurance, and surgery type impacted ET discontinuation and adherence. However, the type of medication only impacted the adherence to ET.

Persistence and adherence to ET in patients with breast cancer remain far from optimal and decrease over time. More attention should be paid to patients aged ≥ 70 years and those without insurance who tend to have early discontinuation of ET.