Vascular events from carotid artery atherosclerosis after radiation therapy for laryngeal and hypopharyngeal cancer: the incidence and risk factors

In this retrospective cohort study, we evaluated the incidence of vascular events from carotid artery atherosclerosis after radiotherapy indication for laryngeal and hypopharyngeal cancer. From January 2007 to December 2016, we investigated 111 laryngeal/hypopharyngeal cancer patients who underwent curative radiotherapy and were followed up for ≥1 year (median follow-up duration, 60 months). We evaluated the incidence of vascular events from carotid artery atherosclerosis, defined as a transient ischemic attack or an atherothrombotic cerebral infarction, or from undergoing treatment such as carotid artery stenting for carotid artery stenosis. The median radiation dose was 66 Gy (range, 60–74); 48 patients (43.2%) received concurrent chemotherapy. The 5-year overall survival was 86.2%. Six patients required treatment for carotid artery disease. Carotid stenting was performed in three patients with carotid artery stenosis; three patients developed atherosclerotic cerebral infarction and received medical treatment, with a median of 51.7 months (range, 0.3–78.3) after radiotherapy initiation. The vascular event occurrence rate was 5.4% within 5 years and 10.7% within 8 years. In the univariate analysis, dyslipidemia, diabetes mellitus, and carotid calcification were significant factors for event occurrence. Because three out of six cases occurred out of the irradiated field, no carotid artery or carotid bulb dosimetric parameters showed significant correlation. As laryngeal/hypopharyngeal cancer patients, particularly with complications including dyslipidemia and diabetes mellitus, are at a high risk of carotid artery stenosis after radiotherapy, long-term carotid artery evaluation is necessary. Early intervention by stroke specialists can reduce the risk of fatal cerebral infarction.

Adherence and persistence to hyperlipidemia medications in patients with atherosclerotic cardiovascular disease and those with diabetes mellitus based on administrative claims data in Japan

BACKGROUND AND AIMS

Real-world data on treatment patterns in Japanese hyperlipidemia patients with diabetes mellitus (DM) or prior atherosclerotic cardiovascular diseases (ASCVD) are lacking.

METHODS

This is a retrospective, longitudinal cohort analysis of administrative claims data (Japan Medical Data Center [JMDC] and Medical Data Vision [MDV] databases) for patients prescribed a new hyperlipidemia medication between 2014 and 2015. Patients were followed for ≥12 months. Outcomes included prescribing patterns, persistence (discontinuations), and adherence (proportion of days covered).

RESULTS

Data were analyzed for 11,718 and 27,746 DM, and 4101 and 14,356 ASCVD patients from the JMDC and MDV databases, respectively. Among previously-untreated patients, index prescriptions were primarily for moderate statins in the DM (JMDC: 74.7%, MDV: 77.5%) and ASCVD (JMDC: 75.4%, MDV: 78.5%) sub-cohorts. Combinations were rarely prescribed (≤2.5%). Previously-treated patients were most frequently prescribed combinations in the DM (JMDC: 46.7%, MDV: 53.6%) and ASCVD (JMDC: 49.3%, MDV: 53.3%) sub-cohorts. Intensive statins were rarely used by previously-untreated (≤1%) or previously-treated (≤8%) patients in either sub-cohort. Approximately half of previously-untreated patients discontinued hyperlipidemia therapy within 12 months. Adherence was ≥80% across most drug classes.

CONCLUSIONS

Many Japanese hyperlipidemia patients with DM or ASCVD are prescribed single-agent lipid-lowering therapy. Use of intensive therapy is lower than expected, and is suggestive of under-treatment. The low persistence rates are concerning, and warrant further study.