Dear Sir:
We read with great interest the study entitled “Incidental statin use and the risk of stroke or transient ischemic attack after radiotherapy for head and neck cancer” by Addison et al. [
With the aim to examine the association between statin and stroke risk after radiotherapy in a larger cohort of HNC patients, we conducted a nationwide population-based study using data from the National Health Insurance Research Database. International Classification of Diseases, Ninth Revision, Clinical Modification was used for disease identification and the cancer status was confirmed using the catastrophic illness registry. We identified newly diagnosed HNC patients receiving radiotherapy from January 1, 2000 to December 31, 2010 (n=48,548), and patients with previous cancer or radiotherapy history were excluded for further analysis. Statin user was defined as use of statin during the entire course of radiotherapy. After propensity score matching of the selected comorbidities, there were 1,073 patients receiving statin (user group) and 1,073 matched patient not receiving statin (nonuser group) during radiotherapy and followup. The demographics were not different between the user and nonuser groups except for the use of antithrombotics and antihypertensives, which were of higher incidence in the user group (
The preliminary findings from this study showed that the legacy effect of statin during radiotherapy does not lower the subsequent risk of TIA and ischemic stroke in patient with HNC, which is contradictory to the report by Addison et al. [
In summary, statin use during radiotherapy was not associated with reduced risk of TIA or ischemic stroke in Taiwanese patients with HNC. Possible difference in statin resistance and types of HNC might be the explanation for the inconsistent result with the previous study. Future large-scale prospective studies are necessary to determine effectiveness of statin in preventing radiation-induced vascular disease and stroke.
Supplementary materials related to this article can be found online at
Incidences and subhazard ratios of ischemic stroke or TIA in head and neck cancer patient with and without statin during radiotherapy stratified by demographics and comorbidity in the competing-risk regression model
The authors have no financial conflicts of interest.
This work was supported by grants from the Ministry of Health and Welfare, Taiwan (MOHW107-TDU-B-212-123004); China Medical University Hospital (DMR-107-192); Academia Sinica Stroke Biosignature Project (BM10701010021); MOST Clinical Trial Consortium for Stroke (MOST 106-2321-B-039-005-); TsengLien Lin Foundation, Taichung, Taiwan; and Katsuzo and Kiyo Aoshima Memorial Funds, Japan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding received for this study.
Cumulative incidence of ischemic stroke or transient ischemic attack (TIA) in the user and nonuser group during follow-up.
Comparisons in demographic characteristics and comorbidities in head and neck cancer patient with and without statin during radiotherapy
Characteristic | Statin |
||
---|---|---|---|
No (n=1,073) | Yes (n=1,073) | ||
Gender | 0.21 | ||
Women | 124 (11.6) | 143 (13.3) | |
Men | 949 (88.4) | 930 (86.7) | |
Age stratified (yr) | 0.69 | ||
≤49 | 149 (13.9) | 163 (15.2) | |
50–64 | 549 (51.2) | 539 (50.2) | |
≥65 | 375 (35.0) | 371 (34.6) | |
Age (yr) |
60.5±10.2 | 60.6±10.5 | 0.90 |
Comorbidity | |||
Hypertension | 840 (78.3) | 830 (77.4) | 0.60 |
Hyperlipidemia | 882 (82.2) | 882 (82.2) | 0.99 |
Diabetes | 531 (49.5) | 524 (48.8) | 0.76 |
Congestive heart failure | 102 (9.5) | 123 (11.5) | 0.14 |
Hypercoagulability | 4 (0.4) | 4 (0.4) | 0.99 |
Atrial fibrillation | 19 (1.8) | 25 (2.3) | 0.36 |
Coronary artery disease | 449 (41.9) | 467 (43.5) | 0.43 |
Chronic kidney disease and ESRD | 170 (15.8) | 181 (16.9) | 0.52 |
Previous stroke | 175 (16.3) | 180 (16.8) | 0.77 |
Medication | |||
Aspirin | 891 (83.0) | 937 (87.3) | 0.01 |
Clopidogrel | 89 (8.3) | 248 (23.1) | <0.01 |
ACEI | 627 (58.4) | 706 (65.8) | <0.01 |
ARB | 463 (43.2) | 604 (56.3) | <0.01 |
Warfarin | 42 (3.9) | 61 (5.7) | 0.06 |
Treatment | |||
Surgery | 181 (16.9) | 182 (17.0) | 0.95 |
Chemotherapy | 776 (72.3) | 765 (71.3) | 0.60 |
Cetuximab | 18 (1.7) | 25 (2.3) | 0.28 |
Values are presented as number (%) or mean±SD. Chi-square test.
ESRD, end-stage renal disease; ACEI, angiotensin-converting-enzyme inhibitor; ARB, angiotensin II receptor blocker.
t-test.