Supplementary Material for: Non hypertensives and those with normal cholesterol more likely to have concomitant cancer amongst patients with ischemic stroke: A retrospective cross sectional registry based study

Introduction: Patients with cancer are known to have an increased risk of ischemic stroke (IS) around the time of their diagnosis. However, there is a paucity of data in Asian populations, and as such, we aimed to determine cancer incidence rates and patterns in Asian IS patients as well as investigate the differences in vascular risk profile of IS patients with and without concomitant cancer. Methods: We conducted a retrospective cross sectional study using data from the Singapore Stroke and Cancer registries. We defined cases as patients with IS and a cancer diagnosis 2 years before or after the index IS. Cancer incidence was determined using the same direct age-standardization method performed for the Singapore general population in the 2015 Singapore cancer report. Multivariable logistic regression was used to analyse differences in vascular risk factors. Results: Among 21,068 IS patients (mean age, 67.9±13.3 years), 6.3% (1330) were found to have concomitant cancer; 4.4% (935) had prior cancer while 1.8% (395) had cancer diagnoses within 2 years following IS. The cancer incidence among IS patients was 3393 (95% CI, 1937-4849) per 100,000 person-years compared to 219-231 per 100,000 person-years in the general population. Older age (odds ratio [OR], 1.02 [95% CI, 1.01-1.02] per year), males (OR, 1.25 [95% CI, 1.11-1.41), Chinese ethnicity (OR, 1.61 [95% CI, 1.37-1.89]) and a lower prevalence of hypertension (OR, 0.84 [95% CI, 0.73-0.97)]) and hyperlipidemia (OR, 0.53 [95% CI, 0.45-0.62]) were independently associated with cancer-related IS. Conclusions: The age-standardized cancer incidence was 15-times higher in IS patients than the general population. IS patients with concomitant cancer were older and had a lower prevalence of vascular risk factors.

引言：已知癌症患者在确诊前后罹患缺血性脑卒中（Ischemic Stroke, IS）的风险显著升高。但目前亚洲人群相关研究数据较为匮乏，为此本研究旨在明确亚洲缺血性脑卒中患者的癌症发病率与发病模式，并对比分析合并癌症与未合并癌症的缺血性脑卒中患者的血管危险因素谱差异。
研究方法：本研究采用回顾性横断面研究设计，依托新加坡脑卒中与癌症登记数据库开展数据分析。本研究将病例定义为在本次缺血性脑卒中发作（索引事件）前后2年内确诊癌症的缺血性脑卒中患者。癌症发病率采用2015年新加坡癌症报告中针对新加坡普通人群所用的直接年龄标化法进行计算。采用多因素logistic回归分析对比两组患者的血管危险因素差异。
研究结果：本研究共纳入21068例缺血性脑卒中患者，平均年龄为67.9±13.3岁，其中6.3%（1330例）合并癌症；4.4%（935例）为既往癌症患者，1.8%（395例）为缺血性脑卒中发作后2年内确诊癌症的患者。缺血性脑卒中患者的癌症发病率为3393例/10万人年（95%置信区间（95% Confidence Interval, CI）：1937~4849），而新加坡普通人群的癌症发病率为219~231例/10万人年。多因素分析显示，高龄（比值比（Odds Ratio, OR）=1.02，95%置信区间：1.01~1.02，每增长1岁）、男性（OR=1.25，95%置信区间：1.11~1.41）、华裔种族（OR=1.61，95%置信区间：1.37~1.89）与较低的高血压患病率（OR=0.84，95%置信区间：0.73~0.97）及高脂血症患病率（OR=0.53，95%置信区间：0.45~0.62）为与癌症相关缺血性脑卒中独立相关的危险因素。
研究结论：缺血性脑卒中患者的年龄标化癌症发病率是普通人群的15倍。合并癌症的缺血性脑卒中患者年龄更大，且血管危险因素患病率更低。