Data_Sheet_1_Association between lifestyle and dietary preference factors and conventional adenomas and serrated polyps.docx

IntroductionBoth conventional adenoma (AD) and serrated polyp (SP) were known precursor lesions of colorectal cancer (CRC). Modifiable lifestyle factors were significantly associated with CRC risk, but whether these factors were related to the risk of different precursors of CRC needed to be clarified. This study aimed to evaluate the risks of AD and SP caused by lifestyle factors and compare the risk differences between AD and SP.
MethodsThe study population was from the CRC screening cohort in Hangzhou, China. A total of 458,457 eligible individuals volunteered to undergo initial screening including the fecal immunochemical test (FIT) and the CRC risk assessment. Finally, 13,993 participants who had undergone colonoscopy tests and had been diagnosed at designated hospitals were selected in this study. All participants were required to fill out a questionnaire during the initial screening for collecting their information. The generalized estimate equation (GEE) model was used to assess the association between lifestyle factors/dietary preferences and AD/SP.
ResultsThe body mass index (BMI) and smoking were positively associated with the risks of only SP (BMI: OR = 1.50, 95%CI: 1.23–1.84; smoking: OR = 1.29, 95%CI: 1.07–1.55), only AD (BMI: OR = 1.53, 95%CI: 1.28–1.82; OR = 1.24, 95%CI: 1.11–1.39), and synchronous SP and AD (BMI: OR = 1.97, 95%CI: 1.40–2.75; smoking: OR = 1.53, 95%CI: 1.27–1.85). In the case-group comparison, smoking was more strongly associated with the risk of synchronous SP and AD than only AD. Alcohol drinking was positively associated with the risk of AD (OR = 1.28, 95%CI: 1.14–1.44), but no statistically significant difference was observed in risks in the case-group comparison. Furthermore, whole-grain intake was associated with a decreased risk of only AD (OR = 0.78, 95%CI: 0.65–0.93). However, white meat intake was positively associated with risks of only SP when compared with AD cases (OR = 1.60, 95%CI: 1.15–2.23).
ConclusionThe current study identified common risk factors such as BMI and smoking as well as different risks of certain factors (e.g., alcohol drinking and whole-grain intake) for SP and AD. However, there were still some factors, especially diet-related factors, that have not been fully elucidated in their association with the two lesions. Further research is needed in future to confirm and develop prevention strategies for different lesions.

引言
传统腺瘤（conventional adenoma, AD）与锯齿状息肉（serrated polyp, SP）均为公认的结直肠癌（colorectal cancer, CRC）癌前病变。可改变的生活方式因素与结直肠癌风险显著相关，但此类因素与结直肠癌不同癌前病变的风险关联仍有待阐明。本研究旨在评估生活方式因素对腺瘤与锯齿状息肉的风险影响，并比较二者的风险差异。

方法
本研究的研究人群来自中国杭州市结直肠癌筛查队列。共计458457名符合条件的志愿者参与了初始筛查，筛查项目包括粪便免疫化学测试（fecal immunochemical test, FIT）与结直肠癌风险评估。最终，本研究纳入了13993名完成结肠镜检查且在定点医院确诊的参与者。所有参与者在初始筛查阶段均需填写调查问卷以收集相关信息。本研究采用广义估计方程（generalized estimate equation, GEE）模型，评估生活方式因素/饮食偏好与腺瘤、锯齿状息肉的关联。

结果
体质指数（body mass index, BMI）与吸烟仅与锯齿状息肉风险呈正相关（BMI：比值比（odds ratio, OR）=1.50，95%置信区间（confidence interval, CI）：1.23~1.84；吸烟：OR=1.29，95%CI：1.07~1.55）、仅与传统腺瘤风险呈正相关（BMI：OR=1.53，95%CI：1.28~1.82；吸烟：OR=1.24，95%CI：1.11~1.39），以及与同时发生锯齿状息肉和传统腺瘤的风险呈正相关（BMI：OR=1.97，95%CI：1.40~2.75；吸烟：OR=1.53，95%CI：1.27~1.85）。在病例组对比分析中，吸烟与同时发生两种病变的风险关联强度高于其与仅发生传统腺瘤的风险关联。饮酒与传统腺瘤风险呈正相关（OR=1.28，95%CI：1.14~1.44），但在病例组对比中未观察到具有统计学意义的风险差异。此外，全谷物摄入仅与降低传统腺瘤风险相关（OR=0.78，95%CI：0.65~0.93）。但与传统腺瘤病例相比，白肉摄入仅与升高锯齿状息肉风险呈正相关（OR=1.60，95%CI：1.15~2.23）。

结论
本研究明确了体质指数、吸烟等与两种病变均相关的共同风险因素，以及饮酒、全谷物摄入等对锯齿状息肉与传统腺瘤存在差异化风险影响的因素。但仍有部分因素（尤其是饮食相关因素）与这两种癌前病变的关联尚未完全阐明。未来需开展进一步研究以验证相关结论，并为不同癌前病变制定针对性预防策略。