Objective: To explore the differences in distribution of colorectal cancer-related risk factors between patients with early-onset colorectal cancer (EOCRC) and those with late-onset colorectal cancer (LOCRC) in a Chinese cohort, and to provide reference and guidance for the prevention, diagnosis, and treatment of EOCRC. Methods: Using data from the National Colorectal Cancer Cohort study cohort, 5377 patients with newly diagnosed colorectal cancer (CRC) attending the Department of Colorectal Surgery and Oncology of the Second Affiliated Hospital, Zhejiang University School of Medicine from June 2018 to February 2023 were included in the study cohort. Questionnaires capturing epidemiological features, including lifestyle and dietary habits, were administered. The patients were divided into two groups, the cut-off age being 50 years. Those aged ≥50 years were defined as having LOCRC and those aged <50 years as having EOCRC. Wilcoxon (continuous variates) or χ2 tests (categorical variates) were performed to compare differences in epidemiological features. Results: A total of 3799 people who had completed the questionnaire were included in this study, 491 of whom had EOCRC and 3308 LOCRC. The response rate to the questionnaire was 70.7%. The median ages of patients in the EOCRC and LOCRC groups were 43 and 66 years, respectively. There was a higher proportion of female patients (48.5% [253/491] vs. 35.8% [1184/3308], χ2=28.8, P<0.001) in the EOCRC than the LOCRC group. Patients with EOCRC and lower body mass index (medium 22.1 kg/m2 vs. 22.9 kg/m2, W=744 793, P=0.005) and lower proportion of abdominal obesity (87.2% [428/491] vs. 93.8% [3103/3308], χ2=38.3, P<0.001). Patients with EORC significantly less commonly reported a history of hypertension (5.9% [29/491] vs. 41.6% [1375/3308], χ2=231.8, P<0.001), diabetes (1.4% [7/491] vs. 14.4% [476/3308], χ2=63.6, P<0.001) and cardiovascular and cerebrovascular diseases (0.8% [4/491] vs. 7.3% [241/3308], χ2=28.6, P<0.001). However, the proportion of patients with a family history of CRC was significantly higher (P<0.05) in the EOCRC group (10.2% [50/491] vs. 6.9% [227/3 308], χ2=6.5, P=0.010]. In terms of lifestyle, patients with EOCRC had shorter sleep duration (median: 8.0 hours vs. 8.5 hours, W=578 989, P<0.001), and were less likely to participate in physical exercise (29.5% [145/491] vs. 38.7% [1281/3308] χ2=15.0, P<0.001) or engage in physical work (65.2% [320/491] vs. 74.1% [2450/3308], χ2=16.7, P<0.001). Meanwhile, in the EOCRC group a lower percentage of patients were smokers (29.3% [144/491] vs. 42.7% [1411/3308], χ2=46.9,P<0.001) and they smoked less (median 17.6 pack/year vs. 30.0 pack/year,W=55 850,P<0.001). Fewer patients in the EOCRC group habitually drank alcohol (21.0% [103/491] vs. 38.0% [1257/3308], χ2=57.5, P<0.001) or tea (17.5% [86/491] vs. 28.7% [948/3308], χ2=26.2, P<0.001) than in the LOCRC group. Compared with the LOCRC group, patients with EOCRC had a higher frequency of intake of fresh meat, fresh fruit, eggs, and dairy products and a lower frequency of intake of preserved meat and pickled vegetables; these differences are statistically significant (all P<0.05). There was no statistically significant difference in consumption of fresh vegetables or a high-sugar diet between the two groups (both P>0.05). Conclusions: This study highlights disparities in adverse lifestyle and dietary habits between patients in China with EOCRC versus LOCRC.
目的： 探究我国早发性结直肠癌（EOCRC）和晚发性结直肠癌（LOCRC）患者中流行病学特征和暴露因素的分布差异，为早发性结直肠癌的预防及临床诊疗提供参考与指导。 方法： 依托于结直肠癌专病队列纳入了2018年6月至2023年2月期间在浙江大学医学院附属第二医院大肠外科首次确诊为原发性结直肠癌的5 377例患者，对患者进行基本信息和流行病学信息的问卷调查。并以50岁为年龄分界值进行分组，将年龄≥50岁者定义为LOCRC，年龄<50岁者定义为EOCRC。采用Wilcoxon检验或χ2检验比较EOCRC组与LOCRC组患者的生活方式与饮食习惯等流行病学特征。 结果： 研究共纳入3 799例完成基线问卷调查者，问卷应答率70.7%。其中，EOCRC组491例，LOCRC组3 308例。EOCRC组患者中位年龄为43岁，LOCRC组患者中位年龄66岁。与LOCRC组一般人口学特征的比较，EOCRC组女性比例偏高［48.5%（253/491）比35.8%（1 184/3 308），χ2=28.8，P<0.001］，体质指数更小（中位数22.1 kg/m2比22.9 kg/m2，W=744 793，P=0.005），腹型肥胖比例更低［87.2%（428/491）比93.8%（3 103/3 308），χ2=38.3，P<0.001］，合并有高血压［5.9%（29/491）比41.6%（1 375/3 308），χ2=231.8，P<0.001］、糖尿病［1.4%（7/491）比14.4%（476/3 308），χ2=63.6，P<0.001］和心脑血管疾病史［0.8%（4/491）比7.3%（241/3 308），χ2=28.6，P<0.001］比例更少，但具有结直肠癌家族史的比例更高［10.2%（50/491）比6.9%（227/3 308），χ2=6.5，P=0.010］；差异均有统计学意义（均P<0.05）。与LOCRC组生活方式比较，EOCRC组睡眠时长缩短（中位数8.0 h比8.5 h，W=578 989，P<0.001），从事体力工作比例偏低［65.2%（320/491）比74.1%（2 450/3 308），χ2=16.7，P<0.001］，更少参加体育锻炼［29.5%（145/491）比38.7%（1 281/3 308），χ2=15.0，P<0.001］，更少有吸烟的习惯［29.3%（144/491）比42.7%（1 411/3 308），χ2=46.9，P<0.001］，吸烟量也更少（中位数17.6包/年比30.0包/年，W=55 850，P<0.001），饮酒［21.0%（103/491）比38.0%（1 257/3 308），χ2=57.5，P<0.001］和喝茶［17.5%（86/491）比28.7%（948/3 308），χ2=26.2，P<0.001］比例更低；差异均有统计学意义（均P<0.05）。与LOCRC组饮食习惯比较，EOCRC组患者进食新鲜肉类、水果、鸡蛋和奶制品的频次更高，进食腌制肉类和腌制蔬菜的频次更低；差异均有统计学意义（均P<0.05）。两组进食新鲜蔬菜和高糖饮食的差异未见统计学意义（均P>0.05）。 结论： 我国的EOCRC与LOCRC患者在不良生活方式以及饮食等流行病学特征方面存在差异。.