Table_1_Trends of colorectal cancer incidence according to age, anatomic site, and histological subgroup in Bavaria: A registry-based study.docx

BackgroundRecent studies reported an increase in colorectal cancer incidence for adults below 50 years. There is a lack of studies distinguishing between histological subgroups, especially from Europe. MethodsUsing data from the Bavarian Cancer Registry, we analyzed incidence trends in colorectal cancer by age (20–29, 30–39, 40–49, and 50 years and above), anatomic site (colon without appendix, appendix, and rectum), and histological subgroup (adenocarcinoma and neuroendocrine neoplasm) from 2005 to 2019. We calculated 3-year average annual age-standardized incidence rates (ASIR) per 100,000 persons for the beginning (2005–2007) and the end (2017–2019) of the study period and estimated average annual percentage change. ResultsData from 137,469 persons diagnosed with colorectal cancer were included. From 139,420 cases in total, 109,825 (78.8%) were adenocarcinomas (ACs), 2,800 (2.0%) were neuroendocrine neoplasms (NENs), and 26,795 (19.2%) had other histologies. This analysis showed a significant increase in the 3-year average annual ASIR of colorectal NENs in all age groups between 2005–2007 and 2017–2019 with the highest increase in the age groups 30–39 years (0.47 to 1.53 cases per 100,000 persons; +226%; p < 0.05) and 20–29 years (0.52 to 1.38 cases per 100,000 persons; +165%; p < 0.05). The increase was driven by appendiceal and rectal NENs but not by colonic NENs. The 3-year average annual ASIR of colorectal ACs did not change significantly for the age groups below 50 years. For those aged 50 years and above, the 3-year average annual ASIR of colorectal ACs decreased significantly (132.55 to 105.95 cases per 100,000 persons; −20%; p < 0.05]). The proportion of NENs increased across all age groups, especially in the younger age groups. ConclusionFuture studies that analyze trends in early-onset colorectal cancer need to distinguish between anatomic sites as well as histological subgroups and may, thus, provide useful information regarding the organization of colorectal cancer screening, which primarily helps to detect adenomas and adenocarcinomas."背景：近期研究显示，50岁以下成年人结直肠癌(colorectal cancer)的发病率呈上升趋势。目前尚缺乏针对结直肠癌组织学亚型进行区分的相关研究，尤其是来自欧洲地区的此类研究。 方法：本研究依托巴伐利亚癌症登记处(Bavarian Cancer Registry)的数据，对2005年至2019年结直肠癌的发病趋势展开分析，分析维度涵盖年龄分组（20~29岁、30~39岁、40~49岁及50岁及以上）、解剖部位（无阑尾的结肠、阑尾、直肠）以及组织学亚型（腺癌(adenocarcinoma)和神经内分泌肿瘤(neuroendocrine neoplasm)）。本研究计算了研究起始阶段（2005~2007年）与结束阶段（2017~2019年）每10万人的3年平均年度年龄标准化发病率（age-standardized incidence rates, ASIR），并估算了年度平均百分比变化。 结果：本研究最终纳入137469例结直肠癌患者的相关数据。在总计139420例病例中，109825例（78.8%）为腺癌(adenocarcinomas, ACs)、2800例（2.0%）为神经内分泌肿瘤(neuroendocrine neoplasms, NENs)，剩余26795例（19.2%）为其他组织学类型。分析显示，2005~2007年至2017~2019年间，所有年龄组的结直肠神经内分泌肿瘤3年平均年度ASIR均呈显著上升趋势，其中30~39岁组（每10万人0.47例升至1.53例；增幅226%；p<0.05）与20~29岁组（每10万人0.52例升至1.38例；增幅165%；p<0.05）的增幅最为显著。该上升趋势主要由阑尾来源与直肠来源的NENs驱动，而非结肠来源的NENs。对于50岁以下年龄组，结直肠腺癌的3年平均年度ASIR无显著变化；而50岁及以上年龄组的结直肠腺癌3年平均年度ASIR则显著下降（每10万人132.55例降至105.95例；降幅20%；p<0.05）。各年龄组中NENs的占比均有所上升，其中年轻年龄组的上升幅度尤为明显。 结论：未来针对早发性结直肠癌发病趋势开展的研究，需同时区分解剖部位与组织学亚型，此类研究可为结直肠癌筛查体系的优化提供有价值的参考依据——当前结直肠癌筛查主要用于检测腺瘤与腺癌。