结直肠癌（CRC）患者通常伴有多种合并症，其中很多会影响治疗和生存。然而，以往的合并症研究主要集中在普遍使用的合并症指数中的疾病上。迄今为止，尚未研究新诊断的CRC患者在整个慢性疾病谱中的合并症状况。本研究旨在运用基于网络的方法和大规模行政卫生数据对所有慢性诊断和共同发生的疾病进行系统分析，提供中国西南地区新诊断的CRC患者合并症态势的完整画像。在这项回顾性观察性研究中，使用中国四川省2015年至2020年678家医院的出院记录，确定了2020年新发CRC病例及其疾病史。我们使用ICD-10（第十版国际疾病分类）码的3位数诊断检视了所有慢性诊断，并着重于在至少一个亚组（单侧检验，P<.025）中的患病率超过1％的慢性疾病，总共涉及66种慢性疾病。根据性别、年龄（18-59岁、60-69岁、70-79岁和≥80岁）、地区（城市和农村）以及癌症部位（结肠和直肠），构建了跨所有CRC患者和不同亚组的表型合并症网络，其中合并症作为节点，连结表示多个合并症之间显著相关性。中国四川省2020年共发生29610例新的CRC病例。平均诊断年龄为65.6岁（标准差12.9），75.5％（22369/29610）的患者至少有一个合并症。最常见的合并症为高血压（8581/29610，29.0％；95％CI 28.5％-29.5％）、前列腺增生（3816/17426，21.9％；95％CI 21.3％-22.5％）和慢性阻塞性肺疾病（COPD；4199/29610，14.2％；95％CI 13.8％-14.6％）。在大多数情况下，单一合并症的患病率在每个亚组中不同。合并症之间存在密切关联，脂蛋白代谢紊乱和前列腺增生在其他合并症之间介导相关性。男性和女性共享58.3％（141/242）的疾病对，而男女差异主要出现在男性与COPD、脑血管疾病、动脉粥样硬化、心力衰竭或肾衰竭共病以及女性与骨质疏松或膝关节病共病之间。城市患者通常有更多慢性疾病、更高患病率和更复杂的疾病共存关系；而农村患者更有可能出现与脑血管疾病后遗症或COPD共病的心力衰竭等并发严重疾病。男女和城乡在新的CRC病例中患单一合并症的患病率及其复杂共存关系的差异并不是简单的巧合。结果反映了CRC患者的临床实践，并强调了从个体和共存疾病角度测量合并症模式的重要性，以更好地理解合并症模式。

Patients with colorectal cancer (CRC) often present with multiple comorbidities, and many of these can affect treatment and survival. However, previous comorbidity studies primarily focused on diseases in commonly used comorbidity indices. The comorbid status of CRC patients with respect to the entire spectrum of chronic diseases has not yet been investigated.This study aimed to systematically analyze all chronic diagnoses and diseases co-occurring, using a network-based approach and large-scale administrative health data, and provide a complete picture of the comorbidity pattern in patients newly diagnosed with CRC from southwest China.In this retrospective observational study, the hospital discharge records of 678 hospitals from 2015 to 2020 in Sichuan Province, China were used to identify new CRC cases in 2020 and their history of diseases. We examined all chronic diagnoses using ICD-10 (International Classification of Diseases, 10th Revision) codes at 3 digits and focused on chronic diseases with >1% prevalence in at least one subgroup (1-sided test, P<.025), which resulted in a total of 66 chronic diseases. Phenotypic comorbidity networks were constructed across all CRC patients and different subgroups by sex, age (18-59, 60-69, 70-79, and ≥80 years), area (urban and rural), and cancer site (colon and rectum), with comorbidity as a node and linkages representing significant correlations between multiple comorbidities.A total of 29,610 new CRC cases occurred in Sichuan, China in 2020. The mean patient age at diagnosis was 65.6 (SD 12.9) years, and 75.5% (22,369/29,610) had at least one comorbidity. The most prevalent comorbidities were hypertension (8581/29,610, 29.0%; 95% CI 28.5%-29.5%), hyperplasia of the prostate (3816/17,426, 21.9%; 95% CI 21.3%-22.5%), and chronic obstructive pulmonary disease (COPD; 4199/29,610, 14.2%; 95% CI 13.8%-14.6%). The prevalence of single comorbidities was different in each subgroup in most cases. Comorbidities were closely associated, with disorders of lipoprotein metabolism and hyperplasia of the prostate mediating correlations between other comorbidities. Males and females shared 58.3% (141/242) of disease pairs, whereas male-female disparities occurred primarily in diseases coexisting with COPD, cerebrovascular diseases, atherosclerosis, heart failure, or renal failure among males and with osteoporosis or gonarthrosis among females. Urban patients generally had more comorbidities with higher prevalence and more complex disease coexistence relationships, whereas rural patients were more likely to have co-existing severe diseases, such as heart failure comorbid with the sequelae of cerebrovascular disease or COPD.Male-female and urban-rural disparities in the prevalence of single comorbidities and their complex coexistence relationships in new CRC cases were not due to simple coincidence. The results reflect clinical practice in CRC patients and emphasize the importance of measuring comorbidity patterns in terms of individual and coexisting diseases in order to better understand comorbidity patterns.©Hang Qiu, Liya Wang, Li Zhou, Xiaodong Wang. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 05.09.2023.