This is a multicenter, retrospective, cross-sectional observational study aiming to investigate the 5-year overall survival (OS) rate of colorectal cancer (CRC) patients in Xinjiang and Shandong provinces of China. A total of no less than 500 pathologically confirmed CRC patients from 7 medical centers during January 1, 2016 to December 31, 2020 will be enrolled. We will collect and analyze the demographic characteristics, lifestyle, clinical pathological features, treatment patterns and survival prognosis data of patients, explore the regional differences of CRC and its key prognostic factors, and construct a CRC prognostic prediction model. The results will provide theoretical guidance for clinical practice and the formulation of public health policies.

Colorectal cancer is one of the most common malignant tumors with obvious regional distribution differences in incidence and prognosis. There are significant differences in economic development, lifestyle, dietary structure and medical resource allocation between Xinjiang (western China) and Shandong (eastern China), which may lead to different epidemiological characteristics and prognosis of CRC patients in the two regions. This study will enroll CRC patients from 7 multicenters in Xinjiang and Shandong, collect retrospective clinical data including demographic information, pathological features, treatment modes and follow-up records, use statistical methods such as Kaplan-Meier survival analysis and Cox proportional hazard regression model to analyze the 5-year OS rate and prognostic factors of patients in the two regions, compare the regional differences of CRC, and construct a Nomogram prognostic prediction model. The study will provide a scientific basis for the personalized treatment and regional public health prevention and control of CRC.

Inclusion Criteria:

• 1. Pathologically confirmed colorectal adenocarcinoma.

  2. Patients diagnosed between January 1, 2016 and December 31, 2020.

  3. Age ≥ 18 years old.

  4. Complete clinical, pathological, treatment and follow-up data available.

  5. Patients from medical centers in Xinjiang and Shandong regions.

Exclusion Criteria:

• 1. Other pathological types of malignant tumors except colorectal adenocarcinoma.

  2. Patients with incomplete clinical data or lost to follow-up.

  3. Patients with severe organ dysfunction or other malignant tumors that may affect survival.

  4. Age < 18 years old.

This is a retrospective, cross-sectional, multicenter observational study. The study population includes patients pathologically diagnosed with colorectal adenocarcinoma between January 1, 2016 and December 31, 2020 from medical centers in Xinjiang Uygur Autonomous Region and Shandong Province. Patients aged 18 years and above with complete clinical, pathological, treatment and follow-up data will be included. The study aims to analyze the regional epidemiological characteristics and prognostic factors of colorectal cancer.

There is no plan to share individual participant data (IPD) from this study. Data will be used only for the purpose of this retrospective observational study and will not be shared with third parties.