Prognostic Impact of Increased Lymph Node Yield in Colorectal Cancer Patients With Synchronous Distant Metastasis: a Population-based Study of the US Database and a Chinese Registry

Study Overview
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Brief Summary
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The National Quality Forum has endorsed at least 12 lymph node yield (LNY) as a surgical quality indicator in colorectal cancer (CRC), but the prognostic value of adequate lymphadenectomy has rarely been investigated for CRC patients with distant metastatic disease.

Detailed Description
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Data on CRC patients with synchronous liver metastasis (LM) were derived from the US Surveillance, Epidemiology, and End Results (SEER) and a Chinese registry (from two Chinese tertiary centers: The Second Affiliated Hospital of Harbin Medical University and National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College) between January 2010 and December 2017. Individual level data on patients with incident CRC were consecutively collected in both registries. The primary tumor site was divided into three subsites according to International Classification of Diseases for Oncology (ICD-O-3) topography codes: proximal colon (C18.0, C18.1, C18.2, C18.3 and C18.4), distal colon (C18.5, C18.6, C18.7) and rectum (C19.9 and C20.9). The synchronous LM were identified by imaging or histopathological examinations. Synchronous LM refers to liver lesions found within 6 months after the diagnosis of primary CRC. Patients were excluded if they did not undergo surgery for CRC, did not have data on number of LNs retrieved and their survival status was unknown.

Official Title
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Prognostic Impact of Increased Lymph Node Yield in Colorectal Cancer Patients With Synchronous Distant Metastasis: a Population-based Study of the US Database and a Chinese Registry

Conditions
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Colorectal Cancer Stage IV, Lymph Node Yield

Intervention / Treatment
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* Other: lymph node yield


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Data on CRC patients with synchronous liver metastasis (LM) undergo surgery for CRC, have data on number of LNs retrieved and their survival status was known Exclusion Criteria: Patients were excluded if they did not undergo surgery for CRC, did not have data on number of LNs retrieved and their survival status was unknown

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| SEER database<br>Data on CRC patients with synchronous liver metastasis (LM) were derived from the US Surveillance, Epidemiology, and End Results (SEER) between January 2010 and December 2017. | Other: lymph node yield<br>* We recorded the number of lymph nodes dissected during surgery in patients with colorectal cancer<br>|
| Chinese cohort<br>Data on CRC patients with synchronous liver metastasis (LM) were derived from two Chinese tertiary centers: The Second Affiliated Hospital of Harbin Medical University and National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College between January 2010 and December 2017. | Other: lymph node yield<br>* We recorded the number of lymph nodes dissected during surgery in patients with colorectal cancer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cancer specific survival | The primary outcome was cancer specific survival (CSS), which was defined as the time interval from the synchronous LM diagnosis until cancer specific death or the end of follow-up in Chinese registry, and the CSS was defined using the SEER cause-of-death codes in SEER registry | 2010.01-2017.12 |