J Cancer 2019; 10(2):313-322. doi:10.7150/jca.26882

Research Paper

Prognostic Value of the Tumor Size in Resectable Colorectal Cancer with Different Primary Locations: A Retrospective Study with the Propensity Score Matching

Xiao Li1,2, Bang An3, Jincai Ma1,4, Bo He1,2, Jianni Qi2,5, Wenwen Wang1,2, Chengyong Qin1,2,6, Qi Zhao1,2✉

1. Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong Province, China;
2. Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan 250021, Shandong Province, China;
3. Department of Cardiology, Central Hospital of Zibo, Zibo 255036, Shandong Province, China;
4. Department of Gastroenterology, The Fifth People's Hospital of Jinan, Jinan 250022, Shandong Province, China;
5. Central Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong Province, China;
6. Health Commission of Shandong Province, Jinan 250014, Shandong Province, China.

Abstract

Objective: To investigate the prognostic value of the tumor size in colorectal cancer (CRC) patients with different primary tumor locations.

Patients and methods: We retrospectively recruited 3971 stage I-III CRC patients with curative resection. The propensity score matching technique was conducted to reduce the selection bias, producing a propensity score matched cohort of 1347 pairs of patients based on the tumor size (≤4 cm and >4 cm groups). Kaplan-Meier survival analyses and univariate and multivariate analyses were used to compare the overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) between the two groups. Subgroup analyses which were stratified by primary tumor locations and several other baseline variables were also performed for conformation.

Results: In the propensity score matched cohort, the Kaplan-Meier survival curves revealed that patients with a tumor size less than 4 cm had similar OS, CSS and DFS, compared to patients with a tumor size greater than 4 cm. While in multivariate analyses, the smaller tumor size was an independent risk factor for CSS (HR, 1.275; 95% CI, 1.006-1.616; P=0.045). Subgroup analyses based on primary tumor locations further suggested that the smaller tumor size was significantly associated with worse OS (HR, 2.455; 95% CI, 1.297-4.649; P=0.006) and CSS (HR, 2.493; 95% CI, 1.202-5.174; P=0.014) in patients with right-side colon cancers (RCC).

Conclusions: Our propensity matching score study indicated that the smaller tumor size was an independent risk factor for CSS in patients with stage I-III CRC, and for OS and CSS in patients with RCC.

Keywords: tumor size, primary tumor location, colorectal cancer, prognosis, propensity score matching

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How to cite this article:
Li X, An B, Ma J, He B, Qi J, Wang W, Qin C, Zhao Q. Prognostic Value of the Tumor Size in Resectable Colorectal Cancer with Different Primary Locations: A Retrospective Study with the Propensity Score Matching. J Cancer 2019; 10(2):313-322. doi:10.7150/jca.26882. Available from http://www.jcancer.org/v10p0313.htm