Impact of primary tumor side on the outcomes of patients with non-metastatic colon cancer; a patient-level pooled analysis of two clinical trials

ABSTRACT

Objective: To assess the impact of primary tumor side on the outcomes of non-metastatic colon cancer patients included in two clinical trials.

Methods: Overall and disease-free survivals were assessed according to the side of the tumor, through Kaplan–Meier analysis. Univariate and Multivariate analysis of predictors of disease-free survival was performed through Cox regression analysis.

Results: Kaplan–Meier analysis of disease-free survival according to the side of the primary tumor was conducted. In the overall cohort, the right-sided disease has longer disease-free survival compared to left-sided disease (p = 0.005). When the analysis was repeated among different treatment strata (observation, adjuvant 5FU/LCV, adjuvant edrecolomab), right-sided colon cancer has longer disease-free survival among observation-treated patients only (p = 0.020). Multivariate analysis was conducted among the three subsets of adjuvant treatment. The left side of the primary tumor was predictive of worse disease-free survival in patients treated with observation only (p = 0.005) but not in patients treated with adjuvant 5FU/LCV (p = 0.345) or patients treated with adjuvant edrecolomab (p = 0.661).

Conclusion: Stage II right-sided colon cancer patients have better disease-free survival compared to stage II left-sided colon cancer patients when treated with surgery only. This survival difference disappears if patients were treated with adjuvant fluoropyrimidines.

KEYWORDS:

• Tumor side
• colon cancer
• adjuvant treatment
• survival

Acknowledgments

This publication is based on research using information obtained from www.projectdatasphere.org, which is maintained by Project Data Sphere, LLC. Neither Project Data Sphere, LLC nor the owner(s) of any information from the web site have contributed to, approved or are in any way responsible for the contents of this publication.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviwer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose

Additional information

Funding

This study was not funded.

Notes on contributors

Omar Abdel-Rahman

Omar Abdel-Rahman Collecting the data and conducting the analysis.

Anwar Giryes, Hani Oweira, Meinrad Mannhart Revising the final manuscript.