Comparison of Resected Malignant Tumors of the Right- and Left-Sided Colon—Is There a Difference?

Abstract

Embryological, anatomical, and immunological differences between the right-sided and left-sided colons are well known, but the difference in oncological behavior of colon tumors has only recently become the main subject of studies. Published articles propose that there is a difference not only in symptoms, but also in survival. Our aim was to analyze the clinicopathological and oncological differences among our patients who had been operated for colon cancer in our department. We examined the historical data of our patients who underwent colon resection for malignancy between 1st of January 2016 and 31st of December 2018. Tumor markers, histological results, postoperative complications, and oncological therapies were investigated. The primary outcome was overall survival. We analyzed our patients’ survival data with Kaplan–Meier log-rank test and Cox regression analysis. In our study, 267 patients were enrolled. One hundred thirty-three (49.8%) patients had right-sided colon cancer; 134 (50.2%) patients had left-sided colon cancer. Patients with right-sided colon cancer were significantly more likely to have mucinous adenocarcinoma (p = 0.037). No significant differences were revealed in overall survival between right-sided colon cancer and left-sided colon cancer patients (p = 0.381). Additional subgroup analysis showed that there were no significant differences in overall survival for laterality neither in the metastatic group (p = 0.824) nor in the non-metastatic group (p = 0.345). Based on the conflicting previous study results, our findings repeatedly highlight that the relationship between tumor location in the colon and overall survival is not straightforward.

Reply to Letter to Editor

“…We would also like to thank Prof. Dr. Kamer for the interest in our article "Comparison of Resected Malignant Tumors of the Right-and Left-Sided Colon-Is There a Difference?" and for taking the time to express his concerns [2].…”

Comparison of Resected Malignant Tumors of the Right- and Left-Sided Colon—Is There a Difference?

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The authors compared right-sided colon cancer (RCC) and left-sided colon cancer (LCC) in their study and reported that they found significantly more mucinous adenocarcinoma histology types in right colon cancer, but, unlike the literature, there was no significant difference between the location of the tumor in the colon and overall survival [1]. The authors reported in their study that they considered rectosigmoid, ascending colon, and splenic flexure tumors as LCC, transverse colon, hepatic flexure, descending colon, and cecum tumors as RCC [1]. However, they did not report how they made this classification.

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