Unraveling the role of tumor sidedness in prognosis of stage II colon cancer

Yun Yang; Xiaobao Yang; Zhigang Bai; Xiaozhe Gu; Saloni Rameshchandra Shah; Kenish Sirajbhai Salewala; Mansi Pankajbhai Kevadiya; Zhongtao Zhang

doi:10.1093/gastro/goae028

Unraveling the role of tumor sidedness in prognosis of stage II colon cancer

Gastroenterol Rep (Oxf). 2024 Apr 12:12:goae028. doi: 10.1093/gastro/goae028. eCollection 2024.

Authors

Yun Yang^{1

2

3}, Xiaobao Yang^{1

2

3}, Zhigang Bai^{1

2

3}, Xiaozhe Gu^{1

2

3}, Saloni Rameshchandra Shah⁴, Kenish Sirajbhai Salewala⁴, Mansi Pankajbhai Kevadiya⁴, Zhongtao Zhang^{1

2

3}

Affiliations

¹ Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, P. R. China.
² State Key Lab of Digestive Health, Beijing Friendship Hospital, Beijing, P. R. China.
³ National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Beijing, P. R. China.
⁴ International School, Capital Medical University, Beijing, P. R. China.

Abstract

Background: Stage II colon cancer has varying risks for metastasis, and treatment strategies depend on molecular and clinicopathological features. While tumor-sidedness is a well-accepted prognostic factor for stage III/IV colon cancer, its role in stage II is controversial. Understanding its effect in stage II is crucial for improving treatment strategies.

Methods: We analyzed clinical and follow-up data of colon cancer from the Surveillance, Epidemiology, and End Results database (2004-2017). Patients were divided into a primary study cohort (2010-2017) and a validation cohort (2004-2009). The baseline characteristics between right-sided colon cancer (RCC) and left-sided colon cancer (LCC) groups were compared. Moreover, the effect of tumor size on cancer-specific survival (CSS) was evaluated using Kaplan-Meier analysis.

Results: The study involved 87,355 patients in the study cohort and 65,858 in the validation cohort. Of the study cohort, 52.3% were diagnosed with RCC. The median age was 64 years old, with 48.5% females and 76.8% of white people. In addition, stage II RCC showed better CSS compared with LCC (5-year CSS 88.0% vs 85.5%, P < 0.001), while stage III/IV RCC demonstrated poorer outcomes. Multivariate Cox regression analysis identified that the right-sidedness was a positive prognostic factor in stages I/II but negative in stages III (HR 1.10, P < 0.001) and IV (HR 1.26, P < 0.001). Chemotherapy rates decreased in RCC, particularly in stage II (RCC vs LCC: 16.2% vs 28.5%, P < 0.001). Subgroup analysis, stratified by T3/T4 stages and chemotherapy status, further highlighted better survival outcomes in RCC.

Conclusions: RCC is associated with a significantly better prognosis in stage II. The importance of considering tumor-sidedness in clinical decision-making and the design of future clinical trials should be emphasized.

Keywords: colonic neoplasms; right-sided colon cancer; stage II; survival; tumor-sidedness.