eP475 - Short- and Long-Term Outcomes After Elective Colectomy for Transverse Colon Cancers: Proximal versus Distal

Purpose/Background: The demarcation of proximal and distal transverse colon cancer remains a relatively uncharted territory in colorectal cancer research. These classifications are important in determining surgical approaches and lymphatic drainage patterns, which subsequently impact prognostic outcomes. However, there was no consensus agreement on the definition of proximal and distal transverse colon. The primary objective of this study is to define the proximal and distal transverse colon and to compare proximal and distal transverse colon cancers in terms of short- and long-term outcomes.Methods/Interventions: A retrospective analysis was conducted at a tertiary healthcare institution, examining short- and long-term outcomes among patients who underwent elective surgical interventions for transverse colon cancer from 2011 to 2021. Tumors located to the left of the middle colic artery were defined as proximal transverse colon cancers, and those to the right were defined as distal transverse colon cancers.Results/Outcomes: A total of 416 patients who underwent elective colectomy for stage I to III adenocarcinoma of the transverse colon were included. The number of subjects in the proximal transverse colon was 279, and in the distal transverse colon was 137. There were no significant differences in the basic characteristics between the two groups. Surgeries involving the distal transverse colon demonstrated longer operative durations (249.49±89.92 vs. 208.83±67.76, p < 0.01), fewer lymph node yields (22.32±10.47 vs. 28.94±10.95, p < 0.01). Regarding short-term outcomes, the distal transverse colon was associated with a higher ileus rate (32.12% vs. 19.71%, p=0.05) and a higher leakage rate (5.11% vs. 1.08%, p=0.012). A statistically significant increase in recurrence rates in the distal transverse colon was also observed (13.98% vs. 22.63%, p=0.027). However, no significant differences in disease-free survival (DFS) and overall survival metrics were found between the two anatomical regions.Conclusion/

Discussion: Our findings suggest that surgical procedures targeting the distal transverse colon are more complex, particularly in terms of lymph node retrieval and anastomotic reconstruction. Additionally, surgeries involving the distal transverse colon are associated with a statistically significant increase in recurrence rates. However, no significant differences in disease-free survival (DFS) or overall survival metrics were observed between cancers of the proximal and distal transverse colon."Figure 1. The flow chart of participant recruitment

A visual representation detailing the step-by-step process of participant recruitment for the study. The flow chart outlines the stages from initial contact to final selection, highlighting key decision points and criteria used for inclusion and exclusion.
Table 2. Operation detail and histological/oncological characteristics

Detailed information on the surgical procedures performed and an in-depth analysis of the histological and oncological traits observed in patients with transverse colon carcinoma.
Table 3. Short and long term outcome

""Table 3: A comprehensive overview of both short-term and long-term outcomes in patients post-surgery. This table provides data on wound complications, ileus, anastomosis leakage, major complications, re-operations, and the duration of post-operative hospital stays. It also covers mortality rates within 30 days post-surgery, 14-day readmission rates, recurrence patterns (both local and distal metastasis), expiration rates, and the median duration of follow-up in months.
Figure 2. DFS (p=0.214), Figure 3. Overall survival(p=0.460)

Graphical representation of Disease-Free Survival (DFS) outcomes for the participants and a chart illustrating the overall survival rates of the participants in the study."