LAUSR

BACKGROUND The management of splenic flexure cancers (SFCs) in the era of complete mesocolic excision (CME) and central vascular ligation (CVL) is challenging because of its variable lymphatic drainage. This study aimed to compare survival outcomes for SFCs and non-SFCs, and better understand the clinicopathological characteristics which may define a distinct SFC phenotype. METHODS An observational cohort study at Concord Hospital, Sydney was conducted with patients who underwent resection for colon adenocarcinoma (1995-2019). Clinicopathological data were extracted from a prospective database. Overall survival (OS) and disease-free survival (DFS) estimates and their associations to clinicopathological variables were investigated with Kaplan-Meier and Cox regression analyses. RESULTS Of 2149 patients with colon cancer, 129 (6%) had an SFC. The overall 5-year OS and DFS rates were 63.6% (95% CI 62.5-64.7) and 59.4% (95% CI 58.3-60.5), respectively. SFCs were not associated with OS (P = 0.6) or DFS (P = 0.5). SFCs were more likely to present urgently (P < 0.001) with obstruction (P < 0.001) or perforation (P = 0.03), and more likely to require an open operation (P < 0.001). These characteristics were associated with poorer survival outcomes. No differences were noted between SFCs and non-SFCs with respect to tumour stage (P = 0.3). CONCLUSION SFCs have a distinct phenotype, the individual characteristics of which are associated with poorer survival. However, the survivals of SFCs and non-SFCs are similar, possibly because the most important determinant of outcome, tumour stage, is no different between the groups. This may have implications for the surgical approach to SFCs with respect to standardization of CME and CVL surgery for these cancers.