Subclassification of Multivisceral Resections for T4b Colon Cancer with Relevance for Postoperative Complications and Oncological Risks

BACKGROUND: Multivisceral resection for T4b colon cancer constitutes a heterogeneous group of surgical procedures. The purpose of this study was to explore clinically distinct categories of multivisceral resection, with subsequent correlation to postoperative complications and oncological outcomes. METHODS: In this multicenter cohort study, all consecutive patients without metastases who underwent multivisceral resection for pT4bN0-2M0 colon cancer between 2000 and 2014 were included. Multivisceral resection was divided into four categories: (i) gastrointestinal (including the stomach), (ii) urologic ((partial) bladder and ureter), (iii) solid organ (spleen, kidney, liver, pancreas, and uterus), and (iv) abdominal wall/omentum/ovaries. The primary outcome was surgical complications and secondary outcomes were 5-year intra-abdominal recurrence, disease-free survival, and overall survival. RESULTS: In total, 130 patients who underwent curative intent resection of pT4 colon cancer were included. Patients who underwent multivisceral resection within multiple categories were assigned to one of the categories based on hierarchy of clinical impact after exploratory analysis. For the primary endpoint, 55 patients were assigned to gastrointestinal, 14 to urologic, 14 to solid organ, and 47 to abdominal wall/omentum/ovaries multivisceral resection. Gastrointestinal multivisceral resection was independently associated with surgical complications (HR 3.9, 95% CI 1.4-10.6). Abdominal wall/omentum/ovaries multivisceral resection was significantly related with intra-abdominal recurrence (HR 7.8, 95% CI 1.0-57.8). The 5-year disease-free survival and overall survival showed no significant differences per multivisceral resection category. CONCLUSIONS: Multivisceral resections for T4b colon cancer are heterogeneous procedures considering risk profiles. The proposed multivisceral resection subclassification needs validation, but might improve comparability between studies and hospitals (auditing).status: publishe

Postoperative abdominal infections after resection of T4 colon cancer increase the risk of intra-abdominal recurrence

INTRODUCTION: Patients with pT4 colon cancer are at risk of developing intra-abdominal recurrence. Infectious complications have shown to negatively influence disease free survival (DFS) and overall survival (OS) in stage I-III colon cancer. The aim of this study was to determine whether surgical site infections (SSIs) also increase the risk of intra-abdominal recurrence in pT4 colon cancer patients. METHODS: All consecutive patients with pT4N0-2M0 colon cancer from four centres between January 2000 and December 2014 were included. Patients were categorized into 2 groups; with and without a postoperative (<30 days) SSIs. SSIs included both deep incisional as well as organ/space SSIs. The primary outcome was intra-abdominal recurrence (including local/incisional recurrence, peritoneal metastases) and was assessed using Kaplan-Meier and Cox regression analyses. Secondary outcome measures were DFS and OS. RESULTS: Out of 420 patients, 62 (15%) developed a SSI. The 5-year intra-abdominal recurrence rates were 44% and 27% for patients with and without a SSI, respectively (p = 0.011). After multivariate analysis, SSI was independently associated with intra-abdominal recurrence (HR 1.807 (1.091-2.992)), worse DFS (HR 1.788 (1.226-2.607)), and worse OS (HR 1.837 (1.135-2.973)). Other independent risk factors for intra-abdominal recurrence were a R1 resection (HR 2.616 (1.264-5.415)) and N2-stage (HR 2.096 (1.318-3.332)). CONCLUSION: SSIs after resection of a pT4N0-2M0 colon cancer are associated with an increased risk of intra-abdominal recurrence and worse survival. This finding supports the hypothesis that infection-based immunologic pathways play a role in colon cancer cell dissemination and outgrowth.status: publishe