Sleeve Gastrectomy Increases Colitis-Associated Colon Tumor Growth Independent of Diet
Cullen Roberts, Andrei Moscalu, Mehran Karvar, James Luo, Alex Hu, James Yoo, Ali Tavakkoli, Eric Sheu
Brigham and Women's Hospital, Boston, MA
Background: We previously found that sleeve gastrectomy (SG) increases colitis-associated tumor number in mice fed a high-fat diet. Here we examine the effects of SG on colitis-associated cancer (CAC) in low-fat diet fed mice.
Methods: 12-week-old C57BL/6J mice were fed a low-fat diet and randomized to SG or sham operation. Postoperatively, CAC was established via administration of azoxymethane and dextran sulfate sodium. Colitis severity was scored from 0-12 by measuring weight loss, stool consistency, and hematochezia. The number of colonic tumors and total tumor surface area were measured at sacrifice and compared using Welch’s t-test.
Results: On low-fat diet, SG mice developed significantly larger tumors than shams (0.67 cm2 vs 0.29 cm2; p=0.046; Figure 1A, 1B). However, low-fat diet SG mice developed similarly severe colitis as shams (maximum colitis severity 4.7 vs 4.1; data not shown) and similar numbers of tumors (4.4 vs 3.6; p=0.61; Figure 1C). In contrast, in high-fat diet fed mice, SG leads to increased tumor numbers (5.5 vs 1.4; p=0.0003; Figure 1D) as well as larger tumors and more severe colitis (data not shown).
Conclusion: SG increases tumor size in a mouse CAC model independent of diet. SG-induced increases in tumor number and colitis severity are present in high-fat diet but not low-fat diet mice. These data suggest that surgery and diet play distinct roles in colon cancer initiation and growth.
Back to 2022 Program