The impact of visceral adipose tissue amount on the adequacy of lymph node retrieval in colorectal cancer surgery

BACKGROUND: Obesity is increasing worldwide, potentially influencing surgical outcomes in colorectal cancer (CRC) patients. We analyzed the effects of obesity indexes on lymph node (LN) retrieval in CRC patients. METHOD: We applied obesity indexes of body mass index (BMI) and visceral (VAT) and subcutaneous (SAT) adipose tissue volumes to stage I-III CRC patients. The primary outcome was the effect of these indexes on the number of retrieved LNs (12 > LNs ≥ 12). RESULTS: Among 519 patients, 35.6% had a BMI ≥ 25 kg/m2 . After adjusting for gender, age, tumor location, resected colon length, and local invasion and LN statuses, patients in the highest VAT quartile showed a 5.848 decrease in the number of retrieved LNs, with an odds ratio of 0.483 (95% confidence interval [CI] 0.260-0.8979) for adequate LN retrieval (≥12), compared with those in the lowest quartile (P < 0.001 for both). Analysis of the model predicting LN retrieval revealed VAT as the only obesity index (area under the curve [AUC] = 0.721) providing significant additional predictive power (P = 0.037) to the model including age, gender, staging, tumor location, and resected colon length (AUC = 0.707). CONCLUSION: Increased VAT may cause inadequate LN retrieval in CRC patients. In viscerally obese patients, VAT volumes should be considered when clinically interpreting LN status.