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/m . 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.