Visceral adipose tissue is associated with occult synchronous peritoneal metastasis in colorectal cancer

Objectives: Synchronous peritoneal metastasis (PM) represents an advanced stage of colorectal cancer (CRC), indicating extensive tumor spread. Visceral adipose tissue (VAT) has been linked to cancer development and progression. This study aims to explore the relationship between VAT and occult synchronous PM in CRC patients before surgery. Methods: We enrolled 681 CRC patients, with 419 in the primary cohort (356 non-metastatic and 63 with PM) and 262 in the validation cohort (239 non-metastatic and 23 with PM). Clinical characteristics and laboratory measurements were collected prior to surgery. Adipose and muscle tissues were delineated on preoperative contrast-enhanced computed tomography (CT) images. The association between visceral adipose tissue and synchronous PM was assessed using univariate and multivariate logistic regression analyses. Results: In the primary cohort, 419 patients were diagnosed with CRC, with 63 presenting with PM. Patients with PM had higher visceral adipose tissue index (VATI) levels compared to those without PM. Additionally, there was a trend towards increased PM incidence with elevated VATI. Multivariate logistic regression analysis confirmed that higher VATI was independently associated with PM. These findings were consistent in the validation cohort. Conclusions: VATI is an independent risk factor for occult synchronous PM in patients with CRC.