Association between muscle mass, visceral adiposity, and histologic tumor stromal features in colon cancer.

Abstract

Background & aims: Sarcopenia and obesity are indicators for poor outcomes in colon cancer. Additionally, aggressive histopathologic tumor stromal features, such as a low tumor-stroma ratio (TSR) and low tumor-infiltrating lymphocytes (TILs) predict survival and treatment response. As their relationship remains underexplored, we studied the association between skeletal muscle mass, visceral adipose tissue (VAT), TSR, and TILs in patients with colon cancer.

Methods: We studied 194 stage II/III colon carcinoma patients who underwent elective surgery. Preoperative computed tomography (CT) scans classified patients into four groups based on skeletal muscle index (normal/low) and visceral adipose tissue index (normal/high). Tumor tissues were assessed for TSR and TILs, and five-year disease recurrence and relative hazard were evaluated.

Results: Among the patients, 56 (28.9 %) were classified as Normal Muscle, Normal VAT, 26 (13.4 %) as Normal Muscle, High VAT, 75 (38.7 %) as Low Muscle, Normal VAT, and 37 (19.1 %) as Low Muscle, High VAT. Patients with low skeletal muscle mass were more often male (62.5 % vs. 39 %, P = 0.005). Stroma-high tumors were less common in Low Muscle, Normal VAT patients (24 %) compared to Normal Muscle, High VAT (50 %), Low Muscle, High VAT (48.6 %), and Normal Muscle, Normal VAT (41.1 %) patients (P = 0.020). Tumors with low TILs were similarly distributed across groups (P = 0.679). Low Muscle, Normal VAT patients had a lower recurrence hazard compared to both Low Muscle, High VAT (hazard ratio [HR] 0.34, 95 % CI 0.12-0.98, P = 0.048) and Normal Muscle, Normal VAT (HR 0.31, 95 % CI 0.11-0.87, P = 0.027) patients.

Conclusions: Low Muscle, Normal VAT colon cancer patients exhibited fewer aggressive tumor features and a lower recurrence risk compared to Low Muscle, High VAT patients. These findings highlight the importance of body composition in tumor biology and prognosis.