Visceral obesity is associated with lower stage colon tumors in males without survival advantage

Abstract

Visceral obesity and systemic inflammatory response (SIR) were suggested to be closely related to colon cancer (CC) oncological and surgical outcomes. The first by producing several soluble factors involved in carcinogenesis and the second for having a key role in the nutritional and functional decline of patients with cancer. Furthermore, gender differences in relative body composition and adipose tissue regional distribution have also been acknowledged to influence CC. The primary aim of this study was to determine whether visceral adiposity, stratified by gender, influenced CC staging and prognosis. As secondary aim, this study evaluated whether visceral adiposity and SIR markers were associated with CC pathological features so that these could be used in clinical practice to predict disease outcomes and potentially influence therapeutic decisions. Case records from patients (n = 300) submitted to CC surgical resection at a single tertiary hospital were retrospectively reviewed to retrieve clinical, laboratory, imaging and pathological data. Visceral fat area was quantified by computerized morphometric analysis in preoperative tomography scans. Visceral obesity was defined as visceral fat area ≥160 cm² for men and ≥80 cm² for women. Preoperative full blood count performed as part of the routine clinical assessment at the hospital laboratory was used to obtain C-reactive protein (CRP) levels and to calculate neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), which were used as SIR markers. One hundred and forty-three (n = 143) patients fulfilled eligibility criteria and were included in the analysis. Patients with high-visceral adipose tissue (vAT) had smaller size CC tumors (p < 0.001), earlier T-stage disease (p = 0.027) and lower nodal involvement (p = 0.039). In gender subgroup analysis, these findings were only confirmed in males. Moreover, male patients with high-vAT also had a lower proportion of metastatic nodes (p = 0.021) and metastatic to dissected lymph node ratio (p = 0.030). Additionally, patients with high-vAT also had lower PLR (p = 0.001). CC survival was not influenced by visceral obesity, gender nor SIR. In conclusion, our study shows that male patients with high visceral adiposity have lower PLR levels and earlier stage tumors. Furthermore, our data suggests that visceral obesity and SIR despite being associated with earlier stage CC tumors do not seem to present a survival advantage.

Keywords: Colon cancer; Computed tomography; Survival; Systemic inflammation; Tumor staging; Visceral obesity.