Visceral-to-subcutaneous fat ratio exhibits strongest association with early post-operative outcomes in patients undergoing surgery for advanced rectal cancer.

AIM: Despite their promise as prognostic factors in colorectal cancer, anthropometric data are frequently contradictory or difficult to interpret, with single body-composition parameters often investigated in isolation or heterogeneous clinical cohorts used in analyses. We sought to assess a spectrum of body-composition parameters in a highly selected cohort with locally advanced rectal cancer in a bid to determine those with strongest prognostic potential in this specific setting. MATERIALS/METHODS: Between 2014 and 2020, 78 individuals received neoadjuvant chemotherapy, or chemoradiotherapy, followed by radical surgery in the treatment of locally advanced rectal adenocarcinoma at Oxford University Hospitals Trust. Demographic, treatment-related, perioperative, and short-term outcomes data were assessed. Body-composition parameters included BMI, and those derived from pre-operative computed-tomography imaging: skeletal mass index (SMI), visceral fat area (VFA), subcutaneous fat area (SFA), perinephric fat area (PFA) visceral-to-subcutaneous fat ratio (V/S), sarcopenia, and sarcopenic obesity (SO). RESULTS: Pre-operative body-composition parameters exhibited particularly strong correlation with post-operative outcomes, with VFA (p = 0.002), V/S (p = 0.019), SO (p = 0.012), and PFA (p = 0.0016) all associated with an increased length of hospital stay. Univariate and multivariate analyses demonstrated V/S to be the sole independent body-composition risk factor to be associated with an increased risk of developing Clavien-Dindo complications ≥ 2 (p = 0.033) as well as an increased length of stay (p = 0.005). CONCLUSION: Among patients with locally advanced rectal cancer, high visceral-to-subcutaneous fat ratio is the body-composition parameter most strongly associated with poor early post-operative outcomes. This should be considered in patient selection and prehabilitation protocols. WHAT DOES THIS PAPER ADD TO THE LITERATURE? : Our study demonstrates that among body composition parameters, high visceral-to-subcutaneous fat ratio is strongly associated with increased risk of post-operative complications and increased length of stay in patients undergoing surgery for advanced rectal cancer.

Influence of incorrect staging of colorectal carcinoma on oncological outcome: are we playing safely?

Accurate preoperative staging of colorectal cancers is critical in selecting patients for neoadjuvant therapy prior to resection. Inaccurate staging, particularly understaging, may lead to involved resection margins and poor oncological outcomes. Our aim is to determine preoperative imaging accuracy of colorectal cancers compared to histopathology and define the effect of inaccurate staging on patient selection for neoadjuvant treatment(NT). Staging and treatment were determined for patients undergoing colorectal resections for adenocarcinomas in a single tertiary centre(2016-2020). Data were obtained for 948 patients. The staging was correct for both T and N stage in 19.68% of colon cancer patients. T stage was under-staged in 18.58%. At resection, 23 patients (3.36%) had involved pathological margins; only 7 of which had been predicted by pre-operative staging. However, the staging was correct for both T and N stage in 53.85% of rectal cancer patients. T stage was understaged in 26.89%. Thirteen patients had involved(R1)margins; T4 had been accurately predicted in all of these cases. There was a general trend in understaging both the tumor and lymphonodal involvement (T p < 0.00001 N p < 0.00001) causing a failure in administrating NT in 0.1% of patients with colon tumor, but not with rectal cancer. Preoperative radiological staging tended to understage both colonic and rectal cancers. In colonic tumours this may lead to a misled opportunity to treat with neoadjuvant therapy, resulting in involved margins at resection.