Visceral obesity, muscle mass and outcome in rectal cancer surgery after neo-adjuvant chemo-radiation

• Visceral obesity is associated with co-morbidity and poor outcome in rectal cancer surgery.
• Visceral obesity is associated with more complications and a longer length of stay in rectal cancer surgery.
• Different cut-off values for visceral obesity different associations with outcome were found.
• Skeletal muscle area increased during chemoradiation, a phenomenon that remains to be explained.

BackgroundPreoperative chemoradiation has become a routine modality in the treatment of rectal carcinoma that may impair a patients general condition. In these patients, it is important to identify factors that influence postoperative recovery. Visceral obesity(VO) as a metabolic risk factor was studied in rectal cancer patients receiving preoperative chemoradiation.AimThe impact of VO on post-operative outcome in rectal carcinoma surgery after preoperative chemoradiation was studied. In addition, the effect of chemoradiation on body composition was studied.MethodThe visceral fat area(VFA), total fat area(TFA) and skeletal muscle area(SMA) were measured on cross-sectional CT-slides in 74 patients who underwent rectal cancer surgery after chemoradiation. CT-scans taken before and after chemoradiation were analysed. Associations between VFA, per- and postoperative complications were studied. A VFA of 100 cm2 and 130 cm2 was used to differentiate between non-VO and VO.ResultsUsing a VO cut-off point of a VFA of 100 cm2, the VO patients had more per-operative blood loss(471 mL vs 271 mL p = 0.020), a higher complication rate(10% vs 49% p = 0.001), more ileus(2% vs 28% p = 0.027) and a longer length of stay(9.7days vs 13days p = 0.027). When a VFA of 130 cm2 was used, VO patients showed more complications(17% vs 55%, p = 0.001) and ileus(10% vs 32% p = 0.017).During chemoradiation the SMA increased(Mean difference: 2.2 cm2 p = 0.024), while the VFA showed no change.ConclusionIt appears that VO is associated with co-morbidity and poor outcome in rectal cancer patients. Using different cutoff values for VO different associations with outcome were found. SMA increased during chemoradiation, a phenomenon that remains to be explained.