The association between body composition and survival in rectal cancer patients is still unclear. Therefore, we aimed to evaluate the impact of computed tomography (CT)-measured body composition on survival in rectal cancer patients, stratifying our analyses by sex, tumour location, tumour stage and radiotherapy. This retrospective cohort study included 173 patients with rectal adenocarcinoma. CT colonography scans at the time of diagnosis were used to assess the skeletal muscle index (SMI) and the visceral adipose tissue area (VAT). The patients were divided into a low or high SMI group and a low or high VAT group according to previously defined cutoff values. Endpoints included cancer-specific survival (CSS) and overall survival (OS). In all patients, low SMI was associated with worse CSS (HR, 2.63; 95% CI, 1.35–5.12; P = 0.004) and OS (HR, 3.57; 95% CI, 2.01–6.34; P < 0.001) compared to high SMI. The differences remained significant after adjusting for potential confounders (CSS: adjusted HR, 2.28; 95% CI, 1.13–4.58; P = 0.021; OS: adjusted HR, 3.17; 95% CI, 1.73–5.82; P < 0.001). Low SMI was still related to a poor prognosis after stratifying by sex, tumour location, stage and radiotherapy (P < 0.05). High VAT was associated with better CSS (HR, 0.31; 95% CI, 0.11–0.84; P = 0.022) and OS (HR, 0.40; 95% CI, 0.17–0.97; P = 0.044) compared to low VAT among men with rectal cancer ≤ 10 cm from the anal verge. High VAT was associated with worse CSS (HR, 4.15; 95% CI, 1.10–15.66; P = 0.036) in women with rectal cancer ≤ 10 cm from the anal verge. Low SMI was associated with worse survival. High VAT predicted better survival in men but worse survival in women. The results suggest that CT-measured body composition is a useful tool for evaluating the prognosis of rectal cancer patients and demonstrate the need to include the sex and the tumour location in the analyses.

中文翻译：

---

计算机断层扫描测量直肠癌患者的身体成分和生存率：一项瑞典队列研究

直肠癌患者的身体成分与生存之间的关联仍不清楚。因此，我们旨在评估计算机断层扫描 (CT) 测量的身体成分对直肠癌患者生存的影响，按性别、肿瘤位置、肿瘤分期和放疗对我们的分析进行分层。这项回顾性队列研究包括 173 名直肠腺癌患者。诊断时的 CT 结肠造影扫描用于评估骨骼肌指数 (SMI) 和内脏脂肪组织面积 (VAT)。根据先前定义的截止值，将患者分为低或高 SMI 组和低或高 VAT 组。终点包括癌症特异性生存期 (CSS) 和总生存期 (OS)。在所有患者中，低 SMI 与较差的 CSS（HR，2.63；95% CI，1.35–5.12；P = 0.004）和 OS（HR，3.57；95% 置信区间，2.01–6.34；P < 0.001) 与高 SMI 相比。调整潜在混杂因素后差异仍然显着（CSS：调整后的 HR，2.28；95% CI，1.13-4.58；P = 0.021；OS：调整后的 HR，3.17；95% CI，1.73-5.82；P < 0.001）。按性别、肿瘤位置、分期和放疗分层后，低 SMI 仍与不良预后相关（P < 0.05）。与低 VAT 男性相比，高 VAT 与更好的 CSS（HR，0.31；95% CI，0.11-0.84；P = 0.022）和 OS（HR，0.40；95% CI，0.17-0.97；P = 0.044）相关距肛缘≤10cm的直肠癌。在距肛缘 ≤ 10 cm 的直肠癌女性中，高 VAT 与较差的 CSS（HR，4.15；95% CI，1.10–15.66；P = 0.036）相关。低 SMI 与较差的生存率相关。高增值税预示着男性的生存率更高，但女性的生存率更差。