Subcutaneous, but not visceral, adipose tissue as a marker for prognosis in gastric cancer patients with cachexia

Adipose tissue loss is one of the features in patients with cancer cachexia. However, whether subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) contribute differently to the progress of cancer cachexia in gastric cancer patients with cachexia remains unclear. This study aim to investigate the effect of SAT and VAT in gastric cancer patients with cachexia.Gastric cancer patients who underwent surgery were divided into cancer cachexia group and non-cachexia group. A new deep learning system was developed to segment SAT and VAT from the computed tomography images at the third lumbar vertebra. Indexes of SAT (SATI) and VAT (VATI) were compared between cachexia and non-cachexia groups. The prognostic values of SATI and VATI for patients with gastric cancer cachexia were analyzed by Kaplan-Meier method and Cox regression.A total of 1627 gastric cancer patients (411 cachexia and 1216 non-cachexia) were included in this study. A new V-Net-Based segmentation deep learning system was developed to quickly (0.02 s/image) and accurately segment SAT (dice scores = 0.96) and VAT (dice scores = 0.98). The SATI of gastric cancer patients with cachexia were significantly lower than non-cachexia patients (44.91 ± 0.90 vs. 50.92 ± 0.71 cm2/m2, P < 0.001), whereas no significant difference was detected in VATI (35.98 ± 0.84 VS. 37.90 ± 0.45 cm2/m2, P = 0.076). Cachexia patients with low SATI showed poor survival than those with high SATI (HR = 1.35; 95% CI = 1.06-1.74). In contrast, VATI did not show close correlation with survival in patients with cachexia (HR = 1.18; 95% CI = 0.92-1.51).SAT and VAT showed different effects on gastric cancer patients with cachexia. More attention should be paid to the loss of SAT during the progress of cancer cachexia.