Pancreatic ductal adenocarcinoma (PDAC) is a dismal disease with a 5-year survival rate as low as 6%. It causes body composition changes and many patients develop muscle loss with disease progression. Computed tomography (CT) is a common, noninvasive method of muscle assessment.Known as myoesteatosis,low muscle radiodensity is reflective of intermuscular adipose tissue that influences survival outcomes in patients with cancer.Serum creatinine (Scr) and cystatin C (CysC) are usually employed to estimate renal function in clinical practice. Scr is a metabolic waste product produced by creatine in skeletal muscle. CysC can be produced by all nucleated cells in the body at a constant production rate. CysC is used as an endogenous marker to reflect the glomerular filtration rate. Some studies have supported that the Scr/CysC ratio (CCR) is a simple and inexpensive measure that can be used to evaluate the skeletal muscle mass of patients with malignancies, such as gastric cancer. Therefore, the purpose of the present study is to explore the association between CCR and myosteatosis upon diagnosis of PDAC, specially whether the co-occurrence of these factors could predict survival outcomes.Preoperative assessment of muscle quality may be valuable for treatment planning and optimization of nutritional support.

This retrospective study enrolls patients who underwent surgery for PDAC, from January 2016 to December 2021. Patients will be divided into myosteatosis and non-myosteatosis groups. Clinical and imaging data are collected.The study does not have any intervention measures and harm to subjects.

Inclusion criteria:

a）aged between 18 and 75; b) pancreatic ductal adenocarcinoma confirmed by biopsy or postoperative pathology; c) CT and renal function related data within 1 month before operation; d) voluntarily participate in this study and have informed consent.

Exclusion criteria:

• pancreatic malignant tumors of other pathological types or other malignant tumors;

  • received local or systemic radiotherapy and chemotherapy before operation; ③ with severe metabolic diseases such as decompensated cirrhosis, nervous system diseases and muscle degenerative diseases; ④ absent of preoperative imaging or clinical data;

Inclusion Criteria:

• a） aged between 18 and 75; b) pancreatic ductal adenocarcinoma confirmed by biopsy or postoperative pathology; c) CT and renal function related data within 1 month before operation; d) voluntarily participate in this study and have informed consent.

Exclusion Criteria:

• ① pancreatic malignant tumors of other pathological types or other malignant tumors;

  • received local or systemic radiotherapy and chemotherapy before operation;

    • with severe metabolic diseases such as decompensated cirrhosis, nervous system diseases and muscle degenerative diseases; ④ absent of preoperative imaging or clinical data; ⑤ Lost interviewers.

This retrospective study enrolled patients who underwent surgery for resectable pancreatic ductal adenocarcinoma, from January 2016 to December 2021. Patients will be divided into myosteatosis and non-myosteatosis groups according to skeletal muscle radiodensity.