C-reactive protein to albumin ratio EMT HNF4A Medicine Oncology PET-CT scan PIWI proteins PIWIL3 PIWIL4 Pancreatic ductal adenocarcinoma biomarker body composition carbohydrate antigen 19-9 chemoresistance completion total pancreatectomy fluorodeoxyglucose inflammation intraductal papillary mucinous neoplasm low muscle mass microRNAs modified Glasgow prognostic score motility neoadjuvant chemotherapy neuropathy neutrophyl lymphocite ratio pancreas pancreatectomy pancreatic adenocarcinoma pancreatic cancer pancreatic cancer prognosis