title: Plasma cathepsin L: a prognostic marker for pancreatic cancer.
abstract: OBJECTIVE
  To assess the prognostic significance of cathepsin L, a cysteine protease that degrades the peri-tumoral tissue, in patients with pancreatic cancer.
  
  
  METHODS
  Plasma samples from 127 pancreatic cancer patients were analyzed for cathepsin L levels by ELISA. Out of these patients, 25 underwent surgery and their paraffin-embedded tissue was analyzed for cathepsin L expression by immunohistochemistry. Survival of patients and clinicopathological parameters was correlated with cathepsin L expression in plasma and tissue using appropriate statistical analysis.
  
  
  RESULTS
  The mean (± SD) cathepsin L in plasma samples of pancreatic cancer patients was 5.98 ± 2.5 ng/mL that was significantly higher compared to the levels in healthy controls (3.83 ± 0.45) or chronic pancreatitis patients (3.97 ± 1.06). Using ROC curve, a cut-off level of 5.0 ng/mL was decided for survival analysis. Elevated plasma levels of cathepsin L were found to be associated with poor prognosis (P = 0.01) in multivariate analysis. The plasma levels of the protease decreased after surgery. Though no significant correlation was seen between plasma and tissue expression of this protease, a trend did emerge that high cathepsin L expression in tissue correlated with its high levels in plasma.
  
  
  CONCLUSIONS
  Cathepsin L levels in plasma of pancreatic cancer patients may be used as a potential prognostic marker for the disease.
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Singh
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Das
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Surabhi
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Vikas
authors.initials: V
authors.lastname: Sachdev
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Srivasatava
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Datta Gupta
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Ravindra Mohan
authors.initials: RM
authors.lastname: Pandey
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Peush
authors.initials: P
authors.lastname: Sahni
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Shyam S
authors.initials: SS
authors.lastname: Chauhan
authors.affiliation: Nidhi Singh, Surabhi Gupta, Vikas Sachdev, Siddhartha Srivasatava, Anoop Saraya, Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Anoop
authors.initials: A
authors.lastname: Saraya
mesh_terms: D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood; D016022:Case-Control Studies; D056668:Cathepsin L / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000097:blood / Q000201:enzymology* / Q000401:mortality / Q000601:surgery; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D012307:Risk Factors; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; C534281:CTSL protein, human; D056668:Cathepsin L
keywords: Cathepsin L; Overall median survival; Pancreatic cancer; Plasma