title: The platelet-lymphocyte ratio improves the predictive value of serum CA19-9 levels in determining patient selection for staging laparoscopy in suspected periampullary cancer.
abstract: BACKGROUND
  The objective of this study was to identify whether the preoperative platelet-lymphocyte (P/L) ratio might improve the predictive value of CA19-9 levels in stratifying a patient group with suspected periampullary malignancy who do not require staging laparoscopy.
  
  
  METHODS
  Patients with suspected periampullary cancer were identified from a prospectively maintained 10-year database. Only patients with resectable disease who underwent staging laparoscopy and subsequent laparotomy were included. Low-risk groups were stratified using a CA19-9 cutoff value of < or = 150 kU/l (or < or = 300 kU/l in patients with a concurrent bilirubin concentration > 35 micromol/l) and a P/L ratio value of < or = 150.
  
  
  RESULTS
  From 263 patients, preoperative CA19-9 levels and P/L ratios were available in 216 and 225 patients, respectively. The positive and negative predictive values for resectability, sensitivity, and specificity for CA19-9 levels < or = 150 kU/l were 83%, 36%, 51%, and 73%, respectively. For P/L ratios < or = 150, these levels were 81%, 38%, 51%, and 72%, respectively. When combining the requirement for both CA19-9 levels and P/L ratios to be < or = 150 (n = 38 out of 183), both positive predictive value (95%) and specificity (96%) were improved (Fisher exact test, P =.065 and P < .001, respectively); 21% of laparoscopies were avoidable when using these criteria. Increasing T stage (P = .005), vascular invasion (P < .001), perineural invasion (P = .008), and resection margin involvement (P < .001) were all associated with greater preoperative P/L ratios in resected periampullary adenocarcinoma (n = 204).
  
  
  CONCLUSIONS
  The preoperative P/L ratio reflects an index of tumor invasiveness and merits prospective evaluation as an adjunct to CA19-9 in determining the requirement for laparoscopic staging in patients with potentially resectable periampullary malignancy.
authors.affiliation: Division of Surgery and Oncology, School of Cancer Studies, University of Liverpool, Liverpool, UK. rsmith3@liverpool.ac.uk
authors.forename: Richard A
authors.initials: RA
authors.lastname: Smith
authors.forename: Lorraine
authors.initials: L
authors.lastname: Bosonnet
authors.forename: Paula
authors.initials: P
authors.lastname: Ghaneh
authors.forename: Robert
authors.initials: R
authors.lastname: Sutton
authors.forename: Johnathan
authors.initials: J
authors.lastname: Evans
authors.forename: Priya
authors.initials: P
authors.lastname: Healey
authors.forename: Connall
authors.initials: C
authors.lastname: Garvey
authors.forename: Mark
authors.initials: M
authors.lastname: Hughes
authors.forename: Michael
authors.initials: M
authors.lastname: Raraty
authors.forename: Fiona
authors.initials: F
authors.lastname: Campbell
authors.forename: John P
authors.initials: JP
authors.lastname: Neoptolemos
mesh_terms: D000368:Aged; D018395:CA-19-9 Antigen / Q000097:blood*; D021441:Carcinoma, Pancreatic Ductal / Q000097:blood* / Q000473:pathology; D003138:Common Bile Duct Neoplasms / Q000097:blood* / Q000473:pathology; D005260:Female; D006801:Humans; D010535:Laparoscopy; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000473:pathology; D018579:Patient Selection; D010976:Platelet Count
chemical_list: D018395:CA-19-9 Antigen