title: Prevalence and significance of subcentimeter hepatic lesions in patients with localized pancreatic adenocarcinoma.
abstract: OBJECTIVE
  To determine the prevalence and significance of incidental, subcentimeter hepatic lesions in patients with a new diagnosis of pancreatic cancer.
  
  
  METHODS
  This Institutional Review Board-approved retrospective study included 101 patients [45% men, median age 63 years (34-85)] treated for localized pancreatic adenocarcinoma at Brigham and Women's Hospital and Dana Farber Cancer Institute from January 1999 to December 2007. Initial staging and follow-up computed tomographic scans were reviewed to determine the frequency of liver lesions that were initially too small to characterize and later proved to be metastases. Clinical variables known to be prognostic for patients with pancreatic cancer were also recorded. Using Cox regression, we calculated adjusted hazard ratios to determine the association between presence of liver lesions and overall survival.
  
  
  RESULTS
  A total of 31 patients (30.7%) had subcentimeter hepatic lesions on staging scans. Of these patients, 21 (20.7% of total, 67.7% of patients with lesions) had eventual metastases to the liver. Finally, of this group, 5 patients (5.0% of total, 16.1% of patients with lesions) eventually had a metastatic focus at the specific site of the original lesion. Liver lesions predicted the occurrence of metastatic disease to the liver compared with patients without lesions (67.7% with lesions vs 44.4% without, P = .034). The presence of subcentimeter liver lesions at diagnosis was significantly associated with reduced overall survival (hazard ratio 1.65; 95% confidence interval 1.03-2.64, P = .036).
  
  
  CONCLUSIONS
  Subcentimeter lesions in the liver are common in patients with a new diagnosis of pancreatic cancer. Approximately 16% of these lesions represent metastases. The presence of indeterminate liver lesions may be associated with reduced overall survival.
authors.affiliation: Harvard Medical School, Boston, Massachusetts. Electronic address: shereef_elnahal@hms.harvard.edu.
authors.forename: Shereef M
authors.initials: SM
authors.lastname: Elnahal
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Atul B
authors.initials: AB
authors.lastname: Shinagare
authors.affiliation: Department of Biostatistics, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Jackie
authors.initials: J
authors.lastname: Szymonifka
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Hong
authors.affiliation: Department of Medicine, Dana Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Enzinger
authors.affiliation: Department of Radiation Oncology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Harvey J
authors.initials: HJ
authors.lastname: Mamon