title: An atypical age-specific pattern of hepatocellular carcinoma in Peru: a threat for Andean populations.
abstract: BACKGROUND
  In South America, the highest incidence of primary liver cancer is observed in Peru. However, national estimations on hepatocellular carcinoma incidence and mortality are approximated using aggregated data from surrounding countries. Thus, there is a lack of tangible information from Peru that impairs an accurate description of the local incidence, presentation, and outcomes of hepatocellular carcinoma. The present study attempts to fill this gap and assesses the clinical epidemiology of hepatocellular carcinoma in this country.
  
  
  METHODS
  A retrospective cohort study was conducted by analysing the medical charts of 1,541 patients with hepatocellular carcinoma admitted between 1997 and 2010 at the Peruvian national institute for cancer. The medical records including liver function, serologic status, and tumor pathology and stage were monitored. Statistical analyses were performed in order to characterize tumor presentation according to demographic features, risk factors, and regional origin.
  
  
  RESULTS
  Surprisingly, the age distribution of the patient population displayed bimodality corresponding to two distinct age-based subpopulations. While an older group was in keeping with the age range observed for hepatocellular carcinoma around the world, a younger population displayed an abnormally juvenile mean age of 25.5 years old. In addition, each subpopulation displayed age-specific pathophysiological and clinical characteristics.
  
  
  CONCLUSIONS
  The analysis suggests two different age-specific natural histories of hepatocellular carcinoma in the Peruvian patient population. This otherwise unusual tumor process that is ongoing in younger patients leads to the hypothesis that there may be a Peru-endemic risk factor driving hepatocarcinogenesis in the local population.
authors.affiliation: Université de Toulouse 3, Unité de Pharmacochimie et Pharmacologie pour le Développement, UMR152, Toulouse, France. stephane.bertani@ird.fr
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bertani
authors.forename: Pascal
authors.initials: P
authors.lastname: Pineau
authors.forename: Sebastian
authors.initials: S
authors.lastname: Loli
authors.forename: Julien
authors.initials: J
authors.lastname: Moura
authors.forename: Mirko
authors.initials: M
authors.lastname: Zimic
authors.forename: Eric
authors.initials: E
authors.lastname: Deharo
authors.forename: Eloy
authors.initials: E
authors.lastname: Ruiz
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology* / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008113:Liver Neoplasms / Q000453:epidemiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010568:Peru / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult