title: Human papillomavirus in esophageal squamous cell carcinoma in Colombia and Chile.
abstract: OBJECTIVE
  To examine the presence of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC) specimens collected from Colombia and Chile located in the northern and southern ends of the continent, respectively.
  
  
  METHODS
  We examined 47 and 26 formalin-fixed and paraffin-embedded ESCC specimens from Colombia and Chile, respectively. HPV was detected using GP5+/GP6+ primer pair for PCR, and confirmed by Southern blot analysis. Sequencing analysis of L1 region fragment was used to identify HPV genotype. In addition, P16(INK4A) protein immunostaining of all the specimens was conducted.
  
  
  RESULTS
  HPV was detected in 21 ESCC specimens (29%). Sequencing analysis of L1 region fragment identified HPV-16 genome in 6 Colombian cases (13%) and in 5 Chilean cases (19%). HPV-18 was detected in 10 cases (21%) in Colombia but not in any Chilean case. Since Chilean ESCC cases had a higher prevalence of HPV-16 (without statistical significance), but a significantly lower prevalence of HPV-18 than in Colombian cases (P = 0.011) even though the two countries have similar ESCC incidence rates, the frequency of HPV-related ESCC may not be strongly affected by risk factors affecting the incidence of ESCC. HPV-16 genome was more frequently detected in p16 positive carcinomas, although the difference was not statistically significant. HPV-18 detection rate did not show any association with p16 expression. Well-differentiated tumors tended to have either HPV-16 or HPV-18 but the association was not statistically significant. HPV genotypes other than HPV-16 or 18 were not detected in either country.
  
  
  CONCLUSIONS
  HPV-16 and HPV-18 genotypes can be found in ESCC specimens collected from two South American countries. Further studies on the relationship between HPV-16 presence and p16 expression in ESCC would aid understanding of the mechanism underlying the presence of HPV in ESCC.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka Kagoshima 890-8544, Japan.
authors.forename: Andres
authors.initials: A
authors.lastname: Castillo
authors.forename: Francisco
authors.initials: F
authors.lastname: Aguayo
authors.forename: Chihaya
authors.initials: C
authors.lastname: Koriyama
authors.forename: Miyerlandi
authors.initials: M
authors.lastname: Torres
authors.forename: Edwin
authors.initials: E
authors.lastname: Carrascal
authors.forename: Alejandro
authors.initials: A
authors.lastname: Corvalan
authors.forename: Juan-P
authors.initials: JP
authors.lastname: Roblero
authors.forename: Cecilia
authors.initials: C
authors.lastname: Naquira
authors.forename: Mariana
authors.initials: M
authors.lastname: Palma
authors.forename: Claudia
authors.initials: C
authors.lastname: Backhouse
authors.forename: Jorge
authors.initials: J
authors.lastname: Argandona
authors.forename: Tetsuhiko
authors.initials: T
authors.lastname: Itoh
authors.forename: Karem
authors.initials: K
authors.lastname: Shuyama
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Eizuru
authors.forename: Suminori
authors.initials: S
authors.lastname: Akiba
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000821:virology*; D002677:Chile / Q000453:epidemiology; D003105:Colombia / Q000453:epidemiology; D004938:Esophageal Neoplasms / Q000235:genetics / Q000821:virology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D019942:Genes, p16; D052162:Human papillomavirus 16 / Q000235:genetics; D052161:Human papillomavirus 18 / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000235:genetics