title: Low prevalence of human papillomavirus in head and neck squamous cell carcinoma in the northwest region of the Philippines.
abstract: BACKGROUND
  Geographic heterogeneity of human papillomavirus (HPV) involvement in head and neck squamous cell carcinoma (HNSCC) has been observed over the last few years. This trend has not been evaluated in the Philippines. Hence, this study aims to provide for the first time a data on the prevalence of HPV in HNSCC in the northwestern region of the Philippines.
  
  
  METHODS
  Two hundred one (201) biopsy samples (179 formalin fixed paraffin embedded and 22 fresh frozen) from 163 Filipino HNSCC cases (oral cavity = 88; larynx = 60; oropharynx = 15) diagnosed between 2003 to 2013 were initially included in this study. HPV DNA was detected by two methods: (1) BSGP5+/6+-PCR/ multiplex human papillomavirus genotyping and (2) TaqMan probes-based real-time qPCR. Presence of HPV type-specific transcripts were also analyzed by reverse transcription-PCR with subsequent hybridization to oligonucleotide probes coupled to Luminex beads. Co-amplification of the β-globin and ubiquitin C genes served as internal positive controls for DNA and RNA analyses, respectively.
  
  
  CONCLUSIONS
  Of the 163, 82 (50.3%) cases had at least one tissue sample that was valid for molecular analysis. Only two of the DNA valid cases (2.4%) were HPV DNA-positive (HPV11 and HPV33). All HPV mRNA assays rendered negative results except for HPV11 transcripts. Results of this study may indicate that there is probably very low prevalence of HPV-associated HNSCC among Filipino adults living in a rural region of the Philippines. This study could serve as a benchmark for designing follow-up studies that would assess possible changes in trends of HNSCC among Filipinos in different ethnic regions of the country, especially urban areas in which the population is expected to adapt Western style sexual behavior. A prospective sampling of fresh frozen tissue is also highly recommended to ensure better molecular analyses.
authors.affiliation: Division of Molecular Diagnostics of Oncogenic Infections, Research Program Infection and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.|Department of Biology, College of Science, University of Santo Tomas, Manila, Philippines.|Research Center for the Natural and Applied Sciences, University of Santo Tomas, Manila, Philippines.
authors.forename: Pia Marie
authors.identifier: http://orcid.org/0000-0002-5024-8819
authors.initials: PM
authors.lastname: Albano
authors.affiliation: Division of Molecular Diagnostics of Oncogenic Infections, Research Program Infection and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Dana
authors.initials: D
authors.lastname: Holzinger
authors.affiliation: Deparment of ENT Head and Neck Surgery, Mariano Marcos Memorial Hospital and Medical Center, Ilocos Norte, Philippines.
authors.forename: Christianne
authors.initials: C
authors.lastname: Salvador
authors.affiliation: Deparment of ENT Head and Neck Surgery, Mariano Marcos Memorial Hospital and Medical Center, Ilocos Norte, Philippines.
authors.forename: Jose
authors.initials: J
authors.lastname: Orosa
authors.affiliation: Department of Pathology and Laboratories, Mariano Marcos Memorial Hospital and Medical Center, Ilocos Norte, Philippines.
authors.forename: Sheryl
authors.initials: S
authors.lastname: Racelis
authors.affiliation: Department of Pathology and Laboratories, Mariano Marcos Memorial Hospital and Medical Center, Ilocos Norte, Philippines.
authors.forename: Modesty
authors.initials: M
authors.lastname: Leaño
authors.affiliation: Deparment of ENT Head and Neck Surgery, Mariano Marcos Memorial Hospital and Medical Center, Ilocos Norte, Philippines.
authors.forename: Danilo
authors.initials: D
authors.lastname: Sanchez
authors.affiliation: Department of Clinical Pathology, University of Santo Tomas Hospital, Manila, Philippines.
authors.forename: Lara Mae
authors.initials: LM
authors.lastname: Angeles
authors.affiliation: Division of Molecular Diagnostics of Oncogenic Infections, Research Program Infection and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Gordana
authors.initials: G
authors.lastname: Halec
authors.affiliation: Division of Molecular Diagnostics of Oncogenic Infections, Research Program Infection and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schmitt
authors.affiliation: Department of Biology, College of Science, University of Santo Tomas, Manila, Philippines.|Research Center for the Natural and Applied Sciences, University of Santo Tomas, Manila, Philippines.
authors.forename: John Donnie
authors.initials: JD
authors.lastname: Ramos
authors.affiliation: Division of Molecular Diagnostics of Oncogenic Infections, Research Program Infection and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Pawlita
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D004279:DNA, Viral / Q000302:isolation & purification / Q000378:metabolism; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D006801:Humans; D007830:Larynx / Q000821:virology; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000821:virology; D009856:Oncogene Proteins, Viral / Q000235:genetics; D009960:Oropharynx / Q000821:virology; D027383:Papillomaviridae / Q000235:genetics* / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D010679:Philippines / Q000453:epidemiology; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: D004279:DNA, Viral; D009856:Oncogene Proteins, Viral