title: Synergistic effect of viral load and alcohol consumption on the risk of persistent high-risk human papillomavirus infection.
abstract: OBJECTIVE
  This prospective study aimed to examine the combined effect of viral load and alcohol consumption on the risk of persistent high-risk (HR) human papillomavirus (HPV) infection.
  
  
  METHODS
  Among women undergoing health screening between 2002 and 2011 at the National Cancer Center, 284 and 122 women with HR-HPV infection and cytological findings of low-grade squamous intraepithelial or lower-grade lesions were followed up for 1 and 2 years, respectively. Multivariate logistic regression analysis was performed, and the relative excess risk due to interaction (RERI) and synergy index (S) were calculated.
  
  
  RESULTS
  Among drinkers, the risks of 1-year (odds ratio [OR] 4.09, 95% confidence interval [CI] 2.05-8.18) and 2-year persistence (OR 8.08, CI 2.36-27.6) were significantly higher for high HPV loads than for low HPV loads; this association was not seen for non-drinkers. The risks for 1-year (OR 4.14, CI 1.89-9.05) and 2-year persistence (OR 6.61, CI 2.09-20.9) were significantly higher in subjects with a high HPV load who were also drinkers than in those who were non-drinkers. A high HPV load together with a longer drinking duration or higher alcohol consumption was associated with increased risks of 1-year (OR 3.07, CI 1.40-6.75 or OR 2.05, CI 0.87-4.83) and 2-year persistence (OR 6.40, CI 1.72-23.8 or OR 4.14, CI 1.18-14.6). The synergistic effect of alcohol consumption and HR-HPV load was stronger on the risk of 2-year persistence (RERI = 3.26, S = 2.38) than on the risk of 1-year persistence (RERI = 1.21, S = 1.63).
  
  
  CONCLUSIONS
  The synergistic effect of HR-HPV load and alcohol consumption was associated with the risk of HR-HPV persistence and was stronger for longer-term HR-HPV infection. Limiting alcohol consumption might be an important measure to prevent the development of cervical cancer in women with a high HR-HPV load.
authors.affiliation: Division of Cancer Epidemiology and Prevention, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Hea Young
authors.initials: HY
authors.lastname: Oh
authors.affiliation: Center for Uterine Cancer, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Seo
authors.affiliation: Division of Cancer Epidemiology and Prevention, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Mi Kyung
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Center for Uterine Cancer, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Dong Ock
authors.initials: DO
authors.lastname: Lee
authors.affiliation: Center for Cancer Prevention and Detection, Hospital, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Youn Kyung
authors.initials: YK
authors.lastname: Chung
authors.affiliation: Center for Uterine Cancer, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Myong Cheol
authors.initials: MC
authors.lastname: Lim
authors.affiliation: Center for Uterine Cancer, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Center for Cancer Prevention and Detection, Hospital, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Chan Wha
authors.initials: CW
authors.lastname: Lee
authors.affiliation: Center for Uterine Cancer, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Park
mesh_terms: D000328:Adult; D000428:Alcohol Drinking; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D027383:Papillomaviridae / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000821:virology*; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D019562:Viral Load