title: The impact of HIV viral control on the incidence of HIV-associated anal cancer.
abstract: BACKGROUND
  Recent studies have shown that the incidence of squamous cell cancer of the anus (SCCA) has increased in the combined antiretroviral therapy (cART) era. The effect of undetectable HIV viral loads as a result of successful cART has not been evaluated.
  
  
  METHODS
  We performed a retrospective cohort study among male US veterans diagnosed with HIV and followed between 1985 and 2009 using the Veterans Affairs Immunologic Case Registry (VA-ICR). We calculated age-adjusted incidence rates and rate ratios for SCCA. We conducted Cox proportional hazards ratios of SCCA in a multivariable model including time-varying covariates of nadir CD4 count and overall percentage of time with an undetectable HIV viral load.
  
  
  RESULTS
  The age-adjusted SCCA incidence rate among the group who ever received cART was 146.8/100,000 person-years (95% confidence interval, 124.1 to 172.6) and was not significantly higher than the SCCA rate of those who never received cART (134.3/100,000 person-years; 95% confidence interval, 112.5 to 159.0). In a multivariable model limited to veterans who had ever received cART (adjusted for demographic variables, nadir, and most recent CD4 counts) individuals who had 61%-80% or 81%-100% of follow-up time with undetectable HIV viral loads had significantly decreased SCCA risk compared with those who had undetectable HIV viral loads <20% of the time (odds ratio, 0.56; P = 0.040 and odds ratio, 0.55; P = 0.0004, respectively).
  
  
  CONCLUSIONS
  HIV control as measured by the percent of time with undetectable HIV viral load seems to decrease the risk of SCCA. Optimizing cART adherence and HIV viral load control may decrease the risk of subsequent SCCA.
authors.affiliation: *Department of Medicine, Baylor College of Medicine, Houston, TX; †Houston Health Services Research and Development Center of Excellence, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX; and ‡Baylor College of Medicine, Department of Medicine, Houston, TX.
authors.forename: Elizabeth Y
authors.initials: EY
authors.lastname: Chiao
authors.forename: Christine M
authors.initials: CM
authors.lastname: Hartman
authors.forename: Hashem B
authors.initials: HB
authors.lastname: El-Serag
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Giordano
mesh_terms: D000328:Adult; D000368:Aged; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D001005:Anus Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000517:prevention & control; D015331:Cohort Studies; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014481:United States; D014728:Veterans; D019562:Viral Load
chemical_list: D044966:Anti-Retroviral Agents