title: Penile Kaposis sarcoma in the state of California.
abstract: BACKGROUND
  Penile Kaposi's sarcoma (PKS) is a rare and poorly characterized disease.  Kaposi's sarcoma is common in HIV disease and is an AIDS-defining illness.  This study aimed to review epidemiologic characteristics and changes in the incidence of PKS using a total population-based database.
  
  
  METHODS
  Data from the California Cancer Registry (CCR) were reviewed for the years 1988-2004, identifying all cases of penile cancer.  Tumors were classified by histology and stage.  Annual age-adjusted incidence and actuarial survival rates were calculated for the overall population and subdivided histology.
  
  
  RESULTS
  From 1988-2004, 2870 cases of penile cancer were identified.  Squamous cell carcinoma accounted for 87% of all penile cancer (n = 2507), and PKS was the second most common, accounting for 4.6% (n = 132).  Patients diagnosed with PKS demonstrated a significantly lower mean age (years) than the overall cohort (43.7 versus 62.6, p <  .0001).  The incidence of PKS peaked in 1992 with a subsequent dramatic decline, the same year as incident AIDS cases.  The percentage of all penile cancer comprised by PKS dropped from 7.4% in the 1988-1995 cohort to 1.7% in the 1995-2004 cohort (p < 0.0001).  Patients diagnosed with PKS demonstrated a significantly lower 5 (32.8% versus 76.6%, p < .0001) and 10 year (29.5% versus 69.6%, p < .0001) relative overall survival than those with squamous cell carcinoma.
  
  
  CONCLUSIONS
  PKS is the second most frequent malignancy of the penis, occurring at a younger age and portending a worse prognosis than other forms of penile cancer.  The proportion of PKS tumors has declined in recent years, reflecting improvements in HIV treatment that occurred during the study period.
authors.affiliation: Division of Urology, University of California San Diego Medical Center, San Diego, California, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Woldrich
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Silberstein
authors.forename: Sidney L
authors.initials: SL
authors.lastname: Saltzstein
authors.forename: Ithaar H
authors.initials: IH
authors.lastname: Derweesh
authors.forename: Tracy M
authors.initials: TM
authors.lastname: Downs
mesh_terms: D000328:Adult; D000367:Age Factors; D002140:California / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000401:mortality; D016009:Chi-Square Distribution; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010412:Penile Neoplasms / Q000453:epidemiology* / Q000401:mortality; D012042:Registries; D012514:Sarcoma, Kaposi / Q000453:epidemiology* / Q000401:mortality; D016019:Survival Analysis