title: An ecological analysis of colorectal cancer incidence and mortality: differences by sexual orientation.
abstract: BACKGROUND
  Some have suggested gays and lesbians may carry a greater burden of colorectal cancer. To date, individual sexual orientation data are not available in cancer surveillance registries. This prevents an assessment of differences in colorectal cancer incidence and mortality by sexual orientation, using individual-level data.
  
  
  METHODS
  We use an ecological approach to examine differences in colorectal cancer incidence and mortality by county-level sexual orientation data. From the Surveillance, Epidemiology and End Results (SEER) Program we obtain population-based surveillance data on colorectal cancer incidence and mortality from 1996 to 2004. We use Census 2000 data on same-sex partnered households, a proxy of sexual orientation, to derive county-level sexual orientation data. Using multiple regression models, we examined the county-level association of sexual minority density with colorectal cancer incidence and mortality.
  
  
  RESULTS
  After controlling for race and SES, we identify a significant positive association between greater density of sexual minority men and women and colorectal cancer incidence. With respect to colorectal cancer mortality, we identify a positive association with density of sexual minority men, but not women.
  
  
  CONCLUSIONS
  In the absence of surveillance data on sexual minority individuals, ecological analyses provide estimates of associations at the aggregate level, thereby providing crucial information for follow-up studies.
authors.affiliation: Department of Community Health Sciences, Boston University School of Public Health, 801 Massachusetts Avenue, Boston, MA 02118, USA. boehmer@bu.edu
authors.forename: Ulrike
authors.initials: U
authors.lastname: Boehmer
authors.forename: Al
authors.initials: A
authors.lastname: Ozonoff
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Miao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D018426:SEER Program; D012725:Sexual Behavior; D014481:United States / Q000453:epidemiology / Q000208:ethnology; D055815:Young Adult