title: Cancer incidence in patients with hereditary hemorrhagic telangiectasia.
abstract: OBJECTIVE
  Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder characterized by deficiency in endoglin, an angiogenic protein. We previously showed that HHT, in which systemic endoglin expression is reduced, was associated with better survival outcomes in cancer patients (Duarte et al. in Cancer Epidemiol Biomarkers Prev 23:117-125, 2014). Here, we evaluated whether HHT was associated with reduced cancer incidence.
  
  
  METHODS
  A matched case-control analysis using SEER Medicare was conducted to evaluate the effect of HHT on diagnosis with breast, colorectal, lung, or prostate cancer between 2000 and 2007 (n = 633,162). Cancer and non-cancer patients were matched on age, sex, SEER registry region, and length of the ascertainment period for HHT. We assessed crude association using a McNemar's test and then adjusted for demographic variables, cancer type, cancer stage, comorbidities, and ascertainment period with a conditional logistic regression model for cancer incidence.
  
  
  RESULTS
  The McNemar's test showed no significant association between HHT and cancer incidence (p = 0.74). Adjusting for covariates with the conditional logistic regression model did not change the result [HHT odds ratio 0.978; 95 % CI (0.795, 1.204)]. The lack of association between HHT and cancer incidence is unexpected given the previously discovered significant association between HHT and improved survival outcomes (Duarte et al. in Cancer Epidemiol Biomarkers Prev 23:117-125, 2014).
  
  
  CONCLUSIONS
  We conclude that the protective effect of reduced systemic endoglin expression in cancer is specific to cancer progression through its effect on vascularization and other stromal effects but does not extend to cancer initiation.
authors.affiliation: Center for Outcomes Research and Evaluation, Maine Medical Center Research Institute, 509 Forest Ave. Suite 200, Portland, ME, USA. duartc@mmc.org.
authors.forename: Christine W
authors.initials: CW
authors.lastname: Duarte
authors.affiliation: Center for Outcomes Research and Evaluation, Maine Medical Center Research Institute, 509 Forest Ave. Suite 200, Portland, ME, USA.
authors.forename: Adam W
authors.initials: AW
authors.lastname: Black
authors.affiliation: Center for Outcomes Research and Evaluation, Maine Medical Center Research Institute, 509 Forest Ave. Suite 200, Portland, ME, USA.
authors.forename: F Lee
authors.initials: FL
authors.lastname: Lucas
authors.affiliation: Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA.
authors.forename: Calvin P H
authors.initials: CP
authors.lastname: Vary
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology*; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D065840:Protective Factors; D018426:SEER Program; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000453:epidemiology*
keywords: Cancer incidence; Case–control; Endoglin; HHT; SEER Medicare