title: Low-dose aspirin and survival in men with prostate cancer: a study using the UK Clinical Practice Research Datalink.
abstract: OBJECTIVE
  Aspirin use is associated with reduced risk of, and death from, prostate cancer. Our aim was to determine whether low-dose aspirin use after a prostate cancer diagnosis was associated with reduced prostate cancer-specific mortality.
  
  
  METHODS
  A cohort of newly diagnosed prostate cancer patients (1998-2006) was identified in the UK Clinical Practice Research Datalink (confirmed by cancer registry linkage). A nested case-control analysis was conducted using conditional logistic regression to compare aspirin usage in cases (prostate cancer deaths) with up to three controls (matched by age and year of diagnosis).
  
  
  RESULTS
  Post-diagnostic low-dose aspirin use was identified in 52 % of 1,184 prostate cancer-specific deaths and 39 % of 3,531 matched controls (unadjusted OR 1.51, 95 % CI 1.19, 1.90; p < 0.001). After adjustment for confounders including treatment and comorbidities, this association was attenuated (adjusted OR  1.02 95 % CI 0.78, 1.34; p = 0.86). Adjustment for estrogen therapy accounted for the majority of this attenuation. There was also no evidence of dose-response association after adjustments. Compared with no use, patients with 1-11 prescriptions and 12 or more prescriptions had adjusted ORs of 1.07 (95 % CI 0.78, 1.47; p = 0.66) and 0.97 (95 % CI 0.69, 1.37; p = 0.88), respectively. There was no evidence of a protective association between low-dose aspirin use in the year prior to diagnosis and prostate cancer-specific mortality (adjusted OR 1.04 95 % CI 0.89, 1.22; p = 0.60).
  
  
  CONCLUSIONS
  We found no evidence of an association between low-dose aspirin use before or after diagnosis and risk of prostate cancer-specific mortality, after potential confounders were accounted for, in UK prostate cancer patients.
authors: Centre for Public Health, Queen's University Belfast, Belfast, BT12 6BA, Northern Ireland, UK, c.cardwell@qub.ac.uk.
authors: Chris R
authors: CR
authors: Cardwell
authors: Evelyn M
authors: EM
authors: Flahavan
authors: Carmel M
authors: CM
authors: Hughes
authors: Helen G
authors: HG
authors: Coleman
authors: Joe M
authors: JM
authors: O'Sullivan
authors: Des G
authors: DG
authors: Powe
authors: Liam J
authors: LJ
authors: Murray
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D001241:Aspirin / Q000008:administration & dosage*; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000401:mortality*; D012306:Risk; D006113:United Kingdom
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin