title: Blood transfusions and the subsequent risk of cancers in the United States elderly.
abstract: BACKGROUND
  Blood transfusions are common in older adults and also may modulate the immune system. However, the impact of transfusion on cancer risk in the elderly has not been studied.
  
  
  METHODS
  Cancer risk after blood transfusion was evaluated in a US population-based case-control study using 552,951 elderly cases identified from cancer registries and 100,000 frequency-matched controls. Transfusions received 0 to 12, 13 to 30, and 31 to 48 months before cancer diagnosis or selection date were identified using Medicare claims. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models. A Bonferroni correction adjusted for multiple testing.
  
  
  RESULTS
  Transfusions received 0 to 12 months before cancer diagnosis and/or selection were associated with significantly elevated risk of cancer overall (OR,2.05; 95% CI, 1.95-2.16) and cancer of the stomach; cancer of the colon; cancer of the liver, kidney, renal pelvis, and/or ureter; lymphoma; myeloma; and leukemia. No significant associations for cancer overall were observed for the two earlier intervals. No site was associated with transfusions received 13 to 30 or 31 to 48 months before diagnosis and/or selection. Nonetheless, overall cancer risk increased with the number of transfused periods (p-trend<0.0001).
  
  
  CONCLUSIONS
  Risk of overall cancer and specific sites was elevated 0 to 12 months after blood transfusion and associated with multiple transfusions, possibly due to reverse causation, that is, incipient cancers or cancer precursors causing anemia.
authors: Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria; Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland; Division of Cancer Control and Population Sciences, National Cancer Institute, Rockville, Maryland; Information Management Services, Rockville, Maryland.
authors: Regina
authors: R
authors: Riedl
authors: Eric A
authors: EA
authors: Engels
authors: Joan L
authors: JL
authors: Warren
authors: Andrea
authors: A
authors: Berghold
authors: Winnie
authors: W
authors: Ricker
authors: Ruth M
authors: RM
authors: Pfeiffer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009369:Neoplasms / Q000209:etiology*; D016017:Odds Ratio; D012306:Risk; D013997:Time Factors; D065227:Transfusion Reaction; D014481:United States