title: Metformin for Reducing Racial/Ethnic Difference in Prostate Cancer Incidence for Men with Type II Diabetes.
abstract: Racial/ethnic disparity in prostate cancer is under studied in men with diabetes who are at a higher risk of aggressive prostate cancer. This study assessed the race/ethnic disparity in prostate cancer incidence for men with type II diabetes (T2D) and whether the impact of metformin on prostate cancer incidence varied by race/ethnicity. We conducted a retrospective study in 76,733 male veterans with T2D during 2003 to 2012. Cox proportional hazards model adjusting for covariates and propensity scores of metformin use and race/ethnic group membership was utilized to compute the HR of prostate cancer incidence associated with race/ethnicity and compare HR associated with metformin use between race/ethnic groups. Mean follow-up was 6.4 ± 2.8 years; 7% were Hispanics; 17% were African Americans (AA); mean age was 67.8 ± 9.8 years; 5.2% developed prostate cancer; and 38.9% used metformin. Among these diabetic men without metformin use, prostate cancer incidence was higher in Hispanics and AA than in non-Hispanic White (NHW). Use of metformin alone or metformin + statins was associated with a greater prostate cancer incidence reduction in Hispanics compared with NHW, but not between AA and NHW. Use of metformin + finasteride was associated with a greater prostate cancer incidence reduction in Hispanics and AA compared with NHW. Our results suggested that metformin treatment could be a potential strategy to reduce prostate cancer incidence in the minority populations who are at high risk for fatal prostate cancer. It will be important to further examine the pleiotropic effects of metformin in multi-race/ethnic prospective studies to better inform clinical management and potentially reduce racial/ethnic disparity in prostate cancer incidence among diabetic men. Cancer Prev Res; 9(10); 779-87. ©2016 AACR.
authors.affiliation: Department of Epidemiology and Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, Texas. wangc3@uthscsa.edu.
authors.forename: Chen-Pin
authors.initials: CP
authors.lastname: Wang
authors.affiliation: Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Donna M
authors.initials: DM
authors.lastname: Lehman
authors.affiliation: Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Yui-Wing F
authors.initials: YF
authors.lastname: Lam
authors.affiliation: Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: John G
authors.initials: JG
authors.lastname: Kuhn
authors.affiliation: Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Devalingam
authors.initials: D
authors.lastname: Mahalingam
authors.affiliation: Department of Pediatrics, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Steven
authors.initials: S
authors.lastname: Weitman
authors.affiliation: Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Carlos
authors.initials: C
authors.lastname: Lorenzo
authors.affiliation: Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: John R
authors.initials: JR
authors.lastname: Downs
authors.affiliation: Department of Mental Health, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Stuart
authors.affiliation: Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Javier
authors.initials: J
authors.lastname: Hernandez
authors.affiliation: Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
authors.affiliation: Department of Epidemiology and Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Amelie G
authors.initials: AG
authors.lastname: Ramirez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D054624:Health Status Disparities; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012189:Retrospective Studies
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin