title: Metformin Does Not Predict for Prostate Cancer Diagnosis, Grade, or Volume of Disease After Transperineal Template-guided Mapping Biopsy.
abstract: OBJECTIVE
  Previous studies have evaluated whether metformin is associated with prostate cancer incidence and outcomes with conflicting conclusions. In this study, we evaluate the incidence of prostate cancer in diabetic patients treated with and without metformin compared with nondiabetic patients.
  
  
  METHODS
  One thousand thirty-four patients underwent transperineal template-guided mapping biopsy secondary to either an elevated prostate-specific antigen (PSA) or a prior biopsy finding of atypical small acinar proliferation/prostatic intraepithelial neoplasia. The cohort included 881 nondiabetic men, 65 diabetic men treated with metformin, and 88 diabetic men not receiving metformin. In metformin-treated patients, the median duration of usage was 6.0 years. Differences in prostate cancer diagnosis, histologic grade, and tumor volume were compared across the 3 cohorts.
  
  
  RESULTS
  There was no statistically significant differences discerned between the 3 cohorts in patient age, prebiopsy PSA, prostate volume, PSA density, PSA doubling time, PSA velocity, or the total number of prior transrectal ultrasound biopsy sessions. Five hundred eighty-four patients were diagnosed with prostate cancer. There was no difference in prostate cancer diagnosis (P=0.153), Gleason score (P=0.960), the number of positive biopsy cores (P=0.764), or risk group stratification (P=0.877) between the 3 cohorts. In multivariate analysis, only older age predicted for prostate cancer diagnosis. In terms of Gleason score ≥7, patient age, PSA velocity, and body mass index predicted for more aggressive histology. Neither diabetes, metformin use or duration was of statistical consequence.
  
  
  CONCLUSIONS
  Metformin did not impact incidence of prostate cancer diagnosis, Gleason score distribution, or volume of disease.
authors.affiliation: *Schiffler Cancer Center, Wheeling Jesuit University Departments of †Urology §Pathology, Wheeling Hospital, Wheeling, WV ‡Ohio University Eastern, St Clairsville, OH.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Merrick
authors.forename: Abbey
authors.initials: A
authors.lastname: Bennett
authors.forename: Travis
authors.initials: T
authors.lastname: Couture
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Butler
authors.forename: Robert W
authors.initials: RW
authors.lastname: Galbreath
authors.forename: Edward
authors.initials: E
authors.lastname: Adamovich
mesh_terms: D000368:Aged; D003920:Diabetes Mellitus / Q000188:drug therapy; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D061705:Image-Guided Biopsy / Q000379:methods*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D060787:Neoplasm Grading; D010502:Perineum; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D014463:Ultrasonography
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin; D017430:Prostate-Specific Antigen