Association of diabetes with prostate cancer risk in the multiethnic cohort.
Among men of European ancestry, diabetics have a lower risk of prostate cancer than do nondiabetics. The biologic basis of this association is unknown. The authors have examined whether the association is robust across populations in a population-based prospective study. The analysis included 5,941 prostate cancer cases identified over a 12-year period (1993-2005) among 86,303 European-American, African-American, Latino, Japanese-American, and Native Hawaiian men from the Multiethnic Cohort. The association between diabetes and prostate-specific antigen (PSA) levels (n = 2,874) and PSA screening frequencies (n = 46,970) was also examined. Diabetics had significantly lower risk of prostate cancer than did nondiabetics (relative risk = 0.81, 95% confidence interval (CI): 0.74, 0.87; P < 0.001), with relative risks ranging from 0.65 (95% CI: 0.50, 0.84; P = 0.001) among European Americans to 0.89 (95% CI: 0.77, 1.03; P = 0.13) among African Americans. Mean PSA levels were significantly lower in diabetics than in nondiabetics (mean PSA levels, 1.07 and 1.28, respectively; P = 0.003) as were PSA screening frequencies (44.7% vs. 48.6%; P < 0.001); however, this difference could explain only a small portion ( approximately 20%) of the inverse association between these diseases. Diabetes is a protective factor for prostate cancer across populations, suggesting shared risk factors that influence a common mechanism.
Waters
Kevin M
KM
Department of Preventive Medicine, Keck School of Medicine, University of Southern California/Norris Comprehensive Cancer Center, Los Angeles, USA.
Henderson
Brian E
BE
Stram
Daniel O
DO
Wan
Peggy
P
Kolonel
Laurence N
LN
Haiman
Christopher A
CA
D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D044467:American Indian or Alaska Native / Q000706:statistics & numerical data; D001213:Asian / Q000706:statistics & numerical data; D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000208:ethnology*; D005006:Ethnicity / Q000706:statistics & numerical data*; D005500:Follow-Up Studies; D006254:Hawaii / Q000453:epidemiology; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D015999:Multivariate Analysis; D011159:Population Surveillance; D015995:Prevalence; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000208:ethnology*; D012307:Risk Factors; D044465:White People / Q000706:statistics & numerical data
D017430:Prostate-Specific Antigen