Allopurinol and prostate cancer survival in a Finnish population-based cohort.

BACKGROUND: Allopurinol is gout medication that inhibits uric acid formation. Its possible anti-carcinogenic properties have been under research in past years. Studies based on Taiwanese registries showed that long term allopurinol use might reduce prostate cancer (PCa) incidence. However, our studies based on Finnish registries did not support those findings. In this study, we evaluate whether allopurinol use is associated with prostate cancer-specific survival (CSS) or overall survival (OS) in a Finnish population-based cohort. METHODS: The study cohort was originally enrolled for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). We included all newly diagnosed PCa cases during 1996-2015, 9252 men in total. Information on allopurinol purchases was from the national prescription registry of the Social Insurance Institution of Finland. Information about deaths, treatments, and use of other medications was obtained from registries, and tumor stage and PSA at diagnosis from medical records. Follow-up started at diagnosis, and we analysed separately two endpoints: PCa-specific death and overall death. We used an extended Cox regression with adjustment for age at diagnosis, Charlson comorbidity index, FinRSPC trial arm, use of other drugs and EAU PCa risk group. RESULTS: During a median follow-up of 9.86 years, 2942 deaths occurred, including 883 from PCa. There was no difference in CSS between allopurinol user and non-users, but allopurinol users had lower OS (multivariable-adjusted hazard ratio 1.77; 95% CI: 1.57-2.00). However, this decrease in OS was mitigated along with increasing intensity of allopurinol use. CONCLUSIONS: We found no marked difference in CSS by allopurinol use. Allopurinol users had lower OS but there were no significant differences by duration or intensity of allopurinol use. Allopurinol use may not have anticancer effects against prostate cancer; instead, it may be a surrogate for metabolic problems causing shorter OS among men with PCa.

Allopurinol and the risk of prostate cancer in a Finnish population-based cohort.

BACKGROUND: Allopurinol reduces oxidative stress and may thus have an anti-inflammatory effect. Previous studies suggest that allopurinol use might decrease the risk of prostate cancer (PCa) among gout patients. We studied the association between allopurinol use and PCa incidence. METHODS: The cohort consists of 76,874 men without prevalent PCa, originally identified for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). The follow-up started at entry to the trial. We excluded men using allopurinol in the year before entry (wash-out). PCa cases detected during 1996-2015 were identified from the Finnish Cancer Registry. Information on tumor Gleason score and TNM stage were obtained from medical files. Information on PSA level was obtained from screening samples for men in the FinRSPC screening arm and from laboratory databases for men in the control arm. Information on BMI was based on a questionnaire sent to men in the FinRSPC screening arm in 2004-2008. Drug purchase information were obtained from the national prescription database. We used Cox regression (adjusted for age, FinRSPC trial arm, PCa family history and use of other medication) to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of PCa risk by allopurinol use. We analyzed medication as a time-dependent variable to minimize immortal time bias. RESULTS: There were 9062 new PCa diagnoses in the cohort. Follow-up time did not differ by allopurinol use (median 17 yr; IQR 11-19 vs median 17 yr; IQR 12.33-19). The risk of PCa did not differ by allopurinol use (multivariable adjusted HR 1.03; 95% CI 0.92-1.16). Allopurinol use did not associate with the risk of high-grade or metastatic cancer. Cumulative duration or average yearly dose of allopurinol use showed no association with PCa risk. No delayed risk associations were observed in the lag-time analyses. CONCLUSIONS: We observed no difference in the PCa risk by allopurinol use.

Allopurinol and risk of benign prostatic hyperplasia in a Finnish population-based cohort.

BACKGROUND: Metabolic syndrome and obesity are linked with hyperuricemia, and it has also been proposed that oxidative stress associated with hyperuricemia may promote benign prostatic hyperplasia (BPH). However, it is currently unknown whether use of antihyperuricemic medication is associated with risk of developing BPH. We studied the association between BPH and use of antihyperuricemic allopurinol in a Finnish population-based cohort. METHODS: The study cohort consisted of 74,754 men originally identified for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). Information on gout and BPH medication usage (5α-reductase inhibitors, 5ARIs) during 1996-2014 was obtained from the National medication reimbursement database. Information on BPH diagnoses from in- and outpatient hospital visits and BPH-related surgery was obtained from the National Health Care Registry. Men with a record of BPH at baseline was excluded. We used Cox regression to analyze risk of starting BPH medication, having a recorded diagnosis or undergoing BPH surgery by allopurinol use with adjustment for age and simultaneous use of statins, antidiabetic or antihypertensive drugs and aspirin or other NSAIDs. Medication use was analyzed as a time-dependent variable to minimize immortal time bias. RESULTS: Men using allopurinol had a decreased risk for all three BPH endpoints: BPH medication (HR 0.81; 95% CI 0.75-0.88), BPH diagnosis (HR 0.78; 95% CI 0.71-0.86) and BPH-related surgery (HR 0.67; 95% CI 0.58-0.76) after multivariable adjustment. The risk association did not change by cumulative use. The risk decrease disappeared after 1-2 years lag time. Only BMI modified the risk association; the risk decrease was observed only among men with BMI above the median (27.3 kg/m2); p for interaction <0.05 for each endpoint. CONCLUSIONS: We found that allopurinol use is associated with lowered risk of BPH medication, diagnosis and surgery. A possible explanation could be antioxidative effects of urate-lowering allopurinol.