Pos0019 Gout and Risk of Prostate Cancer, a Population Based Study From Western Sweden

Background: Gout, as well as prostate cancer, is common in men and the incidence increases with age. Established risk factors for prostate cancer are age and hereditary factors, while evidence for specific environmental factors are scarce. Increased levels of serum urate is the strongest risk factor for gout development and one cohort study has previously shown an increased risk of prostate cancer development in gout patients. Recent findings from a large multicentre genome-wide association study suggests in situ urate production in the prostate. Objectives: To compare the incidence and risk of prostate cancer between male gout patients and general population comparators. Methods: This is a population-based and register-based observational cohort study, comparing the incidence and hazard of prostate cancer in patients with gout and matched general population controls. Male gout cases, 18 years or older, were identified by ICD-10 code M10 for gout, between January 1st 2001 through December 31st 2017, in the Western Sweden Healthcare Care Register (VEGA). To each case, up to five controls without any prior diagnosis of gout, were matched for age, sex and place of residence. Relevant comorbidities, medication and urate levels were also retrieved from VEGA. Follow-up started from first diagnosis of gout and ended at first of a diagnosis of prostate cancer, death, migration or study end at December 31st 2017. Cases and controls with a prevalent diagnosis of prostate cancer were excluded. The crude incidence rates (IR) and incidence rate ratio (IRR) were calculated, and comparisons made between the groups. Adjusting for age, time-dependent COX regression was used to analyse the hazard ratio (HR) of prostate cancer in patients with gout compared to population controls. Results: We identified 29177 cases of gout with a median age of 67 years and 114 441 matched controls, median age 65 years. The gout cases had an overall higher comorbidity burden at baseline (Table 1). During a median follow-up time of 5 years we identified 960 (3.3%) incident cases of prostate cancer in the gout population compared to 4274 (4.1%) in the controls. The gout population had a significantly lower incidence rate of prostate cancer per 1000 person-years (5.67 95% CI 5.32-6.05) compared to controls (7.01 95% CI 6.81-7.21). Adjusting for age in time-dependent COX regression the relative risk reduction in gout patients for incident prostate cancer was 20% (HR 0.77; 95% CI:0.72-0.83). Conclusion: The results in this study show that patients with gout have lower risk of developing prostate cancer than general population comparators. This might imply a protective role of urate in prostate cancer development. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.