(C-218) Use of Systemic Glucocorticoids and Risk of Prostate Adenocarcinoma: Evidence From a Danish Population-Based Case-Control Study

Background: Concerns have been raised that long-term use of glucocorticoids may increase the risk of several cancers, including prostate cancer. However, epidemiological studies evaluating the association between systemic glucocorticoid use and prostate cancer risk are scarce.

Objectives: To investigate the association between systemic glucocorticoids and prostate cancer risk in a case-control study nested in a nationwide cohort.

Methods: Using Danish healthcare registries, cases were identified as all men with a primary diagnosis of prostate adenocarcinoma between 2001 and 2018 (n=56,575). Each case was matched to 10 population controls based on age and calendar time. We used the national prescription registry to identify exposure to systemic glucocorticoids from 1995 onwards. Ever use of glucocorticoids was defined as at least two filled prescriptions, and long-term use as filled prescriptions equivalent to ≥1000 defined daily doses (DDDs). Exposure was further classified by glucocorticoid type and cumulative dose. We examined the association according to prostate cancer clinical stage (localized, non-localized, and unknown). Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer risk. Exposure was lagged by one year. Models were adjusted for age, calendar time, educational level, inflammatory/autoimmune diseases, Charlson comorbidity index score, and use of concomitant drugs.

Results: Among 56,575 incident cases of prostate adenocarcinoma, the median age at the index date was 70 years (interquartile range, 64-75). Overall, twelve percent of men had ever used systemic glucocorticoids. Ever and long-term use, vs. never use, were not associated with prostate cancer risk [OR=1.03 (1.00-1.06) and OR=1.02 (0.92-1.14), respectively]. An inverse association was observed with the highest use category (>1500 DDDs) [OR=0.86 (0.74-0.99)], though without evidence of a dose-response relationship [OR per 500 DDDs=0.98 (0.95-1.01), p=0.18]. Associations did not differ by glucocorticoid type, age at index date and prostate cancer stage.

Conclusions: The findings from this large nationwide nested case-control did not suggest a positive association between systemic glucocorticoid use and prostate adenocarcinoma risk.