Abstract & Overview
Mentor: Bryant England Program: Internal Medicine, Division of Rheumatology Type: Original Research Background: Patients with rheumatoid arthritis (RA) are at a small, but significantly increased risk of cancer compared with the general population. This risk varies by cancer type, with findings relative to prostate cancer conflicting. Recognizing the male predominance and large number of cases available in the Veterans Health System, we estimated the risk of prostate cancer in a national population of male US Veterans with RA. Methods: We identified male patients with RA within the VA Corporate Data Warehouse (1/1/2000-4/1/2018) using an algorithm adapted based on large systematic reviews. Prostate cancer and prostate cancer death were identified from the VA Oncology Raw Domain (ORD) and the National Death Index (NDI). Prostate cancer incidence rates (IR; per 1,000 pt-yrs) and 95% CIs were calculated from the index. SIR and 95% CI were calculated from the Surveillance, Epidemiology, and End Results Program (SEER). Results: There were 56,764 RA patients included in analysis. Over 406,013 pt-yrs of follow-up, there were 1,433 incident prostate cancers (IR 3.53; 95% CI 3.35–3.72 per 1,000 pt-yrs). Relative to SEER rates, SIR of prostate cancer in RA was 0.93 (95% CI 0.88–0.98). Conclusion: In one of the largest studies of prostate cancer in RA, we estimated prostate cancer rates to be similar in a national Veteran population with RA to those in the general population. The small difference may be accounted for by cases not captured within ORD. This study was limited by the indirect standardization of prostate cancer rates to SEER. There is need for future research with direct standardization to US Veterans.