Stratified analyses demonstrated associations for men ages 65–74 at the time of breast cancer diagnosis (SIR = 1.34, 95%CI 1.01–1.73), hormone receptor-positive breast cancer (SIR = 1.23, 95%CI 1.11–1.39) or AJCC stage I breast cancer (SIR = 1.36, 95%CI 1.04–1.75) and second primary prostate cancer diagnosis. Here, NR4A1 is linked to prostate cancer.