Consequently, men perceived the proposed intervention as unnecessary because their PSA level was kept under control by the treatments they had received, which supports the findings of a previous study28 and highlights the significance of using PSA as an outcome measure, despite criticism of its usefulness as a surrogate end-point in prostate cancer trials.35 36 It also illustrates the challenges of informing men that dietary or lifestyle factors may act on prostate cancer independently of PSA. Here, KLK3 is linked to prostate cancer.