Latent prostate cancer among Japanese males: a bibliometric study of autopsy reports from 1980-2016

Prostate cancer is one of the most common malignancies, but a substantial portion remains latent throughout the patients' lifetime. Analysis of temporal change in the latent prostate cancer pool would be beneficial for clinical decision-making, but longitudinal autopsy studies are rare. We conducted a hand-search of the Annual of Pathological Autopsy Cases in Japan from 1980 to 2016 for cases of latent prostate cancer. Of 570 997 males aged 30 or older, latent prostate cancer was detected in 12 562 patients (2.2%). Proportion of detected cases correlated strongly with 'aging rate', the percentage of population aged 65 or older (squared Pearson's correlation coefficient r(2) = 0.972, P value <0.0001). Temporal increase in proportion was also seen in each age group as well. This continuous growth reinforces evidence from past Japanese reports on latent prostate cancer. The rapidly rising ageing rate of Japan may forecast further increase in the latent prostate cancer pool moving forward.