We have analysed the reasons for the low reported incidence of prostate cancer in China and argue for early diagnosis and treatment of this disease.According to the 2002 database of the International Agency for Research on Cancer (IARC),the age-standardized incidence of prostate cancer in China is 1.6/105 person years (PY),with a mortality rate of 1.0/105PY and mortality-to-incidence rate ratio (MR/IR)=0.63.The MR/IR ratio of prostate cancer in China was found to be higher than the average in Asia (MR/IR=0.57) and much higher than that in North America (MR/IR=0.13).These data indicate that in China most prostate cancers were in the advanced stages at the time of diagnosis,and that patients had a short survival time thereafter.In 2004,Stamey et al.reported a retrospective American study of prostate cancer for the years 1983-2003.It was shown that most cases of prostate cancer detected by prostate-specific antigen (PSA) screening were in the advanced stage at the start of this 20-year period.These early follow-up data are quite similar to the results obtained from mass PSA screening of elderly men in Changchun,China.However,after the American programmes for early diagnosis and treatment of prostate cancer were accepted,tumours were diagnosed at earlier stages.On the basis of these findings,mass screening should be performed in the whole of China using serum PSA to facilitate early diagnosis and treatment of prostate cancer.