Mass screening of prostate cancer in Changchun City of China.

OBJECTIVES

Mass screening of prostate cancer in China had not been studied until now. To clarify the incidence of prostate cancer among the population of aged men in Changchun City of China, we performed a mass screening program for prostate cancer using prostate specific antigen (PSA).

METHODS

Men aged more than 50 years were examined by PSA, with a cut-off values 4.1 ng/ml. Subjects, whose serum PSA concentration was more than 4.1 ng/ml, were recommended to secondary examination of transrectal ultrasound-guided systematic six-sextant biopsy examination (TRUS-guided biopsy).

RESULTS

Between April 1998 and December 2000, in the urban area of Changchun City 4218 men over 50 years old were screened. As 190 men were found to have elevated PSA and 116 men underwent a TRUS-guided biopsy of the prostate, of whom 29 men were found to have cancer. In all, the age-adjusted PSA positive rate was 4.80%, cancer detection rate was 0.74%. The age-adjusted cancer detection rate was 0.78%. After adjusted for secondary examination rate, the cancer detection rate reached 1.28%. The cases of stage B with limited cancer within the prostate gland, accounted for 62% of 29 cancer cases. Stage B was much more detected (accounted for 60%) in the PSA range of 4.1-10.0 ng/ml. Stage C and D were much more detected (accounted for 85.71%) in the PSA range over 10.1 ng/ml, with a significant difference by Fisher exact test (P < 0.05). A significant correlation of age-adjusted PSA positive rate and age-adjusted cancer detection rate adjusted by secondary examination rate was showed in six groups of Community and Army, Factory, Corporation, Post and Telecom Office, Government and Academy, and University and Technical School (r = 0.898, P < 0.01). Both of the age-adjusted PSA positive rate and age-adjusted cancer detect rate of "Universities and Technical Schools" were significantly higher than that of "Factories" (chi2 test P < 0.05).

CONCLUSIONS

The prevalence of prostate cancer was not so low in Chinese people as expected. For 50 years or older men, cancer detection rate was 0.74%, The age-adjusted cancer detect rate was 0.78%. Much more early stage cancer could be detected in the screening using serum PSA. For the different company the detection rate of prostate cancer varied each other among the groups. Age-adjusted cancer detection rate in "Universities and Technical Schools" were significantly higher than in "Factories", suggesting environment factor or diet might be associated with the prostate cancer.