Investigation Of The Influence Of Finasteride On Incidence And Pathology Grading Of Prostate Cancer

Objective It is well known that prostate cancer is one of the major malignant rumors in male, and its genesis and development depend on the existence of androgen. Finasteride is selectivity inhibitor of 5 alpha-reductase (SRD5A) II, which could decrease endogenic Dihydrotestosterone (DHT) level significantly. It is still in debate for the contribution of finasteride to development of prostate cancer. In our retrospective study of 1029 cases in our hospital, we investigated the medication, incidence of prostate cancer, and its pathology grading of these patients, in order to analyze the influence of finasteride on incidence and pathology grading of prostate caner in China.Methods The data of 1029 Benign prostatic hyperplasia (BPH) consecutive patients in our hospital from 1998 to 2004 was collected, and depend on their medication, these patients were divided into 4 groups: finasteride group, α-receptor inhibitor group, combination group and control group. We gathered pathology sections of patients in all groups, and gave Gleason Score to each. The difference of incidence and pathology grading of prostate cancer were analyzed using Stata statistic software.Results 1. The incidence of prostate cancer in the population of our study is 13.51%, while in finasteride group, a-receptor inhibitor group, combination group and control group, the incidence is 10.26%, 9.81%, 16.00% and 18.62% respectively. There is significant difference of incidence of prostate cancer between following groups (P< 0.05) : finasteride group vs control group (RR=0.53, CI:0.32-0.87) , finasteride group vs α-receptor inhibitor group(RR=0.61, CI:0.38-0.99), combination group vs α-receptor inhibitor group (RR=0.55, CI:0.35-0.86) , and combination group vs control group (RR=0.55, CI:0.35-0.86) . Compare with non-using of finasteride, using of it could reduce the incidence of prostate cancer 40.63% of non-using group's (RR=0.59, 95%CI:0.43-0.82) .2. In our study, the ratio of middle or high level pathology grading (Gleason≥7 ) in prostate cancer patients is 58.27%, while in the 4 groups, this ratio is 71.43%, 59.62%, 67.74%, and 40.00% respectively. The difference of constituent ratio between followinggroups is significant (P<0.05) : finasteride group vs control group (RR=1.79, CI:1.10-2.91), combination group vs control group (RR= 1.69, CI:1.06-2.72) .The ratio is quite different using finasteride or not, and it increases 33.96% in finasteride groups compare to not using groups (RR=1.34, 95%CI:1.01-1.76) .Conclusions 1 .The risk of prostate cancer in BPH patients could be decreased in finasteride treatment. 2.The malignant degree of prostate caner could be increased in BPH patients of using finaseride. 3.The result of our study is still need to be confirmed by random double-blind investigations of big population in multiple centers.