Early Prediction Of Castration Resistant Prostate Cancer Occurring Time After Hormone Therapy Based On Gleason Score And PSA Ratio

Objective:To study correlation of castration resistant prostate cancer(CRPC)occurring time and patients' characteristics before hormone therapy and PSA level changes after therapy.Methods and Patients:The study retrospectively analyzed 372 cases of prostate cancer patients undergoing hormone therapy from January 2005 and December 2012 and we enrolled 173 cases.The endpoint were appearance of CRPC and time to CRPC.Patients' characteristics before hormone therapy were PSA levels,Gleason score and tumor stage.PSA level changes after therapy included PSA levels of first 6 months,PSA levels changing rate(R2/1: ratio of PSA level in second month to first month after therapy),PSA nadir.Combining Kaplan-Meier survival curve,Cox regression and logistic regression,we constructed a prediction model and test the model with ROC curves to ascertain the appropriate threshold values.Results:111 cases of CRPC patients were identified,while 173 cases were enrolled into the study.Median length of follow up time were 31 months(5-105 months).Median time of CRPC were 20 months,time of P25 was 9 months.PSA level,Gleason score and R2/1 were independent risk factor of CRPC occurring time,and HR(hazard ratio)were 2.826,1.300 and 2.773 respectively.Gleason score and R2/1 were independent risk factor of CRPC occurring in 9 months,and HR were 1.717 and 5.315.The area under curve(AUC)of ROC conducted by prediction model were 0.755,the threshold value was-1.698 and sensitivity was 96.0%,specificity was 50.0%.Conclusion:Gleason score and R2/1 were independent risk factor of prediction CRPC occurring in 9 months.Prediction model based on Gleason score and R2/1 with logistic regression could predict whether CRPC would occur in 9 months.