Improving The Detection Rate Of Prostate Cancer And The Accuracy Of The Gleason Score With Prediction Models And Imaging Technique

IExternal validation of the Prostate Cancer Prevention Trial and the European Randomized Study of Screening for Prostate Cancer risk calculators in a Chinese cohortObjective:Several prediction models have been developed to estimate the outcomes of prostate biopsies. Most of these tools were designed for use with Western populations and have not been validated across different ethnic groups. Therefore, we evaluated the predictive value of the Prostate Cancer Prevention Trial (PCPT) and the European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculators in a Chinese cohort.Materials and Methods:Clinicopathological information was obtained from495Chinese men who had undergone extended prostate biopsies between Jan2009and Mar2011. The estimated probabilities of prostate cancer and high-grade disease (Gleason>6) were calculated using the PCPT and ERSPC risk calculators. Overall measures, discrimination, calibration and clinical usefulness were assessed for the model evaluation.Results:Of these patients,28.7%were diagnosed with prostate cancer, and19.4%had high-grade disease. Compared to the PCPT model and the PSA threshold of4ng/ml, the ERSPC risk calculator exhibited better discriminative ability for predicting positive biopsies and high-grade disease (the area under the curve was0.831and0.852, respectively, p<0.01for both). Decision curve analysis also suggested the favourable clinical utility of the ERSPC calculator in the validation dataset. Both prediction models demonstrated miscalibration:the risk of prostate cancer and high-grade disease was overestimated by approximately20%for a wide range of predicted probabilities.Conclusion:The ERSPC risk calculator outperformed both the PCPT model and the PSA threshold of4ng/ml in predicting prostate cancer and high-grade disease in Chinese patients. However, the prediction tools derived from Western men significantly overestimated the probability of prostate cancer and high-grade disease compared to the outcomes of biopsies in a Chinese cohort. ⅡCombined Using of Diffusion-Weighted MR Imaging and Transrectal Ultrasound for Transrectal Prostate Biopsy:Preliminary StudyObjective:This study aimed to retrospectively analyze the clinical value of Diffusion-Weighted MR Imaging in the detection of prostate cancer in suspected patients.Materials and Methods:Between Jan2009and Dec2010,141patients suspected as prostate cancer underwent a MRDWI and TRUS jointly guided transrectal prostate biopsy. The patients were divided into4groups by PSA<10ng/ml,10ng/ml≤PSA <20ng/ml,20ng/ml≤PSA<50ng/ml and PSA≥50ng/ml, and the diagnostic accuracy of MRDWI was tested based by segment of specimen.Result:The sensitivity in the four groups were85.5%,71.9%,91.5%and94.4%compared with23.4%,34.5%,68.9%and89.3%for TRUS, respectively.Conclusion:The sensitivity of MDWI in the diagnosis of prostate cancer was better than TRUS. The combination of MDWI and TRUS showed the potential to guide biopsy to cancer foci in patients suspected as prostate cancer. ⅢThe value of diffusion-weighted MR imaging combined with transrectal ultrasound for transrectal prostate biopsyObjective:To retrospectively analyze the clinical value of diffusion-weighted MR imaging in the detection of prostate cancer in suspected patients.Materials and Methods:Between January2009and December2010, the551patients suspected as prostate cancer underwent prostate biopsy in our hospital. Patients in group A were accepted to a TRUS guided transrectal prostate biopsy, while patients in group B were accepted to a MRDWI and TRUS jointly guided transrectal prostate biopsy. The two groups were divided into4subgroups by PSA<10ng/ml,10ng/ml≤PSA<20ng/ml,20ng/ml≤PSA<50ng/ml and PSA≥50ng/ml. Then, we compared the diagnostic rate of prostate biopsy guided by combination of MRDWI and TRUS with only TRUS.Results:The diagnostic rate of patients with PSA<10ng/ml,10ng/ml≤PSA<20ng/ml,20ng/ml≤PSA<50ng/ml and PSA≥50ng/ml were12.1%,31.1%,48.0%,91.2%in group A, and23.7%,35.5%,66.7%,96.3%in group B, respectively. In the patients with PSA less than10ng/ml, there were significant differences in diagnostic rate between the two biopsy techniques (χ2=4.405, P<0.05).Conclusion:The combination of MRDWI and TRUS showed the potential to guide biopsy to cancer foci in patients suspected as prostate cancer. For patients with PSA <10ng/ml, a MRDWI and TRUS jointly guided transrectal prostate biopsy was recommended. ⅣDevelopment a Nomogram to Predict Gleason Sum Upgrading in Clinically Diagnosed Localized Prostate CancerObjective:Although several prediction models were developed to estimate the probability of Gleason sum upgrade (GSU) between biopsy and radical prostatectomy specimens, most of them are restricted to screen detected prostate cancer. The objective of this study was to build a nomogram for prediction of GSU in clinically diagnosed prostate cancer.Material and Methods:The study cohort comprised269Chinese prostate cancer patients who underwent prostate biopsy with a minimum of10cores and were subsequently treated with radical prostatectomy. Of all the patients,81.8%was referred with clinical symptom. The prostate-specific antigen level, primary/secondary biopsy Gleason score and clinical T stage were used in a multivariate logistic regression model for addressing the probability of GSU. The developed nomogram was internally validated.Results:GSU was observed in90(33.5%) patients. By using4readily available variables, our nomogram showed a bootstrap corrected concordance index of0.789and good calibration. The nomogram also demonstrated satisfied statistical performance for predicting significant GSU. Externally validation of Chun et al. nomogram in our cohort showed remarkable discordance between observed and predicted probability of GSU.Conclusions:A new nomogram to predict GSU in clinically diagnosed prostate cancer was developed and demonstrated good statistical performance in internal validation.