Pathological outcome for Chinese patients with low-risk prostate cancer eligible for active surveillance and undergoing radical prostatectomy: comparison of six different active surveillance protocols.

INTRODUCTION: Active surveillance is one of the therapeutic options for the management of patients with low-risk prostate cancer. This study compared the performance of six different active surveillance protocols for prostate cancer in the Chinese population. METHODS: Patients who underwent radical prostatectomy for prostate cancer from January 1998 to December 2012 at a university teaching hospital in Hong Kong were reviewed. Six active surveillance protocols were applied to the cohort. Statistical analyses were performed to compare the probabilities of missing unfavourable pathological outcome. The sensitivity and specificity of each protocol in identifying low-risk disease were compared. RESULTS: During the study period, 287 patients were included in the cohort. Depending on different active surveillance protocols used, extracapsular extension, seminal vesicle invasion, pathological T3 disease, and upgrading of Gleason score were present on final pathology in 3.3%-17.1%, 0%-3.3%, 3.3%-19.1%, and 20.6%-34.5% of the patients, respectively. The University of Toronto protocol had a higher rate of extracapsular extension at 17.1% and pathological T3 disease at 19.1% on final pathology than the more stringent protocols from John Hopkins (3.3% extracapsular extension, P=0.05 and 3.3% pathological T3 disease, P=0.03) and Prostate Cancer Research International: Active Surveillance (PRIAS; 8.0% pathological T3 disease, P=0.04). The Royal Marsden protocol had a higher rate of upgrading of Gleason score at 34.5% compared with the more stringent protocol of PRIAS at 20.6% (P=0.04). The specificities in identifying localised disease and low-risk histology among different active surveillance protocols were 59%-98% and 58%-94%, respectively. The John Hopkins active surveillance protocol had the highest specificity in both selecting localised disease (98%) and low-risk histology (94%). CONCLUSIONS: Active surveillance protocols based on prostate-specific antigen and Gleason score alone or including Gleason score of 3+4 may miss high-risk disease and should be used cautiously. The John Hopkins and PRIAS protocols are highly specific in identifying localised disease and low-risk histology.

Impact of skeletal-related events on survival in patients with metastatic prostate cancer prescribed androgen deprivation therapy.

OBJECTIVE: To investigate the impact of skeletal-related events on survival in patients with metastatic prostate cancer prescribed long-term androgen deprivation therapy. METHODS: This historical cohort study was conducted in two hospitals in Hong Kong. Patients who were diagnosed with metastatic prostate cancer and prescribed androgen deprivation therapy between January 2006 and December 2011 were included. Details of skeletal-related events and mortality were examined. RESULTS: The median follow-up was 28 (range, 1-97) months. Of 119 patients, 52 (43.7%) developed skeletal-related events throughout the study, and the majority received bone irradiation for pain control. The median actuarial overall survival and cancer-specific survival for patients with skeletal-related events were significantly shorter than those without skeletal-related events (23 vs 48 months, P=0.003 and 26 vs 97 months, P<0.001, respectively). Multivariate analysis revealed that the adjusted hazard ratio of presence of skeletal-related events on overall and cancer-specific survival was 2.73 (95% confidence interval, 1.46-5.10; P=0.002) and 3.92 (95% confidence interval, 1.87-8.23; P<0.001), respectively. A prostate-specific antigen nadir of >4 ng/mL was an independent poor prognostic factor for overall and cancer-specific survival after development of skeletal-related events (hazard ratio=10.42; 95% confidence interval, 2.10-51.66 and hazard ratio=10.54; 95% confidence interval, 1.94-57.28, respectively). CONCLUSIONS: Skeletal-related events were common in men with metastatic prostate cancer. This is the first reported study to show that a skeletal-related event is an independent prognostic factor in overall and cancer-specific survival in patients with metastatic prostate cancer prescribed androgen deprivation therapy. A prostate-specific antigen nadir of >4 ng/mL is an independent poor prognostic factor for overall and cancer-specific survival following development of skeletal-related events.

Peritoneal implantation of ureter in cadaveric renal transplant.

We report here a case of complication of peritoneal implantation of ureter in cadaveric renal transplant. The patient presented with anuria and delayed graft function. The diagnosis was suspected upon physical examination and radiological investigation. The complication was managed with reimplantation of the ureter into the bladder and the patient recovered with good graft function. We discuss this case, review the literature on this rare complication, and share our suggestions on how it can be prevented.

Diazepam disposition in mature and aged rabbits and rats.

The disposition of diazepam after intravenous administration was investigated in mature young and old female Dutch Belted rabbits (1-1.5 and 5.6.5 years) and Fischer-344 rats (6 and 30 months) to determine whether they exhibited an age-related increase in distribution similar to that previously observed in the human. No significant differences were found in the pharmacokinetic behavior of diazepam or its N,-demethylated metabolite between the young and old rabbits, although there was a suggestion that clearance might have been impaired in the older animals. In contrast, the initial postequilibrium and steady-state volumes of distribution of diazepam were higher in the old rat, but only the latter was statistically significant when adjusted for body weight. No significant differences were found in other pharmacokinetic parameters including plasma binding, nor were the metabolite concentration/time profiles different. The increased steady-state distribution volume could reflect a change in lean body mass/body in the old rat. However, the magnitude of the distributional change (50%) in small fat ratio compared to that in humans (300-400%) and this precludes the female fisher-344 rat as a suitable animal model for further investigation of the effects of age on the distribution of the benzodiazepines.