Leonard Glickman

Changes in Continence and Erectile Function Between 2 and 4 Years After Radical Prostatectomy

PURPOSE There is a paucity of information on changes in continence and erectile function beyond 2 years after radical prostatectomy. We prospectively examined changes in continence and erectile function between 2 and 4 years after radical prostatectomy. MATERIALS AND METHODS Between October 2000 and August 2003, 731 consecutive men underwent open retropubic radical prostatectomy for clinically localized prostate cancer. Preoperative and postoperative continence, and erectile function were ascertained using the UCLA Prostate Cancer Index. The 48-month prospective self-assessment followup questionnaire captured changes in urinary control and erectile function between 24 and 48 months, including marked, moderate or slight improvement, no change or worsening. RESULTS Overall between 24 and 48 months after radical prostatectomy 23.4% and 42.3% of men showed any degree of improvement in continence and erectile function, and 12.2% and 19.8% showed marked and moderate improvement in continence and erectile function, respectively. The probability of experiencing any qualitative improvement in urinary continence was not significantly different in men who were continent or incontinent at 24 months. The likelihood of experiencing any qualitative improvement in erectile function was significantly greater in men who were potent at 24 months compared to those who were impotent. CONCLUSIONS Our study provides compelling evidence that clinically significant improvements in urinary control and erectile function occur beyond 2 years after radical prostatectomy. These qualitative improvements are greatest for erectile function in men who were potent at 2 years. Therefore, men should not be counseled that maximal urinary continence or erectile function are achieved by 24 months after radical prostatectomy.

The impact of metformin use on recurrence and cancer-specific survival in clinically localized high-risk renal cell carcinoma

BACKGROUND Recent data suggest that metformin may have anti-neoplastic properties. We sought to determine what effect metformin had on recurrence and cancer-specific survival (CSS) rates of patients with clinically localized pT2 and pT3 renal cell carcinoma (RCC) following radical or partial nephrectomy. METHODS We obtained data on 784 patients who underwent partial or radical nephrectomy for pT2 or pT3 tumours at our centre between 1996 and 2011. Patients with benign masses, nodal positivity, or metastasis at the time of surgery were excluded. Using a competing-risks regression model, we compared differences in probability of recurrence between patients who used metformin versus those who did not. RESULTS The patients on metformin at the time of surgery had worse disease recurrence than patients not on metformin. However, this was not statistically significant on multivariate analysis when controlling for age, race, body mass index, glomerular filtration rate, and tumour stage and grade (hazard ratio [HR], 1.22; 95% confidence interval [CI], 0.66-2.27 [p = 0.5]). Metformin use was associated with a lower risk of cancer-specific mortality, but this was not statistically significant when adjusted for clinical and tumour characteristics (HR, 0.76; 95% CI 0.21-2.7 [p = 0.7]). Limitations include the retrospective nature of the study and the lack on information on duration of metformin use. CONCLUSIONS Metformin use at the time of surgery for high-risk clinically localized RCC is not protective in terms of recurrence or CSS. Further studies should be done to confirm these findings and determine what effect concurrent metformin use might have on improved response to targeted therapies in the metastatic setting.

Combining Mean and Standard Deviation of Hounsfield Unit Measurements from Preoperative CT Allows More Accurate Prediction of Urinary Stone Composition Than Mean Hounsfield Units Alone

INTRODUCTION AND OBJECTIVES The mineral composition of a urinary stone may influence its surgical and medical treatment. Previous attempts at identifying stone composition based on mean Hounsfield Units (HUm) have had varied success. We aimed to evaluate the additional use of standard deviation of HU (HUsd) to more accurately predict stone composition. METHODS We identified patients from two centers who had undergone urinary stone treatment between 2006 and 2013 and had mineral stone analysis and a computed tomography (CT) available. HUm and HUsd of the stones were compared with ANOVA. Receiver operative characteristic analysis with area under the curve (AUC), Youden index, and likelihood ratio calculations were performed. RESULTS Data were available for 466 patients. The major components were calcium oxalate monohydrate (COM), uric acid, hydroxyapatite, struvite, brushite, cystine, and CO dihydrate (COD) in 41.4%, 19.3%, 12.4%, 7.5%, 5.8%, 5.4%, and 4.7% of patients, respectively. The HUm of UA and Br was significantly lower and higher than the HUm of any other stone type, respectively. HUm and HUsd were most accurate in predicting uric acid with an AUC of 0.969 and 0.851, respectively. The combined use of HUm and HUsd resulted in increased positive predictive value and higher likelihood ratios for identifying a stones mineral composition for all stone types but COM. CONCLUSIONS To the best of our knowledge, this is the first report of CT data aiding in the prediction of brushite stone composition. Both HUm and HUsd can help predict stone composition and their combined use results in higher likelihood ratios influencing probability.