Human spatial memory is biased towards high-calorie foods: a cross-cultural online experiment.

BACKGROUND: Human memory appears to prioritise locations of high-calorie foods, likely as an adaptation for foraging within fluctuating ancestral food environments. Importantly, this "high-calorie bias" in human spatial memory seems to yield consequences for individual eating behaviour in modern food-abundant settings. However, as studies have mainly been conducted in European (Dutch) populations to date, we investigated whether the existence of the cognitive bias can be reasonably generalised across countries that vary on culturally-relevant domains, such as that of the USA and Japan. Furthermore, we investigated whether sociodemographic factors moderate the expression of the high-calorie spatial memory bias in different populations. METHODS: In a cross-cultural online experiment, we measured the food location memory of diverse participants from the USA (N = 72; 44.4% Male; 54 ± 15.99 years) and Japan (N = 74; 56.8% Male; 50.85 ± 17.32 years), using a validated computer-based spatial memory task with standardised images of high-calorie and low-calorie foods. To directly compare the magnitude of the high-calorie spatial memory bias in a broader cultural scope, we also included data from a previous online experiment that identically tested the food spatial memory of a Dutch sample (N = 405; 56.7% Male; 47.57 ± 17.48 years). RESULTS: In the US sample, individuals more accurately recalled (i.e. had lower pointing errors for) locations of high-calorie foods versus that of low-calorie alternatives (Mean difference = -99.23 pixels, 95% CI = [-197.19, -1.28]) - regardless of one's hedonic preferences, familiarity with foods, and encoding times. Likewise, individuals in the Japanese sample displayed an enhanced memory for locations of high-calorie (savoury-tasting) foods (Mean difference = -40.41 pixels, 95% CI = [-76.14, -4.68]), while controlling for the same set of potential confounders. The magnitude of the high-calorie bias in spatial memory was similar across populations (i.e. the USA, Japan, and the Netherlands), as well as across diverse sociodemographic groups within a population. CONCLUSIONS: Our results demonstrate that the high-calorie bias in spatial memory transcends sociocultural boundaries. Since the cognitive bias may negatively impact on our dietary decisions, it would be wise to invest in strategies that intervene on our seemingly universal ability to efficiently locate calorie-rich foods.

Human spatial memory implicitly prioritizes high-calorie foods.

All species face the important adaptive problem of efficiently locating high-quality nutritional resources. We explored whether human spatial cognition is enhanced for high-calorie foods, in a large multisensory experiment that covertly tested the location memory of people who navigated a maze-like food setting. We found that individuals incidentally learned and more accurately recalled locations of high-calorie foods - regardless of explicit hedonic valuations or personal familiarity with foods. In addition, the high-calorie bias in human spatial memory already became evident within a limited sensory environment, where solely odor information was available. These results suggest that human minds continue to house a cognitive system optimized for energy-efficient foraging within erratic food habitats of the past, and highlight the often underestimated capabilities of the human olfactory sense.

Foraging minds in modern environments: High-calorie and savory-taste biases in human food spatial memory.

Human memory may show sensitivity to content that carried fitness-relevance throughout evolutionary history. We investigated whether biases in human food spatial memory exist and influence the eating behavior of individuals within the modern food environment. In two lab studies with distinct samples of 88 participants, individuals had to re-locate foods on a map in a computer-based spatial memory task using visual (Study 1) or olfactory (Study 2) cues that signaled sweet and savory high- and low-calorie foods. Individuals consistently displayed an enhanced memory for locations of high-calorie and savory-tasting foods - regardless of hedonic evaluations, personal experiences with foods, or the time taken to encode food locations. However, we did not find any clear effects of the high-calorie or savory-taste bias in food spatial memory on eating behavior. Findings highlight that content matters deeply for the faculty of human food spatial memory and indicate an implicit cognitive system presumably attuned to ancestral priorities of optimal foraging.

Laparoscopic radical prostatectomy in men older than 70 years of age with localized prostate cancer: comparison of morbidity, reconvalescence, and short-term clinical outcomes between younger and older men.

OBJECTIVES: To analyze the safety and efficacy of extraperitoneal laparoscopic radical prostatectomy (eL-RPE) in elderly versus younger men with localized prostate cancer. METHODS: Patients undergoing eL-RPE were retrospectively subdivided into group eL-RPE1 (72 men aged 71 yr and older) and group eL-RPE2 (132 men aged 59 yr and younger). Group eL-RPE1 was compared with a group of 70 contemporary, comparable patients aged 71 yr and older undergoing open retropubic radical prostatectomy (group OPEN-RPE). RESULTS: Compared with group eL-RPE2, patients of group eL-RPE1 had a higher pathologic stage (45% vs. 32% stage pT3 or greater, p<0.001) and higher Gleason score (median 7 vs. 6, p<0.001). Prostate-specific antigen recurrence was significantly worse compared with age-matched controls for younger patients with high-stage or high-grade lesions (p<0.001). Importantly operative time, analgesic requirements, hospital stay, convalescence, and complication rates were comparable. Urinary continence rate was significantly better in group eL-RPE2 at 6 mo (67% vs. 91%, respectively, p<0.001). Group eL-RPE1 and group OPEN-RPE patients had statistically similar pathologic stage and Gleason score (each p>0.05), similar operative time (p=0.12), but less blood loss (p<0.001), shorter hospital stay (p<0.001), and more rapid convalescence (p<0.001) occurred in eL-RPE1. CONCLUSIONS: eL-RPE is feasible and efficacious even in elderly patients with unfavorable, large-volume disease. eL-RPE offers the advantages of decreased blood loss, shorter hospital stay, and more rapid recovery over OPEN-RPE. However, the elderly patient must be informed preoperatively about the observed higher incontinence rate.

Vesicourethral anastomosis during endoscopic extraperitoneal radical prostatectomy: a prospective comparison between the single-knot running and interrupted technique.

OBJECTIVES: To determine the safety and efficacy of the single-knot running versus interrupted technique for urethrovesical anastomosis during endoscopic extraperitoneal radical prostatectomy. METHODS: A total of 250 consecutive patients who underwent endoscopic extraperitoneal radical prostatectomy were prospectively divided into two groups of 125 patients each who underwent urethrovesical anastomosis using the single-knot running technique (group 1) or the interrupted suture technique (group 2). Surgical data, operative time, difficulty scores, extravasation rate, catheterization time, occurrence of anastomotic strictures, and the early and late continence rates were analyzed statistically. RESULTS: Regarding the clinical and pathologic findings, extravasation rate, catheterization time, and occurrence of anastomotic strictures, no significant differences were found between the two groups (P >0.05). The strongest independent predictors for extravasation were the integrity of the dorsal wall of the anastomosis and the degree of bladder neck opening (P <0.001). Overall, the continence rate at 3 and 6 months was 76% and 91.5% for group 1 and 77.6% and 93% for group 2, respectively (all P >0.05). The anastomosis technique had no impact on extravasation or continence status (all P >0.05). The only significant differences (P <0.001) in favor of the single-knot technique were the mean operative time and difficulty score (16 versus 24 minutes and 1 versus 3, respectively). CONCLUSIONS: Both techniques provide satisfactory and similar functional results. However, because of its simplicity and shorter operative time, the single-knot running technique appears preferable.

Quality of life after laparoscopic and open retroperitoneal lymph node dissection in clinical Stage I nonseminomatous germ cell tumor: a comparison study.

OBJECTIVES: To compare the postoperative quality of life (QOL) and reconvalescence in patients with clinical Stage I nonseminomatous germ cell tumor (NSGCT) after laparoscopic retroperitoneal lymph node dissection (L-RPLND) and the open procedure (O-RPLND). METHODS: Twenty-one patients with NSGCT who underwent transperitoneal L-RPLND were matched and compared with 29 patients who underwent O-RPLND. The operative, QOL, and recovery data and complications and cure rates were analyzed for both groups. RESULTS: The mean follow-up time for the L-RPLND and O-RPLND groups was 14 months (range 6 to 20) and 26 months (range 8 to 38), respectively. No major complication requiring open surgical revision or prolongation of hospitalization was observed intraoperatively or postoperatively in either group. However, the early and late minor postoperative complications were significantly greater in the O-RPLND group than in the L-RPLND group (P <0.001). The L-RPLND patients had a significantly shorter hospitalization, greater QOL scores, and a faster return to normal activities than did the O-RPLND patients (all P <0.001). CONCLUSIONS: L-RPLND for patients with clinical Stage I NSGCT is a safe and efficacious procedure, with a faster reconvalescence and greater postoperative QOL than after O-RPLND.

Induction of spermatogenesis in men with azoospermia or severe oligoteratoasthenospermia after antegrade internal spermatic vein sclerotherapy for the treatment of varicocele.

AIM: To evaluate the treatment outcome of antegrade internal spermatic vein sclerotherapy in men with non-obstructive azoospermia or severe oligoteratoasthenospermia (OTA) as a result of varicocele. METHODS: Between September 1995 and January 2004, 47 patients (mean age 33.8 +/- 6.3 years) underwent antegrade internal spermatic vein sclerotherapy for the treatment of varicocele with azoospermia (14 patients) or severe OTA (33 patients). Testicular core biopsy was also performed in complete azoospermic patients who provided informed consent. The outcome was assessed in terms of improvement in semen parameters and conception rate. RESULTS: Forty-two (89.4%) of 47 patients had bilateral varicocele. Serum follicle stimulating hormone (FSH) did not differ between patients with azoospermia and severe OTA. After the follow-up of 24.8 +/- 9.2 months, significant improvement was noted in mean sperm concentration, motility and morphology in 35 patients (74.5%). Comparison between groups during the follow-up revealed significantly higher values of sperm concentration, motility and normal morphology in the severe OTA group. Pregnancy was achieved in 14 cases (29.8%). Testicular histopathology of the azoospermic patients with postoperative induction of spermatogenesis revealed maturation arrest at spermatid stage, Sertoli-cell-only (SCO) with focal spermatogenesis or hypospermatogenesis. None of the patients with pure SCO pattern or maturation arrest at spermatocyte stage achieved spermatogenesis after the treatment. Preoperative serum FSH levels didn't relate to treatment outcome. CONCLUSION: Antegrade internal spermatic vein sclerotherapy is an easy and effective treatment for symptomatic varicocele. It can significantly reverse testicular dysfunction and improve spermatogenesis in men with severe OTA, as well as induce sperm production in men with azoospermia, improving pregnancy rates in subfertile couples.

Laparoscopic radical prostatectomy: impact of modified apical and posterolateral dissection in reduction of positive surgical margins in patients with clinical stage T2 prostate cancer and high risk of extracapsular extension.

PURPOSE: To determine whether modifications of extraperitoneal endoscopic radical prostatectomy (EERP) reduce the rate of a positive surgical margin (PSM) in men with clinical stage T(2) prostate cancer and a high risk of extracapsular extension. PATIENTS AND METHODS: A consecutive series of 182 men with stage cT(2) tumors and a high risk of extracapsular extension underwent EERP by a single surgeon (VP). The patients were divided into two groups: 71 patients who underwent a standard EERP (group 1) and 111 patients who underwent EERP with the modified technique (group 2). The basic principles of the modified technique are more thorough and wider resection of the posterolateral prostatic pedicles and extensive excision of periprostatic soft tissue at the apex, which results in better mobilization and exposure of the apex before the urethral transection. Differences in PSM rates were analyzed statistically. RESULTS: No significant differences were found between the two groups regarding the clinical and pathologic findings (P > 0.05). The rate of PSM was 28% in group 1 and 10% in group 2 (P < 0.001). Group 2 was less than one third as likely to have PSM as group 2 (odds ratio 2.9; 95% confidence interval 1.6, 3.9). The strongest (P < 0.0001) independent predictors of PSM were the surgical technique, the presence of extracapsular disease, and the volume of the cancer. Preservation of the neurovascular bundles had no impact on margin status (P = 0.93). Functional outcomes and complication rates were not adversely affected by these modifications. CONCLUSION: The modified dissection in EERP significantly reduces the rate of PSM in patients with stage cT(2) prostate cancer and a high risk of extracapsular extension.

Intensive laparoscopic training: the impact of a simplified pelvic-trainer model for the urethrovesical anastomosis on the learning curve.

We prospectively evaluated the learning curve (LC) for laparoscopic urethrovesical anastomosis (L-UVA) in an operator-training model and program using an innovative simplified pelvic-trainer model. Over a period of 12 months, 30 LRP were performed by one urologist skilled in open surgery but inexperienced in laparoscopy. During the first 15 procedures no systematic training was done. Consequentially, a systematic simplified daily program was performed on the pelvic trainer with a videolaparoscopic unit. The training lesson consisted of intracorporal knotting and suturing, linear and circular interrupted suture anastomosis. At the end of each lesson, time and performance error scores were recorded and progression curve was plotted for each task. The performances of each training tasks were plotted against the performance of L-UVA during the LRP. The significance of progression was evaluated using logarithmic regression analysis. A steady improvement in time and accuracy of performance skill was shown during the first 20 lessons (p<0.001). These improved skill acquisitions were proportionally correlated with the time and the accuracy (water-tight) of L-UVA performance during the last 15 L-RPE. Compared to the first 15 L-RPE, where no systematic training was performed, time and accuracy of L-UVA performance in the last 15 L-RPE were improved from a mean 51 (median 48, range: 38-75) to 26 (median 24, range 18-33) min (p<0.001) and from 10 to 15 watertight anastomoses (p<0.001), respectively. Using a continuing, systematic, simplified training model the LC of L-UVA can be improved significantly in a short time.

Extracorporeal shockwave therapy for Peyronie's disease: an alternative treatment?

AIM: To determine retrospectively the safety and efficacy of extracorporeal shock wave therapy (ESWT) in patients with Peyronie's disease. METHODS: Fifty-three patients with stable Peyronie's disease underwent ESWT (group 1). Fifteen patients matched with the baseline characteristic of the patients in group 1, who received no treatment, were used as the control (group 2). The patients' erectile function (International Index of Erectile Function [IIEF-5] score), pain severity (visual analog scale), plaque size and degree of penile angulation were assessed before and after the treatment in group 1 and during the follow-up in group 2. RESULTS: The mean follow-up time was 32 months (range: 6-64 months) in group 1 and 35 months (range: 9-48 months) in group 2. All the patients were available for the follow-up. Considering erectile function and plaque size, no significant changes (P > 0.05) were observed in group 1 before or after the ESWT. A total of 39 patients (74%) reported a significant effect in pain relief in group 1 after ESWT. However, regarding improvement in pain, IIEF-5 score and plaque size, no significant differences were observed between the two groups. In 21 patients (40%) of group 1, the deviation angle was decreased more than 10 degrees with a mean reduction in all patients of 11 degrees (range: 6-20 degrees). No serious complications were noted considering ESWT procedure. CONCLUSION: ESWT is a minimally invasive and safe alternative procedure for the treatment of Peyronie's disease. However, the effect of ESWT on penile pain, sexual function and plaque size remains questionable.

Tension-free vaginal tape (TVT) in morbidly obese patients with severe urodynamic stress incontinence as last option treatment.

OBJECTIVES: To determine the safety and efficacy of tension-free vaginal tape (TVT) in morbidly obese women with severe urodynamic stress incontinence (USI) as last option treatment. METHODS: Thirty-one patients with body mass index (BMI) >40 kg/m2, who had undergone the TVT procedure for urodynamically-confirmed USI were matched with 52 patients with BMI <30 kg/m2 who underwent the same procedure. BMI was calculated at the time of the surgery. Patients' characteristics and surgical data, complications and cure rates were analyzed for both groups. RESULTS: After a mean follow-up of 18.5 (range: 12-24) months the continence rates were 87% and 92% for morbidly obese women and control group, respectively (p = 0.103). No serious intraoperative complications were noted in both groups. However, the early postoperative complications were significantly higher (p < 0.05) in morbidly obese patients. In 4 patients from both group long term postoperative catheterization was necessary for 4 weeks. In one patient (2%) from the control group dilatation of urethra took place. No defect in healing or rejection of the tape occurred. CONCLUSIONS: TVT is a minimal invasive and safe procedure for morbidly obese patients suffering from severe USI with good outcome. Preoperative morbid obesity does not seem to be a risk factor for failure of this procedure.

Erectile dysfunction after transurethral prostatectomy for lower urinary tract symptoms: results from a center with over 500 patients.

AIM: To identify possible risk factors for erectile dysfunction (ED) after transurethral resection of prostate (TURP) for benign prostatic hyperplasia (BPH). METHODS: Between March 1999 and March 2004, 629 patients underwent TURP in our department for the treatment of symptomatic BPH. All patients underwent transrectal ultrasound examination. In addition, the flow rate, urine residue, International Prostate Symptom Score (IPSS) and quality of life (QOL) were recorded for those who presented without a catheter. Finally, the erectile function of the patient was evaluated according to the International Index of Erectile Function Instrument (IIEF-5) questionnaire. It was determined that ED existed where there was a total score of less than 21. The flow rate, IPSS and QOL assessment were performed at 3 and 6 months post-treatment. The IIEF-5 assessment was repeated at a 6-month follow-up. A logistic regression analysis was used to identify potential risk factors for ED. RESULTS: At baseline, 522 (83%) patients answered the IIEF-5 questionnaire. The mean patient age was (63.7+/-9.7) years. The ED rate was 65%. After 6 months, 459 (88%) out of the 522 patients returned the IIEF questionnaire. The rest of the group was excluded from the statistical analysis. Six months after TURP, the rate of patients reporting ED increased to 77%. Statistical analysis revealed that the only important factors associated with newly reported ED after TURP were diabetes mellitus (P = 0.003, r = 3.67) and observed intraoperative capsular perforation (P = 0.02, r = 1.12). CONCLUSION: The incidence of postoperative, newly reported ED after TURP was 12%. Risk factors for its occurrence were diabetes mellitus and intraoperative capsular perforation.

Retroperitoneoscopic versus open surgical radical nephrectomy for large renal cell carcinoma in clinical stage cT2 or cT3a: quality of life, pain and reconvalescence.

OBJECTIVES: To determine whether retroperitoneoscopic radical nephrectomy for large renal cell carcinoma in stage cT2 or cT3a is a feasible, safe and effective therapy option and if it shows any advantage regarding quality of life in comparison to open procedure. METHODS: 23 patients who underwent RPNx for tumor size greater than 7 cm (group 1) were matched and compared with 25 patients, who underwent ONx (group 2) for tumor with similar size characteristics. Patient and surgical data, QoL variables and complications were statistically analyzed. RESULTS: The median followup was 12 (range: 6-18) months for both groups. Group 1 had significantly (p < 0.001) less blood loss, shorter hospital stay, and shorter postoperative analgesic requirements. No conversion to open surgery was necessary, and no major complications requiring an invasive intervention occurred. Retroperitoneoscopic patients had significantly better QoL and pain scores postoperatively to 6 months (p < 0.001) and they return to baseline QoL status faster (p < 0.001). CONCLUSIONS: RPNx for large RCC in stage cT2 or cT3a is a safe and efficacious procedure with good short-term outcome results and significantly shorter recovery of QoL variables.

Laparoscopic radical prostatectomy: the value of intraoperative frozen sections.

OBJECTIVE: To examine the clinical and pathological value of intraoperative frozen section (IFS) in patients undergoing laparoscopic radical prostatectomy (L-RPE) for clinically localized prostate cancer. METHODS: The study includes 198 consecutive cases of L-RPE. After removal of the prostate, a 2-3mm circumferential specimen was obtained from the apical and bladder neck soft-tissue margin and submitted for IFS examination. In cases suspicious for capsular incision (n=57), IFS were taken from the neurovascular bundle/lateral pedicle. RESULTS: The IFS diagnosis from the apical, bladder neck, and neurovascular bundle/lateral pedicle soft-tissue margins was adenocarcinoma in 12 (6%), 1 (0.5%), and 2 (1%) cases, respectively. Patient age, clinical stage, and mean specimen weight were not associated with cancer at the apical IFS. The accuracy, sensitivity, specificity, positive and negative predictive value of the apical IFS to predict cancer in the permanent section of the apical soft-tissue margin was 96%, 70%, 97%, 58%, and 98%, respectively. All the patients (n=15) with cancer at IFS had wide resections of additional tissue in the area of positive soft-tissue margin and all had no cancer in the additional resected tissue. Especially at the apex, IFS decreases the overall PSM status on surgical specimen by 5.1% (apical PSM from 8.6% to 3.5%). CONCLUSION: Because of the low predictive value of IFS of bladder neck and neurovascular bundle/lateral pedicle their use is not recommended. IFS of the apex should be performed to reduce the PSM rate.

Laparoscopic radical prostatectomy: prospective evaluation of the learning curve.

OBJECTIVE: We prospectively evaluated the learning curve (LC) of laparoscopic radical prostatectomy (L-RPE) regarding the improvements in operative times (OT) and technical difficulty in one-operator-practice as it compares with open RPE. METHODS: Over 18 months, 50 L-RPE were performed by an inexperienced surgeon in laparoscopy but skilled in open surgery. Difficulty scores were obtained at the completion of each L-RPE comparing L-RPE to open RPE. OT, estimated blood loss (EBL), length of stay, and catheterization time were also obtained. RESULTS: In the ablative part of L-RPE the median difficulty score was significantly higher (p<0.001) for the first 10 cases, decreased dramatically by case 11 becoming equivalent (p=0.3) to open RPE and by case 31 the L-RPE becomes significantly easier than open RPE (p=0.002). The difficulty scores for the urethrovesical anastomosis performance is always uniformly higher for the whole patient series (p<0.001). Median OT decreased significantly from 293 minutes in the first 10 cases to 114 minutes in the last 10 cases (p<0.001). Catheterization time and length of hospitalization, decreased significantly with the progression of the LC. EBL remained stable throughout the patient cases. Obesity, prior surgery, and extension of the procedure (lymphadenectomy, nerve-sparing) significantly increased the OT. CONCLUSION: Although the ablative part of L-RPE has a relatively short LC for a skilled open surgeon reflected by the rapid decrease in difficulty scores and OT by case 21, the performance of anastomosis shows a longer LC. Intensive training on anastomosis may be necessary to master this skill.

Preoperative neural network using combined magnetic resonance imaging variables, prostate-specific antigen, and gleason score for predicting prostate cancer biochemical recurrence after radical prostatectomy.

OBJECTIVES: To develop and test an artificial neural network (ANN) for predicting biochemical recurrence based on the combined use of pelvic coil magnetic resonance imaging (pMRI), prostate-specific antigen (PSA) measurement, and biopsy Gleason score, after radical prostatectomy and to investigate whether it is more accurate than logistic regression analysis (LRA) in men with clinically localized prostate cancer. METHODS: We evaluated 191 consecutive men who had undergone retropubic radical prostatectomy for clinically localized prostate cancer. None of the men had lymph node metastasis as determined by adequate follow-up and pathologic criteria. The preoperative predictive variables included clinical TNM stage, serum PSA level, biopsy Gleason score, and pMRI findings. The predicted result was biochemical failure (PSA level of 0.1 ng/mL or greater). The patient data were randomly split into four cross-validation sets and used to develop and validate the LRA and ANN models. The predictive ability of the ANN was compared with that of LRA, Han tables, and the Kattan nomogram using area under the receiver operating characteristic curve (AUROC) analysis. RESULTS: Of the 191 patients, 57 (30%) developed disease progression at a median follow-up of 64 months (mean 61, range 2 to 86). Using all the input variables, the AUROC of the ANN was significantly greater (P <0.05) than the AUROC of LRA, Han tables, or the Kattan nomogram for the prediction of PSA recurrence 5 years after radical prostatectomy (0.897 +/- 0.063 versus 0.785 +/- 0.060, 0.733 +/- 0.061, and 0.737 +/- 0.071, respectively). Removing the pMRI findings from the previous models, the AUROC of the ANN decreased statistically significantly (P <0.05) and was comparable to the AUROC of conventional predictive tools (P >0.05). CONCLUSIONS: Using the pMRI findings, the ANN was superior to LRA, predictive tables, and nomograms to predict biochemical recurrence accurately. Confirmatory studies are warranted.

Preoperative neural network using combined magnetic resonance imaging variables, prostate specific antigen, and Gleason score to predict prostate cancer recurrence after radical prostatectomy.

OBJECTIVE: An artificial neural network analysis (ANNA) was developed to predict the biochemical recurrence more effectively than regression models based on the combined use of pelvic coil magnetic resonance imaging (pMRI), prostate specific antigen (PSA) and biopsy Gleason score in patients with clinically organ-confined prostate cancer after radical prostatectomy (RP). METHODS: Two-hundred-and-ten patients undergoing retropubic RP with pelvic lymphadenectomy were evaluated. Predictive study variables included clinical TNM classification, preoperative serum PSA, biopsy Gleason score, transrectal ultrasound (TRUS) findings, and pMRI findings. The predicted result was a biochemical failure (PSA >or=0.1 ng/ml). Using a five-way cross-validation method, the predicted ability of ANNA for a validation set of 200 randomly selected patients was compared with those of Cox regression analysis and "Kattan nomogram" by area under the receiver operating characteristic curve (AUC) analysis. RESULTS: Seventy-three patients (35%) failed at median follow-up of 61 (mean: 60, range: 2-94) months. Using similar input variables, the AUC of ANNA (0.765, 95% Confidence Interval [CI]: 0.704-0.825) was comparable (p > 0.05) to those for Cox regression (0.738, 95%CI: 0.691-0.819) and Kattan nomogram (0.728, 95%CI: 0.644-0.819). Contrarily, adding the pMRI findings, the ANNA is significantly (p < 0.05) superior to any other predictive model (0.897, 95%CI: 0.841-0.977). The Gleason score represented the most influential predictor (relative weight: 2.4) of PSA recurrence, followed by pMRI (2.2), and PSA (2.0). CONCLUSION: ANNA is superior to regression models to predict accurately biochemical recurrence. The relative importance of pMRI and the utility of ANNA to predict the PSA failure in patients referred for RP must be confirmed in further trials.

Preoperative neural network using combined magnetic resonance imaging variables, prostate-specific antigen, and Gleason score to predict positive surgical margins.

OBJECTIVES: To assess whether artificial neural network analysis (ANNA) predicts for positive surgical margins (PSMs) more effectively than logistic regression analysis (LRA) according to the combined use of the findings of pelvic coil magnetic resonance imaging (pMRI) and other preoperatively available tumor variables in patients with clinically organ-confined prostate cancer after radical prostatectomy. METHODS: A total of 205 patients with clinically localized prostate cancer, who underwent retropubic radical prostatectomy were evaluated. The predictive variables included clinical TNM stage, prostate-specific antigen (PSA) level, PSA density, biopsy Gleason score, percentage of cancer in biopsy specimens, and pMRI findings. The predicted outcome was PSMs. The patient data were randomly split into four cross-validation sets and used to develop and validate the ANNA and LRA models. For comparison, the area under the receiver operating characteristic curve was used. RESULTS: The overall PSM rate was 22% (n = 45). Using all input parameters, the accuracy of the ANNA and LRA was 84% and 75% for the prediction of PSMs, respectively. The area under the receiver operating characteristic curve of the ANNA (0.872 +/- 0.014) was significantly greater statistically (P <0.001) than that for LRA (0.791 +/- 0.006). The simplified ANNA models that used the pMRI findings in addition to PSA and Gleason score were as accurate as the model that used all the variables (P = 0.89). A high percentage of cancer in the biopsy specimens, pMRI findings, and high PSA density were equally the most influential predictors (relative weight 1.881, 1.964, and 1.493, respectively). CONCLUSIONS: All the ANNA models in this study were superior to LRA in the prediction of PSMs. The ANNA using pMRI findings, PSA level, and Gleason score as input variables performed as well as the ANNA using all the input parameters. Additional studies seem warranted.

Preoperative neural network using combined magnetic resonance imaging variables, prostate specific antigen and Gleason score to predict prostate cancer stage.

PURPOSE: We developed an artificial neural network analysis (ANNA) to predict prostate cancer pathological stage more effectively than logistic regression (LR) based on the combined use of prostate specific antigen (PSA), biopsy Gleason score and pelvic coil magnetic resonance imaging (pMRI) in patients with clinically organ confined disease before radical prostatectomy. MATERIALS AND METHODS: In 201 consecutive patients undergoing radical retropubic prostatectomy with pelvic lymphadenectomy the radiological-pathological correlation was evaluated using pMRI. Predictive variables were clinical TNM classification, preoperative serum PSA, biopsy Gleason score and pMRI findings. The predicted results were organ confined vs nonorgan confined disease and lymphatic vs no lymphatic involvement. The predicted ability of ANNA with several parameters in a set of 160 randomly selected test data was compared with that of LR and the Partin tables by area under the receiver operating characteristic curve analysis. RESULTS: The overall accuracy of ANNA and LR was 88% and 91%, and 77% and 84% for nonorgan confined and lymphatic involvement, respectively. For nonorgan confined disease and lymph node involvement the area under the curve of ANNA (0.895 and 0.899) was significantly larger than that of LR and the Partin tables (0.722 and 0.751, and 0.750 and 0.733, respectively, p <0.05). Gleason score represented the most influential predictor (relative weight 2.05) of nonorgan confined disease, followed by pMRI findings (1.96), PSA (1.73) and clinical stage (0.89). CONCLUSIONS: ANNA is superior to LR for accurately predicting pathological stage. The relative importance of pMRI findings and the usefulness of ANNA for predicting pathological stage in individuals must be confirmed in a prospective trial.

Quality of life after surgery for localized renal cell carcinoma: comparison between radical nephrectomy and nephron-sparing surgery.

OBJECTIVES: To compare the impact of radical nephrectomy and nephron-sparing surgery (NSS) for localized renal cell carcinoma on quality of life (QOL). METHODS: Retrospectively, 357 patients who had undergone NSS (n = 158) or radical nephrectomy (n = 199) for localized renal cell carcinoma completed postal questionnaires, including measures of QOL with validated instruments (SF-36, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 [EORTC QLQ-C30]), the impact of the stress of cancer, fear of recurrence, and worry about having fewer than two normal kidneys. A subset of 51 patients diagnosed after 2000 were followed up prospectively for at least 1 year. RESULTS: The mental and physical health composite scores were not significantly different from the validated norms for an age and sex-matched community sample. Although the type of operation had no influence on patients' overall QOL, all patients who underwent elective NSS showed a significantly greater score on physical function than patients treated with radical nephrectomy (P <0.001). Predictors for higher scores included elective NSS, comorbidity (assessed with standardized checklist), tumor size, and time since nephrectomy. The overall QOL scores and recovery of stress from cancer in patients treated with NSS for tumor less than 4 cm with a normal contralateral kidney were significantly superior to those who underwent NSS for tumor greater than 4 cm (P <0.05). Patients questioned after mandatory NSS were significantly more concerned about cancer recurrence. CONCLUSIONS: Patients without evidence of disease have relatively normal physical and mental health after operative treatment for localized renal cell carcinoma, independent of the kind of surgery. The QOL correlates proportionally with the size of tumor and is significantly better for patients undergoing NSS for tumor less than 4 cm with a normal contralateral kidney.