Patrick C. Walsh

The development of human benign prostatic hyperplasia with age

In this study we report the prevalence and growth rate of human benign prostatic hyperplasia with age by combining and analyzing data from 10 independent studies containing more than 1,000 prostates. The normal prostate reaches 20 plus or minus 6 gm. in men between 21 and 30 years old, and this weight remains essentially constant with increasing age unless benign prostatic hyperplasia develops. The prevalence of pathological benign prostatic hyperplasia is only 8 per cent at the fourth decade; however, 50 per cent of the male population has pathological benign prostatic hyperplasia when they are 51 to 60 years old. The average weight of a prostate that is recognized at autopsy to contain benign prostatic hyperplasia is 33 plus or minus 16 gm. Only 4 per cent of the prostates in men more than 70 years old reach sizes greater than 100 gm. An analysis of a logistic growth curve of benign prostatic hyperplasia lesions removed at prostatectomy indicates that the growth of benign prostatic hyperplasia is initiated probably before the patient is 30 years old. The early phase of benign prostatic hyperplasia growth (men between 31 and 50 years old) is characterized by a doubling time for the tumor weight of 4.5 years. In the mid phase of benign prostatic hyperplasia growth (men between 51 and 70 years old) the doubling time is 10 years, and increases to more than 100 years in patients beyond 70 years old.

The use of prostate specific antigen, clinical stage and Gleason score to predict pathological stage in men with localized prostate cancer.

Clinical stage, Gleason score and serum prostate specific antigen (PSA) levels are used separately to predict pathological stage in patients with localized prostate cancer. Because the degree of tumor differentiation has a profound influence on the expression of serum PSA, serum PSA levels alone do not reflect tumor burden accurately. To overcome this obstacle we tested these 3 variables alone and in combinations as predictors of final pathological stage in 703 men with clinically localized prostate cancer at our institution. All patients were assigned a clinical stage by 1 urologist. The Gleason score was determined from preoperative needle biopsy and serum PSA levels were measured on an ambulatory basis. Final pathological stage was determined to be either organ confined, established capsular penetration, seminal vesicle involvement or lymph node involvement. Logistic regression analysis with the likelihood ratio chi-square test determined that serum PSA, Gleason score and clinical stage all predicted final pathological stage well. The results were improved with combinations of the 3 variables (serum PSA, Gleason score and clinical stage) and the combination provided the best separation. From these analyses probability plots and nomograms have been constructed to assist urologists in the preoperative prediction of final pathological stage for patients with clinically localized prostate cancer.

The effect of finasteride on the risk of acute urinary retention and the need for surgical treatment among men with benign prostatic hyperplasia

Background Finasteride is known to improve urinary symptoms in men with benign prostatic hyperplasia, but the extent to which the benefit is sustained and whether finasteride reduces the incidence of related events, including the need for surgery and the development of acute urinary retention, are not known. Methods In this double-blind, randomized, placebo-controlled trial, we studied 3040 men with moderate-to-severe urinary symptoms and enlarged prostate glands who were treated daily with 5 mg of finasteride or placebo for four years. Symptom scores (on a scale of 1 to 34), urinary flow rates, and the occurrence of outcome events were assessed every four months in 3016 men. Prostate volume was measured in a subgroup of the men. Complete data on outcomes were available for 2760 men. Results During the four-year study period, 152 of the 1503 men in the placebo group (10 percent) and 69 of the 1513 men in the finasteride group (5 percent) underwent surgery for benign prostatic hyperplasia (reduction in risk with finasteride, 55 percent; 95 percent confidence interval, 41 to 65 percent). Acute urinary retention developed in 99 men (7 percent) in the placebo group and 42 men (3 percent) in the finasteride group (reduction in risk with finasteride, 57 percent; 95 percent confidence interval, 40 to 69 percent). Among the men who completed the study, the mean decreases in the symptom score were 3.3 in the finasteride group and 1.3 in the placebo group (P<0.001). Treatment with finasteride also significantly improved urinary flow rates and reduced prostate volume (P<0.001). Conclusions Among men with symptoms of urinary obstruction and prostatic enlargement, treatment with finasteride for four years reduces symptoms and prostate volume, increases the urinary flow rate, and reduces the probability of surgery and acute urinary retention.

Risk of Prostate Cancer–Specific Mortality Following Biochemical Recurrence After Radical Prostatectomy

ContextThe natural history of biochemical recurrence after radical prostatectomy can be long but variable. Better risk assessment models are needed to identify men who are at high risk for prostate cancer death early and who may benefit from aggressive salvage treatment and to identify men who are at low risk for prostate cancer death and can be safely observed.ObjectivesTo define risk factors for prostate cancer death following radical prostatectomy and to develop tables to risk stratify for prostate cancer–specific survival.Design, Setting, and PatientsRetrospective cohort study of 379 men who had undergone radical prostatectomy at an urban tertiary care hospital between 1982 and 2000 and who had a biochemical recurrence and after biochemical failure had at least 2 prostate-specific antigen (PSA) values at least 3 months apart in order to calculate PSA doubling time (PSADT). The mean (SD) follow-up after surgery was 10.3 (4.7) years and median follow-up was 10 years (range, 1-20 years).Main Outcome MeasureProstate cancer–specific mortality.ResultsMedian survival had not been reached after 16 years of follow-up after biochemical recurrence. Prostate-specific doubling time (<3.0 vs 3.0-8.9 vs 9.0-14.9 vs ≥15.0 months), pathological Gleason score (≤7 vs 8-10), and time from surgery to biochemical recurrence (≤3 vs >3 years) were all significant risk factors for time to prostate-specific mortality. Using these 3 variables, tables were constructed to estimate the risk of prostate cancer–specific survival at year 15 after biochemical recurrence.ConclusionClinical parameters (PSADT, pathological Gleason score, and time from surgery to biochemical recurrence) can help risk stratify patients for prostate cancer–specific mortality following biochemical recurrence after radical prostatectomy. These preliminary findings may serve as useful guides to patients and their physicians to identify patients at high risk for prostate cancer–specific mortality following biochemical recurrence after radical prostatectomy to enroll them in early aggressive treatment trials. In addition, these preliminary findings highlight that survival in low-risk patients can be quite prolonged.

The effect of finasteride in men with benign prostatic hyperplasia

Background Benign prostatic hyperplasia is a progressive, androgen-dependent disease resulting in enlargement of the prostate gland and urinary obstruction. Preventing the conversion of testosterone to its tissue-active form, dihydrotestosterone, by inhibiting the enzyme 5 alpha-reductase could decrease the action of androgens in their target tissues; in the prostate the result might be a decrease in prostatic hyperplasia and therefore in symptoms of urinary obstruction. Methods In a double-blind study, we evaluated the effect of two doses of finasteride (1 mg and 5 mg) and placebo, each given once daily for 12 months, in 895 men with prostatic hyperplasia. Urinary symptoms, urinary flow, prostatic volume, and serum concentrations of dihydrotestosterone and prostate-specific antigen were determined periodically during the treatment period. Results As compared with the men in the placebo group, the men treated with 5 mg of finasteride per day had a significant decrease in total urinary-symptom scores (P less than 0.001), an increase of 1.6 ml per second (22 percent, P less than 0.001) in the maximal urinary-flow rate, and a 19 percent decrease in prostatic volume (P less than 0.001). The men treated with 1 mg of finasteride per day did not have a significant decrease in total urinary-symptom scores, but had an increase of 1.4 ml per second (23 percent) in the maximal urinary-flow rate, and an 18 percent decrease in prostatic volume. The men given placebo had no changes in total urinary-symptom scores, an increase of 0.2 ml per second (8 percent) in the maximal urinary-flow rate, and a 3 percent decrease in prostatic volume. The frequency of adverse effects in the three groups was similar, except for a higher incidence of decreased libido, impotence, and ejaculatory disorders in the finasteride-treated groups. Conclusions The treatment of benign prostatic hyperplasia with 5 mg of finasteride per day results in a significant decrease in symptoms of obstruction, an increase in urinary flow, and a decrease in prostatic volume, but at a slightly increased risk of sexual dysfunction.

Genome-wide association study identifies a second prostate cancer susceptibility variant at 8q24

Prostate cancer is the most prevalent noncutaneous cancer in males in developed regions, with African American men having among the highest worldwide incidence and mortality rates. Here we report a second genetic variant in the 8q24 region that, in conjunction with another variant we recently discovered, accounts for about 11%–13% of prostate cancer cases in individuals of European descent and 31% of cases in African Americans. We made the current discovery through a genome-wide association scan of 1,453 affected Icelandic individuals and 3,064 controls using the Illumina HumanHap300 BeadChip followed by four replication studies. A key step in the discovery was the construction of a 14-SNP haplotype that efficiently tags a relatively uncommon (2%–4%) susceptibility variant in individuals of European descent that happens to be very common (∼42%) in African Americans. The newly identified variant shows a stronger association with affected individuals who have an earlier age at diagnosis.

Major susceptibility locus for prostate cancer on chromosome 1 suggested by a genome-wide search.

Despite its high prevalence, very little is known regarding genetic predisposition to prostate cancer. A genome-wide scan performed in 66 high-risk prostate cancer families has provided evidence of linkage to the long arm of chromosome 1 (1q24-25). Analysis of an additional set of 25 North American and Swedish families with markers in this region resulted in significant evidence of linkage in the combined set of 91 families. The data provide strong evidence of a major prostate cancer susceptibility locus on chromosome 1.

Evidence for a prostate cancer susceptibility locus on the X chromosome.

Over 200,000 new prostate cancer cases are diagnosed in the United States each year, accounting for more than 35% of all cancer cases affecting men, and resulting in 40,000 deaths annually1. Attempts to characterize genes predisposing to prostate cancer have been hampered by a high phenocopy rate, the late age of onset of the disease and, in the absence of distinguishing clinical features, the inability to stratify patients into subgroups relative to suspected genetic locus heterogeneity. We previously performed a genome-wide search for hereditary prostate cancer (HPC) genes, finding evidence of a prostate cancer susceptibility locus on chromosome 1 (termed HPC1; ref. 2). Here we present evidence for the location of a second prostate cancer susceptibility gene, which by heterogeneity estimates accounts for approximately 16% of HPC cases. This HPC locus resides on the X chromosome (Xq27-28), a finding consistent with results of previous population-based studies suggesting an X-linked mode of HPC inheritance. Linkage to Xq27-28 was observed in a combined study population of 360 prostate cancer families collected at four independent sites in North America, Finland and Sweden. A maximum two-point lod score of 4.60 was observed at DXS1113, θ=0.26, in the combined data set. Parametric multipoint and non-parametric analyses provided results consistent with the two-point analysis. evidence for genetic locus heterogeneity was observed, with similar estimates of the proportion of linked families in each separate family collection. Genetic mapping of the locus represents an important initial step in the identification of an X-linked gene implicated in the aetiology of HPC.

BIOCHEMICAL (PROSTATE SPECIFIC ANTIGEN) RECURRENCE PROBABILITY FOLLOWING RADICAL PROSTATECTOMY FOR CLINICALLY LOCALIZED PROSTATE CANCER

PURPOSE We retrospectively reviewed the clinical followup for a large series of men with clinically localized prostate cancer who underwent radical retropubic prostatectomy to identify clinical and/or pathological indicators of biochemical (prostate specific antigen [PSA]) recurrence. We then used those indicators to develop multivariate models for determination of recurrence probability following radical retropubic prostatectomy. MATERIALS AND METHODS From 1982 to 1999, 2,091 consecutive men underwent radical retropubic prostatectomy and pelvic lymphadenectomy for clinically localized adenocarcinoma of the prostate (clinical stage T1c or T2 disease with Gleason score 5 or greater). Actuarial analysis was performed comparing freedom from biochemical recurrence after radical retropubic prostatectomy (PSA 0.2 ng./ml. or greater.) using the Kaplan-Meier method. Event time distributions for the time to recurrence were compared using the log rank statistic or the Cox proportional hazards regression model. The first model was developed using preoperative variables only and the second model using all available variables. Observed and predicted recurrence-free survival curves for different models were compared to select a model for calculation of predicted recurrence-free probabilities and confidence intervals. RESULTS With a median followup of 5.9 years (range 1 to 17) 360 men (17%) had biochemical recurrence. Overall actuarial 5, 10 and 15-year biochemical recurrence-free survival rates were 84%, 72% and 61%, respectively. The relative risk of biochemical recurrence following surgery decreased with time, even after adjusted for other perioperative parameters. Variables identified for the preoperative model were biopsy Gleason score, clinical TNM stage and PSA. Variables identified for the postoperative model were prostatectomy Gleason score, PSA and pathological organ confinement status. Nomograms were generated and corrected for the decreasing relative risk of biochemical recurrence over time. CONCLUSIONS Using 3 preoperative or postoperative parameters, these nomograms can easily be used to determine the 3, 5, 7 and 10-year biochemical recurrence-free survival probabilities among men who undergo radical retropubic prostatectomy for clinically localized prostate cancer in the modern era.

Patient-reported urinary continence and sexual function after anatomic radical prostatectomy

OBJECTIVES After radical prostatectomy, the rates for recovery of urinary continence and sexual function reported by experienced surgeons are much higher than the patient-reported outcomes from other centers. It is uncertain whether this represents differences in surgical technique or in the collection of data. This study was performed to determine patient-reported rates of continence and potency after radical prostatectomy performed by an experienced surgeon at a high-volume referral center for the treatment of localized prostate cancer. METHODS Sixty-four men with localized prostate cancer who were potent preoperatively and who had sexual partners underwent anatomic radical prostatectomy between March 1997 and January 1998. A validated disease-targeted quality-of-life survey that assesses function and bother in two organ systems (urinary and sexual) was administered preoperatively and at 3, 6, 12, and 18 months postoperatively. RESULTS Urinary continence, which was defined as wearing no pads, gradually improved during the first 12 months after surgery, and at 1 2 and 18 months, 93% of the patients were dry. Throughout the study, 93% to 98% of the patients characterized their urinary bother as none or small. Potency, defined as the ability to have unassisted intercourse with or without the use of sildenafil, improved gradually, and by 18 months, 86% of patients were potent and 84% considered sexual bother as none or small. Although one third of patients at 18 months were using sildenafil intermittently, only 2 patients were not able to have intercourse without its use. CONCLUSIONS Patient-reported rates of continence and potency after radical prostatectomy performed by an experienced surgeon are high.