Comparative gene and protein expression in primary cultures of epithelial cells from benign prostatic hyperplasia and prostate cancer

Primary cultures are widely used to investigate the disease-specific biology of prostate cancer and benign prostatic hyperplasia (BPH). To identify genes differentially expressed between epithelial cells cultured from adenocarcinomas versus BPH tissues, we used probe array technology. Gene expression profiles were evaluated on Affymetrix Human Cancer G110 Array Chips containing approximately 1900 cancer-related genes. After defined statistical analysis, genes that were over-expressed in cancer cultures were identified. Protein expression of four of the differentially expressed genes was measured in immunoblots, and the expression of two other genes was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR). While no gene or protein was consistently over-expressed in all cancer versus BPH cell cultures, cytokeratin 16 protein was highly elevated in several of the cancer cultures, suggesting that a hyperproliferative phenotype may be characteristic of prostate cancer cells.

The prostate specific antigen era in the United States is over for prostate cancer: what happened in the last 20 years?

PURPOSE

We assessed how well preoperative serum prostate specific antigen (PSA) reflects the largest cancer in consecutive untreated radical prostatectomies during the last 20 years at Stanford University.

MATERIALS AND METHODS

A total of 1,317 consecutive radical prostatectomies were divided into 4, 5-year periods between August 1983 and July 2003, and examined sequentially in 3 mm step sections by 1 pathologist. The largest cancer and 5 other histological variables in each prostate were measured. Preoperative clinical stages were tabulated for each 5-year period. Means, Pearson correlation coefficients, % change and multiple regression were used to compare selected variables.

RESULTS

Most parameters decreased linearly during the 20 years, including palpable nodules on digital rectal examination from 91% to 17%, mean age from 64 to 59 years, mean serum PSA from 25 to 8 ng/ml, and index (largest) cancer volume from 5.3 to 2.4 cc. Percent Gleason grade 4/5 of the largest cancer averaged 27% to 35% and prostate weight 44 to 53 gm. Contrasting August 1983 to December 1988 with January 1999 to July 2003, 6 histological cancer parameters had statistically significant relationships to serum PSA in the first period. In the last 5 years serum PSA was related only to prostate size.

CONCLUSIONS

Serum PSA was related to prostate cancer 20 years ago. In the last 5 years serum PSA has only been related to benign prostatic hyperplasia. There is an urgent need for serum markers that reflect the size and grade of this ubiquitous cancer.

Frequent HIN-1 Promoter Methylation and Lack of Expression in Multiple Human Tumor Types

HIN-1 (high in normal-1) is a candidate tumor suppressor identified as a gene silenced by methylation in the majority of breast carcinomas. HIN-1 is highly expressed in the mammary gland, trachea, lung, prostate, pancreas, and salivary gland, and in the lung, its expression is primarily restricted to bronchial epithelial cells. In this report, we show that, correlating with the secretory nature of HIN-1, high levels of HIN-1 protein are detected in bronchial lavage, saliva, plasma, and serum. To determine if, similar to breast carcinomas, HIN-1 is also silenced in tumors originating from other organs with high HIN-1 expression, we analyzed its expression and promoter methylation status in lung, prostate, and pancreatic carcinomas. Nearly all prostate and a significant fraction of lung and pancreatic carcinomas showed HIN-1 hypermethylation, and the majority of lung and prostate tumors lacked HIN-1 expression. In lung carcinomas, the degree of HIN-1 methylation differed among tumor subtypes (P = 0.02), with the highest level of HIN-1 methylation observed in squamous cell carcinomas and the lowest in small cell lung cancer. In lung adenocarcinomas, the expression of HIN-1 correlated with cellular differentiation status. Hypermethylation of the HIN-1 promoter was also frequently observed in normal tissue adjacent to tumors but not in normal tissue from noncancer patients, implying that HIN-1 promoter methylation may be a marker of premalignant changes. Thus, silencing of HIN-1 expression and methylation of its promoter occurs in multiple human cancer types, suggesting that elimination of HIN-1 function may contribute to several forms of epithelial tumorigenesis.

Frequent HIN-1 promoter methylation and lack of expression in multiple human tumor types

HIN-1 (high in normal-1) is a candidate tumor suppressor identified as a gene silenced by methylation in the majority of breast carcinomas. HIN-1 is highly expressed in the mammary gland, trachea, lung, prostate, pancreas, and salivary gland, and in the lung, its expression is primarily restricted to bronchial epithelial cells. In this report, we show that, correlating with the secretory nature of HIN-1, high levels of HIN-1 protein are detected in bronchial lavage, saliva, plasma, and serum. To determine if, similar to breast carcinomas, HIN-1 is also silenced in tumors originating from other organs with high HIN-1 expression, we analyzed its expression and promoter methylation status in lung, prostate, and pancreatic carcinomas. Nearly all prostate and a significant fraction of lung and pancreatic carcinomas showed HIN-1 hypermethylation, and the majority of lung and prostate tumors lacked HIN-1 expression. In lung carcinomas, the degree of HIN-1 methylation differed among tumor subtypes (P = 0.02), with the highest level of HIN-1 methylation observed in squamous cell carcinomas and the lowest in small cell lung cancer. In lung adenocarcinomas, the expression of HIN-1 correlated with cellular differentiation status. Hypermethylation of the HIN-1 promoter was also frequently observed in normal tissue adjacent to tumors but not in normal tissue from noncancer patients, implying that HIN-1 promoter methylation may be a marker of premalignant changes. Thus, silencing of HIN-1 expression and methylation of its promoter occurs in multiple human cancer types, suggesting that elimination of HIN-1 function may contribute to several forms of epithelial tumorigenesis.

Genetic profiling of Gleason grade 4/5 prostate cancer: which is the best prostatic control tissue?

PURPOSE

We examined the variation in gene expression profiles of prostate cancer caused by zone specific genes.

MATERIALS AND METHODS

Ten normal central zone, 10 transition zone (benign prostatic hyperplasia) and 6 normal peripheral zone tissues from radical retropubic prostatectomies were compared to each other and to 12 peripheral zone Gleason grade 4/5 cancers. Test chips and HuGeneFL6800 (Affymetrix, Inc., Santa Clara, California) chips were used to assay the transcribed genes. Data were obtained with the Microarray Suite Version 4.0.1 (Affymetrix, Inc.) and analyzed statistically.

RESULTS

Substantially different gene expression profiles were found depending upon which of the 3 zonal tissues were used as a control. All 3 profiles were compared for efficiency (ability to locate genes) and for robustness (the magnitude of difference between the control and the Gleason grade 4/5 tissue). Microscopically normal appearing peripheral zone tissue at the gene level shows many characteristics of Gleason grade 4/5 cancer.

CONCLUSIONS

Gene expression profiles of prostate cancer are affected by the zonal location of the control tissue and the cancer.

Elevated Expression of Inhibin α in Prostate Cancer

PURPOSE

Less than 50% of men who undergo radical prostatectomy for prostate cancer are cured of disease. We evaluate tumor expression of inhibin alpha, a putative tumor suppressor, and the related protein, follistatin, to determine whether expression correlated with failure to be cured by surgery.

MATERIALS AND METHODS

Tissues were selected from an archival collection of 379 prostatectomy specimens from men with followup of at least 5 years after surgery. Since previous studies showed that such men with only Gleason grade 3 cancer had a greater than 95% chance of no biochemical recurrence (increase in serum prostate specific antigen), our investigation was confined to 174 men with 2% or greater grade 4/5 cancer. These men had an intermediate rate of failure, providing an opportunity to analyze the potential contribution of inhibin alpha or follistatin to progression. Intensity of immunohistochemical labeling for inhibin alpha and follistatin in each cancer was compared with that in normal glands within the same tissue section.

RESULTS

The majority of cases showed more intense expression of inhibin alpha in cancer than in normal glands. Those individuals whose cancers had the most elevated expression of inhibin alpha had a higher risk of recurrence, although this association was not statistically significant. Follistatin was expressed equivalently in normal and cancer cells in the majority of cases and did not correlate with recurrence.

CONCLUSIONS

Our finding that inhibin alpha is frequently overexpressed in high grade prostate cancer suggests that the role of inhibin alpha as a tumor suppressor needs to be reevaluated. Furthermore, assessment of inhibin alpha as a serum marker of prostate cancer, as used to diagnose ovarian cancer, may be warranted.

Volume indexes of total, free, and complexed prostate-specific antigen enhance prediction of extraprostatic disease extension in men with nonpalpable prostate cancer

OBJECTIVES

To analyze the ability of volume-adjusted total, complexed, and free prostate-specific antigen (PSA) to predict organ-confined cancer at radical prostatectomy in patients with nonpalpable disease.

METHODS

Collected sera were assayed for total PSA (tPSA), complexed PSA (cPSA), and free PSA (fPSA) in 78 men who underwent radical prostatectomy with nonpalpable prostate cancer. The pathologic results (organ-confined versus extraprostatic extension [EPE]), tPSA, cPSA, fPSA/tPSA ratio, cPSA/tPSA ratio, fPSA/cPSA ratio, tPSA density (tPSAD), cPSA density (cPSAD), and fPSA density (fPSAD) were compared by the Mann-Whitney U test and receiver operating characteristic curves.

RESULTS

Fifteen men (19.2%) had pathologic EPE. After stratifying the patients on the basis of the Beckman tPSA, the cPSAD, tPSAD, and fPSAD were significant predictors of EPE when comparing their respective medians in individuals with tPSA greater than 4.0 ng/mL. Statistically significant differences were noted between patients with and without EPE for tPSAD (P = 0.0015), cPSAD (P = 0.0018), and fPSAD (P = 0.0022), but not for the fPSA/tPSA, cPSA/tPSA, and fPSA/cPSA ratios. The area under the receiver operating characteristic curve was similar for tPSA (0.539) and cPSA (0.542), as it was for tPSAD (0.708), cPSAD (0.700), and fPSAD (0.731). The specificity and diagnostic accuracy of tPSAD, cPSAD, and fPSAD were significantly greater than those of tPSA and cPSA (specificity P <0.001; diagnostic accuracy P <0.05).

CONCLUSIONS

In men with nonpalpable prostate cancer, the density parameters of tPSA, cPSA, and fPSA performed equivalently and appeared to enhance the predictability of EPE.

Prognostic factors for multifocal prostate cancer in radical prostatectomy specimens: lack of significance of secondary cancers

PURPOSE

We evaluated secondary cancers in the prostate in relation to predictions of pathological stage and prognosis.

MATERIALS AND METHODS

A total of 222 men with T1c (impalpable) prostate cancer and 6 or more systematic needle biopsies were matched with radical prostatectomy and classified into 3 groups according to tumor multifocality and secondary cancer volumes, including a single tumor in 54 (24%), an index (largest) tumor with secondary cancers less than 0.5 cc in 86 (39%) and an index tumor with secondary cancers greater than 0.5 cc in 82 (37%). Logistic analysis was used to predict adverse histological features. Cox proportional hazards analysis was used to predict prostate specific antigen (PSA) failure after radical prostatectomy.

RESULTS

There were no differences among the 3 groups with respect to preoperative serum PSA, number of positive cores, percent Gleason grade 4/5 cancer in the needle biopsy or histological features in radical prostatectomy specimens. On logistic analysis neither serum PSA nor pre-radical biopsy predicted adverse histological features in radical prostatectomy specimens. The Cox regression model showed that primary predictors of PSA failure were percent Gleason grade 4/5 cancer in the biopsy (HR = 2.6, p = 0.015) and prostatectomy (HR = 2.4, p = 0.04) specimens, and the number of positive cores (HR = 2.5, p = 0.04). When comparing PSA failure rates among the 3 groups, the multifocal group with smaller secondary cancers showed a better prognosis than the single tumor group (p = 0.019).

CONCLUSIONS

Secondary cancers in multifocal prostate tumors did not adversely influence the results of preoperative clinical parameters, including PSA and needle biopsy findings. Percent Gleason grade 4/5 cancer in needle biopsies and prostatectomy specimens is the most powerful predictor of biochemical failure in men with stage T1c prostate cancer after radical prostatectomy.

Hepsin and maspin are inversely expressed in laser capture microdissectioned prostate cancer

PURPOSE

Recent studies have shown that hepsin, a serine protease, is over expressed in prostate cancers, implicating hepsin activity in tumor invasion. Using microarray technology we have previously identified 22 genes that were up-regulated in high grade prostate cancers compared with benign prostatic hyperplasia. Of them hepsin was the most differentially over expressed. In the current report we compare hepsin to maspin (BD Transduction Laboratories, San Diego, California), a serine protease inhibitor (serpin), to measure the balance between levels of serine proteases and serpins, which are considered to be a critical determinant of net proteolytic activity.

MATERIALS AND METHODS

We combined the technique of laser capture microdissection with gene expression monitoring by micro-array analysis to investigate the gene expression profiles of prostate cells of different histological types. We also studied maspin immunohistochemically.

RESULTS

We observed that hepsin as well as 7 of 22 previously reported up-regulated genes demonstrated a pattern of increasing expression with increasing malignant phenotype. In contrast, the expression of maspin (a serpin) decreased with increasing malignancy of prostate cancers. Using immunohistochemistry we observed that maspin protein is expressed strongly in benign prostatic tissues and slightly in grade 3 prostate cancers, and is absent in grade 4/5 cancers.

CONCLUSIONS

We conclude that the increased ratio of hepsin-to-maspin may have an important role in prostate cancer progression and invasion.

Vitamin D receptor start codon polymorphism (FokI) and prostate cancer progression

Vitamin D plays an important role in cell growth and differentiation and is proposed to protect against cancer initiation and/or progression. The vitamin D receptor (VDR) has a thymine/cytosine (T/C) polymorphism located in the first of two potential start (ATG) codons that can be detected by a RFLP using the endonuclease FokI. The C variant, which lacks the first ATG, results in a shorter VDR and is referred to as the F allele. The T variant (f allele) initiates at the first ATG. We examined the association of the VDR FokI genotype with histopathological characteristics and prognosis of prostate cancer among 191 mostly Caucasian subjects who had undergone radical prostatectomy between 1984 and 1992. The frequencies of the FF, Ff, and ff genotypes were 41%, 38%, and 21%, respectively. Subjects with the ff genotype had a lower mean percentage of Gleason grade 4/5 cancer (30.3%) than subjects with the FF or Ff genotypes (42.8% and 43.8%, respectively; P = 0.015 by t test for ff versus FF + Ff). The data suggest that the presence of an F allele increased the risk of being diagnosed with more aggressive cancer because higher percentage of Gleason grade 4/5 is associated with worse prognosis. The age-adjusted risk of prostate-specific antigen failure was lower for the ff genotype than for the FF genotype by Cox proportional hazards analysis but did not achieve statistical significance (hazard ratio = 0.76; 95% confidence interval, 0.44-1.32). This risk reduction disappeared after further adjustment for percentage of Gleason grade 4/5, cancer volume, and preoperative serum prostate-specific antigen level (hazard ratio = 1.03; 95% confidence interval, 0.58-1.85). In conclusion, the ff genotype was associated with less aggressive histopathological findings than Ff or FF genotypes. Additional studies with a larger sample size and investigation of the functional significance of the FokI polymorphism in prostate cancer cells are warranted.

Complexed prostate-specific antigen as a staging tool: results based on a multicenter prospective evaluation of complexed prostate-specific antigen in cancer diagnosis

Within a 7-site prospective evaluation of the Bayer complexed prostate-specific antigen PSA (cPSA) assay, we analyzed the ability of cPSA to predict extracapsular extension (ECE) before radical prostatectomy. Included in this analysis were 152 men diagnosed with cancer, who subsequently underwent radical prostatectomy. Sera were tested with the Bayer total PSA (tPSA) and cPSA assays, and the Beckman free PSA (fPSA) and tPSA assays. Treating surgical pathology result as a binary variable (organ confined vs ECE), mean tPSA, cPSA, fPSA/tPSA (f/tPSA) ratios, tPSA density (tPSAD), and cPSA density (cPSAD) were compared by receiver operating characteristic (ROC) curves and univariate analysis. In all, 28 men (18.4%) had pathologically identified ECE. Between those with and without ECE, significant differences were observed for tPSA (P = 0.0127), cPSA (P = 0.0120), tPSAD (P = 0.0001), and cPSAD (P = 0.0002), but not f/tPSA (P = 0.3774) or c/tPSA (P = 0.2882). All tested parameters except f/tPSA (P = 0.376) and c/tPSA (P = 0.288) predicted ECE (P <0.05) by logistic regression. The ROC area under the curve (AUC) was identical for tPSA and cPSA (0.621) and for tPSAD (0.692) and cPSAD (0.691). Kendall-tau correlation coefficients also demonstrated the strongest correlation with ECE for cPSAD and tPSAD. Either alone or as a tPSAD calculation, cPSA carries equivalent staging ability to tPSA. The use of f/tPSA appears to be less effective in staging than either cPSA or tPSA, whereas the use of either cPSAD or tPSAD provides maximal staging accuracy. Therefore, cPSA could be applied as an accurate predictor of ECE independently or in a nomogram along with other predictive variables.

Can volume measurement of the prostate enhance the performance of complexed prostate-specific antigen?

We assessed whether volume-based complexed prostate-specific antigen (cPSA) indices could enhance prostate cancer detection in men with serum total PSA (tPSA) between 2.5 and 10.0 ng/mL. Between December 1998 and April 2000, cPSA assay was measured in 480 men who underwent transrectal ultrasound-guided prostate biopsies at 7 institutions. We compared the usefulness of cPSA and its indices with the ratio of free PSA (fPSA) to tPSA (percent fPSA) for early detection of prostate cancer. Overall, 168 men (35%) had cancer. In the 341 men with tPSA between 4.01 and 10.0 ng/mL at approximately 90% sensitivity and areas under the receiver operating characteristics curve, the performances of volume-based parameters were significantly better (P <0.05) than those of tPSA and cPSA. In the 139 men with tPSA between 2.5 and 4.0 ng/mL, at 90% sensitivity, the specificity of the ratio of cPSA to tPSA (percent cPSA) was best, followed by cPSA density (cPSAD). In the 101 men with the history of a previous prostate biopsy, at approximately 90% sensitivity, the specificity of cPSAD was significantly better than those of tPSA and percent fPSA (P <0.05). In the 371 men with a total prostate volume of >or=30 cm(3) at approximately 90% sensitivity, the specificity of the cPSAD was significantly better than that of tPSA, percent fPSA, and cPSA (P <0.05). In the 109 men with a total prostate volume of <30 cm(3), at 90% sensitivity the specificity of cPSA and cPSAD was better than that of percent fPSA. In conclusion, volume-based cPSA can modestly enhance the performance of cPSA.

Complexed prostate-specific antigen for early detection of prostate cancer in men with serum prostate-specific antigen levels of 2 to 4 nanograms per milliliter

Complexed PSA (cPSA) has been shown to improve specificity in the detection of prostate cancer over that of total PSA (tPSA) testing in men with tPSA values greater than the cutoff value of 4.0 ng/mL. However, recent studies have reported a 25% incidence of prostate cancer in men with tPSA values in the 2.5- to 4.0-ng/mL range. We performed a multicenter study of cPSA in a population of men who underwent prostate biopsies because of elevated PSA levels or abnormal digital rectal examination (DRE). As part of this study, we sought to assess the clinical value of cPSA in comparison to tPSA, the free/tPSA ratio (f/tPSA) and the complexed/tPSA ratio (c/tPSA) in early detection of prostate cancer in men with tPSA values in the range of 2 to 4 ng/mL. The study was performed at 7 centers. Sera were drawn from men who underwent biopsy procedures consisting of >10 prostate tissue cores. Receiver operating characteristic (ROC) analysis was performed from the results of patients with tPSA values in the range of 2 to 4 ng/mL, including men with suspicious as well as unremarkable findings on DRE. Sera were collected and tested with the Bayer tPSA and cPSA assay and the Beckman free PSA and tPSA assays. ROC analysis was performed for all samples in the 2- to 4-ng/mL PSA range. At biopsy, 158 men had no evidence of malignancy and 57 (26.5%) were diagnosed with prostate cancer. ROC analysis indicated that the area under the curve (AUC) for cPSA was 0.64, which was statistically significantly greater than that achieved for tPSA (AUC, 0.57; P <0.0001). The AUC for f/tPSA and c/tPSA were 0.60 and 0.63, respectively, which was not statistically significantly different from that of tPSA or cPSA (P >or=0.252). A cutpoint of 2.5 ng/mL for tPSA and 2.1 ng/mL for cPSA provided a specificity of 20.3% and 34.2%, respectively, and sensitivity levels of 86%. Using cutpoints of 25% for f/tPSA and 74% for c/tPSA provided a specificity of 11.0% and 21.5%, respectively, and sensitivity levels of 97%. In all, >92% of the cancers treated with radical prostatectomy were organ confined, and the histologic grading of the tumors ranged from moderately to poorly differentiated with Gleason scores from 5 to 9. These data confirm that there is a high incidence of clinically significant prostate cancer in men with tPSA levels <4.0 ng/mL. Measurement of cPSA proved useful in stratifying men with tPSA values in the 2- to 4-ng/mL range into high- and low-risk groups for prostate cancer. The use of cPSA as a single test was found to enhance detection of prostate cancer over that of testing with tPSA and PSA ratios in men with tPSA values in the range of 2 to 4 ng/mL.

Polymorphisms in the androgen receptor and type II 5 alpha-reductase genes and prostate cancer prognosis

BACKGROUND

Cytosine-adenine-guanine repeat length of the androgen receptor gene and the A49T and V89L polymorphisms of the 5 alpha-reductase (SRD5A2) gene have been associated with prostate cancer.

METHODS

We investigated the relationship of the three genetic polymorphisms to tumor grade among 211 men who had undergone radical prostatectomy. Subjects had prostate cancer <3 cm(3) with a percentage of cancer represented by Gleason grade 4 or 5 (% Gleason grade 4/5) of either > or = 20% or < or = 5%. We also examined the association between those genetic markers and prostate specific antigen (PSA) failure among 112 subjects with > or = 20% Gleason grade 4/5.

RESULTS

In cross-sectional analysis, none of the polymorphisms was a significant predictor of % Gleason grade 4/5. In longitudinal analysis, the LL genotype at the V89L site was associated with statistically significant four- to sixfold increase in PSA failure risk after adjustment for clinicopathologic variables.

CONCLUSIONS

We observed poorer prognosis among men with the LL genotype at codon 89 of the SRD5A2 gene. Lack of consistency between studies must be resolved before clinical utility of this marker is established.

Morphologic and clinical significance of multifocal prostate cancers in radical prostatectomy specimens

OBJECTIVES

To examine the histologic details of small, independent cancers compared with the largest (index) tumor and their impact on prostate-specific antigen (PSA) failure in 486 men treated only by radical retropubic prostatectomy (RRP).

METHODS

The tumor volume and percentage of Gleason grade 4/5 carcinoma were recorded in 3-mm step sections. Univariate statistics were calculated for the largest, total (largest plus smaller cancers), and smaller tumor volumes, number of independent foci, patient age, and follow-up. Cox hazards model determined the relative importance of all variables in relation to failure.

RESULTS

The mean index tumor volume was 4.16 cm3; smaller cancer volumes averaged 0.63 cm3. The index cancer volume was gaussian in distribution; smaller tumor volumes were highly skewed toward 234 carcinomas less than 0.5 cm3. Only 17% of all cases had one carcinoma. The Cox model showed similar hazard rates of PSA failure for both the index (3.43) and the total cancer (3.74) volumes. The hazard rate for the presence of any Gleason grade 4/5 carcinoma was 6.5. As the numbers of smaller tumors increased, the PSA cure rates improved.

CONCLUSIONS

The PSA failure rates (hazard ratios) were similar for the index tumor and the index plus smaller cancers, confirming that predictive estimates only need to measure the largest carcinoma. The greater the number of lesser cancers, the smaller the size of the index cancer. The extraordinary multiplicity of these small independent cancers in 3-mm step sections may explain the poor correlation between six or more biopsies with the index cancer in radical prostatectomy specimens.

Preoperative serum prostate specific antigen levels between 2 and 22 ng./ml. correlate poorly with post-radical prostatectomy cancer morphology: prostate specific antigen cure rates appear constant between 2 and 9 ng./ml

PURPOSE

Serum prostate specific antigen (PSA) is widely used as a guide to initiate prostatic biopsies and to follow men older than 50 years old with and without prostate cancer. However, benign prostatic hyperplasia (BPH) is a common cause of serum PSA values between 2 and 10 ng./ml. A better understanding of the relationships among serum PSA, prostate cancer and BPH is important.

MATERIALS AND METHODS

A total of 875 men underwent radical prostatectomy at our institution between December 1984 and January 1997. Of these men 784 had a serum PSA of 2 to 22 ng./ml., including 579 with the largest cancer located in the peripheral zone of the prostate. Of the 579 men 406 had serum PSA followups for greater than 3 years after radical prostatectomy. We examined Pearson correlations (R2) between preoperative serum PSA, and the volume of Gleason grades 4/5 and 3 to 1 cancer in 784 men, separating peripheral zone from transition zone cancers. We used broken line regression with break points of 7 and 9 ng./ml. preoperative PSA to summarize the relationship of each PSA doubling to 5 different morphological variables in 579 men with peripheral zone cancer. A 9 ng./ml. break point was used for prostate weight. Trend summaries with a local regression line for the relationships between 6 morphological variables and PSA were superimposed on full scatterplots of the 579 men with PSA less than 22 ng./ml. Cox proportional hazard models were used to examine 5-year PSA failure-free probabilities based on 406 men with minimal PSA followups greater than 3 years at break points of 7 to 9 ng./ml. PSA.

RESULTS

Pearson correlation between cancer volume and preoperative serum PSA in 875 men was weak (r2 = 0.27) and driven by large cancers with serum PSA greater than 22 ng./ml. For peripheral zone cancer the overall R2 x 100 for 641 men with low and high grade cancer was 10% and only 3% for low grade cancer, that is almost no PSA produced by these peripheral zone cancers enters the serum. All morphological variables changed at rates of doubtful medical significance below a PSA of 7 to 9 ng./ml. but at rates that were significantly worse above 9 ng./ml. R2 for these relationships was never greater than 15%. Large individual morphological variations at all levels of PSA emphasize the serious limitation of PSA as a predictor of prostate cancer morphology. Below 9 ng./ml. prostate weight increased by 21% for each doubling of PSA but above 9 ng./ml. the increase was only 4.8%.

CONCLUSIONS

Preoperative serum PSA has a clinically useless relationship with cancer volume and grade in radical prostatectomy specimens, and a limited relationship with PSA cure rates at preoperative serum PSA levels of 2 to 9 ng./ml. Trend summaries for prostate weight on broken line regression showed that below 9 ng./ml. BPH is a strong contender for the cause of PSA elevation, constituting the primary cause of the over diagnosis of prostate cancer.

Molecular genetic profiling of Gleason grade 4/5 prostate cancers compared to benign prostatic hyperplasia

PURPOSE

Because Gleason grade 4/5 cancer is the primary cause of failure to cure prostate cancer, we examined the molecular profiles of this high grade cancer in search of potentially new therapeutic interventions as well as better serum markers than prostate specific antigen.

MATERIALS AND METHODS

We compared the gene expressions in fresh frozen tissues from 9 men with Gleason grade 4/5 cancer to 8 men with benign prostatic hyperplasia (BPH) treated with radical retropubic prostatectomy. Labeled complementary RNA from each of the 17 tissues was applied to HuGeneFL probe arrays representing approximately 6,800 genes (Affymetrix, Inc., Santa Clara, California). After removing all genes undetectable in BPH and grade 4/5 cancers, and transforming the data into a parametric distribution, we chose only those up and down-regulated genes with a p difference in fluorescence between grade 4/5 cancer and BPH of p <0.0005. This value reduced the data set to 40 up-regulated and 111 down-regulated genes. We then eliminated all genes that were not expressed in all 8 BPH and 9 grade 4/5 tissues, which produced a final set of 86 genes, of which 22 were up-regulated and 64 were down-regulated.

RESULTS

Cluster analysis cleanly separated men with grade 4/5 cancers from those with BPH. Only 17 of the 86 candidate genes (20%) were known to be prostate cancer related and 42 (49%) were related to other cancers. The most up-regulated gene is Hepsin, a trypsin-like serine protease with its enzyme catalytic domain oriented extracellularly. Prostate specific membrane antigen is the second most up-regulated gene (all other reports on prostate specific membrane antigen have been at the protein level). The genes for prostate specific antigen (hK3) and human glandular kallikrein2 (hK2) showed equivalent expression levels 10 times the average of other genes. Complete lists of all 22 up-regulated genes and 64 down-regulated genes, together with their locus on the chromosome, are presented in rank order.

CONCLUSIONS

We characterize for the first time 64 down-regulated and 22 up-regulated genes in Gleason grade 4/5 cancer, using the gene profile from BPH as control tissue. A number of interesting new genes, previously undescribed in prostate cancer, are presented as possibilities for further study.

Genetic polymorphisms in the androgen receptor and type II 5 alpha-reductase genes in prostate enlargement

PURPOSE

We examined the association of androgen receptor gene cytosine-adenine-guanine (CAG) repeat length and the 2 single nucleotide polymorphisms A49T and V89L in the type II 5 alpha-reductase gene with prostate enlargement measured as the weight of the surgically removed prostate.

MATERIALS AND METHODS

A total of 68 men with a prostate weighing 80 gm. or greater were compared with 197 controls with a prostate weighing less than 80 gm. These men had undergone radical prostatectomy between 1992 and 1996. DNA was extracted from archival prostate tissue uninvolved with cancer and genotyped for 3 polymorphic markers. The effects of genetic variants and clinicopathological variables on prostate enlargement risk were estimated by logistic regression.

RESULTS

The age adjusted odds ratio estimate of prostate enlargement risk in men with 23 or greater versus 20 or fewer CAG repeats was 0.41 (95% confidence interval 0.19 to 0.89). This risk reduction was consistently found when an alternative prostate enlargement definition and subject restriction were used. No consistent association with prostate enlargement risk was observed for A49T or V89L polymorphisms.

CONCLUSIONS

Our finding further supports the hypothesis that the shorter CAG repeat length of the androgen receptor gene is related to prostate enlargement.

Perspectives on prostate cancer diagnosis and treatment: a roundtable

This roundtable was held September 30, 2000. It addressed, first of all, the accuracy and proper interpretation of the available prostate-specific antigen assays. Dr. Brawer presented data to demonstrate the specificity of the complexed prostate-specific antigen assay. Dr. Stamey counterpoised evidence that pretreatment prostate-specific antigen levels less than 9 ng/mL are attributable to benign prostatic hyperplasia and therefore are of little value as an indicator of when to initiate treatment for prostate cancer. The other roundtable participants offered reviews and new data regarding hormonal therapy as primary or adjunctive treatment of prostate cancer. Dr. Fowler presented a large retrospective series of men with locally advanced prostate cancer for whom androgen ablation was the primary therapy. Dr. Droller discussed his center's experience in integrating hormonal therapy with brachytherapy. Finally, Dr. Messing reviewed and critiqued the evidence that the combination of hormonal and radiation therapy improves survival.

Relationship between systematic biopsies and histological features of 222 radical prostatectomy specimens: lack of prediction of tumor significance for men with nonpalpable prostate cancer

PURPOSE

Because of the recent increase in nonpalpable prostate cancer (clinical stage T1c) in men, preoperative needle biopsy findings have had an important role for treatment decisions. We examine the correlation among histopathological features of 6 systematic biopsies and radical prostatectomy specimens in which 1 investigator reviewed all histological sections.

MATERIALS AND METHODS

We studied a total of 450 men with clinical stage T1c prostate cancer from whom needle biopsies were matched with radical prostatectomy specimens, and selected 222 patient biopsies that were obtained from 6 or more separate regions of the prostate. The pretreatment parameters of serum prostate specific antigen (PSA), PSA density, number of positive needle biopsies, distribution of positive cores, linear cancer length, and percent Gleason grade 4/5 on the biopsy were determined and compared with histopathological features of prostate cancer in the radical prostatectomy specimens. All biopsies and radical prostatectomies were evaluated morphologically at the department of urology.

RESULTS

Of the 222 men the largest cancer was clinically insignificant in 23 (10%), as measured by a cancer volume of less than 0.5 cc. Cancer volume in the prostatectomy specimen was significantly related to all parameters in the biopsy, with the surprising exception of cancer distribution in the positive biopsies. However, all of these correlations with cancer volume were weak, with Pearson's correlation squared (R(2)) multiplied by 100 less than 10%. Unfortunately, tumor grade on the biopsy agreed with the prostatectomy specimen in only 81 of 222 (36%) cases. Grade assessment with needle biopsy underestimated the tumor grade in 102 (46%) cases and overestimated it in 39 (18%). No single parameter in the biopsy was a predictor of tumor significance, as measured by a cancer volume of greater than 0.5 cc. However, the best model to predict a tumor less than 0.5 cc in volume was the combination of a single positive core with cancer length less than 3 mm. that contained no Gleason grade 4/5. The use of PSA or PSA density in combination with needle biopsy findings did not enhance prediction of tumor significance.

CONCLUSIONS

These results indicate a weak and disappointing correlation among all pathological features of 6 systematic biopsies and radical prostatectomy specimens. The combination of 1 positive core with cancer length less than 3 mm. that contains no Gleason grade 4/5 is probably the best predictor of prostate cancer less than 0.5 cc in men with nonpalpable tumors, a cancer volume that occurred in only 10% of the 222 (23) men.

Preoperative serum prostate-specific antigen (PSA) below 10 microg/l predicts neither the presence of prostate cancer nor the rate of postoperative PSA failure

Recent information on the relationship of serum prostate-specific antigen (PSA) to prostate cancer and new reports on death rates in men warrant a reassessment of how we diagnose and treat prostate cancer. We now know for the first time that the annual death rate from prostate cancer in men > or =65 years of age is only 226 per 100 000 men. At least 40 000 of 100 000 men over age 65 (40%) have invasive prostate cancer as judged by examination of prostates in 3- to 4-mm step-sections. Thus, only 1 of every 177 men 65 years of age or older (226 in 40 000) with invasive prostate cancer dies annually from his cancer. Serum PSA between 2 and 10 microg/L is used almost universally as an indication to biopsy the prostate. When 10-20 biopsies are commonly taken, it is not surprising that approximately 40% of men are biopsy-positive for prostate cancer. Despite this reliance on serum PSA as an indication for biopsy, data at Stanford show no clinically useful relationship between preoperative serum PSA (in the range 2-10 mg/L) and the volume of Gleason grade 4/5 cancer or the volume of Gleason grades 3, 2, and 1 cancer, nor can we show any useful relationship of such preoperative PSA concentrations (2-10 microg/L) to biochemical PSA failure rates after radical prostatectomy. We urgently need a better serum marker for prostate cancer. Because PSA biochemical failure rates after radical prostatectomy are directly proportional to the amount of Gleason grade 4/5 cancer in the prostate, a serum marker of Gleason grade 4/5 carcinoma could be ideal.

Preoperative Serum Prostate-specific Antigen (PSA) Below 10 μg/L Predicts Neither the Presence of Prostate Cancer Nor the Rate of Postoperative PSA Failure

Recent information on the relationship of serum prostate-specific antigen (PSA) to prostate cancer and new reports on death rates in men warrant a reassessment of how we diagnose and treat prostate cancer. We now know for the first time that the annual death rate from prostate cancer in men ≥65 years of age is only 226 per 100 000 men. At least 40 000 of 100 000 men over age 65 (40%) have invasive prostate cancer as judged by examination of prostates in 3- to 4-mm step-sections. Thus, only 1 of every 177 men 65 years of age or older (226 in 40 000) with invasive prostate cancer dies annually from his cancer. Serum PSA between 2 and 10 μg/L is used almost universally as an indication to biopsy the prostate. When 10–20 biopsies are commonly taken, it is not surprising that ∼40% of men are biopsy-positive for prostate cancer. Despite this reliance on serum PSA as an indication for biopsy, data at Stanford show no clinically useful relationship between preoperative serum PSA (in the range 2–10 mg/L) and the volume of Gleason grade 4/5 cancer or the volume of Gleason grades 3, 2, and 1 cancer, nor can we show any useful relationship of such preoperative PSA concentrations (2–10 μg/L) to biochemical PSA failure rates after radical prostatectomy. We urgently need a better serum marker for prostate cancer. Because PSA biochemical failure rates after radical prostatectomy are directly proportional to the amount of Gleason grade 4/5 cancer in the prostate, a serum marker of Gleason grade 4/5 carcinoma could be ideal.

Preoperative serum prostate specific antigen does not reflect biochemical failure rates after radical prostatectomy in men with large volume cancers

PURPOSE

We compared pathological findings with prostate specific antigen (PSA) failure rates following radical prostatectomy for large volume cancers (6 cc or greater).

MATERIALS AND METHODS

A total of 191 men whose radical prostatectomy specimen had a cancer volume of 6 cc or greater were followed for a mean of 3.6 years (range 0.3 to 11.1) and 112 (58.6%) had PSA failure (PSA 0.07 ng./ml. or greater and increasing). Percent Gleason grade 4/5 (the Stanford modified Gleason scale), cancer volume, seminal vesicle invasion, regional lymph nodes, capsular penetration, positive surgical margin, location of the largest cancer in the peripheral or transition zone, prostate weight, patient age, preoperative PSA and clinical stage were analyzed using univariate and multivariate Cox proportional hazards analyses.

RESULTS

In univariate regression analysis percent Gleason grade 4/5, lymph node involvement, cancer volume, cancer location in the peripheral zone, capsular penetration and positive surgical margins were significant predictors of biochemical failure. Seminal vesicle invasion, preoperative serum PSA, patient age, prostate weight and clinical stage were not statistically significant. Forward stepwise, multivariate analysis showed that percent Gleason grade 4/5 (p <0.0001, relative risk ratio 2.498), cancer location in the peripheral zone (p = 0.0097, 1.887), cancer volume (p = 0.0157, 1.691) and lymph node involvement (p = 0.0317, 1. 666) were the only independent predictors of biochemical failure. When 52 men with organ confined, large volume prostate cancer were analyzed separately, univariate and multivariate analyses showed that only cancer location in the peripheral zone (p = 0.0021, relative risk ratio 13.473) and percent Gleason grade 4/5 (p = 0. 0449, 4.111) were independent predictors of failure.

CONCLUSIONS

Percent Gleason grade 4/5, cancer location in the peripheral zone, cancer volume and lymph node involvement have prognostic value in large volume prostate cancer. Cancer location in the peripheral zone and percent Gleason grade 4/5 are the most powerful predictors of biochemical failure in men whose cancer is 6 cc or greater and contained in the prostatic capsule. Preoperative serum PSA is not helpful in distinguishing biochemical failure rates in these large volume cancers whether they are organ confined or not.

Assessment of morphometric measurements of prostate carcinoma volume

BACKGROUND

The authors have shown that the primary determinants of prostate carcinoma progression are tumor volume and the percent of the tumor comprised of Gleason Grade 4/5 cells. In the current study the authors evaluated six different techniques for the morphometric measurements of prostate carcinoma volume.

METHODS

A computer-assisted image analysis (NIH Image, developed and maintained by the National Institutes of Health, Bethesda, MD) was used to analyze all 108 step-sectioned prostate specimens obtained between January 1 and December 31, 1997. The authors used the Stanford technique of 0.3-cm step-sections, measuring the volume of the tumor at both 0.3-cm and 0.6-cm intervals. The other 4 methods included the authors' previous method based on an earlier image program, the ellipsoidal method (pi / 6 x width x height x length), an estimation of the square area of the largest tumor, and the maximum tumor dimension (MTD).

RESULTS

The authors first checked the accuracy of NIH Image analysis by measuring 24 circles of widely different sizes. The mean coefficient of variation was 1.7% and the correlation between the mean circle areas measured by the NIH Image software and true circle area essentially was perfect (correlation coefficient [r] = 1 and r(2) = 0.999; P < 0.0001). In comparison with the authors' original computer image program using 0.3-cm step-sections measured by a different observer, r(2) with the NIH Image analysis was 0.93. Using NIH Image only, the 0.6-cm step-section method missed measurable cancers in 16.7% of 108 radical prostatectomies in comparison with the 0.3-cm step-method. The mean tumor volume with the 0.6-cm section method (P < 0.0001) and the ellipsoidal method (P < 0.05) were significantly higher than with the 0.3-cm section method. r(2) from linear regressions using the 0.3-cm step section method as the standard versus the ellipsoidal method was 0.594, and was 0.89 versus the 0.6-cm step-section method, 0.652 versus the square area estimation, and 0. 527 versus the MTD method.

CONCLUSIONS

The results of the current study support NIH Image as a powerful software program for the morphometric measurement of prostate carcinoma volume. Pathologic processing with 0.3-cm section slices was found to be more accurate for tumor volume than the 0.6-cm section slices. The ellipsoidal method, the square area of the largest tumor, and the MTD all were found to be inferior to computer-assisted image analysis measurements. In certain clinical situations in which only estimates of tumor volume are required, the square area of the largest tumor appears to be the best choice (r(2) 0.652).

Modified extrafascial radical retropubic prostatectomy technique decreases frequency of positive surgical margins in T2 cancers <2 cm(3)

OBJECTIVES

In an effort to decrease the frequency of postoperative positive surgical margins (+SM), a modified extrafascial radical prostatectomy technique was developed and evaluated.

METHODS

402 consecutive radical prostatectomy specimens removed for clinical stage T2 cancers from 1987 to 1994 were histologically examined prospectively for tumor volume, extraprostatic extension and +SM. Surgical technique modification was introduced in 1990. We compared the histologic status and biological outcome of the prostatectomy cases in 1987-1989 (n = 166) to those treated from 1990 to 1994 (n = 236).

RESULTS

The two series were comparable in (1) clinical stage and preoperative (PSA, (2) tumor volume, grade and location, and (3) capsular penetration, seminal vesicle and lymph node status. +SM fell from 32 to 25% overall, but for 146 (36%) prostates with a tumor volume <2 cm(3), +SM fell from 21 to 6% which was statistically significant. Outcome measured by biological progression showed a decrease from 33% for +SM to 13% for -SM for cases with a tumor volume <2 cm(3). For cancer volumes >2 cm(3), the incidence of +SM did not vary significantly. We describe the anatomic details necessary for exposure of periprostatic fascias and extrafascial dissection at (1) the prostatourethral junction which ensures wide excision of the anterior and apical aspect of the prostate, (2) the posterior and apical area (development of the prerectal space), lateral and posterior areas at the base of the prostate which ensures wide excision of the rectoprostatic fascia (Denonvilliers's fascia) and lateral prostatic fascia.

CONCLUSIONS

Differences in surgical technique probably accounted for the significant decrease in +SM for those T2 cancers with volumes < or =2 cm(3) which represents 36% of the T2 cancers in our series. Recent screening with PSA (T1c cancers) increases the incidence of these cancers < or =2cm(3). This modified uni- or bilateral anatomic extrafascial prostatectomy with improved +SM and biological progression rates for T2 cases should be evaluated for T1c cases.

An analysis of 148 consecutive transition zone cancers: clinical and histological characteristics

PURPOSE

To improve our understanding of transition zone cancer in terms of the diagnosis and biological behavior we examined all morphological and clinical variables in 148 consecutive cases of untreated transition zone cancer after radical retropubic prostatectomy. We matched 79 cases by total cancer volume to 79 of pure peripheral zone cancer with no secondary tumors.

MATERIALS AND METHODS

Using the Stanford technique of prospective 3 mm. step sections we identified 175 of 996 men (18%) with untreated transition zone cancer after radical retropubic prostatectomy who had the largest cancer volume in the transition zone. We excluded 27 patients from study due to previous transurethral prostatic resection or incomplete data. Preoperative serum prostate specific antigen (PSA) was determined by the Tosoh AIA-600 PSA assay. Postoperatively a PSA of 0.07 ng./ml. and increasing represented biochemical failure when the assay was done in the ultrasensitive mode.

RESULTS

Of the 148 cases of transition zone cancer 80% had organ confined disease, 70% stage T1c impalpable disease, 63% a positive initial prostatic biopsy, 62% unilateral cancer in the transition zone, 52% a secondary tumor only in the peripheral zone, 61% serum PSA 10 ng./ml. or greater preoperatively, 36% cancer volume greater than 6 cc and 24% at least 50% Gleason grade 4/5 cancer. Only 20% of the tumors were located in the proximal third of the transition zone near the bladder. The number of secondary tumors in the transition zone ranged from 1 to 12 (median 3) and secondary tumor volume ranged from 0.01 to 4.8 cc (median 0.6). Mean distance plus or minus standard deviation from the posterior prostatic capsule to the posterior border of the transition zone cancer was 12. 0 +/- 7.6 mm. (median 12.3). While only 15% of patients had capsular penetration, 29% had anterior positive surgical margins, 2.7% seminal vesicle invasion and 3.4% lymph node metastasis. When 79 transition zone cancers were matched by volume with 79 peripheral zone cancers, there were no differences in percent Gleason grade 4/5, serum PSA or prostate weight, although differences in clinical stage T1c to T2c and organ confined cancer were highly significant (p <0.0001). Kaplan-Meier curves showed that at 5 years of followup 49.2% of the men with peripheral zone cancer had undetectable PSA compared with 71.5% of those with transition zone cancer (log rank test p = 0.0002).

CONCLUSIONS

Our report should make it easier to diagnose transition zone cancer. The 72% biochemical PSA cure rate is significantly higher than the 49% cure rate for peripheral zone cancer. Since cancer volume and percent Gleason grade 4/5 disease were the same in these 2 groups matched by cancer volume, the differences in behavior of peripheral and transition zone cancers must be sought at the molecular level unless anatomical location alone explains the differences in progression. Pathologists should differentiate transition from peripheral zone cancer when analyzing radical prostatectomy specimens.

Prostate cancer is highly predictable: a prognostic equation based on all morphological variables in radical prostatectomy specimens

PURPOSE

We determine whether biochemical prostate specific antigen (PSA) failure can be accurately predicted from preoperative serum PSA combined with 6 morphological variables from radical retropubic prostatectomy specimens in men with peripheral zone cancers. The unexpected limitation imposed by preoperative serum PSA on biochemical failure led us to compare peripheral zone to transition zone cancers.

MATERIALS AND METHODS

A total of 326 peripheral zone and 46 transition zone cancers treated only with radical retropubic prostatectomy were followed for a minimum of 3 years (mean and median greater than 5). All prostates were sectioned at 3 mm. intervals and morphological variables were quantitated using the Stanford technique. Biochemical failure was defined as serum PSA 0.07 ng./ml. or greater and increasing. Multivariate logistic regression was used to identify variables with the most independent influence on biochemical failure and derive a clinical equation to predict failure in peripheral zone cancers. The validity of the predictive equation was assessed by out of sample validation and cross validation techniques. The 46 transition zone cancers were compared to the 326 peripheral zone cancers by Student's t and Wilcoxon tests.

RESULTS

Of the peripheral zone failures 60% occurred in the first year after radical retropubic prostatectomy and 95% had occurred by the end of year 4. The highest preoperative serum PSA was 23 ng./ml. among the 181 men biochemically free of disease. Only 15.8% of 57 men with PSA greater than 15 ng./ml. were biochemically disease-free. For the 48 transition zone cancers cure rates were independent of serum PSA with 6 men having PSA greater than 50 ng./ml. Biochemical disease-free status was noted in 80% of transition zone compared to 56% of peripheral zone cancers (p = 0.0009). The most important variables predicting biochemical disease-free status for peripheral zone cancers were percent Gleason grade 4/5, cancer volume, serum PSA and prostate weight. Foci of vascular invasion, intraductal cancer and lymph nodes were less significant variables, and capsular penetration, positive surgical margins and seminal vesical invasion were insignificant. The multivariate logistic equation for predicting failure in peripheral zone cancers was highly accurate and requires only 2 to 3 minutes with a simple calculator.

CONCLUSIONS

Failure of radical retropubic prostatectomy to cure peripheral zone prostate cancer is highly predictable based on 6 morphological variables from the prostatectomy specimen and serum PSA. The level of serum PSA profoundly limits biochemical cure rates in peripheral zone cancers. Transition zone cancers have a high cure rate, despite high serum PSA and adverse morphological variables. Men with serum PSA greater than 15 and perhaps even greater than 10 ng./ml. have such a low cure rate for peripheral zone cancer that re-biopsy attempts appear indicated to prove a transition zone location or else therapy other than radical retropubic prostatectomy should be sought. Pathologists should indicate whether the primary (largest) cancer is in the peripheral or transition zone to prevent overoptimistic reports of cure with radical prostatectomy procedures, as 85% of all tumors are in the peripheral zone.

Examination of the 3 molecular forms of serum prostate specific antigen for distinguishing negative from positive biopsy: relationship to transition zone volume

PURPOSE

We evaluated the relative usefulness of total, free and complexed serum prostate specific antigen (PSA), and their ratios for distinguishing positive from negative biopsy of prostates in a university referral practice.

MATERIALS AND METHODS

We compared 90 consecutive men who had 2 sets of 6 negative systematic biopsies with 70 who had at least 5 mm. of prostate cancer in systematic biopsies during the same period at our institution. Total prostate and transition zone volumes were determined by transrectal ultrasound. The Bayer, DPC and Hybritech assays were performed to measure total, free and complexed serum PSA. Receiver operating characteristics curves were constructed for all forms of serum PSA and their ratios as well as prostate size to distinguish true positive (sensitivity) from false-positive (1 minus specificity) fractions.

RESULTS

Complexed PSA was only marginally better than total serum PSA. Free-to-total, complexed-to-total and prostate size had highly significant areas under the curves of greater than 80%. Free PSA only was better than complexed or total PSA. When factored by prostate volume, total PSA performed as well as the PSA ratios, and transition zone volume was consistently better than total prostate volume. DPC free-to-total ratios were equivalent to Hybritech ratios in all respects.

CONCLUSIONS

Complexed PSA is only marginally better than total PSA for distinguishing negative from positive biopsy of prostates. It is inferior to free PSA and far less useful than free-to-total or complexed-to-total ratios. Prostate size is a decisive variable in men in whom we avoided the expected 25% false-negative biopsy rate in terms of specificity and hopefully avoided insignificant cancer in terms of sensitivity. In the future the performance of PSA serum markers should be related to a transition zone volume of less than 20, 20 to 60 and greater than 60 gm. when comparing assays to each other.

Different molecular forms of uncomplexed prostate specific antigen (PSA) show similar immunoreactivities

PSA exists in multiple molecular forms in serum, with the majority complexed to proteinase inhibitors such as alpha 1-antichymotrypsin and alpha 2-macroglobulin. The uncomplexed, or "free" forms of PSA represent a very heterogenous distribution of molecular isoforms. It has been suggested that these variations in uncomplexed PSA may cause differences in their immunologic characteristics which may lead to analytical differences between various PSA assays. We report that various isoforms of uncomplexed PSA purified from seminal fluid as previously described show no differences in relative immunoreactivity and demonstrate equimolar behavior as measured by the TOSOH AIA-600 assay, which is a PSA assay based upon monoclonal PSA and monoclonal detecting antibodies (mono-mono). Furthermore, we show that carbohydrate side-chain modification does not change the equimolar immunoreactivity of these isoforms.

Biological determinants of cancer progression in men with prostate cancer

CONTEXT

The recent increase in ability to diagnose prostatic adenocarcinoma has created a dilemma for treatment decisions.

OBJECTIVE

To determine whether prostate cancer progression is associated with a modified version of the Gleason grading system together with selected morphologic and clinical variables.

DESIGN

Retrospective analysis of a cohort of patients with peripheral zone prostate cancers who underwent surgery between August 1983 and July 1992.

SETTING

University hospital.

PATIENTS

Radical prostatectomy specimens from 379 men treated only by surgical excision were prospectively studied for 8 morphologic variables using previously standardized techniques. Variables were percentage of each cancer occupied by Gleason grade 4/5 (% Gleason grade 4/5, the Stanford modified Gleason scale), cancer volume, vascular invasion, lymph node involvement, seminal vesicle invasion, capsular penetration, positive surgical margin, prostate weight, and preoperative prostate-specific antigen (PSA) level.

MAIN OUTCOME MEASURE

Biochemical progression of prostate cancer as indicated by serum PSA level of 0.07 ng/mL and increasing.

RESULTS

Cancer grade expressed as % Gleason grade 4/5 and cancer volume were highly predictive of disease progression. In a Cox proportional hazards model that included % Gleason grade 4/5, the traditional Gleason score was not an independent predictor of treatment failure. Positive lymph node findings and intraprostatic vascular invasion were the only other variables that remained significant at the .01 level.

CONCLUSION

The % Gleason grade 4/5, cancer volume, positive lymph node findings, and intraprostatic vascular invasion were independently associated with prostate cancer progression, defined by an increasing PSA level. Techniques to accurately measure cancer volume and % Gleason grade 4/5 are needed to better predict which patient will experience cancer progression. The commonly accepted predictors of progression-capsular penetration and positive surgical margins-were not independently predictive of failure after radical prostatectomy.

Most prostate cancers missed by raising the upper limit of normal prostate-specific antigen for men in their sixties are clinically significant

OBJECTIVES

To evaluate the efficacy of applying an age-specific prostate-specific antigen (PSA) reference range to determine whether prostate biopsies are warranted in men 60 to 69 years of age. We estimated the incidence of clinically significant prostate cancer in men in their sixties with PSA levels of 4.01 to 4.50 ng/mL and normal digital rectal examinations (DRE).

METHODS

We reviewed 203 sextant prostate biopsies of men in their sixties with PSA levels of 4.01 to 4.50 ng/mL and normal DRE. Tumors were considered clinically significant if the cancer on biopsy was poorly differentiated (Gleason score of 7 or more), involved more than one core, or included a single focus measuring more than 3 mm.

RESULTS

The positive biopsy rate was 31.5%. More than 80% of the cancers detected satisfied criteria that almost always predict clinically significant cancer. Thus, among men in their sixties with PSA levels of 4.01 to 4.50 ng/mL and normal DRE, the risk of detecting clinically significant cancer on biopsy was approximately 25%.

CONCLUSIONS

Most nonpalpable cancers detected by sextant biopsies in men 60 to 69 years of age with PSA levels of 4.01 to 4.5 ng/mL are clinically significant. Applying an age-specific PSA reference range that increases the upper limit of normal PSA to 4.5 ng/mL results in the failure to detect a substantial number of clinically significant cancers.

Histological and clinical findings in 896 consecutive prostates treated only with radical retropubic prostatectomy: epidemiologic significance of annual changes

PURPOSE

Recognizing that the unprecedented increase in new cases of prostate cancer between 1988 and 1996 actually peaked in 1992 and has now returned to baseline, we examined our clinical and histological database for annual trends in 896 consecutive men treated only with radical prostatectomy for clinical stages T1c to T2c from 1988 to 1996.

MATERIALS AND METHODS

All radical prostatectomy specimens were examined prospectively in 3 mm. step sections by 1 pathologist. Using multiple logistic regression for dichotomous variables and multiple linear regression for continuous variables, both corrected for age, we assessed the annual trends for significant changes in T1c versus T2 clinical stages, preoperative serum prostate specific antigen (PSA), cancer volume, percent Gleason grade 4/5 in the cancer, location of the cancer in the transition or peripheral zone, organ confined status, seminal vesicle invasion, positive surgical margins, prostate weight and presence of clinically insignificant cancers (less than 0.5 cc in volume).

RESULTS

There were no significant annual changes in the proportion of percent Gleason grade 4/5 cancer, serum PSA, prostate weight or clinically insignificant cancers less than 0.5 cc, and the annual changes for cancer volume were only of moderate significance. T1c cancers increased from 10% in 1988 to 73% in 1996 (p=0.0001), organ confined cancers from 40 to 75% (p=0.0001) and transition zone cancers from 10 to 21% (p=0.003). Seminal vesicle invasion decreased from 18 to 5% (p=0.001) and positive surgical margins from 30 to 14 (p=0.006). Mean patient age changed from 65 to 62 years (p=0.0001).

CONCLUSIONS

We believe that the extraordinary rise and fall in prostate cancer detection rates from 1990 to 1994 primarily removed previously undetected T2 cancers from the pool at large, leaving impalpable T1c cancers as the primary reservoir of prostate cancers in the United States. Importantly, cancer volume, percent Gleason grade 4/5 cancer, serum PSA and cancers less than 0.5 cc have not had a highly significant change during these critical 9 years. These data argue strongly that current PSA testing has not resulted in the detection of clinically insignificant cancers, and that PSA screening should be expanded and not restricted.

Monoclonal antibodies 2F5 and 4G10 against prostate specific antigen (PSA) complexed to alpha1-antichymotrypsin

OBJECTIVES

We have shown that an immunoassay (Chugai) for the PSA-ACT complex in serum has 2 to 3 times better specificity than total PSA at sensitivities of 85 to 97% in distinguishing biopsy positive men from biopsy negative men undergoing transrectal ultrasound (TRUS) examination. To increase the specificity of PSA immunoassay for prostate cancer, we produced specific antibodies exclusively against our purified PSA-ACT complex for development of assay kits for PSA-ACT complex.

METHODS

PSA-ACT complex was used as antigen to immunize BALB/c mice. PSA-ACT complex, free PSA, and ACT were used for hybridoma screening. To characterize the new monoclonal antibodies, we used Western blot, immunohistochemistry, and an in house immunoassay.

RESULTS

Two monoclonal antibodies, 2F5 and 4G10 were produced exclusively against PSA-ACT complex without any immunoreactivity to ACT or PSA alone. Western blot analysis indicated that 2F5 and 4G10 recognize conformation-dependent epitopes on PSA-ACT complex. Immunohistochemistry studies showed that 2F5 reacted with prostate cancer in about 30% of the cancer cells (sensitivity), but almost never stained normal prostate glands in the peripheral or transition zone tissue (about 100% specificity). Our in-house assay showed that 2F5 can be used as a tracer antibody specifically to detect PSA-ACT complex.

CONCLUSIONS

Using monoclonal antibody 2F5 as tracer antibody, we have developed a PSA immunoassay exclusively against PSA-ACT complex. This assay should maximize specificity in distinguishing BPH from prostate cancer.

Effect of combined transient androgen deprivation and irradiation following radical prostatectomy for prostatic cancer

PURPOSE

To evaluate whether transient androgen deprivation improves outcome in patients irradiated after radical prostatectomy for locally advanced disease, persistent or rising postoperative prostate specific antigen (PSA), or local recurrence.

METHODS AND MATERIALS

Records of 105 consecutive patients who were treated with pelvic irradiation after radical retropubic prostatectomy between August 1985 and December 1995 were reviewed. Seventy-four patients received radiation alone (mean follow up: 4.6 years), and 31 received transient androgen blockade with a gonadotropin-releasing hormone agonist (4) androgen receptor blocker (1) or both (24) beginning 2 months prior to irradiation (mean follow-up 3.0 years) for a mean duration of 6 months. Two of these patients were excluded from further analysis because they received hormonal therapy for more than 1 year. Patients received a prostatic fossa dose of 60-70 Gy at 2 Gy per fraction; 48 patients also received pelvic nodal irradiation to a median dose of 50 Gy. Survival, freedom from clinical relapse (FFCR), and freedom from biochemical relapse (FFBR) were evaluated by the Kaplan-Meier method. Biochemical relapse was defined as two consecutive PSA measurements exceeding 0.07 ng/ml.

RESULTS

At 5 years after irradiation, actuarial survival for all patients was 92%, FFCR was 77%, and FFBR was 34%. FFBR was significantly better among patients who received transient androgen blockade before and during radiotherapy than among those treated with radiation alone (56 vs. 27% at 5 years, p = 0.004). FFCR was also superior for the combined treatment group (100 vs. 70% at 5 years, p = 0.014). Potential clinical prognostic factors before irradiation did not differ significantly between treatment groups, including tumor stage, summed Gleason histologic score, lymph node status, indication for treatment, and PSA levels before surgery or subsequent treatment. Multivariate analysis revealed that transient androgen deprivation was the only significant predictor for biochemical failure.

CONCLUSION

This retrospective study of irradiation after radical prostatectomy suggests that transient androgen blockade and irradiation may improve freedom from early biochemical and clinically evident relapse compared to radiotherapy alone, although more prolonged follow-up will be needed to assess durability of impact upon clinical recurrence and survival rates.

Calculating prostate cancer volume preoperatively: the D'Amico equation and some other observations

PURPOSE

The primary morphological determinants of cancer progression in the prostate are tumor volume and the percentage of Gleason grades 4 and/or 5 disease. To date the best estimate of cancer volume before therapy has been serum prostate specific antigen (PSA) with Pearson's correlation coefficient value of approximately 0.5. Recently it was reported that prostate cancer volume calculated according to the formula, cancer specific serum PSA/amount of PSA leaking into the serum per cm.3 of cancer, highly correlates with actual cancer volume (R = 0.98). Because there is a definite need for greater accuracy in estimating cancer volume before therapy, we attempt to confirm this proposed equation in our radical prostatectomy series.

MATERIALS AND METHODS

We applied this equation to the initial 318 men with peripheral zone cancer treated only with radical prostatectomy at our institution who were followed for a mean and median of greater than 5 years. Calculated prostate cancer volume was determined according to the aforementioned equation with minor modifications, and correlated with the actual cancer volume measured in radical prostatectomy specimens. Pearson's correlation coefficient and the coefficient of determination were calculated using a linear regression model. Calculated prostate cancer volume was also previously used to predict pathological stage pT3. We compared calculated prostate cancer volume, clinical stage, Gleason grade and preoperative serum PSA in logistic univariate and multivariate regressions to predict stage pT3 disease.

RESULTS

Overall correlations for calculated prostate cancer volume were R = 0.537 and R2 = 0.289 (p <0.0001), which are much less than those previously noted (R = 0.98 and R2 = 0.96). As in the original report, we also divided our 318 cases into the 4 cancer volume subgroups of 0.5 cm.3 or less, 0.5 to 2.0, 2.0 to 4.0 and greater than 4.0 cm.3 (R = 0.251, 0.288, 0.382 and 0.462, and R2 = 0.063, 0.083, 0.146 and 0.213 alone respectively). There was an increasing trend for better R and R2 values with increasing prostate cancer volume. Calculated prostate cancer volume was less than 0.5 cm.3 in 156 of our 318 patients (49%) and less than 0 in 37 (11.6%). In these cases serum PSA alone strongly correlated with calculated prostate cancer volume (R = 0.877 and R2 = 0.77). Univariate analysis demonstrated statistical significance for prediction of stage pT3 disease, Gleason grade, clinical stage, serum PSA and calculated prostate cancer volume but multivariate analysis revealed statistical significance only for Gleason grade (p <0.0001) and clinical stage (p <0.0036). Values for PSA and calculated prostate cancer volume were not significant (p = 0.0640 and 0.7920, respectively).

CONCLUSIONS

Calculated prostate cancer volume did not predict cancer volume in our 318 patients who underwent radical prostatectomy. While we are uncertain how to interpret the excellent correlation of calculated prostate cancer volume with PSA, we believe that this correlation strongly suggests that most predictive information of calculated prostate cancer volume is related to serum PSA. Importantly in our 318 patients serum PSA was a much stronger predictor of cancer volume than calculated prostate cancer volume. As expected, Gleason grade and clinical stage are excellent predictors of stage pT3 disease but not of serum PSA or calculated prostate cancer volume.

Classification of localized untreated prostate cancer based on 791 men treated only with radical prostatectomy: common ground for therapeutic trials and TNM subgroups

PURPOSE

We examined cancer volume, percent Gleason grade 4/5 cancer, cancer location (peripheral versus transition zone), capsular penetration and biochemical cure rates in men undergoing radical prostatectomy to determine differences among clinical stages T1c, T2a, T2b and T2c.

MATERIALS AND METHODS

Detailed chart reviews confirmed the precise clinical stages assigned to 791 consecutive men treated only with radical prostatectomy. All prostates were examined prospectively by the Stanford technique of 3 mm. step sections. For biochemical cure rates a subset of 366 men were followed for a minimum of 5 years. Failure was defined as prostate specific antigen Tosoh 0.07 ng./ml. or greater and rising. T1c was defined as impalpable cancer.

RESULTS

T1c and T2a stages had half as much cancer volume as T2b and T2c cancers, 10 versus 25% Gleason grade 4/5 and half as much capsular penetration (30 versus 61%). Biochemical cure rates were 70 and 72% for T1c and T2a compared to 37 and 27% for T2b and T2c, respectively. Of T1c cancers 25% were in the transition zone compared to 7.9 to 9.9% of T2a to c cancers.

CONCLUSIONS

T1c cancers are similar to T2a cancers in tumor volume and percent Gleason grade 4/5, the primary determinants of therapeutic failure. Minimal 5-year cure rates for T1c and T2a cancers are similar. Transition zone cancers are 2.5 times more common in T1c cancers than in palpable T2 tumors. T2a cancers like T1c cancers are highly favorable tumors and should be retained in TNM classifications. These data suggest that the 4 clinical stages of T1c to T2c can serve as a valid basis for comparing different therapeutic strategies.

The male bulbourethral sling procedure for post-radical prostatectomy incontinence

PURPOSE

We evaluate the efficacy of the male bulbourethral sling procedure in the treatment of post-radical prostatectomy urinary incontinence.

MATERIALS AND METHODS

We reviewed the records of 64 consecutive men with severe post-prostatectomy incontinence who underwent the male bulbourethral sling procedure at Northwestern Memorial Hospital and Stanford University Hospital. Preoperatively 50% of the patients were completely incontinent (diapers, clamps or condom catheter), and the remainder required a mean of 4.7 pads per day. Data were collected by chart review, patient interviews at followup appointments and telephone interviews. Median followup was 18.1 months (mean 22.4, range 6.5 to 53.8).

RESULTS

Following a single sling procedure 36 patients (56%) became dry, and 5 (8%) were significantly improved. In 17 patients 23 retightening procedures were performed, which decreased the median followup to 16 months and increased the success rate to 75% (67% cured, 8% improved). The revision, erosion and infection rates were 27, 6 and 3%, respectively.

CONCLUSIONS

The male bulbourethral sling procedure is effective treatment for post-radical prostatectomy urinary incontinence. Patients who had received adjuvant radiation therapy demonstrated a lower continence rate than those who had not. Further followup is needed to assess long-term efficacy.

Positive prostate biopsy rate consistently increases with age at the same prostate-specific antigen level in patients with normal digital rectal examination

OBJECTIVES

To examine the relationship between positive prostate biopsy rates and age over the range of serum prostate-specific antigen (PSA) concentrations of 4 to 10 ng/mL.

METHODS

The rates for adenocarcinoma were calculated for prostate biopsy specimens received at UroCor Inc., Oklahoma City, Oklahoma between April 1995 and June 1997. The selection criteria were as follows: men between 50 and 79 years of age, normal digital rectal examination (DRE), prebiopsy PSA level between 4.01 and 10.0 ng/mL obtained within a 4-month period prior to receipt of biopsy, and no previous prostate biopsy. Five thousand six cases were selected out of 81,545 prostate biopsy specimens submitted by office-based urologists. The rates of positive prostate biopsies were stratified by age in decade increments and by PSA in increments of 1 ng/mL. The P values were calculated by the chi-square test.

RESULTS

The patient mean age was 65.8 years. An overall increase in the positive prostate biopsy rate for men between 50 and 79 years of age as serum PSA increases from 4.01 to 10.0 ng/mL (P = 0.047) was found; however, this increase was less significant than the increase found in positive biopsy rates caused by age alone (P <0.0001).

CONCLUSIONS

Undetected prostate cancer appears to be a major cause of the increasing serum PSA seen with advancing age.