Elevated expression of inhibin alpha 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.

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 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.

Reference reagents for prostate-specific antigen (PSA): establishment of the first international standards for free PSA and PSA (90:10)

BACKGROUND: Prostate-specific antigen (PSA) measurements in serum by immunoassay are widely used in the screening, diagnosis, and monitoring of patients with prostate cancer although the lack of common reference reagents has led in the past to wide differences in estimates. We report here the results of a WHO international collaborative study in which two preparations of PSA representative of the main immunoreactive components in serum, free PSA and PSA 90:10, and a preparation of recombinant DNA-derived PSA were assessed as potential standards for the calibration of diagnostic immunoassays for PSA. METHODS: Coded vials of the candidate materials and serum preparations containing PSA in the clinically important range were provided to the 10 laboratories in the study, and participants were asked to perform PSA assays currently in use in their laboratories. Data from 89 immunoassays by 26 different method-laboratory combinations were contributed to the study and analyzed centrally at the National Institute for Biological Standards and Control. RESULTS: Potency estimates of the preparations relative to the in-house calibrators were in good agreement with the target value of 1 microg of total PSA/vial, the preparation of free PSA giving 1.10 microg/vial (95% confidence interval, 0.99-1.21 microg/vial) and PSA 90:10, 1.11 microg/vial (95% confidence interval, 1.04-1.18 microg/vial). No immunoreactivity was detected in ampoules containing the recombinant material. Use of a common standard of PSA 90:10 significantly reduced the between-laboratory geometric coefficients of variation for serum samples included in the study and gave a much narrower range of potency estimates. CONCLUSIONS: The preparation of free PSA was established by WHO as the First International Standard for PSA (free) with an assigned content of 1 microg of total PSA per vial. In addition, the preparation of bound PSA was established as the First International Standard for PSA (90:10) with an assigned content of 1 microg of total PSA per vial.

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.