Radiotherapy for high grade clinically localized adenocarcinoma of the prostate

PURPOSE: We defined the efficacy of radiotherapy for the treatment of high grade (Gleason scores 8 to 10) adenocarcinoma of the prostate. MATERIALS AND METHODS: A total of 50 patients underwent radiotherapy with curative intent for clinically localized prostate cancer with Gleason scores of 8 to 10 at 1 of 4 facilities affiliated with the University of California San Francisco. Patients were considered to have biochemical failure if they had a significant increase in prostate specific antigen (PSA) of 0.5 ng./ml. per year, an increase in PSA to greater than 1.0 ng./ml. or a positive biopsy. RESULTS: Among the 50 patients median PSA was 22.7 ng./ml. (range 1.3 to 93.4). Tumors were clinical stage T1 or T2 in 46% of the cases and stage T3 or T4 in 54%. The overall actuarial probability of freedom from biochemical failure at 4 years was 23%. In a multivariate analysis including all patients pretreatment PSA was the only predictor of PSA failure, with 64% free of progression if the pretreatment PSA was 10 ng./ml. or less compared to only 16% at 3 years if PSA was more than 10 ng./ml. (p = 0.01). In a multivariate analysis restricted to patients with PSA less than 20 ng./ml. 83% of those treated to more than 71 Gy. were free of progression compared to 0% for those treated to less than 71 Gy. (p = 0.03). In a multivariate analysis PSA 10 ng./ml. or less (related risk 11.4, p = 0.02), T stage 1 or 2 (relative risk 3.8, p = 0.05) and radiation dose more than 71 Gy. (relative risk 4.0, p = 0.06) were associated with a favorable outcome. CONCLUSIONS: At 4 years the freedom from PSA failure following radiotherapy for high grade prostate cancer was comparable to previously reported surgical series. The high failure rate among patients with PSA greater than 20 ng./ml. suggests that these patients should be considered for investigational approaches. The apparent improvement in freedom from progression with the use of higher doses provides reason for optimism.     

Free-to-total prostate-specific antigen (PSA) ratio improves the specificity for detecting prostate cancer in patients with prostatism and intermediate PSA levels

OBJECTIVE: To investigate the clinical significance of the free-to-total prostate-specific antigen (PSA) ratio in improving the specificity of PSA measurement for detecting prostate cancer within the diagnostic intermediate range (4-10 ng/mL total PSA) in patients referred for the treatment of urinary symptoms. PATIENTS AND METHODS: Serum samples were obtained from 333 consecutive patients with obstructive and irritative urinary symptoms. Of these men, 114 had total PSA levels of 4-10 ng/mL; 22 had prostate cancer (group 1) and 71 had benign prostatic hyperplasia (BPH, group 2). Group 3 consisted of 21 patients with BPH and a chronic indwelling catheter. The concentrations of free and total PSA (ProStatus, Wallac Oy, Turku, Finland) and PSA complexed to alpha-1-antichymotrypsin were measured and the free-to-total PSA ratio calculated. All patients under 70 years of age or with suspicious findings on digital rectal examination or transrectal ultrasonography underwent ultrasound-guided sextant prostate biopsies. Of the 114 patients, 105 (92%) underwent transurethral resection of the prostate and six (5%) radical retropubic prostatectomy. RESULTS: Patients in group 1 had significantly lower median free PSA concentrations (0.78 ng/mL vs 1.13 ng/mL, P < 0.001) and a lower free-to-total PSA ratio (12.1% vs 19.9%, P < 0.001) than those in group 2. The differences were similar between group 1 and group 3 (median free PSA in group 3, 1.06 ng/mL, P = 0.03, and free-to-total PSA ratio 18.7%, P = 0.007). There were no significant differences between patients in groups 2 and 3. The free-to-total PSA ratio had a higher specificity than total PSA at all sensitivity levels, e.g. a threshold free-to-total PSA ratio of 0.20 detected 91% of cancers and spared 48% (group 2) or 46% (group 3) from unnecessary biopsies. The area under the receiver operating characteristic curve for group 1 vs group 2 was 0.56 (total PSA) and 0.78 (free-to-total PSA ratio) and for group 1 vs group 3 was 0.56 (total PSA) and 0.81 (free-to-total PSA ratio). CONCLUSION: In those patients with extensive symptoms from BPH and requiring surgical treatment, the free-to-total PSA ratio improves the specificity for detecting prostate cancer in the diagnostic 'grey zone' of 4-10 ng/mL total PSA. This improvement occurred in patients with or without a chronic indwelling catheter for urinary retention.     

The effect of prostate volume, age, total prostate specific antigen level and acute inflammation on the percentage of free serum prostate specific antigen levels in men without clinically detectable prostate cancer

PURPOSE: We determine the influence of age, prostate volume, total serum prostate specific antigen (PSA) level and histological evidence of acute inflammation in biopsy specimens on the percent free serum PSA level in men without clinically detectable prostate cancer. MATERIALS AND METHODS: We studied 70 men with total PSA levels of 2.6 to 9.9 ng./ml. who had undergone at least 3 sets of prostate biopsies that were negative for cancer as part of our PSA based prostate cancer screening program. Total and free PSA levels were measured using Hybritech immunoassays. Prostate volume and the presence of acute inflammation were determined from the most recent transrectal ultrasonography and prostate needle biopsy. RESULTS: Percent free PSA levels correlated significantly with age (r = 0.48, p = 0.0001) and prostate volume (r = 0.44, p = 0.0002) but not with total PSA (r = 0.04, p = 0.7). The mean percent free PSA did not differ for those with or without acute inflammation. Multivariate regression models demonstrated that age and prostate volume were significant predictors of percent free PSA. CONCLUSIONS: Among men without detectable prostate cancer and a total PSA level between 2.6 and 9.9 ng./ml. percent free serum PSA was higher in older men and in men with a larger prostate gland but was not influenced by total PSA level or the presence of acute inflammation in the prostatic biopsy specimen.     

Comparison of percent free prostate specific antigen and prostate specific antigen density as methods to enhance prostate specific antigen specificity in early prostate cancer detection in men with normal rectal examination and prostate specific antigen between 4.1 and 10 ng./ml

PURPOSE: We analyzed the behavior of prostate specific antigen (PSA) density and percent free PSA to enhance the specificity of PSA in the early diagnosis of prostate cancer in men with normal digital rectal examination and PSA serum level between 4.1 and 10 ng./ml. MATERIALS AND METHODS: PSA serum level, PSA density and percent free PSA were analyzed in 74 men with normal digital rectal examination and PSA serum level between 4.1 and 10 ng./ml. All men underwent systematic prostate biopsy, and the diagnosis was benign prostate hyperplasia in 52 and prostate cancer in 22. Furthermore, we determined the decrease in unnecessary biopsies and the cancer detection rate using 0.10 versus 0.15 as cut points for PSA density, and 20 versus 25 as cut points for percent free PSA. RESULTS: In patients with benign prostatic hyperplasia and prostate cancer, respectively, the median PSA level was 6.7 and 7.0 ng./ml. (p > 0.05), median prostate volume was 50 and 37 cc (p < 0.04), median PSA density was 0.14 and 0.19 (p < 0.007) and median percent free PSA was 18.9 and 10.1 (p < 0.005). Using PSA density cut points of 0.15 and 0.10, the decrease in negative biopsies was 53.8 and 36.5% with a sensitivity of 86.4 and 90.9%, respectively. However, using percent free PSA cut points of 20 and 25, the decrease in negative biopsies was 36.5 and 26.9% with a sensitivity of 77.3 and 95.5%, respectively. CONCLUSIONS: Although both methods could minimize unnecessary biopsies in men with normal digital rectal examination and PSA serum level between 4.1 and 10 ng./ml., the percent free PSA was more cost-effective since transrectal ultrasound was not required. In this small series of symptomatic patients a percent free PSA cut point of 25 could detect at least 95% of prostate cancers and decrease 26.9% of negative biopsies.     

Ratio of free-to-total prostate specific antigen in serum cannot distinguish patients with prostate cancer from those with chronic inflammation of the prostate

PURPOSE: We demonstrate the effect of chronic inflammation of the prostate on the ratio of free-to-total prostate specific antigen (PSA) in serum calculated as a percentage of free PSA and, therefore, that percentage of free PSA is an unspecific means to distinguish among prostate cancer, chronic prostatitis and benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Total, free and percentage of free PSA was measured in 66 men with prostate cancer, 119 with BPH and 17 with asymptomatic chronic prostatitis. In all patients the diagnosis was histopathologically confirmed by microscopic examination of prostatic specimens after sextant biopsy, transurethral prostatic resection or prostatectomy. RESULTS: The median values of total, free and percentage of free PSA were 4.11 microg./l., 0.75 microg./l. and 20.4% in patients with BPH, 10.0 microg./l., 0.84 microg./l. and 8.5% in those with prostate cancer, and 7.60 microg./l., 1.23 microg./l. and 10.6% in those with chronic prostatitis. Patients with prostate cancer and chronic prostatitis had a significantly lower percentage of free PSA than those with BPH. Receiver operating characteristics curve analysis showed that percentage of free PSA as a discriminator between prostate cancer and BPH was not suitable for differentiating between prostate cancer and chronic prostatitis. CONCLUSIONS: Chronic prostatitis is not characterized by elevated total PSA concentrations alone but also by a decreased percentage of free PSA, a tendency similar to that in prostate cancer. This unspecific change in percentage of free PSA must be considered to interpret the percentage of free PSA correctly.     

Laparoscopic pelvic lymph node dissection for prostate cancer: comparison of the extended and modified techniques

PURPOSE: We compared the results of extended (obturator, hypogastric, common and external iliac nodes) to modified (obturator and hypogastric nodes only) laparoscopic pelvic lymph node dissection in patients with clinically localized prostate cancer. MATERIALS AND METHODS: A total of 189 patients with stage T1 to T3 prostate cancer underwent modified (150) or extended (39) laparoscopic pelvic lymph node dissection for pelvic nodal assessment before definitive treatment. RESULTS: Twice as many lymph nodes were removed via extended than modified laparoscopic pelvic lymph node dissection (mean 17:8 versus 9.3). The overall positivity rate was 23 of 189 lymph nodes (12.2%), including 14 of 150 (7.3%) for modified and 9 of 39 (23.1%) for extended dissection (p = 0.02). Two patients (22%) who underwent extended dissection had positive lymph nodes in the external iliac area. Patients who presented with the high risk features of prostate specific antigen (PSA) greater than 20 ng./ml., Gleason score 7 or greater, or stage T2b disease or greater had a 26.5% (p = 0.0002), 22% (p = 0.0006) or 16.4% (p = 0.003) likelihood of positive lymph nodes, respectively. For extended versus modified laparoscopic pelvic lymph node dissection node positivity in high risk patients was 27% versus 18.8% (p = 0.4), 30 versus 26.4% (p = 0.8) and 25.4 versus 14.6% (p = 0.17) for Gleason score 7 or greater, PSA greater than 20 ng./ml. and disease stage T2b to T3a, respectively. Patients who underwent the extended procedure had a higher complication rate (35.9 versus 2%, p < 0.0001). No laparotomy was required. CONCLUSIONS: Despite yielding a 2-fold higher node count and higher node positivity rate, extended laparoscopic pelvic lymph node dissection offers no advantage over modified laparoscopic pelvic lymph node dissection for diagnosing positive lymph nodes when results are analyzed by prognostic factors. The extended procedure is associated with a much higher complication rate. In patients with the high risk features of PSA greater than 20 ng./ml., Gleason score 7 or greater and stage T2b to T3a disease modified laparoscopic pelvic lymph node dissection can be performed safely and effectively to help identify those who may benefit most from curative therapy.     

The contemporary value of pretreatment prostatic acid phosphatase to predict pathological stage and recurrence in radical prostatectomy cases

PURPOSE: We examine the clinical prognostic value of the currently available simple and inexpensive immunoenzymatic prostatic acid phosphatase (PAP) assay for the staging and prognosis of radical prostatectomy cases. MATERIALS AND METHODS: Between February 1, 1990 and May 3, 1996 pretreatment PAP was measured in 295 patients who underwent radical prostatectomy. From February 1, 1990 to May 17, 1992 the Hybritech Tandem-E assay was used in 75 cases, from May 18, 1992 to February 28, 1993 the Abbott EIA assay was used in 49 and from March 1, 1993 to May 3, 1996 the Abbott IMx assay was used in 171. PAP assays were analyzed individually and the results were combined with pretreatment prostate specific antigen (PSA) values to assess the ability to predict organ confined prostate cancer and serological recurrence after radical prostatectomy. RESULTS: PAP testing was not of value for predicting organ confined disease or positive margins. However, this test was useful for predicting the first serological PSA recurrence in the 3 periods (77 to 85% correct) and overall (82% correct, p < 0.001, odds ratio 6.06). The Kaplan-Meier disease-free survival rate at 4 years was 78.8% for men with PAP less than 3 ng./ml. and 38.8% for those with PAP 3 ng./ml. or greater, which was significant when pretreatment PSA was less than 10 ng./ml. (p = 0.047), 10 ng./ml. or greater (p = 0.012) and overall (p < 0.001). PAP testing added prognostic information to pretreatment PSA values and it was an independent predictor of recurrence. CONCLUSIONS: The widely available and inexpensive PAP assays of the 1990s are predictors of recurrence after radical prostatectomy. They should be included in future studies of prostate cancer recurrence modeling. However, they do not predict pathological stage or margin status.     

Prevalence and predictors of a positive repeat transrectal ultrasound guided needle biopsy of the prostate

PURPOSE: We determined the prevalence of and risk factors for carcinoma in patients with 1 previously negative prostate biopsy. MATERIALS AND METHODS: Transrectal ultrasound guided prostate needle biopsies were repeated in 130 men. Risk factors analyzed included age, pathological result of initial biopsy, inter-biopsy interval, prostate specific antigen (PSA), PSA density, PSA velocity, digital rectal examination, abnormal transrectal ultrasound and family history of prostate cancer. RESULTS: A total of 39 patients (30%) had positive biopsies for cancer. Univariate analysis revealed that PSA more than 20 ng./ml. and abnormal transrectal ultrasound were more frequent in men with positive second biopsies. Using multivariate logistic regression analysis only PSA more than 20 ng./ml. was a significant risk factor (adjusted odds ratio 4.48, 95% confidence interval 1.02 to 20.1). We determined the incidence of carcinoma in patients who represent the lowest risk group as defined by PSA less than 10 ng./ml., PSA density less than 0.15 mg./ml./cm.3, PSA velocity less than 0.75, ng./ml. per year, no prostatic intraepithelial neoplasia plus negative transrectal ultrasound, digital rectal examination and family history. Of 21 patients who fit this cohort 5 (23.8%) had carcinoma on repeat biopsy. CONCLUSIONS: A significant false-negative rate for initial transrectal ultrasound guided prostate biopsies exists. Baseline risk in lowest risk patients is sufficiently high such that one cannot define a subset of patients for whom repeat biopsy is unnecessary. We recommend repeat biopsy in all patients who meet the criteria for a transrectal ultrasound guided biopsy and in whom the initial biopsy is negative.     

The clinical utility of measuring free-to-total prostate-specific antigen (PSA) ratio and PSA density in differentiating between benign prostatic hyperplasia and prostate cancer

OBJECTIVE: To evaluate the role of free-to-total prostate-specific antigen ratio (f/tPSA), prostate volume and PSA density in differentiating between men with prostate cancer and benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: The study comprised 51 patients who were assessed after transurethral electroresection of the prostate (16 with prostate cancer and 35 with BPH). Patients with a tPSA of < or = 4.0 ng/mL and > or = 30.0 ng/mL were excluded from the analysis. Total and fPSA were measured using an immunoradiometric assay and prostate volume was determined by transrectal ultrasonography. The incidence of prostate cancer and BPH was then compared with the PSA variables to determine specificity and predictive value. RESULTS: Most patients with BPH had a tPSA of 4.0-6.0 ng/mL; no patients with BPH had a tPSA of > 20.0 ng/mL. Most patients with prostate cancer had a f/tPSA of 6-10%. The area under the receiver operating characteristic curve for f/tPSA was significantly greater than that for tPSA (P < 0.003). CONCLUSIONS: The measurement of f/tPSA and PSA density increase the specificity of the differential diagnosis between BPH and prostate cancer.     

Results of transrectal ultrasound-guided biopsies and clinical significance of Japanese prostate cancer

BACKGROUND: We review the outcomes of ultrasound-guided biopsy in consecutive patients and assess clinical significance of Japanese prostate cancer. METHODS: Examination was made of 1469 patients subsequent to transrectal ultrasound-guided biopsy of the prostate gland. For 84 patients, two or more sets of ultrasound-guided biopsies were conducted following the initial negative results during this period. Two hundred and thirty-two patients with benign histology at the initial biopsy underwent transurethral resection of the prostate (TURP). The clinical significance of the cancers was assessed based on patient age and calculated tumor volume at diagnosis, assumed cancer volume doubling time and life-expectancy in the Japanese male population. RESULTS: Overall, 327 of the 1469 patients (22.3%) had prostate carcinoma. Positive biopsy rates in patients with PSA 2.0 ng/ml or lower, 2.1-4.0 ng/ml, 4.1-10.0 ng/ml and 10.1 ng/ml or greater were 4.6%, 8.6%, 15.8% and 59.5%, respectively. Of the 232 patients who underwent TURP, 15 (6.5%) had cancer. Of the 84 patients subjected to the multiple sets of biopsies, 19 (22.6%) cancers were detected. Of the 203 cancers without distant metastasis at initial biopsy, 13.3%, 25.1%, 32.5% and 40.4% of tumors for 2-, 3-, 4- and 6-year tumor doubling times gave no indication of clinical significance. Nearly half these patients (43-52%) had clinical stage T1c disease. The estimated proportion of clinically insignificant tumors in repeat biopsy was virtually the same as first set biopsies. CONCLUSIONS: Low PSA was not necessarily an indication of indolent cancer and repeat biopsy did not often demonstrate clinically unimportant cancers. Many patients with stage T1c disease may eventually prove to require no treatment.     

The lack of predictive value of prostate specific antigen density in the detection of prostate cancer in patients with normal rectal examinations and intermediate prostate specific antigen levels

PURPOSE: The management of patients with a normal digital rectal examination and a prostate specific antigen (PSA) level of 4.0 to 10.0 ng./ml. remains controversial. To improve the specificity of cancer detection in this group, PSA density has been recommended with biopsies based on a PSA density of 0.15 or more. To evaluate PSA density as a discriminator of prostate cancer we enrolled patients in a prospective study. MATERIALS AND METHODS: A prospective evaluation was done of 44 consecutive patients with a palpably normal digital rectal examination and a serum PSA level of 4.0 to 10.0 ng./ml. enrolled during a 13-month period. All patients underwent transrectal ultrasound with sextant biopsies regardless of calculated PSA density. RESULTS: Overall, 8 of 44 men (18%) had prostate cancer. There was no significant difference in the mean PSA density between the patients with positive and negative biopsies (mean 0.12 and 0.15, respectively, p = 0.258). Also, there was no significant association between PSA or PSA density and a positive biopsy in multivariate analysis (p = 0.863). Receiver operating characteristic curves for PSA and PSA density failed to demonstrate any superior benefit for PSA density in this patient population. A PSA density of 0.15 was an unreliable indicator of cancer (sensitivity 12.5%, specificity 61.1% and positive predictive value 6.7%). CONCLUSIONS: In our study, PSA density did not discriminate between patients with positive and negative biopsies, and in fact most cancers would not have been detected if a PSA density of 0.15 or more had been used as the sole indication for biopsy. Therefore, we recommend systematic biopsies in these patients independent of calculated PSA density.     

Tumor volume and prostate specific antigen: implications for early detection and defining a window of curability

PURPOSE: We attempted to determine the relationship between tumor volume and extent of localized prostate cancer, as well as the interrelationships of tumor volume with prostate specific antigen (PSA) level, grade and stage. MATERIALS AND METHODS: Serial whole mount sections from 128 patients who underwent radical prostatectomy were analyzed using a computer assisted volumetric program. Statistical evaluations were performed using logistic and simple regression analyses. RESULTS: The median tumor volume for patients with organ confined disease was significantly lower than for those with extraprostatic extension (1.25 versus 2.94 cc, p < 0.001). A significant incidence (32%) of small volume cancers (0.51 to 1.5 cc) exhibited extraprostatic extension while that of extraprostatic disease increased to 66% for patients with tumor volumes greater than 1.5 cc (p < 0.001). Of men with clinically significant (greater than 0.5 cc, or Gleason score 7 or more) pathological stage B disease 31% had a serum PSA value of 4 ng./ml. or less. Multivariate regression analysis of tumor volume as a function of PSA, grade and stage demonstrated that log PSA had the strongest association with tumor volume. Goodness-of-fit analysis (coefficient of determination) revealed that only 40 to 50% of the PSA levels are explained by tumor volume. CONCLUSIONS: These data suggest that the window of curability for prostate cancer decreases significantly once the tumor grows to a volume greater than 1.5 cc, and that grade and tumor volume are more significantly related to stage than PSA.     

Radical prostatectomy for prostate cancer: the perineal approach increases the risk of surgically induced positive margins and capsular incisions

PURPOSE: We compare the incidence of positive surgical margins in patients who underwent perineal or retropubic radical prostatectomy for clinically localized (stage T1, T2) prostate cancer. MATERIALS AND METHODS: In this retrospective, nonrandomized study we reexamined the specimens of 94 consecutive patients who underwent radical perineal (48) or retropubic (46) prostatectomy for clinically localized prostate cancer (stage T1, T2) and with pathological stage pT2 (intracapsular), pT3A (established extracapsular extension without positive margins) or pT3B (extracapsular extension with positive margins) without lymph node involvement (N0). We assessed the presence or absence of extracapsular cancer with or without positive margins, incisions of the prostatic capsule exposing cancer (surgically induced positive margins) or benign glandular tissue. Patients were followed for 3 to 66 months (mean 25) using an ultrasensitive prostate specific antigen assay with a lower detection limit of less than 0.05 ng./ml. RESULTS: The overall incidence of positive margins in cancer tissue was 56% in the perineal and 61% in the retropubic group, and biochemical failure-free survival was 67% each. However, surgically induced positive margins in patients with organ confined disease were more frequent in the perineal than retropubic group (43 versus 29%, p < 0.05) and associated with a 37% risk of biochemical failure (prostate specific antigen greater than 0.1 ng./ml.) at mean followup. In addition, capsular incisions exposing benign tissue were more frequent in the perineal than retropubic group (90 versus 37%, p < 0.05) irrespective of pathological stage. CONCLUSIONS: Although overall positive margins and biochemical failure rates are similar or identical for the perineal and retropubic approaches for organ confined prostate cancer, the perineal approach is associated with a significantly higher risk of capsular incisions and surgically induced positive margins and, thus, a higher risk of biochemical failure.     

Transition zone prostate specific antigen density: lack of use in prediction of prostatic carcinoma

PURPOSE: Among the new approaches to enhance the performance of prostate specific antigen (PSA) testing in a biopsy population is the use of the free-to-total PSA as well as the transition zone density, which is calculated by dividing the PSA by the transition zone volume. We compare these manipulations of the PSA to PSA alone in a biopsy population. MATERIALS AND METHODS: We evaluated 917 consecutive men who underwent ultrasound guided biopsy for an elevation in serum PSA or abnormality on digital rectal examination. Total PSA was measured using the Tandem-E or Tandem-R method. Prostate gland volume and transition zone were measured with ultrasound and calculated using the prolate ellipsoid formula. RESULTS: In the overall PSA range 276 men had carcinoma (30.0% of the population), while in the PSA 4.0 to 10.0 ng./ml. range 141 of 477 had cancer (29.6%). Receiver operating characteristics analysis and analysis of variance were performed. In the overall PSA series the Tandem total PSA performed as well as any PSA index to predict carcinoma. In the restricted range of total PSA 4.0 to 10.0 ng./ml. total PSA density as well as transition zone density were more predictive than PSA alone. In both PSA ranges the volume of benign glands was significantly larger than in the prostates exhibiting carcinoma. There was no statistically significant difference in outcomes of analyses between different investigators or different sites of investigation (Veterans Affairs versus university based hospitals). CONCLUSIONS: In this biopsy population transition zone PSA density did not add to the information available with total PSA and gland volume. Neither investigator nor site bias contributed to the failure of transition zone PSA density or PSA density to predict prostatic carcinoma.     

Prostate specific antigen in the expressed prostatic fluid of men with benign prostatic hyperplasia and prostate carcinoma

PURPOSE: We tested the hypothesis that the histochemically demonstrated prostate specific antigen (PSA) content of prostate carcinoma cells does not necessarily reflect PSA production and secretion by evaluating expressed prostatic fluid. MATERIALS AND METHODS: Expressed prostatic fluid and serum from 152 men with clinical benign prostatic hypertrophy (BPH), 132 with histologically proved BPH and 46 with prostate carcinoma were analyzed with the Hybritech PSA assay. RESULTS: Expressed prostatic fluid PSA levels from carcinoma patients (median 1.70 mg./ml., mean 2.25) were significantly higher than in the histologically proved BPH group (median 1.28 mg./ml., mean 1.42, p < 0.05). CONCLUSIONS: PSA concentration is increased in the expressed prostatic fluid of prostates of men with carcinoma compared to those with histological BPH. This finding may be a functional manifestation of a field change or paracrine effects within the prostate.     

Prevalence and pathological extent of prostate cancer in men with prostate specific antigen levels of 2.9 to 4.0 ng./ml

Various authors have recommended different values for the upper limit of normal for the monoclonal prostate specific antigen (PSA) assay (for example 4.0 ng./ml. or less by the manufacturer Hybritech or 2.8 ng./ml. or less by others). To our knowledge, no studies have examined the prevalence and pathological extent of prostate cancer detectable by needle biopsy in ambulatory volunteers with PSA levels in the range of 2.9 to 4.0 ng./ml. We evaluated 121 volunteers by rectal examination and transrectal ultrasonography with PSA levels in that range. We performed ultrasound-directed needle biopsy of the prostate if abnormal findings were present on either examination. The prevalence of detectable prostate cancer in this group was 7.2% (8 of 111). All 8 patients had pathologically organ confined cancer, and only 2 had suspicious findings on rectal examination but all had abnormal or suspicious ultrasound findings. We believe that the 7.2% yield from ultrasonography and biopsy in patients with a PSA level of 2.9 to 4.0 ng./ml. is too low to justify further invasive evaluation. Rather, we recommend careful followup and monitoring of these patients with serial PSA measurements and rectal examination, and advise performance of ultrasonography and biopsy if the rectal examination becomes suspicious for cancer or the PSA level increases above 4.0 ng./ml.     

Influence of age on serum prostate specific antigen concentration

322 men who had not prostatic diseases were selected at random for defining the characteristics of serum prostate specific antigen (PSA) in order to use PSA more appropriately in detecting clinically significant prostate cancer. The serum PSA concentration is correlated with patient age (r = 0.301; P < 0.0001), PSA is increased with age. The recommended upper limits (mean +2 standard deviations) for serum PSA for men aged 20-49 years was 2.71 ng/ml; for 50-59 years, 5.01ng/ml; for 60-69 years, 6.05 ng/ml; and for greater than or equal to 70 years, 7.92 ng/ml. Our findings led to proposals for using age-specific PSA reference range instead of a single reference range for men of all age groups. These age-specific reference ranges have the potential to increase the specificity of using PSA for detecting prostate cancer.     

Genetic alterations in the development of mammary and prostate cancer in the C3(1)/Tag transgenic mouse model

PURPOSE: Finasteride therapy for benign prostatic hyperplasia (BPH) results in a marked lowering of serum prostate specific antigen (PSA) levels. However, little is known about the effect of finasteride on unbound or free serum levels of PSA. Such information would be important since percent free PSA may substantially improve the cancer specificity of PSA testing. Thus, we prospectively studied the effect of finasteride therapy on total and free serum PSA levels. MATERIALS AND METHODS: In a randomized, placebo controlled, double-blind trial 40 men with histologically confirmed BPH (age range 52 to 78 years) were treated with either 5 mg. finasteride daily (26 patients) for 9 months or placebo (14) for 6 months. Prostate volume was assessed by transrectal ultrasound. Serum levels of free and total PSA were measured from archived serum samples stored at -70C at baseline and for as long as 9 months of treatment. RESULTS: In the finasteride group mean total PSA levels declined from 3.0 ng./ml. at baseline to 1.5 ng./ml. after 6 months of treatment (50% decrease, p <0.01). In the placebo group, with similar baseline levels, no significant change was observed. PSA density declined significantly in finasteride treated men (p <0.01) but not in men receiving placebo. The mean percent free PSA (13 to 17% at baseline) was not altered significantly by finasteride or placebo. CONCLUSIONS: Total PSA serum levels decreased by an average of 50% during finasteride therapy but percent free PSA did not change significantly. This information is potentially useful in the interpretation of PSA data used for early detection of prostate cancer in men receiving finasteride. However, further studies are required to demonstrate the use of percent free PSA to detect the development of cancer.     

Physiological variation of serum prostate specific antigen in the 4.0 to 10.0 ng./ml. range in male volunteers

PURPOSE: Because some patients show a surprising variation in serial serum prostate specific antigen (PSA) values, we determined the intra-individual or physiological variation in serum PSA by collecting sera 2 to 3 week apart without any prostatic manipulation. MATERIALS AND METHODS: Because 4.0 to 10.0 ng./ml. PSA is the critical range for decision making, we asked all men with a PSA in this range to return 2 to 3 weeks later for a second measurement. Total serum PSA was determined by the Hybritech Tandem-R, automated Tosoh AIA-600 and Delfia section immunoassays. Free and complexed serum PSA was determined by the Delfia assays. Between assay variation (first blood specimen retested on a separate day with the second blood specimen) was compared to the physiological variation (first versus second blood specimens). RESULTS: Mean coefficient of variation (95% confidence limits) was 10.5% for between assay and 23.5% for physiological evaluations. The preferred analysis of ratio difference variation provided a factor of 0.138 (between assay) and 0.298 (physiological) for 95% confidence limits. Changes in free or complexed PSA were not the cause of physiological variation. CONCLUSIONS: The intra-individual physiological variation is 2 to 3 times the between assay variation for sera drawn 2 to 3 weeks apart with a PSA of 4 to 10 ng./ml. A serum PSA of 4.0 ng./ml. can increase to 5.2 ng./ml. (4.0 x 0.298) and still be within the physiological variability for 95% confidence limits.     

The quotient of prostate-specific antigen and prostate volume. Improved differentiation between benign prostatic hyperplasia and locally circumscribed prostate cancer

Absolute serum prostate-specific antigen (PSA) values are of little help in the identification of locally confined prostatic cancer (PCA), because of a considerable overlap with the PSA values found in benign prostatic hyperplasia (BPH). Prostate gland volumes were estimated sonographically in 112 patients using the product of the three maximal diameters (longitudinal, anterior-posterior, transverse) and the factor 0.52. PSA was determined with a monoclonal immunoenzymetric assay (Tandem-E, Hybritech). The prostates were removed by either transvesical prostatectomy (for BPH) or radical retropubic prostatovesiculectomy (for PCA). In each case the diagnosis was verified by systematic histological examination. The ratio of serum PSA to estimated prostate volume did not exceed 0.4 ng/(ml x ml) in any of the 74 patients with BPH, whereas 23 of the 38 patients with PCA had a ratio above 0.4 ng/(ml x ml). The information provided by the PSA-prostate volume ratio is superior to absolute PSA values in preoperative differentiation between BPH and PCA. With a PSA-prostate volume ratio over 0.4 ng/(ml x ml) patients are at high risk for PCA and should be evaluated by prostate biopsy.