Cheryl M. Yemoto

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 Pearsons 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.

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 Students 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.

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.

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.

Assessment of morphometric measurements of prostate carcinoma volume.

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.

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.

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.

Significance of Demonstrable Vascular Space Invasion for the Progression of Prostatic Adenocarcinoma

Histologically demonstrable vascular invasion by tumor has been reported as an index of poor prognosis correlating with increased probability of metastasis in many types of cancer other than prostatic. We quantitated vascular invasion foci in 357 radical prostatectomy specimens and developed improved criteria for their diagnosis and their distinction from fixation artifact. Vascular invasion foci were found in 7% of cancers less than 4 cc in volume and 24% of larger cancers. Most foci were selectively located either near the basal end of the cancer or near the transition zone border. Correlations among multiple morphologic variables showed significant correlation of vascular invasion only with the presence of intraductal carcinoma. The only statistically significant independent predictors of disease progression (serum prostate-specific antigen elevation) were vascular invasion, carcinoma grade, and cancer volume. Our findings suggest that further study of vascular invasion foci may disclose additional information about the biologic features of local and distant spread of prostatic carcinoma.

Modified Extrafascial Radical Retropubic Prostatectomy Technique Decreases Frequency of Positive Surgical Margins in T2 Cancers 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 cm3, +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 cm3. For cancer volumes >2 cm3, 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 ≤2 cm3 which represents 36% of the T2 cancers in our series. Recent screening with PSA (T1c cancers) increases the incidence of these cancers ≤2cm3. This modified uni– or bilateral anatomic extrafascial prostatectomy with improved +SM and biological progression rates for T2 cases should be evaluated for T1c cases.

Prostate specific antigen releases a kinin-like substance on proteolysis of seminal vesicle fluid that stimulates smooth muscle contraction.

PURPOSE We investigated whether purified prostate specific antigen (PSA), a seminal plasma serine protease of the kallikrein enzyme family, is capable of releasing kinin-like peptides from natural substrate glycoproteins in human seminal vesicle fluid. MATERIALS AND METHODS An in vivo rat bladder model was used to monitor for release of substances capable of inducing smooth muscle contractions. Purified PSA, seminal vesicle fluid (SVF) from radical prostatectomy specimens, bradykinin, saline and a bradykinin antagonist were injected intravesically into urethane-anesthetized rats, and the resulting bladder contractions were measured. RESULTS Injection of either PSA or SVF alone did not induce bladder contractions. Injection of a mixture of SVF and PSA preincubated 15 minutes, however, induced strong bladder contractions (23 +/- 7 cm. H2O) that decreased with time (4 +/- 2 cm. H2O, after 90 minutes). Similar contractions were observed after injection of bradykinin (10(-4) M. = 39 +/- 14, 10(-6) M. = 27 +/- 9, 10(-8) M. = 7 +/- 4 cm. H2O). Addition of a bradykinin antagonist to the PSA-SVF mixture prior to injection blocked the observed bladder contractions (23 +/- 7 cm. H2O before, versus 0.3 +/- 1.2 cm. H2O after adding antagonist). CONCLUSIONS We conclude that PSA produces a kinin-like substance by enzymatic cleavage of glycoproteins in human seminal fluid. This substance induces smooth muscle contractions which can be specifically blocked by addition of a bradykinin antagonist.