Evaluating radical prostatectomy specimens: therapeutic and prognostic importance

Morphological assessment of radical prostatectomy specimens. A protocol with clinical relevance

The increase in prostate cancer detection has induced a sharp increase in the number of radical prostatectomies Proper examination of radical prostatectomy (RP) specimens by pathologists is critical in determining the need for adjuvant treatment and prediction of patient outcome. The pathology report should include relevant clinical information as well as provide prognostically useful information derived from the macroscopic examination and microscopic evaluation of the RP specimen

Neuroendocrine expression in node positive prostate cancer: correlation with systemic progression and patient survival

PURPOSE

Neuroendocrine cells are ubiquitous but uncommon in benign and neoplastic prostate epithelium, and they are considered important for regulating cell growth and differentiation. The predictive value of neuroendocrine immunoreactivity for patient outcome after radical prostatectomy is uncertain. In this study we determined the expression of 2 important neuroendocrine markers, chromogranin and serotonin, in benign epithelium, primary prostate cancer and lymph node metastases, and correlated cellular expression with patient outcome.

MATERIALS AND METHODS

We studied 196 patients with node positive prostate adenocarcinoma who underwent bilateral pelvic lymphadenectomy and radical prostatectomy at Mayo Clinic between 1987 and 1992. Mean followup was 6.8 years (range 0.3 to 11). The cellular expression of chromogranin and serotonin in matched samples of benign tissue, primary prostate cancer and lymph node metastases from the same patients was evaluated by immunohistochemical staining using commercially available monoclonal antibodies. Results were correlated with patient age, pathological findings (Gleason score, DNA ploidy and cancer volume) and patient outcome, including clinical progression, cancer specific and all cause survival.

RESULTS

Chromogranin immunoreactivity was greater in benign prostatic epithelium and primary cancer cases (99% each) than in those of lymph node metastases (37.5%) (pairwise comparisons with metastases p <0.001). The mean incidence of immunoreactive cells in benign epithelium, primary cancer and metastases was 6% (median 5%), 6% (median 3%) and 2.2% (median 0%), respectively. Serotonin immunoreactivity was greatest in benign prostate epithelium cases (98.5%) with less in primary cancer (95%) and lymph node metastases (21.5%) (pairwise comparisons p <0.001). The mean incidence of immunoreactive cells in benign epithelium, primary cancer and metastases was 2.2% (median 3%), 2.4% (median 2%) and 0.4% (median 0%), respectively. Chromogranin expression was invariably greater than that of serotonin for all 3 diagnostic categories (p <0.0001). There was a marginally significant positive trend in the level of chromogranin expression in benign prostatic epithelium and systemic progression (p = 0.05) but no significant association with cancer specific or all cause survival (p >0.1). No significant association was observed of chromogranin expression in primary cancer or lymph node metastases with any patient outcomes (p >0.1). There was a significant association of the level of serotonin expression in benign prostatic epithelium with cancer specific survival (p = 0.03) but no significant association with systemic progression or all cause survival (p > 0.1). There were positive trends in the association of serotonin immunoreactivity in primary cancer with systemic progression (p = 0.09) and cancer specific survival (p = 0.05) but not with all cause survival (p >0.1). No significant association was observed of serotonin expression in lymph node metastases with any patient outcomes (p >0.1).

CONCLUSIONS

Benign prostatic epithelium and primary prostate cancer express a significantly greater number of chromogranin and serotonin immunoreactive cells than lymph node metastases, suggesting that decreased expression of neuroendocrine markers is involved in cancer progression. However, neuroendocrine expression was marginally useful for predicting the outcome in patients with node positive prostate cancer treated with radical prostatectomy.

Does the completeness of prostate sampling predict outcome for patients undergoing radical prostatectomy?: data from the CAPSURE database

OBJECTIVES

To determine whether more complete sampling of the radical prostatectomy (RP) specimen better predicts outcome after surgery.

METHODS

We reviewed pathology reports from 1383 patients enrolled in CaPSURE (a longitudinal registry of patients with prostate cancer) who underwent RP. Specimens were considered step-sectioned only if the entire specimen was submitted for analysis and if sections were taken at 0.5-cm intervals or less. Otherwise, specimens were considered non-step-sectioned. Pathologic stage, Gleason score, surgical margin status, and outcome were compared between groups. Prostate-specific antigen (PSA) recurrence was defined as a PSA level of 0.2 ng/mL or greater on two consecutive occasions after RP. Secondary cancer treatment consisted of radiation or androgen deprivation after RP. Adjuvant treatments occurred within 6 months of RP, and nonadjuvant treatments occurred more than 6 months after RP. Kaplan-Meier event rates of PSA recurrence and secondary treatment were calculated for patients in the step-sectioned and non-step-sectioned groups.

RESULTS

No significant differences were found between patients in the step-sectioned and non-step-sectioned groups with respect to pathologic tumor stage, prostatectomy Gleason score, or margin status. Patients in whom step-sectioning was performed had a lower serum PSA at diagnosis than patients in the non-step-sectioned group. When examining all patients, no differences were observed in the use of secondary treatments or PSA recurrence based on the method of pathologic analysis. However, patients with negative margins in whom step-sectioning was performed exhibited significantly lower secondary nonadjuvant treatment use and appeared to have a lower risk of PSA recurrence than similar patients in the non-step-sectioned group.

CONCLUSIONS

These data suggest that more complete pathologic analysis of the surgical specimen may better predict outcome for some patients undergoing RP. Additional research is warranted to determine whether such differences justify the additional resources necessary to recommend routine step-sectioning.

Prognostic factors in prostate cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, a multidisciplinary group of clinicians, pathologists, and statisticians considered prognostic and predictive factors in prostate cancer and stratified them into categories reflecting the strength of published evidence and taking into account the expert opinions of the Prostate Working Group members.

MATERIALS AND METHODS

Factors were ranked according to the previous College of American Pathologists categorical rankings: category I, factors proven to be of prognostic importance and useful in clinical patient management; category II, factors that have been extensively studied biologically and clinically but whose importance remains to be validated in statistically robust studies; and category III, all other factors not sufficiently studied to demonstrate their prognostic value. Factors in categories I and II were considered with respect to variations in methods of analysis, interpretation of findings, reporting of data, and statistical evaluation. For each factor, detailed recommendations for improvement were made. Recommendations were based on the following aims: (1) increasing uniformity and completeness of pathologic evaluation of tumor specimens, (2) enhancing the quality of data collected pertaining to existing prognostic factors, and (3) improving patient care.

RESULTS AND CONCLUSIONS

Factors ranked in category I included preoperative serum prostate-specific antigen level, TNM stage grouping, histologic grade as Gleason score, and surgical margin status. Category II factors included tumor volume, histologic type, and DNA ploidy. Factors in category III included perineural invasion, neuroendocrine differentiation, microvessel density, nuclear roundness, chromatin texture, other karyometric factors, proliferation markers, prostate-specific antigen derivatives, and other factors (oncogenes, tumor suppressor genes, apoptosis genes, etc).

Prostate. Practice parameters, pathologic staging, and handling radical prostatectomy specimens

This article addresses the handling, processing, and reporting of radical prostatectomy specimens with the goal of providing general guidelines and practical suggestions for the surgical pathologist. During the last decade, pathologists in academic and community institutions have witnessed a surge in the number of radical prostatectomy specimens evaluated in their departments. Unlike the relative familiarity most pathologists have with other major oncologic resections, radical prostatectomy specimens present an interesting and occasionally frustrating challenge with respect to gross evaluation, sampling, and reporting.

The genetics of cancer--a 3D model

Gene expression microarrays hold great promise for studies of human disease states. There are significant technical issues specific to utilizing clinical tissue samples which have yet to be rigorously addressed and completely overcome. Precise, quantitative measurement of gene expression profiles from specific cell populations is at hand, offering the scientific community the first comprehensive view of the in vivo molecular anatomy of normal cells and their diseased counterparts. Here, we propose a model for integrating-in three dimensions-expression data obtained using the microarray.

Prostate-specific membrane antigen expression is greatest in prostate adenocarcinoma and lymph node metastases

OBJECTIVES

Prostate-specific membrane antigen (PSMA) is an integral membrane protein highly specific for the prostate. PSMA may be clinically useful for predicting outcome in patients with prostate cancer. We compared the expression of PSMA in prostate adenocarcinoma and lymph node metastases in a large series of patients with node-positive cancer.

METHODS

We studied 232 patients with node-positive adenocarcinoma who underwent bilateral pelvic lymphadenectomy and radical retropubic prostatectomy at the Mayo Clinic between 1987 and 1992. Immunohistochemistry was performed using monoclonal antibody 7E11-5.3 directed against PSMA. For each case, the percentage of immunoreactive cells in benign prostate tissue, adenocarcinoma, and lymph node metastases was estimated in 10% increments. Intensity was recorded using a scale of 0 to 3 (0 = no staining, 3 = highest).

RESULTS

Cytoplasmic immunoreactivity for PSMA was observed in all cases in benign epithelium and cancer, and most lymph node metastases. The number of cells stained was lowest in benign epithelium; cancer and lymph node metastases were similar (46.2% +/- 27.5% versus 79.3% +/- 18.5% versus 76.4% +/- 26.1%, respectively; all pairs P < 0.05). Intensity of staining was greatest in primary cancer and lowest in lymph node metastases.

CONCLUSIONS

PSMA is expressed in benign prostatic epithelium and primary cancer in all cases and in 98% of cases with lymph node metastases. Expression of PSMA was greatest in primary cancer for both percentage and intensity of immunoreactive cells. PSMA expression allows the identification of benign and malignant prostatic epithelium and may be a potentially valuable marker in the treatment of patients with prostate cancer.

Prostate specific membrane antigen expression in prostatic intraepithelial neoplasia and adenocarcinoma: a study of 184 cases

BACKGROUND

Prostate specific membrane antigen (PSM) is a membrane-bound antigen that is highly specific for benign and malignant prostate epithelial cells. Its expression in high grade prostatic intraepithelial neoplasia (PIN) has not been compared with that in prostate carcinoma.

METHODS

The authors performed an immunohistochemical study of representative sections from 184 radical prostatectomies from previously untreated patients with pathologic stage T2N0M0 adenocarcinoma treated at the Mayo Clinic between 1987 and 1991. Affinity-purified monoclonal antibody 7E11-5.3 directed against PSM was employed at a concentration of 20 microg/mL overnight. For comparison, serial sections in each case were stained with prostate specific antigen (PSA). Staining for all antibodies was performed using the streptavidin-biotin method. For each case, the percentage of immunoreactive cells in benign epithelium, PIN, and adenocarcinoma was estimated in increments of 10%. Cox proportional hazards models were used to identify the risk of carcinoma recurrence according to the number of immunoreactive PIN or cancer cells for PSM and PSA; the date of radical prostatectomy was used as the starting time, and serum PSA (biochemical) failure or clinical failure was the event. PSA biochemical failure was defined as serum PSA > 0.2 ng/mL at least 30 days after surgery.

RESULTS

Intense cytoplasmic immunoreactivity for PSM was observed in the benign and neoplastic epithelial cells in all cases (100% of cases staining). The number of cells staining was lower in benign epithelium and PIN than in adenocarcinoma (69.5+/-17.3% [range, 20-90%] vs. 77.9+/-13.2% [range, 30-100%] vs. 80.2+/-13.7% [range, 30-100%], respectively). With rare exceptions, basal cells were negative, and there was no immunoreactivity of the prostate stroma, urothelium, or vasculature. Adenocarcinoma gave the most intense and extensive staining, and the highest grades of adenocarcinoma (Gleason primary patterns 4 and 5) showed staining in virtually every cell; there was greater heterogeneity of staining in lower grades of adenocarcinoma. By contrast, PSA immunoreactivity was more intense and extensive in benign epithelium than in PIN and adenocarcinoma. The number of immunoreactive PIN or cancer cells for PSM and PSA was not predictive of PSA biochemical or clinical failure as defined in this study.

CONCLUSIONS

PSM was expressed in all cases of prostate adenocarcinoma, with the greatest extent and intensity observed in the highest grades. The expression increased incrementally from benign epithelium to high grade PIN or adenocarcinoma. Conversely, PSA showed the greatest staining in benign epithelium, with decreased expression incrementally from benign epithelium to high grade PIN or adenocarcinoma. Expression of PSM is clinically useful for the identification of prostate epithelium, particularly PIN or adenocarcinoma, and its expression is regulated independent of PSA. The number of PSM immunoreactive cells was not predictive of recurrence, most likely because of the presence of abundant immunoreactivity in most cases, or because of differential expression in primary and metastatic disease.

Influence of prostate-specific antigen testing on the spectrum of patients with prostate cancer undergoing radical prostatectomy at a large referral practice

OBJECTIVE

To analyze trends in the clinical stage and pathologic outcome of patients with prostate cancer who underwent radical prostatectomy at a large referral practice during the prostate-specific antigen (PSA) testing era.

MATERIAL AND METHODS

Between January 1987 and June 1995, 5,568 patients with prostate cancer (4,774 with clinically localized disease of stage T2c or less) underwent pelvic lymphadenectomy and radical retropubic prostatectomy at our institution. Patient age, preoperative serum PSA level, clinical stage, pathologic stage, Gleason score, and tumor ploidy were assessed. Outcome was based on clinical and PSA (increases in PSA level of 0.2 ng/mL or more) progression-free survival.

RESULTS

Patient age (65 to 63 years old; P<0.001) and serum PSA level (median, 8.4 to 6.8 ng/mL; P<0.001) decreased during the study period. The percentage of patients with clinical stage T1c prostate cancer increased from 2.1% in 1987 to 36.4% in 1995 (P<0.001), and clinical stage T3 cancer decreased from 25.3% to 6.5% (P<0.001). Nondiploid tumors decreased from 38.3% to 24.6% (P<0.001), and the proportion of patients with pathologically organ-confined disease increased from 54.9% to 74.3% (P<0.001). More cT1c than cT2 tumors were diploid (80% versus 72%; P<0.001), had a Gleason score of 7 or less (75% versus 65%; P<0.001), and were confined to the prostate (75% versus 57%; P<0.001). Five-year progression-free survival was 85% and 76% for patients with clinical stage T1c and T2, respectively (P<0.001).

CONCLUSION

Since the advent of PSA testing, patients referred to our institution for radical prostatectomy have shown a significant migration to lower-stage, less-nondiploid, more often organ-confined prostate cancer at the time of initial assessment. Cancer-free survival associated with PSA-detected cancer (cT1c) is superior to that with palpable tumors (cT2). Whether these trends translate into improved long-term cancer-specific survival remains to be confirmed with longer follow-up.