A pathologist's view of prostatic carcinoma

Clinical, Histopathological, and Prognostic Characteristics of Patients with Prostate Cancer in Lubumbashi, Democratic Republic of Congo

INTRODUCTION

Prostate cancer is currently a public health problem with a frequency that varies from country to country. This study aims to describe the epidemiological, clinical, and histopathological and outcome features of prostate cancer in Lubumbashi in the Democratic Republic of Congo.

MATERIALS AND METHODS

This was a descriptive longitudinal study of patients diagnosed with prostate cancer at the University Clinics of Lubumbashi. The study period was 3 years (2017 to 2019). Parameters studied were age and clinical, biological (PSA level, prostatic specific antigen), histopathological, and outcome features.

RESULTS

The mean age of patients was 68.7 years (range: 47 and 90 years). The 60 to 69 age group was the most affected (43.18%). Elderly subjects (≥60 years old) represented 89.77% of the cases (n = 79). Voiding disorders were the main reason for consultation in 55.68% of the cases. The mean PSA level was 133.7 ng/ml (range: 4 and 1564.5 ng/ml) at diagnosis and 125.4 ng/ml after 3 months of follow-up (range: 0.16 and 1782.1 ng/ml). Adenocarcinoma was the predominant histological type (100%). In prognosis, 31.82% of patients had a Gleason score greater than 7 and 59.10% had a high risk at the D'Amico risk classification for Prostate Cancer. Hormone therapy was administered alone in 75% of the cases and in combination with pulpectomy in 13.64% of the cases. The 3-year overall survival was 56.82%.

CONCLUSION

Prostate cancer is frequent and has a poor outcome in our country. The establishment of an individual screening policy would be an undeniable advantage in improving the prognosis.

Diagnostic performance of imaging techniques for detecting of local recurrence after prostate brachytherapy

PURPOSE

The purpose of this study was to evaluate MRI and fluorocholine PET/CT diagnostic performances for the detection of local recurrence following prostate brachytherapy for localised prostate cancer.

MATERIAL AND METHODS

In this single-centre study, we retrospectively reviewed data from 21 patients treated by brachytherapy for localised prostate cancer and diagnosed with biochemical recurrence according to Phoenix Criteria, who underwent MRI and fluorocholine PET/CT. We included patients with local relapse suspicion according to imaging exams, with biopsy for the final assessment of local recurrence. Patient analysis data were supplemented by segment analysis using an 8-segment model.

RESULTS

The fluorocholine PET/CT was positive for 81% and negative for 19% of patients. The sensitivity and specificity were 92% and 33% with diagnosis accuracy of 67%. The MRI was positive for 57% and negative for 43% of patients. The sensitivity and specificity were 67% and 56% with diagnosis accuracy of 62%. There was no statistically significant difference between fluorocholine PET/CT and MRI accuracy (P=0.63). On a segment-based analysis, the sensitivity and specificity were 44% and 82% for fluorocholine PET/CT with diagnosis accuracy of 78%. For MRI, specificity was 91% diagnosis accuracy was 82%.

CONCLUSION

Both MRI and fluorocholine PET/CT permit to highlight local recurrence sites after prostate brachytherapy. Confirmation biopsies are, however, necessary since this accuracy is insufficient.

Histopathology of Prostate Cancer

This review focuses on histopathological aspects of carcinoma of the prostate. A tissue diagnosis of adenocarcinoma is often essential for establishing a diagnosis of prostate cancer, and the foundation for a tissue diagnosis is currently light microscopic examination of hematoxylin and eosin (H&E)-stained tissue sections. Markers detected by immunohistochemistry on tissue sections can support a diagnosis of adenocarcinoma that is primary in the prostate gland or metastatic. Histological variants of carcinoma of the prostate are important for diagnostic recognition of cancer or as clinicopathologic entities that have prognostic and/or therapeutic significance. Histological grading of adenocarcinoma of the prostate, including use of the 2014 International Society of Urological Pathology (ISUP) modified Gleason grades and the new grade groups, is one of the most powerful prognostic indicators for clinically localized prostate cancer, and is one of the most critical factors in determination of management of these patients.

The role of metabolic imaging in radiation therapy of prostate cancer

The goal of this study was to correlate prostatic metabolite concentrations from snap-frozen patient biopsies of recurrent cancer after failed radiation therapy with histopathological findings, including Ki-67 immunohistochemistry and pathologic grade, in order to identify quantitative metabolic biomarkers that predict for residual aggressive versus indolent cancer. A total of 124 snap-frozen transrectal ultrasound (TRUS)-guided biopsies were acquired from 47 men with untreated prostate cancer and from 39 men with a rising prostate-specific antigen and recurrent prostate cancer following radiation therapy. Biopsy tissues with Ki-67 labeling index ≤ 5% were classified as indolent cancer, while biopsy tissues with Ki-67 labeling index > 5% were classified as aggressive cancer. The majority (15 out of 17) of cancers classified as aggressive had a primary Gleason 4 pattern (Gleason score ≥ 4 + 3). The concentrations of choline-containing phospholipid metabolites (PC, GPC, and free Cho) and lactate were significantly elevated in recurrent cancer relative to surrounding benign tissues. There was also a significant increase in [PC] and reduction in [GPC] between untreated and irradiated prostate cancer biopsies. The concentration of the choline-containing phospholipid metabolites was significantly higher in recurrent aggressive (≈ twofold) than in recurrent indolent cancer biopsies, and the receiver operating characteristic (ROC) curve analysis of total choline to creatine ratio (tCho/Cr) demonstrated an accuracy of 95% (confidence interval = 0.88-1.00) for predicting aggressive recurrent disease. The tCho/Cr was significantly higher for identifying recurrent aggressive versus indolent cancer (tCho/Cr = 2.4 ± 0.4 versus 1.5 ± 0.2), suggesting that use of a higher threshold tCho/Cr ratio in future in vivo (1)H MRSI studies could improve the selection and therapeutic planning for patients who would benefit most from salvage focal therapy after failed radiation therapy.

Current management of prostate cancer: dilemmas and trials

The past decade has witnessed significant advances in our understanding of the biology of prostate cancer. Androgen ablation/androgen receptor inhibition remains as the mainstay of treatment for advanced prostate cancer. Our understanding of the biology of prostate cancer has increased exponentially owing to advances in molecular biology. With this knowledge many intriguing issues have come to light, which clinicians and scientists alike strive to answer. These include why prostate cancer is so common, what drives the development of prostate cancer at a molecular level, why prostate cancer appears refractory to many families of cytotoxic chemotherapeutics, and why prostate cancer preferentially metastasizes to bone. Two clinical forms of prostate cancer have been identified: indolent organ confined disease, which elderly men often die of, and aggressive metastatic disease. A method of distinguishing between these two forms of the disease at an organ-confined stage remains elusive. Understanding the mechanisms of castrate resistance is a further issue of clinical importance. New trials of treatments, including molecular agents that target prostate cancer from a range of angles, have been instituted over the past 10-15 years. We can look at these trials not only as a chance to investigate the effectiveness of new treatments but also as an opportunity to further understand the complex biology of this disease.

Conditionally ablated Pten in prostate basal cells promotes basal-to-luminal differentiation and causes invasive prostate cancer in mice

Prostate glands comprise two major epithelial cell types: luminal and basal. Luminal cells have long been considered the cellular origin of prostate cancer (CaP). However, recent evidence from a prostate regeneration assay suggests that prostate basal cells can also give rise to CaP. Here, we characterize Pten-deficient prostate lesions arising from keratin 5-expressing basal cells in a temporally controlled system in mice. Pten-deficient prostate lesions arising from basal cells exhibited luminal phenotypes with higher invasiveness, and the cell fate of Pten-deficient basal cells was traced to neoplastic luminal cells. After temporally ablating Pten in keratin 8-expressing luminal cells, luminal-derived Pten-deficient prostate tumors exhibited slower disease progression, compared with basal-derived tumors, within 13 weeks after Pten ablation. Cellular proliferation was significantly increased in basal-derived versus luminal-derived Pten-deficient prostate lesions. Increased tumor invasion into the smooth muscle layer and aberrantly regulated aggressive signatures (Smad4 and Spp1) were identified exclusively in basal-derived Pten-deficient lesions. Interestingly, p63-expressing cells, which represent basal stem and progenitor cells of basal-derived Pten-deficient prostate lesions, were significantly increased, relative to cells of the luminal-derived prostate lesion. Furthermore, castration did not suppress cellular proliferation of either basal-derived or luminal-derived Pten-deficient prostate tumors. Taken together, our data suggest that, although prostate malignancy can originate from both basal and luminal populations, these two populations differ in aggressive potential.

Markers and meaning of primary treatment failure

BCR is the most clinically used endpoint for identification of treatment failure. Approximately 15% to 53% of patients undergoing primary curative therapy will develop BCR. BCR often precedes clinically detectable recurrence by years. It does not necessarily translate directly into PCa morbidity and mortality, nor does it always reflect the desired endpoint. Furthermore, it has not been validated as a surrogate endpoint, in that interventions that have been shown to alter the PSA level have not been shown to also alter survival. The utility of PSA level as a surrogate endpoint is brought into question by the knowledge that the overall survival rate of patients at 10 years is similar in patients with and without BCR, and that in a significant proportion of men, the only evidence of disease during their lifetime will be a detectable PSA level. The likelihood of developing BCR post-therapy can be predicted by using multiple clinical and pathologic variables. With the development of nomograms that incorporate several markers, the accuracy of prediction has improved. Until recently, the natural history of BCR post-RRP has not been well understood. Pound et al showed the heterogenous and prolonged natural history of BCR. In this large series of men with BCR following RRP, only 34% of men developed metastatic disease. The median time from development of BCR to identification of metastases was 8 years, and the median time from the development of metastatic disease to death was just under 5 years. These data highlight the extremely variable and potentially indolent nature of BCR. The risk of metastatic disease following BCR has been relatively well defined and relates to PSADT and time to PSA recurrence. It generally is accepted that a PSADT of less than 6 to 10 months and a time to PSA recurrence of less than 1 to 2 years relates to a higher risk of developing metastatic disease. Local recurrence, however, remains poorly understood with respect to its true incidence, clinical significance, and natural history. The significance of BCR post-RT remains unclear due to the lack of data on its natural history. Attempts have been made to identify patients at high risk for metastatic progression by looking at time to PSA recurrence and PSADT. A PSADT of less than 6 to 12 months and a time to PSA recurrence of less than 12 months reflects a higher risk of developing metastatic disease. Accurate risk stratification by means of an algorithm similar to that produced by Pound et al has not been performed on a large cohort, thus making risk assessment for an individual patient difficult. The major dilemma for clinicians in the management of BCR is the identification of the site of disease recurrence, which ultimately guides therapy decisions. Clinicopathologic features allow for risk stratification for recurrence, and multiple investigations have attempted to localize the site of recurrence. Time to biochemical progression, Gleason score, and PSADT are predictive of the probability and time to development of metastatic disease, and allow for stratification of patients into different risk groups (see Table 2). TRUS, CT, PET, and DRE all have limited utility in the identification of local recurrence. ProstaScint and MRI have demonstrated encouraging initial results: however, they require further investigation. Bone scintigraphy is of little value for the initial investigation of BCR. In patients with a PSA level of less than 10 ng/mL, the risk of having a positive bone scan is less than 1% and, until the PSA level rises above 40 ng/mL, the risk of having a positive bone scan is less than 5%. Therefore, bone scintigraphy should be reserved for patients with a PSA level greater than 10 to 20 ng/mL or patients with a rapidly rising PSA level. Using new MRI sequences, there is some evidence that MRI is better for the detection of bony metastatic disease; however, this technique requires further investigation. BCR causes anxiety for the patient and the treating doctor, because the best way to manage patients with PSA-only progression is unknown. Currently, there are no validated treatment recommendations for the management of BCR. The information in this review provides the framework for assignment of patients into clinical trials based on different risk categories. Patients at high risk for metastatic progression could be identified early and thus entered into appropriate clinical trials for systemic therapies. Similarly, patients with a low risk of progression could be placed into observation protocols, potentially sparing them from exhaustive and inappropriate investigations.

[Clinical and biological surveillance after radiotherapy for localized prostate cancer]

Serum PSA is an excellent marker of disease status after external beam radiotherapy or brachytherapy for patients with prostate carcinoma. A low PSA nadir < or = 1 even < or = 0.5 ng/mL has been shown to be as a surrogate end point for disease control. Three successive increases of this marker after achieving the nadir defines recurrence as recommended by the American Society for Therapeutic Radiology and Oncology. The biochemical relapse or PSA failure after treatment precedes clinical disease relapse by several months. PSA profile or kinetics may have implications for patterns of failure and prognosis. Prostate post-radiotherapy biopsies should not be part of routine follow-up as its interpretation is frequently problematic. Other exams should not be performed unless clinical symptoms are present. Post-radiotherapy relapse treatment has generally no curative intent.

Prognostic significance of histologic grading in patients with prostate carcinoma who are assessed by the Gleason and World Health Organization grading systems in needle biopsies obtained prior to radiotherapy

BACKGROUND

The current study was conducted to evaluate and compare the impact of two major histologic grading systems on failure-free survival in patients with prostate carcinoma who are treated with definitive radiation.

METHODS

Eligible patients for the current study had localized adenocarcinoma of the prostate (T1-4pN0M0, T3/4: 67%, median observation time: 69 months) and were treated with intent-to-cure external radiotherapy between 1989 and 1995. The specimens from 178 patients, obtained by needle biopsies, were reviewed simultaneously by two pathologists assigning World Health Organization (WHO) and Gleason grades. Three-tiered Gleason grouping distributed patients into three groups (those with a score < 7, those with a score of 7, and those with a score of 8--10), whereas two-tiered Gleason categorization distributed patients into two groups (those with a Gleason score of 7A, major 3 + minor 4 patients were added to the group of patients with a Gleason score < 7 and patients with a Gleason score of 7B, major 4 + minor 3 were added to the group of patients with a Gleason score of 8--10). Univariate and multivariate analyses were performed. A P value < 0.05 was considered to be statistically significant.

RESULTS

Three-tiered Gleason grouping resulted in a relatively even distribution of the patients (44 patients had a Gleason score < 7, 58 patients had a Gleason score of 7, and 76 patients had a Gleason score of 8--10) whereas 130 patients were determined to have Grade 2 tumors based on WHO criteria. Separating those patients with a Gleason score of 7 (score 3+4 vs. score 4+3) led to the two-tiered Gleason grouping (88 patients in the favorable group and 90 patients in the unfavorable group). The two-tiered Gleason grouping displayed differences with regard to failure-free survival with the lowest P values for all patients and separately for T1/2 versus T3/4 tumors. Together with T category and pretreatment prostate specific antigen, WHO grading, three-tiered Gleason grouping, and two-tiered Gleason grouping resulted in independent parameters in the Cox regression model. The proportional variance estimate confirmed the superior discrimination for survival of two-tiered Gleason grouping.

CONCLUSIONS

The equal allocation of patients to subgroups based on the Gleason system helps the clinician to overcome the dilemma of overrepresentation of Grade 2 patients as occurs with WHO grading. The Gleason grading system and, most likely, the two-tiered Gleason grouping appear to result in better prognostic separation of patients referred to radiotherapy for relatively advanced primary tumors. Therefore the authors recommend the routine use of Gleason grading for these patients.

Postradiotherapy prostate biopsies: what do they really mean? Results for 498 patients

PURPOSE

Postradiotherapy (RT) prostate biopsies are prone to problems in interpretation. False negatives due to sampling error, false positives due to delayed tumor regression, and indeterminate biopsies showing radiation effect in residual tumor of uncertain viability are common occurrences.

METHODS AND MATERIALS

A cohort of 498 men treated with conventional RT from 06/87-10/96 were followed prospectively with systematic transrectal ultrasound (TRUS)-guided post-RT prostate biopsies, starting 12-18 months after RT. If there was residual tumor but further decline in serum prostate-specific antigen (PSA), biopsies were repeated every 6-12 months. Patients with negative biopsies were rebiopsied at 36 months. Residual tumor was evaluated for RT effect and proliferation markers. The 498 men had 978 biopsies. Median time of the first biopsy (n = 498) was 13 months, biopsy #2 (n = 342) 28 months, biopsy #3 (n = 110) 36 months, biopsy #4 (n = 28) 44 months, and biopsy #5 (n = 4) 55 months. Median follow-up is 54 months (range 13-131). One hundred seventy-five patients (34%) had prior hormonal therapy for a median of 5 months (range 1-60).

RESULTS

Clinical stage distribution was T1b: 46; T1c: 50; T2a: 115; T2b/c: 170; T3: 108; T4: 11; Tx: 1. Distribution by Gleason score was: 28% Gleason score 2-4; 42%: 5-6; 18%: 7; and 12%: 8-10. Seventy-one men have died, 26 of prostate cancer and 45 of other causes. Actuarial failure-free survival by T stage at 5 years is T1b: 78%; T1c: 76%; T2a: 60%; T2b/c: 55%; T3: 30%; and T4: 0%. Actuarial freedom from local failure at 5 years is T1b: 83%; T1c: 88%; T2a: 72%; T2b/c: 66%; T3: 58%; and T4: 0%. The proportion of indeterminate biopsies decreases with time, being 33% for biopsy 1, 24% for biopsy 2, 18% for biopsy 3, and 7% for biopsy 4. Thirty percent of indeterminate biopsies resolved to NED status, regardless of the degree of RT effect, 18% progressed to local failure, and 34% remained as biopsy failures with indeterminate status within the time frame of this report. Positive staining for proliferation markers was associated with both subsequent local failure and also any type of failure. In multivariate analysis, only PSA nadir (p = 0.0002) and biopsy status at 24-36 months (p = 0. 0005) were independent predictors of outcome.

CONCLUSIONS

Post-RT prostate biopsies are not a gold standard of treatment efficacy, but are an independent predictor of outcome. Positive immunohistochemical staining for markers of cellular proliferation is associated with subsequent local failure. Indeterminate biopsies, even when showing marked RT effect, cannot be considered negative.

Microautoradiographic quantitation of vascular endothelial growth factor mRNA levels in human prostate specimens containing normal and neoplastic epithelium

Human prostate specimens commonly contain a spectrum of epithelial changes, including normal acinar and ductal structures, hyperplasia, intraepithelial neoplasia (dysplasia), and carcinoma. Since vascular endothelial growth factor (VEGF) expression is dependent on cell type and tissue microenvironment, meaningful quantitation of the levels of this mRNA in pathological specimens requires analysis at the microscopic level. Phosphorimage analysis of the binding of radiolabeled cRNA probes to tissue sections allows quantitation of mRNA levels, but the resolution is limited. Alternatively, emulsion autoradiography allows visualization of mRNA levels at cellular resolution, but quantitation is difficult. We have developed a method of quantitating steady state mRNA levels in tissue sections at the microscopic level, using autoradiography and quantitative image analysis. In this study, we describe the method and apply it to quantitation of VEGF mRNA in human prostate specimens. The VEGF mRNA level was low in nonepithelial stromal tissue (0.8 dpm/mm2), high in normal and benign hyperplastic epithelium (17-18 dpm/mm2), and significantly decreased in intraepithelial neoplasia (6.4 dpm/mm2) and in microacinar carcinoma that had invaded the stroma (3.5 dpm/mm2). Immunohistochemical staining detected VEGF protein in epithelial and stromal cells, with highest levels on the luminal surface of normal epithelium and in stromal cells, and lower levels in benign hyperplasia, intraepithelial neoplasia, and carcinoma. No correlation between VEGF expression in epithelium and nearby vessel density was observed. The results indicate a decrease in the steady state level of VEGF mRNA when prostate epithelial cells become transformed, escape the confines of glandular structure and invade the stroma, and suggest that the progression of prostatic carcinoma through the stages examined in this study is not associated with increased VEGF expression, in contrast to the elevated VEGF expression associated with progression of several other tumor types.

[Indications and results of exclusive radiotherapy in early prostatic adenocarcinoma]

Prostate adenocarcinoma incidence are rising rapidly, especially in early stages. Even if some of these carcinomas may be latent or slow growing either spontaneously or under hormonal therapy, most patients 75 years old or less presenting a localized tumor, T1b-c, T2, T3, N0, M0, whatever the grading, will require treatment with curative intent: radical prostatectomy, external beam radiation therapy (ERT) and/or brachytherapy. After ERT limited to the prostate or including seminal vesicles and/or pelvic lymph nodes, the overall survival and the survival without clinical evolution at 5, 10 and 15 years are good. However survival rates without biochemical evolution are about 30% lower and 70% or less at 5 years for the more favorable group (T < or = T2a and Gleason < 7 and PSA < 10 ng/mL). Brachytherapy alone yields good results for the same favorable group. In the unfavorable group (T > or = 2c and Gleason > or = 7 and PSA > or = 20 ng/mL), adjuvant hormonal therapy improves survival. Conformal radiation therapy allows an increase in dose to the tumor by about 15% without increasing complications. It can increase the biological remission rate in the intermediate group (T < or = 2a or Gleason > or = 7 or PSA > or = 20 ng/mL).

Osteopontin stimulates a subpopulation of quiescent human prostate epithelial cells with high proliferative potential to divide in vitro

BACKGROUND

Osteopontin (OPN) is a secreted extracellular matrix (ECM) protein found in bone, as well as associated with epithelial cells. The main objective of these studies was to test in vitro the hypothesis that interaction with OPN stimulates proliferation of a quiescent subpopulation of prostate epithelial cells with high proliferative potential.

METHODS

To simulate conditions that restrict proliferation and inhibit terminal differentiation of basal cells in vivo, control cultures grew on substrate coated with collagen (CO) or fibronectin (FN), in medium containing low levels of growth factors.

RESULTS

Under growth-restricting conditions, most prostate epithelial cells with high proliferative potential, seeded in control secondary cultures, were quiescent within the time frame of the studies, as indicated by the small number of large colonies in these cultures. Growing prostate epithelial cells (PR) under the same growth-restricting conditions, but on substrate coated with OPN instead of CO or FN, stimulated proliferation of a subpopulation of single cells with high proliferative ability as indicated by: 1) dose-dependent increase in the percentage of single cells incorporating bromodeoxyuridine, i.e., proliferating PR; and 2) subsequent dose-dependent increase in the percentage of large colonies. The OPN effect was not merely due to preferential attachment to OPN, because PR attachment to OPN, CO, or FN was identical. PR attachment to OPN was inhibited in the presence of GRGDTP or an antibody against the integrin subunit alphav, but not in the presence of an RGES peptide or a nonspecific IgG.

CONCLUSIONS

Integrin-mediated OPN/PR interaction stimulates proliferation of a quiescent subpopulation of prostate epithelial cells with high proliferative potential, possibly stem cells.

Interstitial implantation techniques in prostate cancer

Brachytherapy is a radiotherapeutic technique that allows the physician to implant radioactive isotopes into a body cavity or directly into tissue. Different radioisotopes have unique characteristics that the brachytherapist may utilize for a particular situation. The use of brachytherapy is part of standard radiation oncology practice in gynecological and head and neck cancer management. The prostate is approachable for interstitial implantation due to its close proximity to the perineum. Over 20 years ago, primitive methods of brachytherapy were utilized in the treatment of prostate cancer. However, poor results due to inconsistency in achieving adequate coverage of the entire prostate and poor patient selection caused this treatment modality to fall out of favor. Technological advances over the last decade have restored attention to brachytherapy for prostate cancer. Particularly important has been the development of transrectal ultrasound, new radioisotopes such as palladium-103, computer tomography, computerized dosimetry systems, and earlier diagnosis. Modern interstitial implantation utilizing transperineal template and transrectal ultrasound guidance has resulted in improved consistency in radiation dose delivery to the entire prostate. Early results are encouraging in terms of the relatively low morbidity of the procedure, improved local control rates, and biochemical progression free survival. This has resulted in an outpatient treatment that has high patient acceptance.

Radiotherapy for localized prostate carcinoma. The correlation of pretreatment prostate specific antigen and nadir prostate specific antigen with outcome as assessed by systematic biopsy and serum prostate specific antigen

BACKGROUND

The objective of this study was to correlate the failure pattern of localized prostate carcinoma after radiotherapy (RT) with pretreatment (preTx) PSA and post-RT nadir PSA, using systematic biopsies and serum PSA in the assessment of outcome.

METHODS

From January 1990 to February 1994, 207 patients treated with external beam RT were followed prospectively with systematic transrectal ultrasound-guided biopsies and measurements of serum PSA levels. Three hundred forty-three biopsies were performed, with 4-7 samples taken per session. The distribution of T classification was as follows: 19 patients had T1b, 15 had T1c, 34 had T2a, 79 had T2b/c, 53 had T3, and 7 had T4. Median follow-up was 36 months (range, 12-70 months). Failures were categorized as biochemical (chemF) (PSA > 2.0 ng/mL and > 1 ng/ mL over nadir), local (LF) (positive biopsy and PSA > 2), and distant (DF). The Cox proportional hazards model was used for multivariate analysis (MVA).

RESULTS

Overall, failures were seen in 68 of 207 patients: 20 LF, 24 DF, 7 LF + DF, and 17 chemF. In univariate analysis, failures correlated significantly with preTx PSA, post-RT nadir PSA, T classification, and Gleason's score (GS). The total failure rate was 12% for T1b, T1c, and T2a; 39% for T2b and T2c; and 60% for T3 and T4 (P < 0.0001). By evaluation with preTx PSA, at 36 months the total failure rate was 3% for preTx PSA < or = 5 ng/mL 16% for 5.1-10 ng/mL, 32% for 10.1-15 ng/mL, 42% for 15.1-20 ng/mL, 63% for 20.1-50 ng/mL, and 88% for > 50 ng/mL (P < 0.0001). By evaluation with post-RT nadir PSA, at 36 months the total failure rate was 4% for nadir PSA < or = 0.5 ng/ mL, 26% for 0.6-1 ng/mL, 33% for 1.1-2 ng/mL, and 92% for > 2 ng/mL (P < 0.0001). In MVA, nadir PSA (P < 0.0001) and T classification (P < 0.0005) were independent predictors for any failure. LF occurred in 13% of patients (27 of 207). For these 27 patients, the categorization of T classification was: T1b/T1c/T2a, 7%; T2b/T2c, 16%; and T3/T4, 15% (P = not significant). In MVA, only nadir PSA (P = 0.0004) predicted for LF. DF occurred in 15% of patients (31 of 207). In MVA, nadir PSA (P < 0.0001) and T classification (P < 0.0001) predicted for DF, with pretreatment PSA of borderline significance (P < 0.05). To assess preTx predictors of outcome, post-RT nadir PSA was removed from the model. PreTx PSA then became the dominant variable to predict any failure (P < 0.0001), LF (P = 0.05), chemF (P = 0.0001), and DF (P < 0.003), while T classification also predicted for any failure (P = 0.03), chemF (P = 0.05), and DF (P < 0.0001).

CONCLUSIONS

Systematic prostate biopsies, performed as part of the rigorous followup of prostate carcinoma after RT, define the patterns of failure and confirm the prognostic value of preTx PSA, post-RT nadir PSA, and T classification. Prior to treatment, preTx PSA is the overwhelming independent predictor of failure, but it is surpassed by post-RT nadir PSA when this is added to the model.

Posttreatment biopsy results following interstitial brachytherapy in early-stage prostate cancer

PURPOSE

To assess pathologic control rates for prostatic carcinoma as determined by postimplant prostate biopsy in a large series of consecutive patients who have received permanent interstitial brachytherapy using a contemporary transrectal ultrasound-directed, transperineal, computer generated, volume technique.

METHODS AND MATERIALS

Four hundred and two patients received permanent 125I or 103Pd interstitial brachytherapy as primary treatment for early stage prostatic carcinoma at the Northwest Tumor Institute between January 1988 and January 1994. Of these, 201 have consented to biopsy 12 or more months postimplant with a median follow-up of 40 months (range: 12-83 months). None had received hormonal manipulation. A total of 361 biopsies was performed on 201 patients with a range of one to six annual biopsies per patient (91 received multiple, serial biopsies). Of the 161 patients more than 12 months postimplant who have not been biopsied, most have been unwilling or unable to submit to biopsy. Only six patients with biochemical progression have not been biopsied. There was no difference in the presenting characteristics or implant parameters between those patients biopsied and those that were not. One hundred and forty-three received 125I (71%) prescribed to a MPD of 160 Gy with a median activity of 35.5 mCi, and 58 (29%) received 103Pd prescribed to a MPD of 115 Gy with a median activity of 123 mCi. Multiple biopsies were performed under transrectal ultrasound guidance, and all specimens were classified as either negative, indeterminate, or positive.

RESULTS

At the time of last biopsy, 161 (80%) have achieved negative pathology, 34 (17%) remain indeterminate, and 6 (3%) have been positive. Only 2 of the 186 patients with a PSA < 4.0 ng/ml at the time of biopsy were positive. Among those 33 indeterminate patients with a subsequent biopsy, 28 have converted to negative, 2 to positive, and 3 remain unchanged to date.

CONCLUSIONS

These data demonstrate at least an 80% pathologically confirmed local control rate following permanent interstitial brachytherapy for early stage prostate cancer. A higher local control rate is expected with further follow-up as the majority of indeterminate biopsies convert to negative over time. The indeterminate category of postirradiation biopsy described here includes specimens that have probably been interpreted as positive in other series, but correlate clinically and biochemically with negative biopsies. These results support the use of modern interstitial brachytherapy techniques for selected patients with early stage adenocarcinoma of the prostate.

Should brachytherapy be considered a therapeutic option in localized prostate cancer?

Contemporary prostate brachytherapy incorporates advances in computer analysis, imaging technology, and delivery apparatus, allowing exacting and reproducible results compared with historical approaches. The advances permit brachytherapy to be performed on a cost-effective, outpatient basis with low morbidity in the appropriately selected patient. Although unsettled questions remain regarding dosimetric issues, long-term outcomes, and morbidity, the weight of evidence to date appears to support the use of brachytherapy in selected patients. Brachytherapy may be considered a therapeutic option: as monotherapy for early-stage disease and also a boost following moderate doses of external beam irradiation for locally advanced disease.

Intraobserver and interobserver reproducibility of WHO and Gleason histologic grading systems in prostatic adenocarcinomas

In this study a total of 96 patients with prostatic carcinoma were evaluated retrospectively. Sections prepared from paraffin blocks were examined and all cases were scored according to the World Health Organization (WHO) and Gleason grading systems. We investigated intraobserver and interobserver reproducibility of two grading systems in prostatic adenocarcinomas. In our study the intraobserver reproducibilities of the WHO and Gleason systems were 75.0% and 78.1%, respectively. The interobserver reproducibilities of the WHO and Gleason grading systems were 60.4% and 70.8%, respectively. While there was no difference between intraobserver and interobserver variations in the Gleason system (p > 0.05), there was significant difference between intraobserver and interobserver variations in the WHO system (p < 0.05).

Distant metastasis after radical prostatectomy in patients without an elevated serum prostate specific antigen level

BACKGROUND

Serum prostate specific antigen (PSA) is a sensitive indicator of prostate cancer recurrence after radical prostatectomy. Prostate cancer rarely recurs after radical surgery without PSA elevation. Of the few patients noted in the literature who had a recurrence of cancer without PSA elevation, all had local recurrence alone, except for one, who had bone metastases.

METHODS

In the authors' series of 628 patients, PSA was the first indicator of recurrence in all but 2 (2.6%) of 77 patients with clinical T1-T3NxM0 classification prostate cancer.

RESULTS

Two of our patients, despite having undetectable PSA levels, had distant recurrence, including one with multiple visceral (lung and brain) metastases.

CONCLUSIONS

These two cases demonstrate that although uncommon, prostate cancer can recur and metastasize after radical prostatectomy without an increase in the serum PSA level.

Pathology review in an early prostate cancer detection program: results from the American Cancer Society-National Prostate Cancer Detection Project

Biopsy materials obtained in the American Cancer Society National Prostate Cancer Detection Project were reviewed at the Central Pathology Laboratory at the Armed Forces Institute of Pathology. Of 265 cases submitted, 177 were diagnosed as prostatic carcinoma, 7 as prostatic intraepithelial neoplasia (PIN), 13 as atypical glands or atypical hyperplasia, and the remaining 68 were benign hyperplasias. Irrespective of the means of detectin or the grading system used (Gleason or WHO-Mostofi), a large majority of the cancers were detected as low-grade tumors. Of 27 cases of PIN reported, 20 were associated with cancer, leaving 7 cases with the sole diagnosis of PIN. These data may indicate the increased use of prostate-specific antigen (PSA), digital rectal examination (DRE), and transrectal ultrasound (TRUS) in the United States is shifting the spectrum of prostate cancer pathology toward early low-grade tumors.

Routine prostate biopsies following radiotherapy for prostate cancer: results for 226 patients

OBJECTIVES

To determine the time course of histologic resolution of prostate cancer following radiotherapy (RT) and to correlate biopsy results with clinical outcome.

METHODS

Since July 1990, all patients treated with radical external beam RT for prostate cancer at the General Division of the Ottawa Regional Cancer Centre have had systematic transrectal ultrasound (TRUS) and TRUS-guided biopsies beginning 12 months after RT and then every 6 months until negative or until clinical failure. Thus, 226 patients have had 375 TRUS with four to seven specimens per examination. Stage distribution was T1b: 32, T1c: 11, T2a: 45, T2b: 82, T3: 50, and T4: 6. Median follow-up was 33 months.

RESULTS

Biopsy results were negative in 69.5% of patients by 30 months of follow-up. Thirty-two (14%) had local failure (T1b: 12.5%, T1c: 0%, T2a: 11%, T2b: 15%, T3: 18%, T4: 33%). Seven (3%) had chemical failure, and 47 (21%) had biopsy-only failure. Median follow-up for the biopsy-only failure group is only 19.5 months and mean prostate-specific antigen (PSA) is 1.0 ng/mL. Thirty-nine patients, initially with biopsy-only failure, have converted to negative biopsies at a median of 26 months. Nadir PSA for patients with local failure was 3.9 ng/mL at 14 months versus 0.7 ng/mL at 23 months for those without failure. Patients with late conversion to negative biopsy results had a later nadir PSA of 1.3 ng/mL at 27.3 months.

CONCLUSIONS

Routine prostate biopsy specimens after RT in an unselected population show tumor clearance that is in agreement with long-term clinical follow-up, although tumor may take more than 30 months to resolve. Nadir PSA can be used to predict outcome.

Differential expression of uPA in an aggressive (DU 145) and a nonaggressive (1013L) human prostate cancer xenograft

Prostate cancer has a slow growing noninvasive phase, but, in general, is invasive on diagnosis. An initial step in the invasion of surrounding normal tissue is the activity of proteolytic enzymes such as components of the plasminogen activator system (PA). In cell culture, the primary human prostate cancer cell line 1013L expressed no urokinase type-PA (uPA), while DU 145, a cell line derived from a metastatic lesion, expressed high levels of uPA. The DU 145 cells grew easily as xenografts but the establishment of 1013L in the SCID mice was possible only with the aid of a gelatin sponge (Spongostan). The latency period was 42-64 days, followed by a slow growth phase before a fast growth phase occurred. This fast growth phase was characterized by rapid degeneration of tumor tissue, while high proliferation occurred around the blood vessels. On serial transplantation of tumor material, the growth pattern was similar. Furthermore, the 1013L tumor was encapsulated by connective tissue and no invasiveness could be detected. We found that 1013L tumor homogenates had hardly detectable levels of uPA, i.e., 300-fold lower than we found in the invasive prostate xenograft DU 145. In addition, no expression of uPA was found in the plasma of 1013L tumor-bearing mice whilst uPA antigen was detected in the plasma of DU 145 tumor-bearing mice. In conclusion, the 1013L cell line, which exhibits a nonaggressive pattern, could be a good model for studying progression of prostate cancer to a more aggressive phenotype in vivo and in vitro.

The prognostic importance of Gleason grade in prostatic adenocarcinoma: a long-term follow-up study of 648 patients treated with radiation therapy

PURPOSE

It is common practice to histologically grade adenocarcinoma of the prostate using the Gleason system. Whereas the prognostic utility of this grading is well known, few studies have comprehensively evaluated it for patients undergoing definitive radiation therapy and generally accepted guidelines as to which Gleason grades should be "lumped" have not been established. This study reports the results of univariate and multivariate evaluation of the prognostic significance of Gleason grade in 648 patients followed for a median of 6.5 years after radiation therapy for T1 to T4, N0, or NX, MO prostate cancer.

METHODS AND MATERIALS

The correlation between Gleason grade and local recurrence, metastatic relapse, any disease relapse, and patient survival was evaluated using univariate and multivariate methods. Analysis was also stratified according to whether the grading was assigned on a needle biopsy or on a transurethral resection specimen.

RESULTS

The large number of Gleason grades required grouping of grades for meaningful analysis and we found that a four-tier system (grades 2 and 3, 155 patients; grades 4-6, 290 patients; grade 7, 92 patients; and grades 8-10, 111 patients) correlated best with outcome. In univariate analysis, this four-tier grouping correlated significantly with local recurrence, distant metastases, any relapse, and survival. The incidences of distant metastasis at 10 years were: grades 2 and 3, 13%; grades 4-6, 34%; grade 7, 52%; and, grades 8-10, 63%. The survival rates at 10 years were: grades 2 and 3, 64%; grades 4-6, 60%; grade 7, 46%; and grades 8-10, 24%. In multivariate analysis, Gleason grade was the single most important determinant of outcome for each endpoint. These results applied equally to needle biopsy and transurethral resection specimens.

CONCLUSION

Tumor grade is the single most significant determinant of outcome following radiotherapy for clinically localized prostate cancer. The Gleason system is a valid method for grading tumors to be irradiated. A four-tier grouping into grades 2 and 3, grades 4-6, grade 7, and grades 8-10 appears to be adequate and simple.

Proliferative cell nuclear antigen in postradiotherapy prostate biopsies

PURPOSE

To determine if staining for proliferative cell nuclear antigen (PCNA) can distinguish between biologically active and inactive "residual tumor" in postradiotherapy prostate biopsies by correlating PCNA staining with clinical outcome.

METHODS AND MATERIALS

Since July 1990 all patients treated at the General Division of the Ottawa Regional Cancer Center with radical external beam radiotherapy for prostate cancer have had systematic transrectal ultrasound and transrectal ultrasound-guided biopsies beginning 12 months postradiotherapy. One hundred sixty-two patients have had 278 transrectal ultrasounds with four to seven biopsy specimens per examination. All biopsies were stained for prostate specific antigen and prostatic acid phosphatase. Keratin 903 was used to distinguish radiation atypia in benign glands from residual cancer. PCNA staining was done on all suspicious biopsies. Stage distribution was 31 T1b, 35 T2a, 61 T2b, and 35 T3-4. Median follow-up was 32 months (range 13-74).

RESULTS

Negative biopsies have been obtained in 83% of T1b and T2a tumors and 70% of T2b and T3-4. Twenty-six tumors have recurred locally (T1b: 10%, T2a: 3%, T2b: 21%, T3-4: 26%), six with concurrent distant metastases. Of these 26 local failures, 23 had positive PCNA (mean 15.4 nuclei per 100) and three could not be determined (insufficient tissue). In 34 patients showing residual carcinoma at the first postradiotherapy biopsy, subsequent negative biopsies were obtained at a median of 25 months. Proliferative cell nuclear antigen staining could be performed in 23 of these 34 patients. Sixty-five percent (15/23) were negative on the first biopsy, indicating a nonproliferative state. In those with PCNA positive residual on initial biopsy, none retained PCNA staining on subsequent negative biopsies. One patient with an initial PCNA negative biopsy has failed locally.

CONCLUSION

Proliferative cell nuclear antigen staining is useful in postradiotherapy prostate biopsies. Negative PCNA in a positive biopsy predicts (83-97%) for eventual resolution of tumor. Positive PCNA correlates with local failure (49-79%), but when present in an early biopsy (12-18 months), may still disappear.

Endometrioid adenocarcinoma of the prostate: a clinicopathologic and immunohistochemical study

On retrospective review of the tumor registry files between 1979 and 1992 at the North Iowa Medical Center, six cases of endometrioid adenocarcinoma of the prostate were identified among 1582 cases of prostatic carcinoma. Along with long-term clinicopathologic follow-up, immunohistochemical studies of the prostatic tumor tissues were performed. All six cases of endometrioid carcinoma, together with control cases of benign prostatic hypertrophy (BPH) and ordinary adenocarcinoma of the prostate had unequivocal diffuse positive staining for PSA and similar reactivity to ER-D5 and PS2. Thus, endometrioid carcinoma is most likely derived from the prostate or prostatic urethral duct rather than the utricle. However, due to its unusual initial clinical manifestations, biological behavior, and distinctive histomorphology, the term "endometrioid adenocarcinoma of the prostate" is worth preserving.

Proliferating cell nuclear antigen/cyclin in incidental carcinoma of the prostate

Monoclonal antibody to proliferating cell nuclear antigen (PCNA) has been used to identify the growth fraction in ten cases of benign prostatic hyperplasia (BPH), in 20 prostatic microcarcinomas (PMC) and in 30 cases of infiltrating prostatic carcinoma (PC). Ten year follow-up was available on all cases by means of clinical, serological, radiological and echographic examinations. The percentage of PCNA-staining nuclei was independently counted by two observers. Statistical analysis showed significant differences between PCNA/cyclin score of BPH and PMC without recurrences with respect to those of PMC with progression and of PC. PCNA immunostaining may represent a reliable method for assessing cellular proliferative activity. It may be used as a more powerful diagnostic hallmark of PMC than patterns of non-malignant microglandular proliferation and is also a useful additional test for assigning histological grades to PMC and PC. Statistical analysis indicated that PCNA/cyclin index was an independent significant prognostic indicator of predicting malignant progression (P < or = 0.01) and survival rates (P < or = 0.05) of PC and PMC (> 5 mm diameter).