Phillip Brenner

Multiparametric Magnetic Resonance Imaging Guided Diagnostic Biopsy Detects Significant Prostate Cancer and could Reduce Unnecessary Biopsies and Over Detection: A Prospective Study

PURPOSE Multiparametric magnetic resonance imaging appears to improve prostate cancer detection but prospective studies are lacking. We determined the accuracy of multiparametric magnetic resonance imaging for detecting significant prostate cancer before diagnostic biopsy in men with abnormal prostate specific antigen/digital rectal examination. MATERIALS AND METHODS In this single center, prospective study men older than 40 years with abnormal prostate specific antigen/digital rectal examination and no previous multiparametric magnetic resonance imaging underwent T2-weighted, diffusion-weighted and dynamic contrast enhanced imaging without an endorectal coil. Imaging was allocated alternately to 1.5/3.0 Tesla. Imaging was double reported independently using PI-RADS (Prostate Imaging Reporting and Data System) by specialist radiologists. Transperineal grid directed 30-core biopsy was performed with additional magnetic resonance imaging directed cores for regions of interest outside template locations. Four significant cancer definitions were tested. Chi-square and logistic regression analysis was done. Men undergoing prostatectomy were analyzed. RESULTS Of the 165 men who enrolled in the study 150 were analyzed. Median age was 62.4 years, median prostate specific antigen was 5.6 ng/ml, 29% of patients had an abnormal digital rectal examination and 88% underwent initial biopsy. Multiparametric magnetic resonance imaging was positive (PI-RADS 3 to 5) in 66% of patients, 61% had prostate cancer and 30% to 41% had significant prostate cancer (definitions 1 to 4). For significant cancer sensitivity was 93% to 96%, specificity was 47% to 53%, and negative and positive predictive values were 92% to 96% and 43% to 57%, respectively (definitions 1 to 4). Radical prostatectomy results in 48 men were similar. Aggregate PI-RADS (4 to 20) performed similarly to overall PI-RADS (1 to 5). Negative and positive predictive values (100% and 71%, respectively) were similar in men at higher risk, defined as prostate specific antigen greater than 10 ng/ml with abnormal digital rectal examination. On multivariate analysis PI-RADS score was associated with significant prostate cancer (p <0.001) but magnet strength was not. Adding PI-RADS to the multivariate model improved the AUC from 0.810 to 0.913 (95% CI 0.038-0.166, p = 0.002). Radiologist agreement was substantial (weighted κ = 0.626). CONCLUSIONS Multiparametric magnetic resonance imaging reported by expert radiologists achieved an excellent negative predictive value and a moderate positive predictive value for significant prostate cancer at 1.5 and 3.0 Tesla.

Prognostic significance of Gleason pattern in patients with Gleason score 7 prostate carcinoma

In the current study, the authors sought to further stratify the prognosis of patients with Gleason score (GS) 7 prostate carcinoma. They assessed the influence on outcome of a predominant poorly differentiated Gleason pattern (primary Gleason pattern [GP] 4) and/or a coincident small focus of poorly differentiated tumor of higher grade (tertiary GP 5).

Prognostic significance of preoperative factors in localized prostate carcinoma treated with radical prostatectomy

Predicting outcome for men with clinically localized prostate carcinoma treated with curative intent remains imprecise and further evaluation of accepted and potential predictive factors is needed.

Pathologic findings at the time of nephrectomy for renal mass

AbstractBackground: Ultrasound (US) and computed tomography (CT) have improved the diagnosis of solid renal masses. Nevertheless, some patients still undergo exploration for a presumptive diagnosis of renal cell carcinoma (RCC) and are found to have other pathology. We report a contemporary series of non-RCC renal masses (both incidental and symptomatic) among nephrectomies performed for suspected RCC. Materials and Methods: All nephrectomies performed by the Urology Service at the Memorial Sloan-Kettering Cancer Center from July of 1989 through July of 1996 for a parenchymal renal mass were reviewed, and patients without a final diagnosis of RCC were identified. Cases were excluded if RCC was not suspected preoperatively. Presentation, preoperative radiographic evaluation, type of operation, and pathologic features were assessed. Results: Of the 636 nephrectomies performed, 108 patients (16.9%) had a diagnosis other than RCC. Conclusions: Of patients undergoing nephrectomy for renal masses, 16.9% have other pathologic diagnoses. Sixty-six percent of these non-RCC masses are discovered incidentally, and the majority are treated with radical nephrectomy. Preoperative radiographic evaluation reflects both clinical presentation, with IVP used to evaluate symptomatic tumors, and diagnostic uncertainty, with multiple modalities used to evaluate cystic lesions. This information has important implications for preoperative counseling and surgical planning.

Expression of the zinc transporter ZnT4 is decreased in the progression from early prostate disease to invasive prostate cancer.

We have utilized oligonucleotide microarrays to identify novel genes of potential clinical and biological importance in prostate cancer. RNA from 74 prostate cancers and 164 normal body samples representing 40 different tissues were analysed using a customized Affymetrix GeneChip® oligonucleotide microarray representative of over 90% of the expressed human genome. The gene for the zinc transporter ZnT4 was one of several genes that displayed significantly higher expression in prostate cancer compared to normal tissues from other organs. A polyclonal antipeptide antibody was used to demonstrate ZnT4 expression in the epithelium of all 165 elements of benign and 326 elements of localized prostate cancers examined and in nine of 10 advanced prostate cancer specimens by immunohistochemistry. Interestingly, decreased intensity of ZnT4 immunoreactivity occurred in the progression from benign to invasive localized prostate cancer and to metastatic disease. Immunofluorescence analysis and surface biotinylation studies of cells expressing ZnT4 localised the protein to intracellular vesicles and to the plasma membrane. These findings are consistent with a role for ZnT4 in vesicular transport of zinc to the cell membrane and potentially in efflux of zinc in the prostate.

Membranous Expression of Secreted Frizzled-Related Protein 4 Predicts for Good Prognosis in Localized Prostate Cancer and Inhibits PC3 Cellular Proliferation in Vitro

Purpose: Activation of the Wnt-signaling pathway is implicated in aberrant cellular proliferation in a variety of cancers. Secreted frizzled-related protein 4 (sFRP4) is a secreted protein with putative inhibitory activity of the Wnt-signaling cascade through binding and sequestering Wnt ligands. Because sFRP4 mRNA is overexpressed in prostate cancers (PCs), the aim of this study was to define the pattern of sFRP4 protein expression in normal and malignant human prostate tissue and to determine whether changes in expression were associated with disease progression and prognosis, as well as to define the phenotype of sFRP4-overexpression in an in vitro model of PC. Experimental Design: Polyclonal antibodies were raised against a COOH-terminal peptide of sFRP4, characterized and used to assess sFRP4 protein expression in benign prostate tissue and 229 patients with clinically localized PC (median follow-up 77 months, range 1–156). In vitro studies of the function of sFRP4 overexpression were performed using PC3 cells transfected with sFRP4. Results: Benign and malignant prostate tissue demonstrated cytoplasmic sFRP4 immunoreactivity, but there was a decrease in the expression of membranous sFRP4 in PCs compared with the hyperplastic lesions (P < 0.0001). Kaplan-Meier analysis revealed that patients whose PC expressed membranous sFRP4 in >20% of cells had improved relapse-free survival compared with those with ≤20% membranous expression (P = 0.002). Moreover, membranous sFRP4 expression (P = 0.04) was an independent predictor of relapse when modeled with Gleason score (P = 0.006), pathological stage (P = 0.002), and pre-operative prostate-specific antigen levels (P = 0.004). In addition, in vitro studies demonstrated a decrease in the proliferation rate of PC3 cells transfected with sFRP4 when compared with the control PC3-empty vector cells (P < 0.0001). Decreased levels of phosphorylated glycogen synthase kinase 3β in PC3-sFRP4 cells suggested that this phenotype is mediated by the “Wnt/β-catenin” pathway. Conclusions: These data suggest that sFRP4 expression may be prognostic for localized PC, potentially as a consequence of an inhibitory effect on PC cell proliferation.

Simultaneous retroperitoneal, thoracic, and cervical resection of postchemotherapy residual masses in patients with metastatic nonseminomatous germ cell tumors of the testis.

PURPOSE We report our experience with simultaneous resection of residual masses above and below the diaphragm in patients with metastatic nomseminomatous germ cell tumor (NSGCT) of the testis. MATERIALS AND METHODS Twenty-four patients underwent simultaneous resection of residual postchemotherapy masses in the retroperitoneum and chest, including three who also had radical neck dissection. All had been heavily pretreated with chemotherapy and five had undergone previous retroperitoneal lymph node dissections (RPLNDs). RESULTS The combined procedure was performed with no mortality and low morbidity. The median length of the procedure was 5 hours 45 minutes, median blood loss 500 mL, and median length of hospital stay 9 days. Complications included one patient with chylous ascites and one with a prolonged air leak, both of which resolved with conservative management. Eighteen patients had similar pathologic findings in all sites: 13 with necrosis only and five with teratoma only. Six patients had discordant pathology in the abdomen and chest, including one with viable tumor in the chest only and two with viable tumor in the abdomen only. The overall actuarial 5-year survival rate for all patients was 79%. CONCLUSION Simultaneous resection of neck, chest, and abdominal residual masses after chemotherapy for germ cell tumors is both a feasible and safe alternative to staged excision in selected patients who require surgical intervention at multiple sites and fulfills the objective of rendering patients disease-free in a single operative procedure.

Prognostic Significance of Pathologic Features in Localized Prostate Cancer Treated With Radical Prostatectomy: Implications for Staging Systems and Predictive Models

PURPOSE Although predicting outcome for men with clinically localized prostate cancer (PC) has improved, the staging system and nomograms used to do this are based on results from the North American health system. To be internationally applicable, these models require testing in cohorts from a variety of different health systems based on the predominant PC case identification methods used. PATIENTS AND METHODS We studied 732 men with localized PC treated with radical prostatectomy and no preoperative therapy between 1986 and 1999 at one Australian institution to determine the effect of clinicopathologic features on disease-free survival. RESULTS Preoperative serum prostate-specific antigen (PSA) concentration, Gleason score, pathologic stage, and year of surgery were independent predictors of outcome. Although margin status demonstrated only a trend toward significance in multivariate modeling overall, it proved to be independent in subgroups based on later year of surgery (1986 to 1994 v 1995 to 1998), preoperative PSA of less than 10 ng/mL, and Gleason score > or = 7. Adjuvant radiation therapy improved disease-free survival rates in patients with multiple surgical margin involvement. CONCLUSION This work confirms the prognostic significance of pathologic stage, Gleason score, and preoperative serum PSA. In the context of a contemporaneous screening effect in Australia, these findings may have implications for methods that predict outcome following surgery as screening becomes more prevalent in a population. The independent prognostic effect of margin status may alter with an increase in the proportion of screening-identified PCs. Staging systems and nomograms that predict outcome following surgery require validation in cohorts with different health practices before being universally applied.

Lower levels of nuclear β‐catenin predict for a poorer prognosis in localized prostate cancer

β‐catenin in its role as a nuclear signaling molecule has been implicated in prostate carcinogenesis primarily through modulation of androgen receptor activity. We defined the pattern of β‐catenin protein expression in the nuclei of normal, hyperplastic and malignant human prostate tissue and determined whether differences in expression were associated with disease progression and prognosis. Five normal prostates, 26 benign prostatic hypertrophy specimens, 232 radical prostatectomy specimens from patients with clinically localized prostate cancer (PC) and 20 cases of advanced PC were assessed for β‐catenin expression using immunohistochemistry. Nuclear β‐catenin expression in localized PC was significantly lower than that in benign prostate tissue (p < 0.001) and significantly higher than that in advanced PC tissue (p < 0.001). In addition, lower levels of nuclear β‐catenin expression (< 10% of cancer cells) predicted for a shorter biochemical relapse‐free survival in patients with localized PC (p = 0.008) and were inversely correlated with preoperative prostate‐specific antigen (PSA) levels (p = 0.01). Analysis of the low‐risk subgroup of patients with preoperative PSA levels < 10 ng/ml demonstrated that lower levels of nuclear β‐catenin expression (< 10% of cancer cells) again predicted for a poorer prognosis (p = 0.006). In conclusion, lower levels of nuclear β‐catenin expression are found in malignant compared to benign prostate tissue. In addition, lower nuclear β‐catenin expression is associated with a poorer prognosis in localized PC, in particular, in the low‐risk subgroup of patients with preoperative PSA levels < 10 ng/ml. Thus, the level of nuclear β‐catenin expression may be of clinical utility as a preoperative prognostic marker in low‐risk localized PC.

Location and Pathological Characteristics of Cancers in Radical Prostatectomy Specimens Identified by Transperineal Biopsy Compared to Transrectal Biopsy

PURPOSE Anterior tumors are estimated to constitute 20% of prostate cancers. Current data indicate that transperineal biopsy is more reliable than transrectal biopsy in identifying these tumors. If correct, this superior reliability should result in an increased proportion of anterior tumors identified by transperineal biopsy. We investigated this hypothesis with reference to prostatectomy specimens. MATERIALS AND METHODS Radical prostatectomy histopathology records were retrospectively examined. Patients were grouped based on primary transperineal or transrectal biopsy as the modality used to identify the initial cancer. After grouping, tumor location and size were recorded and, thus, the proportion of anterior tumors was determined. RESULTS A total of 1,132 (414 transperineal and 718 transrectal) prostatectomy specimens were examined. Overall mean tumor size (1.8 and 2.0 cm(3)), stage (pT2 63.3% and 61%) and significance (5.1% and 5.1%) for the transperineal and transrectal methods were similar. However, the transperineal method was associated with proportionally more anterior tumors (16.2% vs 12%, p = 0.046), and identified them at a smaller size (1.4 vs 2.1 cm(3), p = 0.03) and lower stage (extracapsular extension 13% vs 28%, p = 0.03) compared to the transrectal method. The pT3 positive surgical margin rate for anterior vs other tumors was 69% vs 34.9%, respectively. CONCLUSIONS Overall transrectal and transperineal biopsy identify cancers that are similar in size, stage and significance. However, transperineal biopsy detected proportionally more anterior tumors (16.2% vs 12%), and identified them at a smaller size (1.4 vs 2.1 cm(3)) and stage (extracapsular extension 13% vs 28%) compared to transrectal biopsy. Identifying anterior tumors early is important because the positive surgical margin rate for anterior pT3 lesions is significantly higher.