A four-kallikrein panel for the prediction of repeat prostate biopsy: data from the European Randomized Study of Prostate Cancer screening in Rotterdam, Netherlands.

BACKGROUND: Most men with elevated levels of prostate-specific antigen (PSA) do not have prostate cancer, leading to a large number of unnecessary biopsies. A statistical model based on a panel of four kallikreins has been shown to predict the outcome of a first prostate biopsy. In this study, we apply the model to an independent data set of men with previous negative biopsy but persistently elevated PSA. METHODS: The study cohort consisted of 925 men with a previous negative prostate biopsy and elevated PSA (>or=3 ng ml(-1)), with 110 prostate cancers detected (12%). A previously published statistical model was applied, with recalibration to reflect the lower positive biopsy rates on rebiopsy. RESULTS: The full-kallikrein panel had higher discriminative accuracy than PSA and DRE alone, with area under the curve (AUC) improving from 0.58 (95% confidence interval (CI): 0.52, 0.64) to 0.68 (95% CI: 0.62, 0.74), P<0.001, and high-grade cancer (Gleason >or=7) at biopsy with AUC improving from 0.76 (95% CI: 0.64, 0.89) to 0.87 (95% CI: 0.81, 0.94), P=0.003). Application of the panel to 1000 men with persistently elevated PSA after initial negative biopsy, at a 15% risk threshold would reduce the number of biopsies by 712; would miss (or delay) the diagnosis of 53 cancers, of which only 3 would be Gleason 7 and the rest Gleason 6 or less. CONCLUSIONS: Our data constitute an external validation of a previously published model. The four-kallikrein panel predicts the result of repeat prostate biopsy in men with elevated PSA while dramatically decreasing unnecessary biopsies.

Molecular characterisation of ERG, ETV1 and PTEN gene loci identifies patients at low and high risk of death from prostate cancer.

BACKGROUND: The discovery of ERG/ETV1 gene rearrangements and PTEN gene loss warrants investigation in a mechanism-based prognostic classification of prostate cancer (PCa). The study objective was to evaluate the potential clinical significance and natural history of different disease categories by combining ERG/ETV1 gene rearrangements and PTEN gene loss status. METHODS: We utilised fluorescence in situ hybridisation (FISH) assays to detect PTEN gene loss and ERG/ETV1 gene rearrangements in 308 conservatively managed PCa patients with survival outcome data. RESULTS: ERG/ETV1 gene rearrangements alone and PTEN gene loss alone both failed to show a link to survival in multivariate analyses. However, there was a strong interaction between ERG/ETV1 gene rearrangements and PTEN gene loss (P<0.001). The largest subgroup of patients (54%), lacking both PTEN gene loss and ERG/ETV1 gene rearrangements comprised a 'good prognosis' population exhibiting favourable cancer-specific survival (85.5% alive at 11 years). The presence of PTEN gene loss in the absence of ERG/ETV1 gene rearrangements identified a patient population (6%) with poorer cancer-specific survival that was highly significant (HR=4.87, P<0.001 in multivariate analysis, 13.7% survival at 11 years) when compared with the 'good prognosis' group. ERG/ETV1 gene rearrangements and PTEN gene loss status should now prospectively be incorporated into a predictive model to establish whether predictive performance is improved. CONCLUSIONS: Our data suggest that FISH studies of PTEN gene loss and ERG/ETV1 gene rearrangements could be pursued for patient stratification, selection and hypothesis-generating subgroup analyses in future PCa clinical trials and potentially in patient management.

Updated postoperative nomogram incorporating the number of positive lymph nodes to predict disease recurrence following radical prostatectomy.

BACKGROUND: A significant number of patients with minimal lymph node disease at radical prostatectomy (RP) and pelvic lymph node dissection (PLND) have better than expected long-term outcomes. We explored whether stratification by number of positive nodes enhances our institutional prediction model for biochemical recurrence after RP. METHODS: A total of 7789 patients underwent RP and pelvic lymph node dissection from 1995 to 2012 at a tertiary referral center. We compared two recurrence prediction models: one incorporated lymph node invasion and the other tracked the number of positive nodes. Existing and updated models' discrimination was assessed using Harrell's c-index and calibration. The 10-fold cross-validation was performed to correct for model overfitting. RESULTS: Of the 491 patients (6.3%) harboring nodal disease, 387 (5.0%) had 1-2 positive nodes and 104 (1.3%) had ⩾3 positive nodes. Data on number of positive nodes did not improve the c-index for the cohort as a whole. When we assessed discrimination for node-positive patients only, c-index for the model with number of positive nodes was 0.01 (95% confidence interval 0.001-0.024) higher than the model with lymph node invasion. Illustrative examples were provided by reclassification tables using number of positive lymph nodes. For instance, 40 of 7789 patients would be reclassified with a cutoff point of 50% for biochemical recurrence at 1 year, and 36 of 7789 patients would be reclassified with a cutoff point of 40% for biochemical recurrence at 10 years. CONCLUSIONS: Stratification by number of positive lymph nodes provided additional discriminative ability for evaluating risk in node-positive patients. Pending external validation, this model could be used for patient counseling and clinical trial stratification in this subpopulation.

Periprostatic adipose inflammation is associated with high-grade prostate cancer.

BACKGROUND: Obesity, a cause of subclinical inflammation, is associated with increased risk of high-grade prostate cancer (PC) and poor outcomes. Whether inflammation occurs in periprostatic white adipose tissue (WAT), and contributes to the negative impact of obesity on PC aggressiveness, is unknown. METHODS: In a single-center, cross-sectional design, men with newly diagnosed PC undergoing radical prostatectomy were eligible for study participation. The primary objective was to examine the prevalence of periprostatic WAT inflammation defined by the presence of crown-like structures (CLS-P) as detected by CD68 immunohistochemistry. Secondary objectives were to explore the clinical and systemic correlates of periprostatic WAT inflammation. Tumor characteristics and host factors including BMI, adipocyte diameter, and circulating levels of lipids, adipokines, and other metabolic factors were measured. Wilcoxon rank-sum, Chi-square, or Fisher's exact tests, and generalized linear regression were used to examine the association between WAT inflammation and tumor and host characteristics. RESULTS: Periprostatic fat was collected from 169 men (median age 62 years; median BMI 28.3). Periprostatic WAT inflammation was identified in 49.7% of patients and associated with higher BMI (P=0.02), larger adipocyte size (P=0.004) and Gleason grade groups IV/V tumors (P=0.02). The relationship between WAT inflammation and high Gleason grade remained significant after adjusting for BMI (P=0.04). WAT inflammation correlated with higher circulating levels of insulin, triglycerides, and leptin/adiponectin ratio, and lower high density lipoprotein cholesterol, compared to those without WAT inflammation (P's <0.05). CONCLUSION: Periprostatic WAT inflammation is common in this cohort of men with PC and is associated with high-grade PC.

A preoperative nomogram for disease recurrence following radical prostatectomy for prostate cancer.

BACKGROUND: Few published studies have combined clinical prognostic factors into risk profiles that can be used to predict the likelihood of recurrence or metastatic progression in patients following treatment of prostate cancer. We developed a nomogram that allows prediction of disease recurrence through use of preoperative clinical factors for patients with clinically localized prostate cancer who are candidates for treatment with a radical prostatectomy. METHODS: By use of Cox proportional hazards regression analysis, we modeled the clinical data and disease follow-up for 983 men with clinically localized prostate cancer whom we intended to treat with a radical prostatectomy. Clinical data included pretreatment serum prostate-specific antigen levels, biopsy Gleason scores, and clinical stage. Treatment failure was recorded when there was clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on a separate sample of 168 men, also from our institution. RESULTS: Treatment failure (i.e., cancer recurrence) was noted in 196 of the 983 men, and the patients without failure had a median follow-up of 30 months (range, 1-146 months). The 5-year probability of freedom from failure for the cohort was 73% (95% confidence interval = 69%-76%). The predictions from the nomogram appeared accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (i.e., comparison of the predicted probability with the actual outcome) of 0.79. CONCLUSIONS: A nomogram has been developed that can be used to predict the 5-year probability of treatment failure among men with clinically localized prostate cancer treated with radical prostatectomy.

DNA ploidy by image analysis of individual foci of prostate cancer: a preliminary report.

The malignant potential of an individual focus of prostate cancer is difficult to determine. The established pathological features associated with malignant behavior include tumor volume, grade, and invasiveness (local extension or metastasis). We used nuclear image analysis to determine the DNA ploidy value of each cancer in a series of 30 radical prostatectomy specimens from patients with early stage prostate cancer in order to further explore the malignant potential of each separate focus of cancer. The volume, grade, invasiveness (extracapsular extension or seminal vesicle invasion), and zone of origin of each of the 63 separate cancers were determined. The DNA ploidy histogram of 200 cancer cells was compared with 50 normal epithelial nuclei on the same Feulgen-stained tissue sections. Sixty % of the cancers were diploid, and 40% were nondiploid. Ploidy correlated with volume and grade. All cancers less than 0.02 cm3 were diploid; 26% of foci 0.02 to 2.0 cm3 and 82% of foci greater than 2.0 cm3 were nondiploid. There were 16 cancers of transition zone origin ranging in size from 0.02 to 12.1 cm3 and only one (7.3 cm3) was nondiploid. There were 47 cancers of peripheral zone origin (range, 0.01 to 18.98) and 24 (51%) were nondiploid. Eight of the 24 nondiploid cancers were small (less than 1.0 cm3), and two were only 0.03 cm3. We conclude that some very small prostate cancers are nondiploid and that progression of prostate cancer is not a function of volume alone, whereby tumors only acquire full malignant potential at large volumes. Cancers of peripheral zone origin acquire a nondiploid cell population at a smaller volume than do cancers of transition zone origin, further supporting a fundamental difference between cancers arising in these zones.

Dietary fenretinide, a synthetic retinoid, decreases the tumor incidence and the tumor mass of ras+myc-induced carcinomas in the mouse prostate reconstitution model system.

Several epidemiological studies have implicated low dietary and serum levels of retinol with an increased risk for the development of human prostate cancer. In a recent report, dietary fenretinide [N-[(4-hydroxyphenyl)] retinamide], a synthetic retinoid with low toxicity, decreased the incidence of experimentally induced prostate cancer. Fenretinide is currently being evaluated in phase I and phase II clinical trials as an agent for both the treatment and chemoprevention of human prostate cancer. Because of these findings, we investigated whether dietary fenretinide could alter the incidence of phenotype of oncogene-induced prostate cancer in the mouse prostate reconstitution model system. When compared to control-fed animals, dietary fenretinide reduced the tumor incidence by 49% and the tumor mass by 52% of ras+myc-induced cancers in the mouse prostate reconstitution model system, which was modified to prolong the latency period before cancer development. Retinoids have a wide ranging effect on cellular differentiation, growth factor synthesis, and immune function. While its mechanism of action in this system remains unclear, fenretinide is an effective agent for the chemoprevention and growth modulation of oncogene-induced prostate cancer in the mouse prostate reconstitution model system and may be effective for the chemoprevention of human prostate cancer.

Number of metastatic lymph nodes as determinant of outcome after salvage radical prostatectomy for radiation-recurrent prostate cancer. / Número de ganglios linfáticos metastásicos como determinante de los resultados de la prostatectomía radical de rescate en el cáncer de próstata de recidivante tras radioterapia.

BACKGROUND: Presence of lymph node metástasis (LNM) at salvage radical prostatectomy (sRP) is associated with poor outcome. Predictors of outcome in this context remain undetermined. ThE objective was to assess the role of number of positive lymph node on outcome of patients with LNM after sRP and for radio-recurrent prostate cancer. MATERIAL AND METHODS: We analyzed data from a consecutive cohort of 215 men treated with sRP at a single institution. We used univariate Cox proportional hazard regression models for biochemical recurrence (BCR) and metastatic outcomes, with prostate-specific antigen, Gleason score, extraprostatic extension, seminal vesicle invasion, time between radiation therapy and sRP, and number of positive nodes as predictors. RESULTS: Of the 47 patients with LNM, 37 developed BCR, 11 developed distant metastasis and 4 died with a median follow-up of 2.3 years for survivors. The risk of metastases increased with higher pre-operative PSA levels (HR 1.19 per 1ng/ml; 95% CI: 1.06-1.34; P=.003). The remaining predictors did not reach conventional levels of significance. However, removal of 3 or more positive lymph nodes demonstrated a positive association, as expected, with metastatic disease (HR 3.44; 95% CI: 0.91-13.05; P=.069) compared to one or 2 positive nodes. Similarly, the presence of extraprostatic extension, seminal vesicle invasion and Gleason grade greater than 7 also demonstrated a positive association with higher risk of metástasis, with hazard ratios of 3.97 (95% CI: 0.50, 31.4; P=.2), 3.72 (95% CI: 0.80-17.26; P=.1), and 1.45 (95% CI: 0.44-4.76; P=.5), respectively. CONCLUSIONS: In patients with LNM after sRP for radio-recurrent prostate cancer, the risk of distant metástasis is likely to be influenced by the number of positive nodes (3 or more), high preoperative PSA, Gleason grade and advanced pathologic stage. These results are consistent with the findings of number of nodes (1 to 2 vs. 3 or more nodes positive) as a prognostic indicator after primary radical prostatectomy and strengthen the plea for a revision of the nodal staging for prostate cancer.

Postoperative nomogram for disease recurrence after radical prostatectomy for prostate cancer.

PURPOSE: Although models exist that place patients into discrete groups at various risks for disease recurrence after surgery for prostate cancer, we know of no published work that combines pathologic factors to predict an individual's probability of disease recurrence. Because clinical stage and biopsy Gleason grade only approximate pathologic stage and Gleason grade in the prostatectomy specimen, prediction of prognosis should be more accurate when postoperative information is added to preoperative variables. Therefore, we developed a postoperative nomogram that allows more accurate prediction of probability for disease recurrence for patients who have received radical prostatectomy as treatment for prostate cancer, compared with the preoperative nomogram we previously published. PATIENTS AND METHODS: By Cox proportional hazards regression analysis, we modeled the clinical and pathologic data and disease follow-up for 996 men with clinical stage T1a-T3c NXM0 prostate cancer who were treated with radical prostatectomy by a single surgeon at our institution. Prognostic variables included pretreatment serum prostate-specific antigen level, specimen Gleason sum, prostatic capsular invasion, surgical margin status, seminal vesicle invasion, and lymph node status. Treatment failure was recorded when there was either clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on this set of men and a separate sample of 322 men from five other surgeons' practices from our institution. RESULTS: Cancer recurrence was noted in 189 of the 996 men, and the recurrence-free group had a median follow-up period of 37 months (range, 1 to 168 months). The 7-year recurrence-free probability for the cohort was 73% (95% confidence interval, 68% to 76%). The predictions from the nomogram appeared to be accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (ie, a comparison of the predicted probability with the actual outcome) of 0.89. CONCLUSION: A postoperative nomogram has been developed that can be used to predict the 7-year probability of disease recurrence among men treated with radical prostatectomy.

Pretreatment nomogram for predicting the outcome of three-dimensional conformal radiotherapy in prostate cancer.

PURPOSE: Several studies have defined risk groups for predicting the outcome after external-beam radiotherapy of localized prostate cancer. However, most models formed patient risk groups, and none of these models considers radiation dose as a predictor variable. The purpose of this study was to develop a nomogram to improve the accuracy of predicting outcome after three-dimensional conformal radiotherapy. MATERIALS AND METHODS: This study was a retrospective, nonrandomized analysis of patients treated at the Memorial Sloan-Kettering Cancer Center between 1988 and 1998. Clinical parameters of the 1,042 patients included stage, biopsy Gleason score, pretreatment serum prostate-specific antigen (PSA) level, whether neoadjuvant androgen deprivation therapy was administered, and the radiation dose delivered. Biochemical (PSA) treatment failure was scored when three consecutive rises of serum PSA occurred. A nomogram, which predicts the probability of remaining free from biochemical recurrence for 5 years, was validated internally on this data set using a bootstrapping method and externally using a cohort of patients treated at the Cleveland Clinic, Cleveland, OH. RESULTS: When predicting outcomes for patients in the validation data set from the Cleveland Clinic, the nomogram had a Somers' D rank correlation between predicted and observed failure times of 0.52. Predictions from this nomogram were more accurate (P<.0001) than the best of seven published risk stratification systems, which achieved a Somers' D coefficient of 0.47. CONCLUSION: The development process illustrated here produced a nomogram that seems to predict more accurately than other available systems and may be useful for treatment selection by both physicians and patients.

Fifteen-year survival and recurrence rates after radiotherapy for localized prostate cancer.

PURPOSE: To determine 15-year survival and recurrence rates after radiotherapy for localized prostate cancer. METHODS: One hundred thirty-six patients with clinically localized prostate cancer treated from 1966 to 1974 with interstitial gold seed and external-beam irradiation were evaluated to determine the probability of recurrence and survival > or = 15 years after therapy. All patients were surgically staged with pelvic lymphadenectomy and none received hormonal therapy before relapse. RESULTS: Overall, 60 patients (44%) have never recurred, although 57% (34 of 60) of these same patients have died of causes other than prostate cancer. Local progression developed in 39% of patients and distant metastases in 42%. At 15 years, the probability of dying of prostate cancer was 33%+/-8% (% +/- 2SE) and of all causes was 72%+/-8%. In clinical stage A2 and B, 29%+/-9% of patients died of their cancer within 15 years, compared with 57%+/-21% in stage C1, while only 18%+/-8% with clinical stage A2 and B and negative lymph nodes died of cancer within this period. In contrast, the prostate cancer mortality rate at 15 years was high for patients with positive nodes regardless of the stage of the primary tumor (73% for A2 and B; 71% for C1). Patients with nodal metastases, poorly differentiated tumors, and advanced local disease all had a significantly (P < .0001) increased risk of cancer death. CONCLUSION: The cancer-specific mortality rate for patients with stage A2 and B tumors and negative nodes compares favorably with other series of patients treated with radiation therapy and > or = 15 years' follow-up evaluation. While local progression rates are high and associated with a substantial risk of prostate cancer death, many patients live with the disease and ultimately die of causes other than prostate cancer.

Prostate-specific antigen doubling times are similar in patients with recurrence after radical prostatectomy or radiotherapy: a novel analysis.

PURPOSE: Some investigators have analyzed the rate of growth of prostate cancer that has recurred after definitive radiotherapy or radical prostatectomy using serum prostate-specific antigen (PSA) doubling times (DT). We examined all PSA values in recurrent patients to determine the pattern and rate of increase in PSA after radiation therapy and radical prostatectomy. PATIENTS AND METHODS: Charts of 96 recurrent radical prostatectomy patients (mean age, 62.8 years; range, 47 to 76) and 42 recurrent radiation therapy patients (mean age, 67.2 years; range, 52 to 83) were reviewed. All available PSA values between the date of operation/radiation treatment and last follow-up evaluation or the initiation of second-line therapy are included. Rate of PSA DT was not assumed to be constant over time; it was instead allowed to vary. We use a piecewise linear random-coefficients model in time for log (PSA), which allowed different mean models for both treatments. RESULTS: The PSA DT in the first year after radiation therapy was--1.17 years, which reflects the continuous decline in PSA in the average patients during the first year after radiotherapy despite eventual biochemical progression. In contrast, the PSA DT in the radical prostatectomy group was 0.66 in the first year. In year 2, after radiation therapy, the PSA DT was lengthy at 1.82 years, significantly longer (P = .0025) than in the radical prostatectomy group (0.76 years). After year 2, there were no significant differences between the two groups (P > .05). CONCLUSION: A piecewise linear random-coefficients model enables interval analysis of PSA DT. While the PSA DT after radiation therapy and radical prostatectomy are different in the first 2 years, the rate of increase in PSA appears to be similar in the two groups after year 2, which suggests the rate of growth of cancers that recur after radiation therapy and radical prostatectomy is similar.

Clustered p53 immunostaining: a novel pattern associated with prostate cancer progression.

Abnormal p53 protein accumulation is typically defined as present when greater than 5 or 10% of cancer cells stain positively. We present a novel approach whereby immunopositivity is defined when 15 or more cells within a 300 x 400-micrometer(2) field exhibit p53 protein accumulation; a feature that we have called "clustered" staining. We assessed p53 immunostaining of moderately differentiated, clinically localized prostate cancers derived from two patient groups: those without cancer recurrence 5 years after radical prostatectomy, and those in whom cancer had recurred following radical prostatectomy. Clustered p53 immunopositivity was present in 10 (63%) of 16 patients in the recurrent group and in only 7 (21%) of 33 in the nonrecurrent group. Clustered p53 staining was clearly associated with cancer recurrence (P < 0.01). This refinement of a commonly used assay may help define the biological aggressiveness of a cancer.

Reduced levels of transforming growth factor beta receptor type II in human prostate cancer: an immunohistochemical study.

In previous studies we demonstrated that the growth of human prostatic adenocarcinoma is associated with aberrant accumulation of transforming growth factor (TGF) beta1, a growth factor that has been shown to be a potent inhibitor of epithelial cell proliferation. We investigated the expression of TGF-beta receptor II (TGFbetaR-II) in benign prostate tissue and in prostate cancer using standard immunohistochemical techniques. Quantitation of immunopositivity for TGFbetaR-II was assessed on a visual analogue scale ranging from 0 (absence of staining) to 4+ (intensely positive staining). All of the benign glandular epithelia stained intensely, either 3+ or 4+, representative of the ubiquitous nature of TGFbetaR-II in normal tissue. Overall, staining was reduced in prostate cancer sections, and there was progressively diminished staining as the histological grade of the cancer increased (P < 0.01, Kruskal-Wallis test). This immunohistochemical study indicates that a decline in the levels of TGFbetaR-II is correlated with advancing histological aggressiveness of the cancer and suggests that aberrant TGFbetaR-II function may play a role in human prostate carcinogenesis.

Association of p53 mutations with metastatic prostate cancer.

In prostate cancer, mutation of the p53 tumor suppressor gene has been associated with locally advanced disease and hormone-resistant disease that is predominantly localized to bone. However, little is known regarding the status of the p53 gene in metastatic prostate cancer that has not been treated with hormonal manipulation. We evaluated formalin-fixed, paraffin-embedded malignant tissues from 86 patients with various stages of prostate cancer, including pathologically confined, locally advanced, and metastatic disease, to detect abnormal p53 nuclear protein accumulation using immunohistochemistry. No abnormal p53 immunostaining was detected in 18 patients with prostate cancer confined to the gland. Two tumors from 21 patients with locally advanced disease (extracapsular extension and/or seminal vesicle invasion) had abnormal nuclear p53 accumulation, and a mutation in exon 7 of the p53 gene was detected in tumor DNA from one patient using single-strand conformation polymorphism-direct sequencing analysis. Of the remaining 47 patients studied in whom tissues from the prostate gland and a metastatic site (44 lymph node, 2 bone, and 1 lung) were available, only 3 had received hormonal therapy prior to obtaining metastatic tissue. In four patients both primary and metastatic tumors demonstrated accumulation of p53 protein, whereas seven additional patients exhibited p53 accumulation only at the metastatic site. In three patients the metastatic tumors harbored missense single-base substitutions in exon 5, as detected using single-strand conformation polymorphism-direct sequencing. These results indicate that p53 abnormalities are associated with lymph node metastases derived from prostate cancer patients that had not undergone hormonal therapy.

Primary human prostate cancer cells harboring p53 mutations are clonally expanded in metastases.

Recent studies suggest a role for p53 in prostate cancer progression. Although p53 mutations in primary prostate cancer tissues are relatively infrequent, they occur at significant levels in metastatic disease. Here we describe a novel approach to the molecular analysis of p53 in paired specimens of primary and metastatic prostate cancer that results in quantitative estimates of the extent of clonal expansion. In 20 pairs with 1 or both specimens p53 immunopositive and in 6 pairs with both specimens immunonegative, the frequency of mutations was estimated by microdissection of the cancer from fixed and sectioned tissues, isolation of the DNA followed by PCR amplification of p53 genomic fragments, and cloning of the PCR products into plasmid vectors. At least 90 clones/tissue specimen were screened for mutations by single-strand conformational polymorphism analysis. DNA from abnormally migrating single-strand conformational polymorphism samples was sequenced to confirm mutations. Missense mutations in exon 5, 7, or 8 were detected in 9 of 20 immunopositive pairs and in 1 of 6 immunonegative pairs. A marked heterogeneity of mutations in primary prostate cancer was apparent. The frequency of p53 mutations was greater in the metastases than in the primary tumors. In three immunopositive pairs, the same p53 mutation was demonstrated at a low frequency in the primary tumor but was demonstrated at a greater frequency in the metastasis, indicating relatively limited clonal expansion of cells harboring specific p53 mutations in the primary tumor, yet significant clonal growth at metastatic sites as determined by this novel method.

Elevated expression of caveolin is associated with prostate and breast cancer.

To identify genes associated with prostate cancer progression, we developed a strategy involving the use of differential display-PCR with a panel of genetically matched primary tumor- and metastasis-derived mouse prostate cancer cell lines. We isolated a cDNA fragment with homology to the mouse caveolin-1 gene. Northern blotting with this fragment revealed increased caveolin expression in metastasis-derived cell lines relative to primary tumor-derived cell lines. Western blotting with a polyclonal caveolin antibody confirmed increased caveolin protein in metastasis-derived mouse cell lines and expression in three of four human prostate cancer cell lines. Immunohistochemical analysis of a human prostate cancer cell line demonstrated a prominent granular pattern of caveolin accumulation. Subsequent analysis of mouse and human prostate specimens revealed minimal caveolin expression in normal epithelium with abundant staining of smooth muscle and endothelium. The frequency of caveolin-positive cells was increased in prostate cancer with markedly increased accumulation of caveolin and a granular staining pattern in lymph node metastatic deposits. In human breast cancer specimens, increased caveolin staining was detected in intraductal and infiltrating ductal carcinoma as well as nodal disease. Caveolin therefore appears to be associated with human prostate cancer progression and is also present in primary and metastatic human breast cancer.

Elevated transforming growth factor-beta 1 and beta 3 mRNA levels are associated with ras + myc-induced carcinomas in reconstituted mouse prostate: evidence for a paracrine role during progression.

Mouse prostate reconstitution is a useful model for studying the progression of ras + myc-induced carcinomas. When these oncogenes were introduced into both the epithelial and the mesenchymal compartments, poorly differentiated adenocarcinomas resulted. Restricted introduction of both oncogenes into the epithelium produced epithelial hyperplasia. Malignancies were produced in two out of 17 cases of selectively transformed epithelium, suggesting that the hyperplastic condition represents a premalignant phenotype. Restricted introduction of both oncogenes into the mesenchyme produced only mesenchymal dysplasia. Transforming growth factor-beta 1 (TGF-beta 1) and beta 3 (TGF-beta 3) mRNA levels were elevated in the ras + myc-induced carcinomas when compared to the normal controls or to the epithelial hyperplasias. In contrast, TGF-beta 2 mRNA levels were similar in all control and ras + myc-induced carcinomas. Elevated TGF-beta 1 mRNA levels were also found in mesenchymal dysplasia pointing to a potential paracrine activity by the ras + myc transformed mesenchyme. We conclude that elevated TGF-beta 1 and beta 3 are correlated with progression to malignancy and that mesenchyme derived TGF-beta 1 may play an important role in the promotion of ras + myc-induced carcinomas in this model system.

The diffusion of minimally invasive radical prostatectomy in the United States: a case study of the introduction of new surgical devices.

BACKGROUND: The diffusion of minimally invasive radical prostatectomy (MIRP) in the United States may have led to adverse patient outcomes due to rapid surgeon adoption and collective inexperience. We hypothesized that throughout the early period of minimally invasive surgery, MIRP patients had inferior outcomes as compared with those who had open radical prostatectomy (ORP). METHODS: We used the Surveillance, Epidemiology and End RESULTS-Medicare dataset and identified men who had ORP and MIRP for prostate cancer from 2003-2009. Study endpoints were receipt of subsequent cancer treatment, and evidence of postoperative voiding dysfunction, erectile dysfunction (ED) and bladder outlet obstruction. We used proportional hazards regression to estimate the impact of surgical approach on each endpoint, and included an interaction term to test for modification of the effect of surgical approach by year of surgery. RESULTS: ORP (n=5362) and MIRP (n=1852) patients differed in their clinical and demographic characteristics. Controlling for patient characteristics and surgeon volume, there was no difference in subsequent cancer treatments (hazard ratio (HR) 0.89, 95% confidence interval (CI) 0.76-1.05), although MIRP was associated with a higher risk of voiding dysfunction (HR 1.31, 95% CI 1.20-1.43) and ED (HR 1.43, 95% CI 1.31-1.56), but a lower risk of bladder outlet obstruction (HR 0.86, 95% CI 0.75-0.97). There was no interaction between approach and year for any outcome. When stratifying the analysis by year, MIRP consistently had higher rates of ED and voiding dysfunction with no substantial improvement over time. CONCLUSIONS: MIRP patients had adverse urinary and sexual outcomes throughout the diffusion of minimally invasive surgery. This may have been a result of the rapid adoption of robotic surgery with inadequate surgeon preparedness.

In situ gene therapy for adenocarcinoma of the prostate: a phase I clinical trial.

For patients with local recurrence of prostate cancer after definitive irradiation therapy there is no treatment widely considered safe and effective. After extensive preclinical testing of prodrug gene therapy in vitro and in vivo, we conducted a phase I dose escalation clinical trial of intraprostatic injection of a replication-deficient adenovirus (ADV) containing the herpes simplex virus thymidine kinase gene (HSV-tk) injected directly into the prostate, followed by intravenous administration of the prodrug ganciclovir (GCV). Our goal was to determine safe dose levels of the vector for future trials of efficacy. Patients with a rising serum prostate-specific antigen (PSA) level and biopsy confirmation of local recurrence of prostate cancer without evidence of metastases one or more years after definitive irradiation therapy were eligible for the trial. After giving informed consent, patients received injections of increasing concentrations of ADV/HSA-tk in 1 ml into the prostate under ultrasound guidance. Ganciclovir was then given intravenously for 14 days (5 mg/kg every 12 hr). Patients were monitored closely for evidence of toxicity and for response to therapy. Eighteen patients were treated at 4 escalating doses: group 1 (n = 4) received 1 x 10(8) infectious units (IU); group 2 (n = 5) received 1 x 10(9) IU; group 3 (n = 4) received 1 x 10(10) IU; group 4 (n = 5) received 1 x 10(11) IU. Vector was detected by PCR of urine samples after treatment, increasing in frequency and duration (up to 32 days) as the dose increased. All cultures of blood and urine specimens were negative for growth of adenovirus. Minimal toxicity (grade 1-2) was encountered in four patients. One patient at the highest dose level developed spontaneously reversible grade 4 thrombocytopenia and grade 3 hepatotoxicity. Three patients achieved an objective response, one each at the three highest dose levels, documented by a fall in serum PSA levels by 50% or more, sustained for 6 weeks to 1 year. This study is the first to demonstrate the safety of ADV/HSV-tk plus GCV gene therapy in human prostate cancer and the first to demonstrate anticancer activity of gene therapy in patients with prostate cancer. Further trials are underway to identify the optimal distribution of vector within the prostate and to explore the safety of repeat courses of gene therapy.