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This study demonstrates the feasibility of using a novel 2D spectrum ultrasonic tissue characterization (UTC) technique for prostate-cancer diagnosis. Normalized 2D spectra are computed by performing Fourier transforms along the range (beam) and the cross-range directions of the digital radio-frequency echo data, then dividing by a reference spectrum. This 2D spectrum method provides axial and lateral information of tissue microstructures, an improvement over the current 1D spectrum analysis which only provides axial information. A pilot study was conducted on four prostate-cancer patients who underwent radical prostatectomies. Cancerous and noncancerous regions of interest, identified through histology, were compared using four 2D spectral parameters: peak value and 3 dB width of the radially integrated spectral power (RISP), slope and intercept of the angularly integrated spectral power (AISP). For noncancerous and cancerous prostatic tissues, respectively, our investigation yielded 23 +/- 1 and 26 +/- 1 dB for peak value of RISP, 7.8 +/- 0.5 degrees and 7.6 +/- 0.6 degrees for 3 dB of RISP, -2.1 +/- 0.2 and -2.7 +/- 0.4 dB/MHz for slope of AISP, and 92 +/- 5 and 112 +/- 6 dB for intercept of AISP. Preliminary results indicated that 2D spectral UTC has the potential for identifying tumor-bearing regions within the prostate gland.

TREK-1 is a two-pore domain (K(2P)) potassium channel that carries a leak current that is time- and voltage-independent. Recently, potassium channels have been related to cell proliferation and some K(2P) family channels, such as TASK-3, have been shown to be overexpressed in specific neoplasms. In this study, we addressed the expression of TREK-1 in prostatic tissues and cell lines, and we have found that this potassium channel is highly expressed in prostate cancer but is not expressed in normal prostate nor in benign prostatic hyperplasia. Furthermore, expression of TREK-1 correlates strongly with the grade and the stage of the disease, suggesting a causal link between channel expression and abnormal cell proliferation. In vitro studies showed that TREK-1 is highly expressed in PC3 and LNCaP prostate cancer cell lines but is not detectable in normal prostate epithelial cells (NPE). In this report, we show that overexpression of TREK-1 in NPE and Chinese hamster ovary (CHO) cells leads to a significant increase in proliferation. Moreover, the increased cell proliferation rate of PC3 cells and TREK-1 overexpressing CHO cells could be reduced when TREK-1 current was reduced by overexpression of a dominant-negative TREK-1 mutant or when cells were exposed to a TREK-1 inhibitor. Taken together, these data suggest that TREK-1 expression is associated with abnormal cell proliferation and may be a novel marker for and a molecular target in prostate cancer.

Objectives: To describe the changes in the Gleason grading system over time and evaluate how a shift in Gleason grading has affected the overall predictive accuracy of the system in predicting biochemical disease-free survival after radical prostatectomy., Methods: The Columbia University Urologic Oncology Database was reviewed, and 1515 patients who met the inclusion criteria were identified who had undergone radical prostatectomy from 1988 to 2004. The patients were divided into two time cohorts (1988 to 1997 and 1998 to 2004). To determine whether a shift in the Gleason sum distribution has occurred, a chi-square test was performed. Survival curves and log-rank tests were used to compare the biochemical disease-free survival between cohorts stratified by the Gleason sum. To estimate the predictive ability of the Gleason system over time, concordance indexes were calculated., Results: A shift toward greater Gleason sums over time was confirmed using the chi-square test (P <0.001). A significant difference was observed in biochemical disease-free survival between the two time cohorts for those with Gleason sum 6 cancer (P <0.01). The concordance indexes corresponding to Gleason sum alone for each time cohort were 0.71 and 0.87, demonstrating that the Gleason sum's predictive ability improved significantly over time. After adjusting for other variables, the Gleason sum continued to demonstrate a significantly improved predictive ability in the more recent time cohort., Conclusions: We found a trend toward the assignment of increasing Gleason sums over time in our data set. This shift in Gleason sum distribution between the two time cohorts has resulted in a significant improvement in the predictive ability of the Gleason system.

Objectives: To retrospectively compare the biochemical disease-free survival (BDFS) of patients treated with standard dose external beam radiotherapy (SD-EBRT), SD-EBRT plus androgen deprivation (AD), and brachytherapy-based treatment (brachytherapy with or without EBRT with or without AD)., Methods: All 297 patients with intermediate-risk prostate cancer treated with these radiation-based treatments at our institution from August 1989 to June 2001 were included. Biochemical relapse was defined according to the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, a prostate-specific antigen level of 1.5 ng/mL or greater and rising on two consecutive occasions (the "Bolla" definition), and the current prostate-specific antigen nadir plus 2 ng/mL with failure dated "at call" (the "Houston/Phoenix" definition). The number of patients treated with SD-EBRT, SD-EBRT plus AD, and brachytherapy-based treatment was 141, 84, and 72, respectively. The year of treatment was analyzed as a prognostic factor. The median follow-up was 32.3, 34.7, and 41.5 months for the ASTRO, Bolla, and Houston/Phoenix definitions, respectively., Results: The brachytherapy-based treatment resulted in improved BDFS compared with SD-EBRT (ASTRO definition, 5-year BDFS rate 88% +/- 5% versus 49% +/- 5%, P <0.01; Bolla definition, 88% +/- 8% versus 49% +/- 5%, P <0.01; Houston/Phoenix definition, 81% +/- 10% versus 64% +/- 5%, P = 0.01). SD-EBRT plus AD was superior to SD-EBRT alone using the Bolla definition (5-year BDFS 76% +/- 7% versus 49% +/- 5%, P <0.01) and the Houston/Phoenix definition (85% +/- 6% versus 64% +/- 5%, P = 0.01), but not using the ASTRO definition (P = 0.17). Multivariate analysis, including prostate-specific antigen, clinical stage, Gleason score, and year of treatment, demonstrated improved biochemical outcomes for brachytherapy-based treatment versus SD-EBRT (ASTRO, P <0.01; Bolla, P <0.01; and a trend toward significance with Houston/Phoenix, P = 0.07) and for the addition of AD to SD-EBRT (Bolla, P <0.01 and Houston/Phoenix, P = 0.03). The year of treatment trended toward significance (P = 0.077) on multivariate analysis using the ASTRO definition., Conclusions: For patients with intermediate-risk prostate cancer, brachytherapy-based treatment and the addition of AD to SD-EBRT resulted in improved biochemical outcomes compared with the outcomes with SD-EBRT alone; however, these findings were dependent on the definition of biochemical failure used. The year of treatment may be an important prognostic factor in intermediate-risk prostate cancer.

Purpose: To evaluate the toxicity and efficacy of individualized neoadjuvant androgen deprivation (AD) to maximal response followed by external beam radiotherapy (RT) with continued AD for a total of 9 months in a prospective phase II trial., Patients and Methods: One hundred twenty-three patients received a total of 9 months of flutamide and luprolide combined with RT. RT initiation was individualized to begin after maximum response to AD as assessed by monthly digital rectal examination and prostate-specific antigen (PSA). The neoadjuvant phase was restricted to no more than 6 months., Results: Median time to initiation of RT was 4.7 months. Indications to begin RT (and their rates) were undetectable PSA (28%), PSA unchanged from one month to the next (46%), PSA rising from one month to the next (10%), 6 months of AD (14%), and other (2%). Five-year outcomes were biochemical disease-free survival, (DFS) 63% +/- 7%; clinical DFS, 75% +/- 5%; cancer-specific survival, 99% +/- 1%; and overall survival, 89% +/- 3%. Patients initiating RT after 6 months of AD had significantly lower biochemical and clinical DFS. Those patients whose testosterone recovered to normal after completion of AD had a significantly superior survival rate. Of those patients potent before treatment, 65% remained so at last follow-up., Conclusion: The combination of 9 months of AD and RT, with initiation of RT individualized on the basis of maximum response to AD, achieves disease control rates comparable with past studies, while preserving potency in many patients. Further studies are warranted to determine the optimal combination of AD and RT in this patient population.

Cyclin-dependent kinase 6 (CDK6) binds to and is activated by cyclin D1 and thereby enhances the transition of cells through the G1 phase of the cell cycle. The present study indicates that, in human prostate cancer cells, CDK6 can also bind to the androgen receptor (AR) and stimulate its transcriptional activity in the presence of dihydrotestosterone. This effect of CDK6 does not require its kinase activity and is inhibited by cyclin D1 and p16INK4a. The T877A mutant of the AR frequently found in advanced cases of prostate cancer displays an exaggerated stimulation of transcriptional activity by CDK6. Androgen-sensitive LNCaP prostate cancer cells engineered to stably overexpress CDK6 display increased expression of the prostate-specific antigen and enhanced growth in the presence of dihydrotestosterone. CDK6 is present in the chromatin structure of these cells in association with the AR and the promoter region of the prostate-specific antigen gene. These findings suggest that CDK6 may play an important role in the development and/or progression of a subset of human prostate cancers by stimulating the activity of the AR.

Purpose: Hispanic-Americans are the fastest growing minority group in the United States. Many studies have compared prostate cancer treatment outcomes between black and white men, but few such studies have been done with Hispanic men. We compared clinical and pathological features as well as the treatment failure rate of radical prostatectomy in contemporaneously treated groups of Hispanic and white men with prostate cancer., Materials and Methods: Between 1995 and 2002, 136 Hispanic men and 315 white men underwent radical prostatectomy. Treatment failure was defined as having a prostate specific antigen (PSA) of 0.2 or greater more than 8 weeks after surgery or receiving any adjuvant therapy. Known predictors of failure and race were evaluated for their ability to predict treatment failure., Results: Median followup was 32 months for Hispanic and 36 months for white patients. Hispanic men were older, had a higher percentage of abnormal rectal examinations, Gleason 7 tumors and preoperative PSA levels greater than 10. Preoperative PSA, specimen Gleason score, pathological stage and surgical margin were all strongly associated with treatment failure (p<0.001). Despite differences in clinical characteristics, overall failure rates did not differ between Hispanic and white men (18.7% vs 17.8%). The odds ratio for treatment failure for Hispanic relative to white men after adjusting for the previously mentioned risk factors was 0.87 (95% CI [0.44, 1.68], p = 0.670)., Conclusions: This study shows that Hispanic race does not influence the treatment failure rate of radical prostatectomy in contemporaneously treated patients with prostate cancer at 1 institution. To our knowledge this study represents the largest of its kind, but longer followup and other confirmatory studies are needed.

Purpose: Hispanic-Americans are the most rapidly growing population in the United States. Although many studies have assessed differences in pathological stage at radical prostatectomy between white and black American men, to our knowledge none has assessed it in Hispanic men. We compared pathological stage at radical prostatectomy in contemporaneous groups of Hispanic and white American men., Materials and Methods: A total of 141 consecutive Hispanic and 314 consecutive white American men underwent radical retropubic prostatectomy for clinically localized prostate cancer from 1995 to 2002 at a single institution, as performed by one of us (ETG or MCB). Preoperative prostate specific antigen (PSA), age at diagnosis, race, clinical stage, biopsy and specimen Gleason score, pathological stage, specimen volume and calculated specimen PSA density were collected for each patient. Data were compared using standard statistical methods., Results: Biopsy Gleason score, biopsy Gleason score distribution, specimen Gleason score, specimen Gleason distribution, pathological stage, calculated specimen PSA density, Gleason score change from biopsy to specimen and specimen prostate volume did not differ statistically between Hispanic and white men. Mean age and median preoperative PSA were statistically significantly higher in Hispanic vs white men (62.1 vs 59.5 years and 6.6 vs 5.4 ng/ml, respectively). In addition, no differences in the incidence of positive surgical margins, nonorgan confined disease, seminal vesicle invasion or positive lymph nodes were found between Hispanic and white men undergoing radical prostatectomy., Conclusions: This study shows that in contemporaneously treated groups of Hispanic and white men at the same institution pathological stage was similar between the groups. To our knowledge this is the largest comparison of surgically treated prostate cancer between these 2 groups. Further followup in terms of PSA outcome in these groups is planned.

Purpose: It has been reported that genistein, an isoflavone used in soybeans, has antiprostate cancer effects. Genistein Combined Polysaccharide (GCP trade mark; AMino Up, Sapporo, Japan), a nutritional supplement manufactured in Japan, is composed of genistein and a polysaccharide obtained from basidiomycetes (mycelia) that grows in a variety of mushrooms., Methods: We report a case of a patient with a biopsy proven prostate cancer showing clinical and pathologic evidence of regression following administration of GCP. The patient was enrolled in an Institutional Review Board (IRB)-approved protocol and received GCP for 6 weeks prior to radical prostatectomy., Results: The patient's prostate-specific antigen (PSA) decreased from an initial value of 19.7 to 4.2 ng/mL after 44 days of low-dose GCP. No cancer was identified in the radical prostatectomy specimen and no side effects were observed in this patient., Conclusion: This case suggests that GCP, which has shown potent inhibitory effects against prostate cancer in vitro, may have some potential activity in the treatment and prevention of prostate cancer.