Understanding prostate cancer

Ureteral Metastasis From Prostate Cancer: A Report of Two Cases

Prostate adenocarcinoma (PCa) is the second most common cause of cancer in men, but metastases to the ureter are exceedingly rare. Here, we present two cases with differing clinical symptoms and treatment courses but ultimately the same diagnosis. The two cases presented here had differing clinical presentations: one with lower urinary tract symptoms and the other with hydronephrosis. Systemic therapy with a luteinizing hormone-releasing hormone (LHrH) agonist appears to help with clinical outcomes in both cases reported here. Although such cases are extremely rare, consideration as a differential and early detection can impact a patient's clinical outcomes. For patients with PCa that present with obstructive urinary symptoms, there may be a clinical benefit to perform a thorough metastatic work-up for seeding to other parts of the urinary tract.

An In Vitro Evaluation and Network Pharmacology Analysis of Prospective Anti-Prostate Cancer Activity from Perilla frutescens

Perilla frutescens (L.) Britt. is extensively cultivated in East Asia as a dietary vegetable, and nutraceuticals are reportedly rich in bioactive compounds, especially with anticancer activities. This study explored the in vitro cytotoxic effects of P. frutescens parts' (stems, leaves, and seeds) extracts on prostate cancer cells (DU-145) and possible interactions of putative metabolites to related prostate cancer targets in silico. The ethanol extract of P. frutescens leaves was the most cytotoxic for the prostate cancer cells. From high-performance liquid chromatography analysis, rosmarinic acid was identified as the major metabolite in the leaf extracts. Network analysis revealed interactions from multiple affected targets and pathways of the metabolites. From gene ontology enrichment analysis, P. frutescens leaf metabolites could significantly affect 14 molecular functions and 12 biological processes in five cellular components. Four (4) KEGG pathways, including for prostate cancer, and six (6) Reactome pathways were shown to be significantly affected. The molecular simulation confirmed the interactions of relevant protein targets with key metabolites, including rosmarinic acid. This study could potentially lead to further exploration of P. frutescens leaves or their metabolites for prostate cancer treatment and prevention.

Comparison of Dual-Tracer PET and CT Features to Conventional Risk Categories in Assessing Response to 177Lu-PSMA-617 Therapy for Metastatic Prostate Adenocarcinoma with Urinary Bladder Involvement

The present communication details the imaging characteristics, peculiarities, and response to ¹⁷⁷Lu-labeled prostate-specific membrane antigen (PSMA)-617-targeted radioligand therapy (PRLT) in accordance with Gleason score and use of dual-tracer PET (⁶⁸Ga-PSMA-11 and ¹⁸F-FDG) in patients with urinary bladder invasion or metastasis by prostate cancer, including the prognostic value of ¹⁸F-FDG PET in predicting response to treatment. The CT attenuation units (Hounsfield units) correlated with the prostate primary in the case of direct tumor extension from the prostate, whereas in hematogenous metastatic seeding the Hounsfield units were lower than in the primary prostatic tumor. A favorable outcome to ¹⁷⁷Lu-PSMA-617 PRLT was observed in patients with low or no baseline ¹⁸F-FDG uptake despite a high Gleason score and a high-risk National Comprehensive Cancer Network prognostic category and did not correlate with the latter alone, whereas a high SUV_max on ¹⁸F-FDG PET/CT was associated with an adverse outcome. These findings suggest a promising role for ¹⁸F-FDG PET/CT in predicting therapeutic outcomes more confidently, and hence the concept of dual-tracer PET appears to hold good in prostate adenocarcinoma theranostics.

Triptorelin relieves lower urinary tract symptoms in Chinese advanced prostate cancer patients: a multicenter, non-interventional, prospective study

BACKGROUND

Although triptorelin is increasingly used in China for biochemical castration, its effects on primary prostate cancer symptoms remain unclear. This study aimed to assess the prevalence of lower urinary tract symptoms (LUTS) in Chinese prostate cancer patients and the effectiveness of triptorelin on LUTS.

METHODS

In this 48-week multicenter, non-interventional, prospective study, we enrolled patients with locally advanced or metastatic prostate cancer. Patients received triptorelin (15 mg) intramuscularly at baseline and at weeks 12, 24, and 36 with symptom assessment using the International Prostate Symptoms Score (IPSS). The primary endpoints were the prevalence of LUTS at baseline per IPSS categories and the percentage of patients with moderate to severe LUTS (IPSS > 7) at baseline, having at least a 3-point reduction of IPSS score at week 48.

RESULTS

A total of 398 patients were included; 211 (53.0%) and 160 (40.2%) among them had severe and moderate LUTS, respectively. Of the patients with IPSS scores available at baseline and at week 48 (n = 213), 81.2% achieved a reduction in IPSS of at least 3 points. Of the patients with moderate to severe LUTS at baseline and IPSS scores available at baseline and at week 48 (n = 194), 86.6% achieved a total IPSS reduction of at least 3 points.

CONCLUSIONS

The vast majority of Chinese patients with locally advanced or metastatic prostate cancer scheduled to receive triptorelin as part of their standard treatment have severe or moderate LUTS. Triptorelin therapy resulted in sustained improvement of LUTS in these patients.

Abiraterone acetate and prednisone in chemotherapy-naïve prostate cancer patients: rationale, evidence and clinical utility

Abiraterone acetate 1000 mg/day, combined with prednisone 5 mg PO twice daily, is indicated for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Abiraterone acetate is the oral prodrug of abiraterone, a specific CYP17 inhibitor that blocks androgen biosynthesis within the adrenal glands, testes and tumor microenvironment. In a phase III trial of men with asymptomatic or minimally symptomatic, chemotherapy-naïve mCRPC, treatment with oral abiraterone acetate plus prednisone led to a statistically significant improvement in the co-primary endpoints of overall survival and radiographic progression-free survival when compared with placebo plus prednisone. In long-term follow-up of phase III trials, the incidence of corticosteroid-associated adverse events was 25.5% in the abiraterone acetate plus prednisone arm compared with 23.3% in the placebo plus prednisone arm. The need for regular patient monitoring and appropriate management of symptoms during long-term use of prednisone must be placed in context with the improvement in survival seen with abiraterone plus prednisone. Within the multidisciplinary environment that is emerging to meet quality and cost imperatives, abiraterone acetate plus prednisone is suitable for use in the chemotherapy-naïve population with minimal symptoms as well as in patients who have been treated with docetaxel and may have symptomatic disease. Ongoing trials are evaluating the role of abiraterone acetate plus prednisone in patients with nonmetastatic CRPC and metastatic hormone-sensitive prostate cancer, while further trials in the mCRPC setting are evaluating its use in combination regimens.

Suppression of LASP-1 attenuates the carcinogenesis of prostatic cancer cell lines: Key role of the NF-κB pathway

Prostate cancer (PCa) is one of the most frequently diagnosed cancers among males worldwide and causes a considerable number of deaths each year. One of the newly explored targets for the development of therapies against PCa is LIM and SH3 protein 1 (LASP-1). In the present study, the function of LASP-1 in the oncogenesis and metastasis of PCa was investigated using a series of in vitro experiments. Moreover, the mechanism through which LASP-1 exerted its effect on the carcinogenesis of PCa was also explored. The expression levels of LASP-1 in clinical PCa specimens were determined both at the mRNA and protein levels. Afterwards, the activity of LASP-1 in human PCa cell lines PC3 and DU145 was inhibited using a short hairpin RNA (shRNA) interfering method. The effects of LASP-1 knockdown on the cell growth, apoptosis, cell cycle distribution, migration and invasion were assessed. It was demonstrated that the expression of LASP-1 was significantly higher in the clinical PCa tissues than the level in the corresponding para-carcinoma tissues. Following the knockdown of the LASP-1 gene in human PCa cell lines, the viability, migration and invasion of the cancer cells were decreased. It was also demonstrated that the change in the cell viability and motile ability were associated with an induction of cell apoptosis and G1 phase cell cycle arrest. Based on the results of the detection of the expression of NF-κB-related factors, it was indicated that LASP-1 may affect the carcinogenesis of PCa through a NF-κB inhibition-dependent manner. Although the detailed explanation of the mechanism of LASP-1 in the carcinogenesis of PCa requires further elucidation, the present study highlights the potential of LASP-1 as a promising therapeutic target to ameliorate the oncogenesis and metastasis of PCa.

Disease and Treatment Characteristics of Men Diagnosed With Metastatic Hormone-Sensitive Prostate Cancer in Real Life: Analysis From a Commercial Claims Database

BACKGROUND

Our understanding of the clinical characteristics and treatment patterns of men who present with newly diagnosed metastatic (M1) hormone-sensitive prostate cancer is based mainly on clinical trial data. We sought to characterize the M1 population seen in routine clinical practice using a commercial claims database.

PATIENTS AND METHODS

A US claims (2000-2013) database was used to identify patients with an index diagnosis of prostate cancer. M1 patients were identified by "International Classification of Diseases, 9th revision, Clinical Modification" diagnosis codes of metastasis to bone, viscera, distant lymph node, and unspecified sites within 90 days of the prostate cancer diagnosis. Progression to castration-resistant prostate cancer was identified by exposure to ≥ 1 drugs approved for castration-resistant prostate cancer, including docetaxel, abiraterone acetate, cabazitaxel, enzalutamide, sipuleucel-T, mitoxantrone, estramustine, and radium-223.

RESULTS

Among 326,907 patients with an index prostate cancer diagnosis, 9199 (2.8%) had M1 disease, including 6955 with specified metastatic disease involving the bone (77%), viscera (38%), or lymph nodes (21%). The initial treatment of M1 disease was castration in 51%, localized therapy in 16%, prostate cancer drug only in 18%, and no treatment in 15%. The median time to first castration was 33 days.

CONCLUSION

The proportion of men with prostate cancer who presented with M1 disease was consistent with other observations. Only 51% of the patients were treated according to national guidelines recommending medical or surgical castration. The proportion with visceral involvement at presentation was greater than expected from the clinical trials data in the same population. Just as seen in other medical conditions, clinical trial data are not representative of real-life patients seen in routine clinical practice.

Sodium phenylbutyrate antagonizes prostate cancer through the induction of apoptosis and attenuation of cell viability and migration

BACKGROUND

Prostate cancer (PCa) is a leading cause of cancer-related death in men. Sodium phenylbutyrate (SPB) has shown its potential as an anticancer therapy in numerous cancer types. In the present study, we attempted to assess the effect of SPB against PCa and whether this treatment was associated with the regulation of survivin.

METHODS

Two human PCa cancer cell lines, DU145 and PC3, were used in the present study. Cell Counting Kit-8 (CCK-8) assay was conducted to measure the proliferation of PCa cells incubated with SPB. The effect of SPB on the cell apoptosis, cell colony formation ability, and cell morphological change was also assessed. Transwell experiment and Western blotting assay were performed to determine the effect of SPB on the migration and invasion ability of both cell types. Moreover, the expression pattern of survivin and MAPK members in both cell types after the treatment of SPB was also detected. Additionally, an in vivo tumor formation assay was performed to evaluate the treatment potential of SPB against PCa.

RESULTS

We found that the viability of PCa cells was significantly inhibited by SPB treatment. As illustrated by flow cytometry, for DU145 cell line the average apoptotic rate of SPB-treated cells was significantly lower than that of the control group (P<0.05); similar results were also seen for PC3 (P<0.05). SPB administration also attenuated the colony formation and migration abilities in both cell lines. The expression level of survivin in SPB-treated cells was significantly downregulated, while the phosphorylation of p-38 and ERK was enhanced. Furthermore, in vivo tumor formation of both cell lines was suppressed by SPB as well.

CONCLUSION

The above results confirmed the potential of SPB as an effective therapeutic agent for the prevention or treatment of PCa. This amelioration might be due to the blockade of the survivin pathway.

Biomarkers for evaluation of prostate cancer prognosis

Prostate cancer, with a lifetime prevalence of one in six men, is the second cause of malignancy-related death and the most prevalent cancer in men in many countries. Nowadays, prostate cancer diagnosis is often based on the use of biomarkers, especially prostate-specific antigen (PSA) which can result in enhanced detection at earlier stage and decreasing in the number of metastatic patients. However, because of the low specificity of PSA, unnecessary biopsies and mistaken diagnoses frequently occur. Prostate cancer has various features so prognosis following diagnosis is greatly variable. There is a requirement for new prognostic biomarkers, particularly to differentiate between inactive and aggressive forms of disease, to improve clinical management of prostate cancer. Research continues into finding additional markers that may allow this goal to be attained. We here selected a group of candidate biomarkers including PSA, PSA velocity, percentage free PSA, TGFβ1, AMACR, chromogranin A, IL-6, IGFBPs, PSCA, biomarkers related to cell cycle regulation, apoptosis, PTEN, androgen receptor, cellular adhesion and angiogenesis, and also prognostic biomarkers with Genomic tests for discussion. This provides an outline of biomarkers that are presently of prognostic interest in prostate cancer investigation.

Metastatic prostate adenocarcinoma posing as urothelial carcinoma of the right ureter: a case report and literature review

This is a case report of a 67-year-old patient with distant metastasis of prostate cancer to the right ureter which caused hydronephrosis. At the beginning, both of the cytology of the morning urine and imaging findings were consistent with urothelial carcinoma. Nephroureterectomy was subsequently performed. Interestingly, the pathological examination of the excised ureter revealed that the malignancy was derived from the prostate. No skeletal metastasis was detected. However, after four months of follow-up, several abnormal signal shadows were reported in skeletal scintigraphy and the prostate specific antigen (PSA) was gradually increasing. We present such a case for its unique presentation. A review of the literature is also provided.

Positive association between circulating 25-hydroxyvitamin D levels and prostate cancer risk: new findings from an updated meta-analysis

PURPOSE

To investigate and clarify the relationship between circulating 25-hydroxyvitamin D level and prostate cancer risk.

METHODS

We conducted the meta-analysis to better evaluate the association. Terms "25-Hydroxyvitamin D"/"vitamin D" and "prostate cancer" were used for literature search.

RESULTS

We identified 21 relevant publications from databases of PubMed and MEDLINE and included 11,941 cases and 13,870 controls in the meta-analysis. Overall studies revealed a significant 17 % elevated risk of prostate cancer for individuals with higher level of 25-hydroxyvitamin D (OR = 1.17, 95 % CI = 1.05-1.30, P  = 0.004), and no publication bias was found in the calculations (P  = 0.629). Subgroup analysis confirmed the association from nested case-control study group, studies from USA group and studies using serum samples group (nested case-control studies: OR = 1.17, 95 % CI = 1.08-1.27, P < 0.001; USA: OR = 1.15, 95 % CI = 1.03-1.29, P = 0.017; serum: OR = 1.20, 95 % CI = 1.01-1.42, P = 0.042); moreover, sensitivity tests also indicated significant results in studies from Europe and studies conducting with plasma samples after exclusion of some influential single study from the analysis, respectively (Europe: OR = 1.21, 95 % CI = 1.04-1.40, P = 0.014; plasma: OR = 1.13, 95 % CI = 1.00-1.27, P = 0.05).

CONCLUSIONS

Our meta-analysis, for the first time, suggested significant positive relationship between high level of 25-hydroxyvitamin D and increased risk of prostate cancer, reminding us that more concern should be taken into account during assessing the effect of 25-hydroxyvitamin D.

Seminal plasma as a source of prostate cancer peptide biomarker candidates for detection of indolent and advanced disease

BACKGROUND

Extensive prostate specific antigen screening for prostate cancer generates a high number of unnecessary biopsies and over-treatment due to insufficient differentiation between indolent and aggressive tumours. We hypothesized that seminal plasma is a robust source of novel prostate cancer (PCa) biomarkers with the potential to improve primary diagnosis of and to distinguish advanced from indolent disease.

METHODOLOGY/PRINCIPAL FINDINGS

In an open-label case/control study 125 patients (70 PCa, 21 benign prostate hyperplasia, 25 chronic prostatitis, 9 healthy controls) were enrolled in 3 centres. Biomarker panels a) for PCa diagnosis (comparison of PCa patients versus benign controls) and b) for advanced disease (comparison of patients with post surgery Gleason score <7 versus Gleason score >7) were sought. Independent cohorts were used for proteomic biomarker discovery and testing the performance of the identified biomarker profiles. Seminal plasma was profiled using capillary electrophoresis mass spectrometry. Pre-analytical stability and analytical precision of the proteome analysis were determined. Support vector machine learning was used for classification. Stepwise application of two biomarker signatures with 21 and 5 biomarkers provided 83% sensitivity and 67% specificity for PCa detection in a test set of samples. A panel of 11 biomarkers for advanced disease discriminated between patients with Gleason score 7 and organ-confined (<pT3a) or advanced (≥pT3a) disease with 80% sensitivity and 82% specificity in a preliminary validation setting. Seminal profiles showed excellent pre-analytical stability. Eight biomarkers were identified as fragments of N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase, prostatic acid phosphatase, stabilin-2, GTPase IMAP family member 6, semenogelin-1 and -2. Restricted sample size was the major limitation of the study.

CONCLUSIONS/SIGNIFICANCE

Seminal plasma represents a robust source of potential peptide makers for primary PCa diagnosis. Our findings warrant further prospective validation to confirm the diagnostic potential of identified seminal biomarker candidates.

Identification of markers of prostate cancer progression using candidate gene expression

BACKGROUND

Metastatic prostate cancer (PCa) has no curative treatment options. Some forms of PCa are indolent and slow growing, while others metastasise quickly and may prove fatal within a very short time. The basis of this variable prognosis is poorly understood, despite considerable research. The aim of this study was to identify markers associated with the progression of PCa.

METHODS

Artificial neuronal network analysis combined with data from literature and previous work produced a panel of putative PCa progression markers, which were used in a transcriptomic analysis of 29 radical prostatectomy samples and correlated with clinical outcome.

RESULTS

Statistical analysis yielded seven putative markers of PCa progression, ANPEP, ABL1, PSCA, EFNA1, HSPB1, INMT and TRIP13. Two data transformation methods were utilised with only markers that were significant in both selected for further analysis. ANPEP and EFNA1 were significantly correlated with Gleason score. Models of progression co-utilising markers ANPEP and ABL1 or ANPEP and PSCA had the ability to correctly predict indolent or aggressive disease, based on Gleason score, in 89.7% and 86.2% of cases, respectively. Another model of TRIP13 expression in combination with preoperative PSA level and Gleason score was able to correctly predict recurrence in 85.7% of cases.

CONCLUSION

This proof of principle study demonstrates a novel association of carcinogenic and tumourigenic gene expression with PCa stage and prognosis.

Urine proteomics in kidney and urogenital diseases: Moving towards clinical applications

To date, multiple biomarker discovery studies in urine have been conducted. Nevertheless, the rate of progression of these biomarkers to qualification and even more clinical application is extremely low. The scope of this article is to provide an overview of main clinically relevant proteomic findings from urine focusing on kidney diseases, bladder and prostate cancers. In addition, approaches for promoting the use of urine in clinical proteomics including potential means to facilitate the validation of existing promising findings (biomarker candidates identified from previous studies) and to increase the chances for success for the identification of new biomarkers are discussed.

Urinary proteomics: ready for prime time in urological cancer diagnostics?

The impact of clinical proteomics on the diagnosis and treatment of urological malignancies is modest in comparison with the high expectations of the past. However, most available studies suffer from flawed clinical designs rather than from technical limitations. This article will briefly introduce the main technological approaches taken, their advantages and disadvantages and will highlight the different challenges associated with urinary proteome analysis. Furthermore, several examples of the successful application of urinary clinical proteomics in the field of prostate and bladder cancer will be introduced. These examples suggest careful validation of novel biomarkers, appropriate study designs using blinded cohorts enrolled from appropriate target populations and the standardization of techniques as key elements required for successful urinary proteomics studies. These prerequisites are essential for turning the old promise of a personalized medicine approach into a new reality to optimize patients’ preventive and therapeutic care.

Radiobiological impact of reduced margins and treatment technique for prostate cancer in terms of tumor control probability (TCP) and normal tissue complication probability (NTCP)

Dose escalation in prostate radiotherapy is limited by normal tissue toxicities. The aim of this study was to assess the impact of margin size on tumor control and side effects for intensity-modulated radiation therapy (IMRT) and 3D conformal radiotherapy (3DCRT) treatment plans with increased dose. Eighteen patients with localized prostate cancer were enrolled. 3DCRT and IMRT plans were compared for a variety of margin sizes. A marker detectable on daily portal images was presupposed for narrow margins. Prescribed dose was 82 Gy within 41 fractions to the prostate clinical target volume (CTV). Tumor control probability (TCP) calculations based on the Poisson model including the linear quadratic approach were performed. Normal tissue complication probability (NTCP) was calculated for bladder, rectum and femoral heads according to the Lyman-Kutcher-Burman method. All plan types presented essentially identical TCP values and very low NTCP for bladder and femoral heads. Mean doses for these critical structures reached a minimum for IMRT with reduced margins. Two endpoints for rectal complications were analyzed. A marked decrease in NTCP for IMRT plans with narrow margins was seen for mild RTOG grade 2/3 as well as for proctitis/necrosis/stenosis/fistula, for which NTCP <7% was obtained. For equivalent TCP values, sparing of normal tissue was demonstrated with the narrow margin approach. The effect was more pronounced for IMRT than 3DCRT, with respect to NTCP for mild, as well as severe, rectal complications.

The E-cadherin (CDH1)--160 C/A polymorphism and prostate cancer risk: a meta-analysis

Published data on the association between E-cadherin (CDH1) -160 C/A polymorphism and prostate cancer (PCA) risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A logistic regression approach proposed for molecular association studies was used to estimate a biological model of the gene effect. A total of 11 studies including 2637 cases and 2673 controls were involved in this meta-analysis. Logistic regression analysis indicated that the CDH1 -160 C/A genotypes were associated with PCA risk. The genetic model test indicated that the genetic model was most likely to be dominant (CA+AA vs CC). Overall, meta-analysis indicated that the -160A allele carriers (CA+AA) had a 21% elevated risk of PCA, when compared with the homozygotes (CC) (odds ratio (OR)=1.21; 95% confidence interval (CI): 0.97-1.51; P=0.090, P(heterogeneity)=0.001). In the subgroup analyses by ethnicity, significantly elevated risks were associated with -160 variant genotypes (CA+AA) in both European and Asian populations (OR=1.24; 95% CI: 1.08-1.43; P=0.003, P(heterogeneity)=0.220 and OR=1.54; 95% CI: 1.23-1.93; P<0.001, P(heterogeneity)=0.200). However, no significant associations were found in Africans (OR=0.59; 95% CI: 0.32-1.09; P=0.090, P(heterogeneity)=0.070). Although some modest bias could not be eliminated, this meta-analysis suggests that the CDH1 -160A allele is a low-penetrant risk factor for developing PCA, especially in Europeans and Asians.

Metastatic prostate cancer masquerading clinically and radiologically as a primary caecal carcinoma

BACKGROUND

Prostatic carcinoma is the second most common cause of cancer-related deaths in males in the West. Approximately 20% of patients present with metastatic disease. We describe the case of a patient with metastatic prostate cancer to the bowel presenting clinically and radiologically as a primary caecal cancer.

CASE PRESENTATION

A 72 year-old man presented with abdominal discomfort and a clinically palpable caecal mass and a firm nodule on his thigh, the latter behaving clinically and radiologically as a lipoma. Computed tomographic (CT) scan showed a luminally protuberant caecal mass with regional nodal involvement. The patient was being treated (Zoladex) for prostatic cancer diagnosed 6 years previously and was known to have bony metastases. On admission his PSA was 245.4 nmol/ml. The patient underwent a right hemicolectomy. Histology showed a poorly differentiated adenocarcinoma which was PSA positive, confirming metastatic prostatic adenocarcinoma to the caecum. The patient underwent adjuvant chemotherapy and is free from recurrence a year later.

CONCLUSION

Metastasis of prostatic carcinoma to the bowel is a very rare occurrence and presents a challenging diagnosis. The diagnosis is supported by immunohistochemistry for PSA. The treatment for metastatic prostate cancer is mainly palliative.

E-cadherin polymorphisms and haplotypes influence risk for prostate cancer

BACKGROUND

The E-cadherin (CDH1) gene has been implicated in prostate cancer (PCA) risk, however, the exact mechanism is unknown. Several polymorphisms, such as the C/A variant -160 base pairs from the transcription start site, in the CDH1 gene promoter region have been associated with cancer risk, mainly in European descent populations.

METHODS

We screened the entire coding region and 3.0 kilobases of the CDH1 promoter for polymorphisms in 48 African Americans using dHPLC. Twenty-one (21) polymorphisms were observed. Four polymorphisms, including -160C/A, were genotyped in a genetic association study using incident PCA cases (N = 427) and unaffected controls (N = 337) of similar age from three different ethnic groups consisting of African Americans, Jamaicans, and European Americans.

RESULTS

We observed a significantly higher frequency of the -160A allele among European American PCA patients (27.5%) compared to the control group (19.7%) (P = 0.04). More importantly, among men of European ancestry under the age of 65 who possess the -160 A allele there was over three times increased risk for prostate cancer (P = 0.05). Also, the AACT haplotype bearing the -160A allele was significantly associated with PCA in European Americans (P = 0.04).

CONCLUSIONS

Our data indicate that CDH1 likely is a low-penetrant PCA susceptibility gene, however, population differences in linkage disequilibrium within the CDH1 gene region may influence the effect of susceptibility alleles such as -160A.

Feasibility study using a Ni–Ti stent and electronic portal imaging to localize the prostate during radiotherapy

BACKGROUND AND PURPOSE

A new method for localization of the prostate during external beam radiotherapy is presented. The method is based on insertion of a thermo-expandable Ni-Ti stent. The stent is originally developed for treatment of bladder outlet obstruction caused by benign hyperplasia. The radiological properties of the stent are used for precise prostate localization during treatment using electronic portal images.

PATIENTS AND METHODS

Patients referred for intended curative radiotherapy and having a length of their prostatic urethra in the range from 25 to 65 mm were included. Pairs of isocentric orthogonal portal images were used to determine the 3D position at eight different treatment sessions for each patient.

RESULTS

Fourteen patients were enrolled in the study. The data obtained demonstrated that the stent position was representative of the prostate location. The stent may also improve delineation of the prostate GTV, and prevent obstruction of bladder outlet during treatment. Precision in localization of the stent was less than 1 mm. Random errors in stent position were left-right 1.6 mm, cranial-caudal 2.2 mm and anterior-posterior 3.2 mm. In four of 14 patients a dislocation of the stent to the bladder occurred. Dislocation only occurred in patients with length of prostatic urethra less than 40 mm.

CONCLUSIONS

A new method for radiological high precision localization of the prostate during radiotherapy is presented. The method is based on insertion of a standard Ni-Ti thermo-expandable stent, designed for treatment of benign prostate hyperplasia.

Accumulation of p53 and reductions in XIAP abundance promote the apoptosis of prostate cancer cells

Toward the goal of developing effective treatments for prostate cancers, we examined the effects of cyclin-dependent kinase inhibitors on the survival of prostate cancer cells. We show that roscovitine, R-roscovitine, and CGP74514A (collectively referred to as CKIs) induce the apoptosis of LNCaP and LNCaP-Rf cells, both of which express wild-type p53. Apoptosis required caspase-9 and caspase-3 activity, and cytochrome c accumulated in the cytosol of CKI-treated cells. Amounts of p53 increased substantially in CKI-treated cells, whereas amounts of the endogenous caspase inhibitor XIAP decreased. CKIs did not appreciably induce the apoptosis of LNCaP cells treated with pifithrin-alpha, which prevents p53 accumulation, or of prostate cancer cells that lack p53 function (PC3 and DU145). Ectopic expression of p53 in PC3 cells for 44 hours did not reduce XIAP abundance or induce apoptosis. However, p53-expressing PC3 cells readily apoptosed when exposed to CKIs or when depleted of XIAP by RNA interference. These findings show that CKIs induce the mitochondria-mediated apoptosis of prostate cancer cells by a dual mechanism: p53 accumulation and XIAP depletion. They suggest that these events in combination may prove useful in the treatment of advanced prostate cancers.