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Demirel CH, Altok M, Davis JW. Focal therapy for localized prostate cancer: is there a "middle ground" between active surveillance and definitive treatment? Asian J Androl 2018; 21:240302. [PMID: 30178774 PMCID: PMC6337958 DOI: 10.4103/aja.aja_64_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/12/2018] [Indexed: 01/02/2023] Open
Abstract
In recent years, it has come a long way in the diagnosis, treatment, and follow-up of prostate cancer. Beside this, it was argued that definitive treatments could cause overtreatment, particularly in the very low, low, and favorable risk group. When alternative treatment and follow-up methods are being considered for this group of patients, active surveillance is seen as a good alternative for patients with very low and low-risk groups in this era. However, it has become necessary to find other alternatives for patients in the favorable risk group or patients who cannot adopt active follow-up. In the light of technological developments, the concept of focal therapy was introduced with the intensification of research to treat only the lesioned area instead of treating the entire organ for prostate lesions though there are not many publications about many of them yet. According to the initial results, it was understood that the results could be good if the appropriate focal therapy technique was applied to the appropriate patient. Thus, focal therapies have begun to find their "middle ground" place between definitive therapies and active follow-up.
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Affiliation(s)
- Cihan H Demirel
- Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Muammer Altok
- Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - John W Davis
- Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Gorin MA, Rowe SP, Denmeade SR. Clinical Applications of Molecular Imaging in the Management of Prostate Cancer. PET Clin 2017; 12:185-192. [PMID: 28267452 DOI: 10.1016/j.cpet.2016.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
At the heart of selecting an optimal management strategy for men with prostate cancer is accurately determining a given patient's clinical stage and extent of disease. Molecular imaging with PET using properly selected radiotracers offers the opportunity for improved contrast resolution over conventional imaging and thus increased sensativity for detecting sites of disease. In addition, molecular imaging provides the prospect of obtaining functional or biological information regarding a patient's cancer. To date, several PET radiotracers have been developed for prostate cancer imaging. This review summarizes the potential clinical applications of molecular imaging in the management of men with prostate cancer.
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Affiliation(s)
- Michael A Gorin
- Department of Urology, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Marburg 118, Baltimore, MD 21287, USA.
| | - Steven P Rowe
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Samuel R Denmeade
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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Toner L, Weerakoon M, Bolton DM, Ryan A, Katelaris N, Lawrentschuk N. Magnetic resonance imaging for prostate cancer: Comparative studies including radical prostatectomy specimens and template transperineal biopsy. Prostate Int 2015; 3:107-14. [PMID: 26779455 PMCID: PMC4685231 DOI: 10.1016/j.prnil.2015.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 03/31/2015] [Indexed: 11/18/2022] Open
Abstract
Purpose Multiparametric magnetic resonance imaging (mpMRI) is an emerging technique aiming to improve upon the diagnostic sensitivity of prostate biopsy. Because of variance in interpretation and application of techniques, results may vary. There is likely a learning curve to establish consistent reporting of mpMRI. This study aims to review current literature supporting the diagnostic utility of mpMRI when compared with radical prostatectomy (RP) and template transperineal biopsy (TTPB) specimens. Methods MEDLINE and PubMed database searches were conducted identifying relevant literature related to comparison of mpMRI with RP or TTPB histology. Results Data suggest that compared with RP and TTPB specimens, the sensitivity of mpMRI for prostate cancer (PCa) detection is 80–90% and the specificity for suspicious lesions is between 50% and 90%. Conclusions mpMRI has an increasing role for PCa diagnosis, staging, and directing management toward improving patient outcomes. Its sensitivity and specificity when compared with RP and TTPB specimens are less than what some expect, possibly reflecting a learning curve for the technique of mpMRI.
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Affiliation(s)
- Liam Toner
- University of Melbourne, Department of Surgery, Urology Unit, Austin Health, Melbourne, Australia
| | - Mahesha Weerakoon
- University of Melbourne, Department of Surgery, Urology Unit, Austin Health, Melbourne, Australia
| | - Damien M Bolton
- University of Melbourne, Department of Surgery, Urology Unit, Austin Health, Melbourne, Australia; Olivia Newton-John Cancer Research Institute, Austin Health, Melbourne, Australia
| | - Andrew Ryan
- Department of Pathology, TissuPath Specialist Pathology Services, Melbourne, Australia
| | - Nikolas Katelaris
- University of Melbourne, Department of Surgery, Urology Unit, Austin Health, Melbourne, Australia
| | - Nathan Lawrentschuk
- University of Melbourne, Department of Surgery, Urology Unit, Austin Health, Melbourne, Australia; Olivia Newton-John Cancer Research Institute, Austin Health, Melbourne, Australia; Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia
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Katelaris NC, Bolton DM, Weerakoon M, Toner L, Katelaris PM, Lawrentschuk N. Current role of multiparametric magnetic resonance imaging in the management of prostate cancer. Korean J Urol 2015; 56:337-45. [PMID: 25964833 PMCID: PMC4426504 DOI: 10.4111/kju.2015.56.5.337] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/06/2015] [Indexed: 01/04/2023] Open
Abstract
The purpose of this review was to evaluate the current role of multiparametric magnetic resonance imaging (mp-MRI) in the management of prostate cancer (PC). The diagnosis of PC remains controversial owing to overdetection of indolent disease, which leads to overtreatment and subsequent patient harm. mp-MRI has the potential to equilibrate the imbalance between detection and treatment. The limitation of the data for analysis with this new technology is problematic, however. This issue has been compounded by a paradigm shift in clinical practice aimed at utilizing this modality, which has been rolled out in an ad hoc fashion often with commercial motivation. Despite a growing body of literature, pertinent clinical questions remain. For example, can mp-MRI be calibrated to reliably detect biologically significant disease? As with any new technology, objective evaluation of the clinical applications of mp-MRI is essential. The focus of this review was on the evaluation of mp-MRI of the prostate with respect to clinical utility.
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Affiliation(s)
| | - Damien Michael Bolton
- Department of Surgery, Austin Hospital, University of Melbourne, Melbourne, VIC, Australia
| | - Mahesha Weerakoon
- Department of Surgery, Austin Hospital, University of Melbourne, Melbourne, VIC, Australia
| | - Liam Toner
- Department of Surgery, Austin Hospital, University of Melbourne, Melbourne, VIC, Australia
| | | | - Nathan Lawrentschuk
- Department of Surgery, Austin Hospital, University of Melbourne, Melbourne, VIC, Australia. ; Olivia Newton-John Cancer Research Institute, Austin Hospital, Heidelberg, VIC, Australia. ; Division of Cancer Surgery, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
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Abstract
CLINICAL/METHODICAL ISSUE A present goal is to improve detection and staging of prostate cancer using innovative imaging technology such as PET/MRI. STANDARD RADIOLOGICAL METHODS The modality of choice for detection of prostate cancer is multiparametric MRI. Furthermore, PET/CT is used, in particular, for the detection and staging of distant metastases and recurrent disease. For assessment of bone metastases, the method most commonly used is bone scintigraphy. METHODICAL INNOVATIONS The development of a simultaneous hybrid PET/MRI system is the last great "fusion" of the known cross-sectional image modalities. In addition, synthesis of new, innovative tracers such as (18)F-FACBC or (68)Ga-PSMA allows more specific detection of prostate cancer. PERFORMANCE Hybrid PET/MRI imaging has the potential to replace conventional imaging techniques in the future. ACHIEVEMENTS The method is just starting the broad application. Clinical studies must be expanded in order to substantiate the additional value of the method. PRACTICAL RECOMMENDATIONS Currently, there is still a low distribution situation, since it is a new and cost-intensive method. At the same time, there is still no consistent solution for reimbursement. The importance in practice first rises by clarifying the payment situation and further demonstration of the method's benefit by larger studies.
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Affiliation(s)
- M C Röthke
- Abteilung für onkologische Radiologie, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Deutschland.
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Thompson J, Lawrentschuk N, Frydenberg M, Thompson L, Stricker P. The role of magnetic resonance imaging in the diagnosis and management of prostate cancer. BJU Int 2013; 112 Suppl 2:6-20. [PMID: 24127671 DOI: 10.1111/bju.12381] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The diagnosis of prostate cancer has long been plagued by the absence of an imaging tool that reliably detects and localises significant tumours. Recent evidence suggests that multi-parametric MRI could improve the accuracy of diagnostic assessment in prostate cancer. This review serves as a background to a recent USANZ position statement. It aims to provide an overview of MRI techniques and to critically review the published literature on the clinical application of MRI in prostate cancer. TECHNICAL ASPECTS The combination of anatomical (T2-weighted) MRI with at least two of the three functional MRI parameters - which include diffusion-weighted imaging, dynamic contrast-enhanced imaging and spectroscopy - will detect greater than 90% of significant (moderate to high risk) tumours; however MRI is less reliable at detecting tumours that are small (<0.5 cc), low grade (Gleason score 6) or in the transitional zone. The higher anatomical resolution provided by 3-Tesla magnets and endorectal coils may improve the accuracy, particularly in primary tumour staging. SCREENING The use of mpMRI to determine which men with an elevated PSA should undergo biopsy is currently the subject of two large clinical trials in Australia. MRI should be used with caution in this setting and then only in centres with established uro-radiological expertise and quality control mechanisms in place. There is sufficient evidence to justify using MRI to determine the need for repeat biopsy and to guide areas in which to focus repeat biopsy. IMAGE-DIRECTED BIOPSY MRI-directed biopsy is an exciting concept supported by promising early results, but none of the three proposed techniques have so far been proven superior to standard biopsy protocols. Further evidence of superior accuracy and core-efficiency over standard biopsy is required, before their costs and complexities in use can be justified. TREATMENT SELECTION AND PLANNING When used for primary-tumour staging (T-staging), MRI has limited sensitivity for T3 disease, but its specificity of greater than 95% may be useful in men with intermediate-high risk disease to identify those with advanced T3 disease not suitable for nerve sparing or for surgery at all. MRI appears to be of value in planning dosimetry in men undergoing radiotherapy, and in guiding selection for and monitoring on active surveillance.
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Affiliation(s)
- James Thompson
- St Vincents Prostate Cancer Centre, Garvan Institute of Medical Research, Department of Surgery Research, University of New South Wales, Sydney, New South Wales
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Abstract
Transperineal prostate biopsy is re-emerging after decades of being an underused alternative to transrectal biopsy guided by transrectal ultrasonography (TRUS). Factors driving this change include possible improved cancer detection rates, improved sampling of the anteroapical regions of the prostate, a reduced risk of false negative results and a reduced risk of underestimating disease volume and grade. The increasing incidence of antimicrobial resistance and patients with diabetes mellitus who are at high risk of sepsis also favours transperineal biopsy as a sterile alternative to standard TRUS-guided biopsy. Factors limiting its use include increased time, training and financial constraints as well as the need for high-grade anaesthesia. Furthermore, the necessary equipment for transperineal biopsy is not widely available. However, the expansion of transperineal biopsy has been propagated by the increase in multiparametric MRI-guided biopsies, which often use the transperineal approach. Used with MRI imaging, transperineal biopsy has led to improvements in cancer detection rates, more-accurate grading of cancer severity and reduced risk of diagnosing clinically insignificant disease. Targeted biopsy under MRI guidance can reduce the number of cores required, reducing the risk of complications from needle biopsy.
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Johnston R, Wong LM, Warren A, Shah N, Neal D. The role of 1.5 Tesla magnetic resonance imaging in staging prostate cancer. ANZ J Surg 2013; 83:234-8. [PMID: 23463964 DOI: 10.1111/ans.12094] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2012] [Indexed: 01/17/2023]
Abstract
BACKGROUND To review the role of 1.5T (standard) magnetic resonance imaging (MRI) in predicting pathological T stage of prostate cancer in patients undergoing radical prostatectomy. METHODS All patients undergoing radical prostatectomy between 2005 and 2010, who had a preoperative MRI, were included in the study. All MRI examinations were performed with a 1.5-T magnet without an endorectal coil. All the MRIs and prostate specimen histology slides were reviewed by genitourinary radiologists and pathologists at a centralized multidisciplinary team meeting. We calculated the sensitivity and specificity according to D'Amico risk classification. Likelihood ratios were used to test the discriminative ability of MRI. RESULTS A total of 568 patients were identified as eligible. Median age was 62 years (35-74). Average prostate-specific antigen was 8.70 ng/mL (0.5-63). Risk categories included low, intermediate and high risk and contained 198 (34.9%), 303 (53.3%) and 67 (11.8%) patients, respectively. Comparisons between MRI findings and final histology gave a sensitivity of 20.0% and specificity of 80.2%. The positive likelihood ratio was 1.25. Although there was a trend (sr rho = 0.79) towards improved sensitivity as the clinical stage increased, this did not reach statistical significance (P = 0.68). CONCLUSION Standard MRI does not improve preoperative local staging. Therefore, we recommend that standard MRI has no role in the local staging of prostate cancer. The use of higher field strength magnets (e.g. 3.0 T) and/or endorectal coil or the addition of other techniques such as dynamic contrast-enhanced MRI, diffusion-weighted MRI and MR spectroscopy imaging should therefore be preferentially used in routine clinical practice.
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Vasarainen H, Lahdensuo K, Savolainen R, Ruutu M, Taari K, Rannikko A. Diffusion-weighted magnetic resonance imaging in prostate cancer patients on active surveillance one year after diagnosis and before repeat biopsy. Scand J Urol 2013; 47:456-61. [DOI: 10.3109/21681805.2013.765910] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Vargas HA, Akin O, Shukla-Dave A, Zhang J, Zakian KL, Zheng J, Kanao K, Goldman DA, Moskowitz CS, Reuter VE, Eastham JA, Scardino PT, Hricak H. Performance characteristics of MR imaging in the evaluation of clinically low-risk prostate cancer: a prospective study. Radiology 2012; 265:478-87. [PMID: 22952382 PMCID: PMC3480819 DOI: 10.1148/radiol.12120041] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate diagnostic performance of T2-weighted magnetic resonance (MR) imaging and MR spectroscopic imaging in detecting lesions stratified by pathologic volume and Gleason score in men with clinically determined low-risk prostate cancer. MATERIALS AND METHODS The institutional review board approved this prospective, HIPAA-compliant study. Written informed consent was obtained from 183 men with clinically low-risk prostate cancer (cT1-cT2a, Gleason score≤6 at biopsy, prostate-specific antigen [PSA] level<10 ng/mL [10 μg/L]) undergoing MR imaging before prostatectomy. By using a scale of 1-5 (score 1, definitely no tumor; score 5, definitely tumor), two radiologists independently scored likelihood of tumor per sextant on T2-weighted images. Two spectroscopists jointly recorded locations of lesions with metabolic features consistent with tumor on MR spectroscopic images. Whole-mount step-section histopathologic analysis constituted the reference standard. Diagnostic performance at sextant level (T2-weighted imaging) and detection sensitivities (T2-weighted imaging and MR spectroscopic imaging) for lesions of 0.5 cm3 or larger were calculated. RESULTS For T2-weighted imaging, areas under the receiver operating characteristic curves for sextant-level detection were 0.77 (reader 1) and 0.82 (reader 2). For lesions of ≥0.5 cm3 and, 1 CONCLUSION In men with clinically low-risk prostate cancer, detection of lesions of <1 cm3 with T2-weighted imaging is significantly dependent on lesion Gleason score; detection of lesions of ≥1 cm3 is significantly better than detection of smaller lesions and is not affected by lesion Gleason score. The role of MR spectroscopic imaging alone in this population is limited.
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Affiliation(s)
- Hebert Alberto Vargas
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Room C-278, New York, NY 10065, USA
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13
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Abstract
PURPOSE OF REVIEW This article reviews recent developments in the use of active surveillance for localized prostate cancer. RECENT FINDINGS The treatment of localized prostate cancer continues to be a major challenge for urologic oncologists. Screening with prostate-specific antigen has resulted in increased numbers of low-risk prostate cancers being detected. Aggressive whole-gland therapy with surgery, or radiation therapy is associated with potentially life-altering treatment-related side effects such as urinary incontinence, bowel toxicity and erectile dysfunction. The goal of active surveillance is to avoid or delay the adverse events associated with prostate cancer therapy while still allowing for curative intervention in the future, if needed. SUMMARY Active surveillance is a reasonable treatment option for many men with low-risk, and some men with intermediate-risk, prostate cancer. Additional research is needed to determine the optimal active surveillance inclusion criteria, monitoring schedule, and treatment triggers. It is hoped that advances in prostate imaging, biomarkers, and focal therapy will foster greater use of active surveillance in appropriately selected men to optimize quality-of-life without compromising cancer outcomes.
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Gorin MA, Eldefrawy A, Ekwenna O, Soloway MS. Active surveillance for low-risk prostate cancer: knowledge, acceptance and practice among urologists. Prostate Cancer Prostatic Dis 2011; 15:177-81. [PMID: 22143447 DOI: 10.1038/pcan.2011.57] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND This study aimed to survey urologists regarding their knowledge, acceptance and practice of active surveillance (AS) for low-risk prostate cancer. METHODS An email-based survey was distributed to 4987 urologists. Respondents were surveyed regarding their knowledge and acceptance of AS. Those who felt AS was a reasonable strategy were asked their opinions on the criteria for AS enrollment and the details of their practice of AS. Respondents who felt AS was not a reasonable alternative were queried as to the reasons why. RESULTS A total of 425 (9%) urologists successfully completed the survey and 387 (91%) were both familiar with AS and aware that AS differed from watchful waiting. Of this latter group, 370 (96%) respondents felt AS was a reasonable management strategy, 95% of whom manage patients with this approach. A minority of respondents (6%) felt that patients with a PSA>10 ng ml(-1) were eligible for AS. Further, most participants (74%) felt that patients required a Gleason score ≤6. There was little agreement on the timing of follow-up biopsies. Respondents who objected to AS were most commonly concerned with missing an opportunity for curative treatment (76%) and the risk of tumor undergrading (65%). CONCLUSIONS The majority of participants were knowledgeable and accepting of AS. Respondents were in relative agreement regarding the PSA and Gleason score criteria for AS enrollment. In contrast, there was a lack of agreement on the timing of follow-up biopsies. In the future, comparative studies are required to determine the optimal enrollment criteria and follow-up protocol for patients managed with AS.
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Affiliation(s)
- M A Gorin
- Department of Urology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
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Natarajan S, Marks LS, Margolis DJA, Huang J, Macairan ML, Lieu P, Fenster A. Clinical application of a 3D ultrasound-guided prostate biopsy system. Urol Oncol 2011; 29:334-42. [PMID: 21555104 DOI: 10.1016/j.urolonc.2011.02.014] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 02/16/2011] [Accepted: 02/17/2011] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Prostate biopsy (Bx) has for 3 decades been performed in a systematic, but blind fashion using 2D ultrasound (US). Herein is described the initial clinical evaluation of a 3D Bx tracking and targeting device (Artemis; Eigen, Grass Valley, CA). Our main objective was to test accuracy of the new 3D method in men undergoing first and follow-up Bx to rule out prostate cancer (CaP). MATERIALS AND METHODS Patients in the study were men ages 35-87 years (66.1 ± 9.9), scheduled for Bx to rule out CaP, who entered into an IRB-approved protocol. A total of 218 subjects underwent conventional trans-rectal US (TRUS); the tracking system was then attached to the US probe; the prostate was scanned and a 3D reconstruction was created. All Bx sites were visualized in 3D and tracked electronically. In 11 men, a pilot study was conducted to test ability of the device to return a Bx to an original site. In 47 men, multi-parametric 3 Tesla MRI, incorporating T2-weighted images, dynamic contrast enhancement, and diffusion-weighted imaging, was performed in advance of the TRUS, allowing the stored MRI images to be fused with real-time US during biopsy. Lesions on MRI were delineated by a radiologist, assigned a grade of CaP suspicion, and fused into TRUS for biopsy targeting. RESULTS 3D Bx tracking was completed successfully in 180/218 patients, with a success rate approaching 95% among the last 50 men. Average time for Bx with the Artemis device was 15 minutes with an additional 5 minutes for MRI fusion and Bx targeting. In the tracking study, an ability to return to prior Bx sites (n=32) within 1.2 ± 1.1 mm SD was demonstrated and was independent of prostate volume or location of Bx site. In the MRI fusion study, when suspicious lesions were targeted, a 33% Bx-positivity rate was found compared with a 7% positivity rate for systematic, nontargeted Bx (19/57 cores vs. 9/124 cores, P=0.03). CONCLUSION Use of 3D tracking and image fusion has the potential to transform MRI into a clinical tool to aid biopsy and improve current methods for diagnosis and follow-up of CaP.
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Affiliation(s)
- Shyam Natarajan
- Biomedical Engineering IDP, University of California, Los Angeles, CA 90095, USA.
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Siddique HR, Mishra SK, Karnes RJ, Saleem M. Lupeol, a novel androgen receptor inhibitor: implications in prostate cancer therapy. Clin Cancer Res 2011; 17:5379-91. [PMID: 21712449 DOI: 10.1158/1078-0432.ccr-11-0916] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Conventional therapies to treat prostate cancer (CaP) of androgen-dependent phenotype (ADPC) and castration-resistant phenotype (CRPC) are deficient in outcome which has necessitated a need to identify those agents that could target AR for both disease types. We provide mechanism-based evidence that lupeol (Lup-20(29)-en-3b-ol) is a potent inhibitor of androgen receptor (AR) in vitro and in vivo. EXPERIMENTAL DESIGN Normal prostate epithelial cell (RWPE-1), LAPC4 (wild functional AR/ADPC), LNCaP (mutant functional/AR/ADPC), and C4-2b (mutant functional/AR/CRPC) cells were used to test the anti-AR activity of lupeol. Cells grown under androgen-rich environment and treated with lupeol were tested for proliferation, AR transcriptional activity, AR competitive ligand binding, AR-DNA binding, and AR-ARE/target gene binding. Furthermore, in silico molecular modeling for lupeol-AR binding was done. Athymic mice bearing C4-2b and LNCaP cell-originated tumors were treated intraperitoneally with lupeol (40 mg/kg; 3 times/wk) and tumor growth and surrogate biomarkers were evaluated. To assess bioavailability, lupeol serum levels were measured. RESULTS Lupeol significantly inhibited R1881 (androgen analogue) induced (i) transcriptional activity of AR and (ii) expression of PSA. Lupeol (i) competed antagonistically with androgen for AR, (ii) blocked the binding of AR to AR-responsive genes including PSA, TIPARP, SGK, and IL-6, and (iii) inhibited the recruitment of RNA Pol II to target genes. Lupeol sensitized CRPC cells to antihormone therapy. High-performance liquid chromatography analysis showed that lupeol is bioavailable to mice. Lupeol inhibited the tumorigenicity of both ADPC and CRPC cells in animals. Serum and tumor tissues exhibited reduced PSA levels. CONCLUSION Lupeol, an effective AR inhibitor, could be developed as a potential agent to treat human CaP.
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Affiliation(s)
- Hifzur Rahman Siddique
- Section of Molecular Chemoprevention and Therapeutics, The Hormel Institute, University of Minnesota, Austin, USA
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Halin S, Hammarsten P, Adamo H, Wikström P, Bergh A. Tumor indicating normal tissue could be a new source of diagnostic and prognostic markers for prostate cancer. ACTA ACUST UNITED AC 2010; 5:37-47. [PMID: 23484475 DOI: 10.1517/17530059.2011.540009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Prostate cancer is a common and multifocal disease but the diagnostic methods available are unsatisfactory. Most tumors present are of low malignant potential, whereas others are highly aggressive. At present, imaging cannot be used to guide tissue biopsies safely towards the most aggressive tumor present. To handle this problem multiple needle biopsies are taken. The biopsies often contain only normal prostate tissue, and even if the tumor is sampled it is not known whether a more aggressive cancer is present elsewhere in the organ. If changes in the normal tissue indicate the presence and nature of tumors, this information could be used to improve diagnostics and prognostics of prostate cancer. AREAS COVERED IN THIS REVIEW Current evidence that the tumor-adjacent morphologically normal prostate tissue is not completely normal is reviewed, and that this tissue, named tumor indicating normal tissue (TINT) by the authors, can be used to diagnose prostate cancer. WHAT THE READER WILL GAIN The reader will understand that tumors need to affect their surroundings in order to grow and metastasize and that the normal prostate tissue is therefore tinted by the presence and nature of cancer and that this knowledge can be used to develop new diagnostic and prognostic markers. TAKE HOME MESSAGE TINT changes could probably, when more rigorously defined and validated, be used to diagnose and prognosticate prostate cancer.
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Affiliation(s)
- Sofia Halin
- Umeå University, Department of Medical Biosciences, Pathology, Building 6M, Second Floor, S-90187 Umeå, Sweden +46 90 785 15 30 ; +46 90 785 44 84 ;
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Lawrentschuk N, Klotz L. Active surveillance for favorable-risk prostate cancer: a short review. Korean J Urol 2010; 51:665-70. [PMID: 21031084 PMCID: PMC2963777 DOI: 10.4111/kju.2010.51.10.665] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 10/04/2010] [Indexed: 11/20/2022] Open
Abstract
Active surveillance is becoming a more widely accepted management strategy in men with low-risk localized prostate cancer. This is in recognition of the knowledge that most men with such cancer are likely to die from other causes. The obvious benefits of active surveillance are reduced morbidity by delaying or avoiding radical gland therapy. These advantages should be balanced against appropriate selection criteria and triggers for moving to radical therapy while on active surveillance. The optimal method by which to identify the small number of men who will progress by use of clinical, biopsy, and imaging data is yet to be defined. Nevertheless, active surveillance is an appealing management option in selected men with prostate cancer and represents a solution to the significant problem of the overdiagnosis of clinically insignificant disease that accompanies prostate-specific antigen (PSA) screening.
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Affiliation(s)
- Nathan Lawrentschuk
- Department of Urology, University of Toronto, Sunnybrook Health Sciences Centre, Toronto, Canada
- Ludwig Institute for Cancer Research and University of Melbourne, Department of Surgery, Austin Hospital, Melbourne, Victoria, Australia
| | - Laurence Klotz
- Department of Urology, University of Toronto, Sunnybrook Health Sciences Centre, Toronto, Canada
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