Diagnostic Performance of 68Ga-PSMA-11 PET/CT Versus Multiparametric MRI for Detection of Intraprostatic Radiorecurrent Prostate Cancer

For men with prostate cancer who develop biochemical failure after radiotherapy, European guidelines recommend reimaging with 68Ga-PSMA-11 PET/CT and multiparametric MRI (mpMRI). However, the accuracy of 68Ga-PSMA-11 PET/CT for detecting intraprostatic recurrences is unclear, both with and without mpMRI. Methods: A single-center retrospective study of a series of patients investigated for radiorecurrence between 2016 and 2022 is described. All patients underwent 68Ga-PSMA-11 PET/CT, mpMRI, and prostate biopsy. PET/CT images were interpreted independently by 2 expert readers masked to other imaging and clinical data. The primary outcome was the diagnostic accuracy of PET/CT versus mpMRI and of PET/CT with mpMRI together versus mpMRI alone. The secondary outcome was the proportion of cancers missed by mpMRI but detected by PET/CT. Diagnostic accuracy analysis was performed at the prostate hemigland level using cluster bootstrapping. Results: Thirty-five men (70 hemiglands) were included. Cancer was confirmed by biopsy in 43 of 70 hemiglands (61%). PET/CT sensitivity and negative predictive values (NPVs) were 0.89 (95% CI, 0.78-0.98) and 0.79 (95% CI, 0.62-0.95), respectively, which were not significantly different from results by MRI (sensitivity of 0.72; 95% CI, 0.61-0.83; P = 0.1) (NPV of 0.59; 95% CI, 0.41-0.75; P = 0.07). Specificity and positive predictive values were not significantly different. When PET/CT and MRI were used together, the sensitivity was 0.98 (95% CI, 0.92-1.00) and NPV was 0.93 (95% CI, 0.75-1.00), both significantly higher than MRI alone (P = 0.003 and P < 0.001, respectively). Specificity and positive predictive values remained not significantly different. MRI missed 12 of 43 cancers (28%; 95% CI, 17%-43%), of which 11 of 12 (92%; 95% CI, 62%-100%) were detected by PET/CT. Conclusion: For detecting intraprostatic radiorecurrence, 68Ga-PSMA-11 PET/CT has high sensitivity that is not significantly different from mpMRI. When 68Ga-PSMA-11 PET/CT and mpMRI were used together, the results conferred a significantly greater sensitivity and NPV than with mpMRI alone. 68Ga-PSMA-11 PET/CT may therefore be a useful tool in the diagnosis of localized radiorecurrence.

Prostagram magnetic resonance imaging in a screening population: Prostate Imaging-Reporting and Data System or Likert?

OBJECTIVE

To compare biopsy recommendation rates and accuracy of the Prostate Imaging-Reporting and Data System, version 2 (PI-RADSv2) with the Likert scale for detection of clinically significant and insignificant prostate cancer in men screened within the Imperial Prostate 1 Prostate Cancer Screening Trial Using Imaging (IP1-PROSTAGRAM).

PATIENTS AND METHODS

Men aged 50-69 years were screened with Prostagram MRI. Scans were prospectively reported using both PI-RADSv2 (excluding dynamic contrast-enhanced sequence score) and 5-point Likert scores by expert uro-radiologists. Systematic and targeted transperineal biopsy was recommended if the scan was scored ≥ 3, based on either reporting system. The proportion of patients recommended for biopsy and detection rates for Grade Groups (GGs) 1 and ≥ 2 were compared. Receiver operating characteristic (ROC) analysis was performed to compare performance.

RESULTS

A total of 406 men underwent Prostagram MRI. The median (interquartile range) age and prostate-specific antigen level were 57 (53-61) years and 0.91 (0.56-1.74) ng/mL, respectively. At MRI score ≥ 3, more patients were recommended for biopsy based on Likert criteria (94/406; 23%, 95% confidence interval [CI] 19.2%-27.6%) compared to PI-RADSv2 (72/406; 18%, 95% CI 14.2%-21.9%; P = 0.03). For MRI scores ≥ 4, PI-RADSv2 and Likert scales led to 43/406 (11%, 95% CI 7.9%-14.1%) and 35/406 (9%, 95% CI 6.2%-11.9%) men recommended for biopsy (P = 0.40). For GG ≥ 2 detection, PIRADSv2 and Likert detected 22% (95% CI 11.4%-30.8%, 14/72) and 16% (95% CI 9.5%-25.3%, 15/94), respectively (P = 0.56). For GG1 cancers detection these were 11% (95% CI 4.3%-19.6%, seven of 72) vs 11% (95% CI 4.7%-17.8%, nine of 94; P = 1.00). The accuracy of PI-RADSv2 and Likert scale was similar (area under the ROC curve 0.64 vs 0.65, P = 0.95).

CONCLUSIONS

In reporting non-contrast-enhanced Prostagram MRI in a screening population, the PI-RADSv2 and Likert scoring systems were equally accurate; however, Likert scale use led to more men undergoing biopsy without a subsequent increase in significant cancer detection rates. To improve reporting of Prostagram MRI, either the PI-RADSv2 or a modified Likert scale or a standalone scoring system should be developed.

Perceived patient burden and acceptability of MRI in comparison to PSA and ultrasound: results from the IP1-PROSTAGRAM study

BACKGROUND

The IP1-PROSTAGRAM study showed that a short, non-contrast MRI detected more significant cancers with similar rates of biopsy compared to PSA. Herein, we compare the expected and perceived burden of PSA, MRI and ultrasound as screening tests.

METHODS

IP1-PROSTAGRAM was a prospective, population-based, paired screening study of 408 men conducted at seven UK primary care practices and two imaging centres. The screening tests were serum PSA, non-contrast MRI and ultrasound. If any test was screen-positive, a prostate biopsy was performed. Participants completed an Expected Burden Questionnaire (EBQ) and Perceived Burden Questionnaire (PBQ) before and after each screening test.

RESULTS

The overall level of burden for MRI and PSA was minimal. Few men reported high levels of anxiety, burden, embarrassment or pain following either MRI or PSA. Participants indicated an overall preference for MRI after completing all screening tests. Of 408 participants, 194 (47.5%) had no preference, 106 (26.0%) preferred MRI and 79 (19.4%) preferred PSA. This indicates that prior to screening, participants preferred MRI compared to PSA (+6.6%, 95% CI 4.4-8.4, p = 0.02) and after completing screening, the preference for MRI was higher (+21.1%, 95% CI 14.9-27.1, p < 0.001). The proportion of participants who strongly agreed with repeating the test was 50.5% for ultrasound, 65% for MRI and 68% for PSA. A larger proportion of participants found ultrasound anxiety-inducing, burdensome, embarrassing and painful compared to both MRI and PSA.

CONCLUSIONS

Prostagram MRI and PSA are both acceptable as screening tests among men aged 50-69 years. Both tests were associated with minimal amounts of anxiety, burden, embarrassment and pain. The majority of participants preferred MRI over PSA and ultrasound.

REGISTRATION

This study was registered on clinicaltrials.gov at https://clinicaltrials.gov/ct2/show/NCT03702439 .

The rapid assessment for prostate imaging and diagnosis (RAPID) prostate cancer diagnostic pathway

OBJECTIVE

To report outcomes within the Rapid Assessment for Prostate Imaging and Diagnosis (RAPID) diagnostic pathway, introduced to reduce patient and healthcare burdens and standardize delivery of pre-biopsy multiparametric magnetic resonance imaging (MRI) and transperineal biopsy.

PATIENTS AND METHODS

A total of 2130 patients from three centres who completed the RAPID pathway (3 April 2017 to 31 March 2020) were consecutively entered as a prospective registry. These patients were also compared to a pre-RAPID cohort of 2435 patients. Patients on the RAPID pathway with an MRI score 4 or 5 and those with PSA density ≥0.12 and an MRI score 3 were advised to undergo a biopsy. Primary outcomes were rates of biopsy and cancer detection. Secondary outcomes included comparison of transperineal biopsy techniques, patient acceptability and changes in time to diagnosis before and after the introduction of RAPID.

RESULTS

The median patient age and PSA level were 66 years and 6.6 ng/mL, respectively. Biopsy could be omitted in 43% of patients (920/2130). A further 7.9% of patients (168/2130) declined a recommendation for biopsy. The percentage of biopsies avoided among sites varied (45% vs 36% vs 51%; P < 0.001). In all, 30% (221/742) had a local anaesthetic (grid and stepper) transperineal biopsy. Clinically significant cancer detection (any Gleason score ≥3 + 4) was 26% (560/2130) and detection of Gleason score 3 + 3 alone constituted 5.8% (124/2130); detection of Gleason score 3 + 3 did not significantly vary among sites (P = 0.7). Among participants who received a transperineal targeted biopsy, there was no difference in cancer detection rates among local anaesthetic, sedation and general anaesthetic groups. In the 2435 patients from the pre-RAPID cohor, time to diagnosis was 32.1 days (95% confidence interval [CI] 29.3-34.9) compared to 15.9 days (95% CI 12.9-34.9) in the RAPID group. A total of 141 consecutive patient satisfaction surveys indicated a high satisfaction rate with the pathway; 50% indicated a preference for having all tests on a single day.

CONCLUSIONS

The RAPID prostate cancer diagnostic pathway allows 43% of men to avoid a biopsy while preserving good detection of clinically significant cancers and low detection of insignificant cancers, although there were some centre-level variations.

Landmarks in the evolution of prostate biopsy

Approaches and techniques used for diagnostic prostate biopsy have undergone considerable evolution over the past few decades: from the original finger-guided techniques to the latest MRI-directed strategies, from aspiration cytology to tissue core sampling, and from transrectal to transperineal approaches. In particular, increased adoption of transperineal biopsy approaches have led to reduced infectious complications and improved antibiotic stewardship. Furthermore, as image fusion has become integral, these novel techniques could be incorporated into prostate biopsy methods in the future, enabling 3D-ultrasonography fusion reconstruction, molecular targeting based on PET imaging and autonomous robotic-assisted biopsy.

Predicting the Need for Biopsy to Detect Clinically Significant Prostate Cancer in Patients with a Magnetic Resonance Imaging-detected Prostate Imaging Reporting and Data System/Likert ≥3 Lesion: Development and Multinational External Validation of the Imperial Rapid Access to Prostate Imaging and Diagnosis Risk Score

BACKGROUND

Although multiparametric magnetic resonance imaging (MRI) has high sensitivity, its lower specificity leads to a high prevalence of false-positive lesions requiring biopsy.

OBJECTIVE

To develop and externally validate a scoring system for MRI-detected Prostate Imaging Reporting and Data System (PIRADS)/Likert ≥3 lesions containing clinically significant prostate cancer (csPCa).

DESIGN, SETTING, AND PARTICIPANTS

The multicentre Rapid Access to Prostate Imaging and Diagnosis (RAPID) pathway included 1189 patients referred to urology due to elevated age-specific prostate-specific antigen (PSA) and/or abnormal digital rectal examination (DRE); April 27, 2017 to October 25, 2019.

INTERVENTION

Visual-registration or image-fusion targeted and systematic transperineal biopsies for an MRI score of ≥4 or 3 + PSA density ≥0.12 ng/ml/ml.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Fourteen variables were used in multivariable logistic regression for Gleason ≥3 + 4 (primary) and Gleason ≥4 + 3, and PROMIS definition 1 (any ≥4 + 3 or ≥6 mm any grade; secondary). Nomograms were created and a decision curve analysis (DCA) was performed. Models with varying complexity were externally validated in 2374 patients from six international cohorts.

RESULTS AND LIMITATIONS

The five-item Imperial RAPID risk score used age, PSA density, prior negative biopsy, prostate volume, and highest MRI score (corrected c-index for Gleason ≥3 + 4 of 0.82 and 0.80-0.86 externally). Incorporating family history, DRE, and Black ethnicity within the eight-item Imperial RAPID risk score provided similar outcomes. The DCA showed similar superiority of all models, with net benefit differences increasing in higher threshold probabilities. At 20%, 30%, and 40% of predicted Gleason ≥3 + 4 prostate cancer, the RAPID risk score was able to reduce, respectively, 11%, 21%, and 31% of biopsies against 1.8%, 6.2%, and 14% of missed csPCa (or 9.6%, 17%, and 26% of foregone biopsies, respectively).

CONCLUSIONS

The Imperial RAPID risk score provides a standardised tool for the prediction of csPCa in patients with an MRI-detected PIRADS/Likert ≥3 lesion and can support the decision for prostate biopsy.

PATIENT SUMMARY

In this multinational study, we developed a scoring system incorporating clinical and magnetic resonance imaging characteristics to predict which patients have prostate cancer requiring treatment and which patients can safely forego an invasive prostate biopsy. This model was validated in several other countries.

A Systematic Review of Patients' Values, Preferences, and Expectations for the Treatment of Metastatic Prostate Cancer

CONTEXT

Advances in systemic agents have increased overall survival for men diagnosed with metastatic prostate cancer. Additional cytoreductive prostate treatments and metastasis-directed therapies are under evaluation. These confer toxicity but may offer incremental survival benefits. Thus, an understanding of patients' values and treatment preferences is important for counselling, decision-making, and guideline development.

OBJECTIVE

To perform a systematic review of patients' values, preferences, and expectations regarding treatment of metastatic prostate cancer.

EVIDENCE ACQUISITION

The MEDLINE, Embase, and CINAHL databases were systematically searched for qualitative and preference elucidation studies reporting on patients' preferences for treatment of metastatic prostate cancer. Certainty of evidence was assessed using Grading of Recommendation, Assessment, Development and Evaluation (GRADE) or GRADE Confidence in the Evidence from Reviews of Qualitative Research (CERQual). The protocol was registered on PROSPERO as CRD42020201420.

EVIDENCE SYNTHESIS

A total of 1491 participants from 15 studies met the prespecified eligibility for inclusion. The study designs included were discrete choice experiments (n = 5), mixed methods (n = 3), and qualitative methods (n = 7). Disease states reported per study were: metastatic castration-resistant prostate cancer in nine studies (60.0%), metastatic hormone-sensitive prostate cancer in two studies (13.3%), and a mixed cohort in four studies (26.6%). In quantitative preference elicitation studies, patients consistently valued treatment effectiveness and delay in time to symptoms as the two top-ranked treatment attributes (low or very low certainty). Patients were willing to trade off treatment-related toxicity for potential oncological benefits (low certainty). In qualitative studies, thematic analysis revealed cancer progression and/or survival, pain, and fatigue as key components in treatment decisions (low or very low certainty). Patients continue to value oncological benefits in making decisions on treatments under qualitative assessment.

CONCLUSIONS

There is limited understanding of how patients make treatment and trade-off decisions following a diagnosis of metastatic prostate cancer. For appropriate investment in emerging cytoreductive local tumour and metastasis-directed therapies, we should seek to better understand how this cohort weighs the oncological benefits against the risks.

PATIENT SUMMARY

We looked at how men with advanced (metastatic) prostate cancer make treatment decisions. We found that little is known about patients' preferences for current and proposed new treatments. Further studies are required to understand how patients make decisions to help guide the integration of new treatments into the standard of care.

Diagnostic accuracy of magnetic resonance imaging targeted biopsy techniques compared to transrectal ultrasound guided biopsy of the prostate: a systematic review and meta-analysis

Background

Multiparametric MRI localizes cancer in the prostate, allowing for MRI guided biopsy (MRI-GB) 43 alongside transrectal ultrasound-guided systematic biopsy (TRUS-GB). Three MRI-GB approaches exist; visual estimation (COG-TB); fusion software-assisted (FUS-TB) and MRI ‘in-bore’ biopsy (IB-TB). It is unknown whether any of these are superior.

We conducted a systematic review and meta-analysis to address three questions. First, whether MRI-GB is superior to TRUS-GB at detecting clinically significant PCa (csPCa). Second, whether MRI-GB is superior to TRUS-GB at avoiding detection of insignificant PCa. Third, whether any MRI-GB strategy is superior at detecting csPCa.

Methods

A systematic literature review from 2015 to 2019 was performed in accordance with the START recommendations. Studies reporting PCa detection rates, employing MRI-GB and TRUS-GB were included and evaluated using the QUADAS-2 checklist. 1553 studies were found, of which 43 were included in the meta-analysis.

Results

For csPCa, MRI-GB was superior in detection to TRUS-GB (0.83 vs. 0.63 [p = 0.02]). MRI-GB was superior in detection to TRUS-GB at avoiding detection of insignificant PCa. No MRI-GB technique was superior at detecting csPCa (IB-TB 0.87; COG TB 0.81; FUS-TB 0.81, [p = 0.55]). There was significant heterogeneity observed between the included studies.

Conclusions

In patients with suspected PCa on MRI, MRI-GB offers superior rates of csPCa detection and reduces detection of insignificant PCa compared to TRUS-GB. No individual MRI-GB technique was found to be better in csPCa detection. Prospective adequately powered randomized controlled trials are required.

Population-Based Prostate Cancer Screening With Magnetic Resonance Imaging or Ultrasonography: The IP1-PROSTAGRAM Study

Question

In men invited to undergo screening for prostate cancer with magnetic resonance imaging (MRI), ultrasonography, and prostate-specific antigen testing, what is the prevalence of positive test results, rates of biopsy, and detection of prostate cancer?

Findings

In this cohort study in which 408 men underwent 3 screening tests, an MRI score of 4 or 5 was associated with improved detection of clinically significant prostate cancer without an increase in the number of men who underwent biopsy or were overdiagnosed with clinically insignificant prostate cancer if prostate-specific antigen testing alone was used. Ultrasonography was not associated with improved screening performance.

Meaning

These findings suggest that a short, noncontrast MRI may have favorable performance characteristics as a community-based screening test.

Importance

Screening for prostate cancer using prostate-specific antigen (PSA) testing can lead to problems of underdiagnosis and overdiagnosis. Short, noncontrast magnetic resonance imaging (MRI) or transrectal ultrasonography might overcome these limitations.

Objective

To compare the performance of PSA testing, MRI, and ultrasonography as screening tests for prostate cancer.

Design, Setting, and Participants

This prospective, population-based, blinded cohort study was conducted at 7 primary care practices and 2 imaging centers in the United Kingdom. Men 50 to 69 years of age were invited for prostate cancer screening from October 10, 2018, to May 15, 2019.

Interventions

All participants underwent screening with a PSA test, MRI (T2 weighted and diffusion), and ultrasonography (B-mode and shear wave elastography). The tests were independently interpreted without knowledge of other results. Both imaging tests were reported on a validated 5-point scale of suspicion. If any test result was positive, a systematic 12-core biopsy was performed. Additional image fusion–targeted biopsies were performed if the MRI or ultrasonography results were positive.

Main Outcomes and Measures

The main outcome was the proportion of men with positive MRI or ultrasonography (defined as a score of 3-5 or 4-5) or PSA test (defined as PSA ≥3 μg/L) results. Key secondary outcomes were the number of clinically significant and clinically insignificant cancers detected if each test was used exclusively. Clinically significant cancer was defined as any Gleason score of 3+4 or higher.

Results

A total of 2034 men were invited to participate; of 411 who attended screening, 408 consented to receive all screening tests. The proportion with positive MRI results (score, 3-5) was higher than the proportion with positive PSA test results (72 [17.7%; 95% CI, 14.3%-21.8%] vs 40 [9.9%; 95% CI, 7.3%-13.2%]; P < .001). The proportion with positive ultrasonography results (score, 3-5) was also higher than the proportion of those with positive PSA test results (96 [23.7%; 95% CI, 19.8%-28.1%]; P < .001). For an imaging threshold of score 4 to 5, the proportion with positive MRI results was similar to the proportion with positive PSA test results (43 [10.6%; 95% CI, 7.9%-14.0%]; P = .71), as was the proportion with positive ultrasonography results (52 [12.8%; 95% CI, 9.9%-16.5%]; P = .15). The PSA test (≥3 ng/mL) detected 7 clinically significant cancers, an MRI score of 3 to 5 detected 14 cancers, an MRI score of 4 to 5 detected 11 cancers, an ultrasonography score of 3 to 5 detected 9 cancer, and an ultrasonography score of 4 to 5 detected 4 cancers. Clinically insignificant cancers were diagnosed by PSA testing in 6 cases, by an MRI score of 3 to 5 in 7 cases, an MRI score of 4 to 5 in 5 cases, an ultrasonography score of 3 to 5 in 13 cases, and an ultrasonography score of 4 to 5 in 7 cases.

Conclusions and Relevance

In this cohort study, when screening the general population for prostate cancer, MRI using a score of 4 or 5 to define a positive test result compared with PSA alone at 3 ng/mL or higher was associated with more men diagnosed with clinically significant cancer, without an increase in the number of men advised to undergo biopsy or overdiagnosed with clinically insignificant cancer. There was no evidence that ultrasonography would have better performance compared with PSA testing alone.

Retrograde migration of a vesicoureteric junction calculus: A potential pitfall of the noncontrast limited pelvic computerized tomography

Retrograde ureteric calculus migration is a rare phenomenon. Herein, we report two such cases where each patient presented with a calculus, measured at 5 mm and 6 mm, respectively, at the vesicoureteric junction (VUJ) on noncontrast computerized tomography kidneys, ureters, and bladder (CTKUB). Following acute presentation with renal colic, each patient opted for conservative management of their ureteric stone and became asymptomatic when undergoing their follow-up imaging. The first patient underwent a follow-up noncontrast limited pelvic computerized tomography (CT) where it had appeared that the radiolucent VUJ calculus had passed. This stone was then discovered incidentally 3 months later in the upper ureter when the patient had undergone a CT colonography. The other patient underwent a follow-up X-ray KUB where the stone was shown to have migrated to the lower renal pole calyx which was confirmed with noncontrast CTKUB imaging. In all reported cases of retrograde VUJ calculus migration, the use of a noncontrast limited pelvic CT scan either missed or would have missed this phenomenon. This potential pitfall of the noncontrast limited pelvic CT scan should be appreciated and the use of full upper renal tract imaging should be considered for the follow-up of radiolucent VUJ calculus cases whereby there is no clear history of calculus passage.

A Multicenter Study of the Clinical Utility of Nontargeted Systematic Transperineal Prostate Biopsies in Patients Undergoing Pre-Biopsy Multiparametric Magnetic Resonance Imaging

PURPOSE

The added value of nontargeted systematic prostate biopsies when performed alongside magnetic resonance imaging targeted biopsies in men referred with a suspicion of prostate cancer is unclear. We aimed to determine the clinical utility of transperineal nontargeted systematic prostate biopsies, when performed alongside targeted systematic prostate biopsies, using pre-biopsy multiparametric magnetic resonance imaging.

MATERIALS AND METHODS

Consecutive patients referred with a suspicion of prostate cancer (April 2017 to October 2019) underwent pre-biopsy multiparametric magnetic resonance imaging. A transperineal biopsy was advised if multiparametric magnetic resonance imaging PI-RADS® (v.2.0) score was 4 or 5, and score 3 required a prostate specific antigen density 0.12 ng/ml or greater. Primary threshold for clinically significant prostate cancer was defined as any Gleason 3+4 or greater. Multivariable logistic regression analysis identified pre-biopsy predictors of clinically significant prostate cancer in nontargeted systematic prostate biopsies, regardless of targeted pathology (p <0.05, R, version 3.5.1).

RESULTS

A total of 1,719 men underwent a pre-biopsy multiparametric magnetic resonance imaging, with 679 (39.5%) proceeding to combined targeted systematic prostate biopsies and nontargeted systematic prostate biopsies. In these men clinically significant prostate cancer was detected in 333 (49%) and 139 (20.5%) with targeted systematic prostate biopsies and nontargeted systematic prostate biopsies, respectively. In those men with clinically significant prostate cancer in targeted systematic prostate biopsies, clinically significant prostate cancer was also present in nontargeted systematic prostate biopsies in 117 (17.2%); Gleason 3+3 was present in 50 (7.4%). In 287 men without any cancer in the targeted systematic prostate biopsies, 13 (1.9%) had clinically significant prostate cancer in nontargeted systematic prostate biopsies. In addition 18/679 (2.7%) had Gleason 3+3 disease and no Gleason greater than 4+3 was detected. Predictors associated with clinically significant prostate cancer in nontargeted systematic prostate biopsies were prostate specific antigen 5 ng/ml or greater (OR 2.05, 95% CI 1.13-3.73, p=0.02), PI-RADS score 5 (OR 2.26, 95% CI 1.51-3.38, p <0.001) and prostate volume less than 50 cc (OR 2.47, 95% CI 1.57-3.87, p <0.001).

CONCLUSIONS

Detection of clinically significant prostate cancer in exclusively nontargeted transperineal systematic biopsies in a pre-biopsy multiparametric magnetic resonance imaging pathway was low (1.9%).

Targeting Oligometastasis with Stereotactic Ablative Radiation Therapy or Surgery in Metastatic Hormone-sensitive Prostate Cancer: A Systematic Review of Prospective Clinical Trials

CONTEXT

Metastasis-directed therapy (MDT) in the form of stereotactic ablative radiation therapy (SABR), or in combination with surgical metastasectomy, may have a role in cancer control and disease progression.

OBJECTIVE

To perform a systematic review of MDT (surgery or SABR) for oligometastatic (up to 10 metastases, recurrent or de novo) hormone-sensitive prostate cancer in addition to or following primary prostate gland treatment.

EVIDENCE ACQUISITION

Medline, Embase, Cochrane Review Database, and clinical trial Databases were systematically searched for clinical trials reporting oncological outcomes and safety. The risk of bias was assessed with the Cochrane 2.0 or ROBINS-I tool.

EVIDENCE SYNTHESIS

From 1025 articles identified, four clinical trials met the prespecified criteria. These included two randomised and two nonrandomised clinical trials (n=169). Baseline prostate-specific antigen level, age, and metastasis ranged from 2.0 to 17.0 ng/ml, 43 to 75 yr, and one to seven lesions, respectively. Nodal, bone, nodal and bone, and visceral metastases were present in 49.7% (84/169), 33.7% (57/169), 15.9% (27/169), and 0.5% (1/169) of patients, respectively. Diagnostic conventional imaging was used in 43.7% (74/169) and positron emission tomography/computerised tomography in 56.2% (95/169) of patients. SABR and surgical metastasectomy with SABR were used in 78.3% (94/120) and 21.6% (26/120) of patients, respectively. Early progression-free survival ranged from 19% to 60%. Local control was reported as 93-100%. Grade II and III SABR toxicities were reported in 8% (8/100) and 1% (1/100) of patients, respectively. Grade IIIa and IIIb surgical complications were reported in 7.69% (2/26) and 0% (0/26) of patients, respectively.

CONCLUSIONS

MDT is a promising experimental therapeutic approach in men with hormone-sensitive oligometastatic prostate cancer. Randomised comparative studies are required to ascertain its role and optimal timing in oligometastatic recurrence and efficacy in de novo synchronous disease.

PATIENT SUMMARY

We looked at the evidence regarding the use of surgery or radiotherapy at target areas of cancer spread in men with newly diagnosed or relapsed advanced (metastatic) prostate cancer. Evidence supports both treatment options as promising approaches, but further large trials are required.

Filariasis an Unusual Cause of Retroperitoneal Fibrosis, Hydronephrosis, and Infertility in a Young Adult Male

Background: Filariasis is a tropical disease caused by infection with nematode parasites of the Filarioidea family. Filariasis is an endemic disease in parts of India, Sub-Saharan Africa, and Southeast Asia. Filariasis is a progressive disease predominantly affecting the lymphoreticular system, which can result in genitourinary complications (hydrocele, scrotal pain, and infertility), lymphedema, and elephantitis. Retroperitoneal fibrosis has a broad etiology, including secondary to chronic infection. Currently an estimated 25 million men are suffering from lymphatic filariasis with urogenital involvement worldwide. Case Presentation: We present a rare case of a 40-year-old man presenting with fever, groin lymphadenopathy, and a history of infertility. Imaging confirmed significant hydronephrosis and retroperitoneal fibrosis. Filariasis serology was positive. Prior bilateral testicular biopsy demonstrated chronic inflammation and atrophy. Disease course was not improved by empirical eradication and supportive retrograde ureteral stenting. The patient developed elephantitis and progressive retroperitoneal fibrosis leading to a solitary functioning right kidney with nephrostomy. Conclusion: Urologists should be aware of index presentations of filariasis and its associated urological complications, particularly in the travelling adult population in whom the etiology of renal impairment and infertility remains unclear.

Value of systematic sampling in an mp-MRI targeted prostate biopsy strategy

The clinical utility of systematic prostate biopsy in addition to multi-parametric magnetic resonance imagining (mp-MRI) targeted biopsy pathways remains unclear. Despite radiological advancements in mp-MRI and utilisation of international standardised reporting systems (i.e., PI-RADS, LIKERT), undetected clinically significant prostate cancer (csPCa) on imaging persists. This has prevented the widespread adoption of an exclusively targeted biopsy approach. The current evidence on csPCa cancer detection rates in mp-MRI targeted alone and combined with a non-targeted systematic sampling is presented. Arguments for and against routine limited systematic sampling as an adjunct to an mp-MRI targeted biopsy are discussed. Our review will report the clinical utility of a combined sampling strategy on csPCa detection rate. The available evidence suggests that we are yet to reach a stage where non-targeted systematic prostate biopsy can be routinely omitted in mp-MRI targeted prostate biopsy pathways. Research should focus on improving the accuracy of mp-MRI, prostate biopsy techniques, and in identifying those men that will most benefit from a combined prostate biopsy. Such strategies may help future urologists reduce the burden of non-targeted cores in modern mp-MRI prostate biopsy pathways.

A Multicentre Analysis of the Detection of Clinically Significant Prostate Cancer Following Transperineal Image-fusion Targeted and Nontargeted Systematic Prostate Biopsy in Men at Risk

BACKGROUND

Prostate biopsy guided by magnetic resonance imaging (MRI) is increasingly used to obtain tissue from men with suspected prostate cancer (PC).

OBJECTIVE

To report a multicentre series of image-fusion transperineal prostate biopsies and compare the diagnostic yield of clinically significant PC (csPC) between targeted and nontargeted biopsies.

DESIGN, SETTING, AND PARTICIPANTS

The study included 640 consecutive patients with elevated prostate specific antigen (PSA) presenting for first biopsy or following a previous negative transrectal biopsy under the care of 13 urologists in 11 centres in the UK (April 2014-June 2017).

INTERVENTION

Multiparametric MRI was carried out in 61 approved prostate MRI centres with transperineal targeted alone (n=283) or targeted plus nontargeted (n=357) transperineal rigid image-fusion targeted biopsy (MIM-Symphony-DX).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Rates of csPC and insignificant cancer detection in targeted and nontargeted biopsies were measured using a number of thresholds to define clinical significance. The primary definition was Gleason≥4+3 or any grade ≥6mm.

RESULTS AND LIMITATIONS

The mean age, median PSA, and median prostate volume for the cohort were 63.8yr (standard deviation [SD] 8.4), 6.3 ng/ml (SD 5.8), and 42.0cm3 (SD 24.7), respectively. Overall, 276/640 men (43.1%) were diagnosed with csPC. csPC was detected from targeted biopsies alone in 263/640 cases (41.1%). Of the 357 men who underwent nontargeted biopsies, three (0.8%) had csPC exclusively in nontargeted cores, with no evidence of cancer in targeted cores. Overall, 32/357 (9.0%) had csPC in nontargeted biopsies regardless of the targeted biopsy findings. Clinically insignificant disease in nontargeted biopsies was detected in 93/357 men (26.1%). Our findings were consistent across all other thresholds of clinical significance. Limitations include the lack of nontargeted biopsies in all men.

CONCLUSIONS

In this large multicentre series, nontargeted prostate biopsy cores had a low yield of csPC and a high yield of clinically insignificant PC. An image-fusion targeted-biopsy-only approach maintains high detection for csPC and low detection of clinically insignificant cancers.

PATIENT SUMMARY

In this report, we found that following prostate multiparametric magnetic resonance imaging and targeted transperineal biopsies of suspicious areas, the clinical value of performing additional extensive unguided biopsies of nonsuspicious areas is limited and can often find insignificant cancers that do not need treatment.

Can transrectal prostate ultrasound compete with multiparametric MRI in the detection of clinically significant prostate cancer?

We consider the current and future role of transrectal ultrasound imaging in the diagnosis of prostate cancer, with a particular focus on the pre-biopsy localization and targeting role that multiparametric MRI (mpMRI) has come to occupy for some men in recent years. We draw a distinction between transrectal ultrasound (TRUS) used only as a means of distributing zonal biopsies with its employment as a means for identifying and targeting sonographically abnormal lesions. The role of AI in lesion identification and targeting will be reviewed. Comparisons of cost and availability, frequency of contraindications and diagnostic accuracy between these two imaging modalities will be drawn.

Prostate cancer biology & genomics

Prostate Cancer is now the second biggest cause of cancer mortality in the UK. Media coverage has been rising, with some attributing to a rise in the cases diagnosed and treated in the NHS down to the “Fry and Turnbull effect”. Our understanding of prostate cancer has increased tremendously in the past decades, with advances in molecular biology and genomics driving the way to new treatments and diagnostics. This Special Edition of Translational Andrology and Urology 2019: Prostate Cancer Biology and Genomics aims to review the current state of prostate cancer genomics, proteomics, diagnostics and treatment.

A systematic review of salvage focal therapies for localised non-metastatic radiorecurrent prostate cancer

Although radiotherapy to the prostate for cancer is effective, recurrence occurs in 10–15% within 5 years. Traditional salvage treatments for men with radiorecurrent prostate cancer comprise of watchful waiting (WW) with or without androgen deprivation therapy (ADT) or radical prostatectomy (RP). Neither strategy provides ideal therapeutic ratios. Salvage focal ablation is an emerging option. We performed a systematic review of the Medline and Embase databases for studies reporting outcomes of focal salvage brachytherapy (sBT), cryotherapy (sCT) or high-intensity focused ultrasound (sHIFU) for radiorecurrent prostate cancer (conception to April 2019). Results were screened for inclusion against predetermined eligibility criteria. Certain data were extracted, including rates of biochemical disease-free survival (BDFS), metastasis, conversion to second-line therapies and adverse events. Of a total 134 articles returned from the search, 15 studies (14 case series and 1 comparative study) reported outcomes after focal sBT [5], sCT [7] and sHIFU [3]. Cohort size varied depending on intervention, with eligible studies of sBT being small case series. Median follow-up ranged from 10 to 56 months. Although pre-salvage demographics were similar [median age range, 61–75 years; prostate-specific antigen (PSA) range, 2.8–5.5 ng/mL], there was heterogeneity in patient selection, individual treatment protocols and outcome reporting. At 3 years, BDFS ranged from 61% to 71.4% after sBT, 48.1–72.4% after sCT and 48% after sHIFU. Only studies of sCT reported 5-year BDFS, which ranged from 46.5% to 54.4%. Rates of metastasis were low after all salvage modalities, as were conversion to second-line therapies (although this was poorly reported). Grade 3 adverse events were rare. This systematic review indicates that salvage focal ablation of radiorecurrent prostate cancer provides acceptable oncological outcomes and is well tolerated. Unfortunately, there is heterogeneity in the study design of existing evidence. Level 1 research comparing salvage focal therapies to existing whole-gland strategies is needed to further establish the role of these promising treatments.

Current techniques of prostate biopsy: an update from past to present

Knowing the demerits of the transrectal ultrasound guided biopsy has led to a shift in the general techniques and technology of the prostate biopsy. In addition, the advances in magnetic resonance imaging (MRI) sensitivity and the evidence from the PROMIS trial about its ability to detect clinically significant tumours encourage urologists and industry to implement MRI-guided targeted biopsy. However, the science is still looking how to improve safety and increase its cancer detection rate (CDR).

Focal therapy for localized prostate cancer in the era of routine multi-parametric MRI

BACKGROUND

Prostate cancer focal therapy aims to minimize the side-effects of whole gland treatments, such as radical prostatectomy and radiotherapy without compromising oncological efficacy. However, concerns exist regarding the multifocal nature of prostate cancer and the lack of long-term oncological data for this form of treatment. In recent years, the routine adoption of multi-parametric magnetic resonance imaging (mpMRI) of the prostate has improved our ability to select candidates for focal therapy and to accurately deliver this form of prostate cancer treatment.

METHODS

We performed a review of the literature to provide a summary of the oncological and functional outcomes of men receiving primary prostate focal therapy. Furthermore, we discuss the impact of the routine implementation of mpMRI as part of the initial prostate cancer diagnostic pathway on the selection of candidates and delivery of focal therapy. Finally, we summarize knowledge gaps in the field and highlight active clinical trials in this arena.

RESULTS

Primary focal therapy involves the application of one of a number of energies that ablate tissue, such as cryotherapy and high intensity focused ultrasound (HIFU). Success is principally dependent on highly accurate patient selection and disease localization underpinned in large part by the routine integration of pre-biopsy mpMRI. Prospective medium-term follow-up data for primary HIFU and cryotherapy for men with intermediate-risk disease have shown acceptable cancer control with low risk of side effects and complications. Additional research is needed to clearly define an appropriate follow-up approach and to guide the management of in- and out-of-field recurrences. Multiple comparative trials with randomization against standard care are currently underway in men with intermediate- and high-risk prostate cancer.

CONCLUSION

The widespread adoption of prostate mpMRI has led to improved disease localization, enabling the performance of focal therapy as a viable treatment strategy for men with low volume intermediate-risk prostate cancer.

Cytoreductive treatment strategies for de novo metastatic prostate cancer

In the past decade, a revolution in the treatment of metastatic prostate cancer has occurred with the advent of novel hormonal agents and life-prolonging chemotherapy regimens in combination with standard androgen-deprivation therapy. Notwithstanding, the use of systemic therapy alone can result in a castrate-resistant state; therefore, increasing focus is being placed on the additional survival benefits that could potentially be achieved with local cytoreductive and/or metastasis-directed therapies. Local treatment of the primary tumour with the established modalities of radiotherapy and radical prostatectomy has been explored in this context, and the use of novel minimally invasive ablative therapies has been proposed. In addition, evidence of the potential clinical benefits of metastasis-directed therapy with ionizing radiation (primarily stereotactic ablative radiotherapy) is accumulating. Herein, we summarize the pathobiological rationale for local cytoreduction and the potentially systemic immunological responses to radiotherapy and ablative therapies in patients with metastatic prostate cancer. We also discuss the current evidence base for a cytoreductive strategy, including metastasis-directed therapy, in the current era of sequential multimodal therapy incorporating novel treatments. Finally, we outline further research questions relating to this complex and evolving treatment landscape.

Likert vs PI-RADS v2: a comparison of two radiological scoring systems for detection of clinically significant prostate cancer

OBJECTIVE

To compare the clinical validity and utility of Likert assessment and the Prostate Imaging Reporting and Data System (PI-RADS) v2 in the detection of clinically significant and insignificant prostate cancer.

PATIENTS AND METHODS

A total of 489 pre-biopsy multiparametric magnetic resonance imaging (mpMRI) scans in consecutive patients were subject to prospective paired reporting using both Likert and PI-RADS v2 by expert uro-radiologists. Patients were offered biopsy for any Likert or PI-RADS score ≥4 or a score of 3 with PSA density ≥0.12 ng/mL/mL. Utility was evaluated in terms of proportion biopsied, and proportion of clinically significant and insignificant cancer detected (both overall and on a 'per score' basis). In those patients biopsied, the overall accuracy of each system was assessed by calculating total and partial area under the receiver-operating characteristic (ROC) curves. The primary threshold of significance was Gleason ≥3 + 4. Secondary thresholds of Gleason ≥4 + 3, Ahmed/UCL1 (Gleason ≥4 + 3 or maximum cancer core length [CCL] ≥6 or total CCL≥6) and Ahmed/UCL2 (Gleason ≥3 + 4 or maximum CCL ≥4 or total CCL ≥6) were also used.

RESULTS

The median (interquartile range [IQR]) age was 66 (60-72) years and the median (IQR) prostate-specific antigen level was 7 (5-10) ng/mL. A similar proportion of men met the biopsy threshold and underwent biopsy in both groups (83.8% [Likert] vs 84.8% [PI-RADS v2]; P = 0.704). The Likert system predicted more clinically significant cancers than PI-RADS across all disease thresholds. Rates of insignificant cancers were comparable in each group. ROC analysis of biopsied patients showed that, although both scoring systems performed well as predictors of significant cancer, Likert scoring was superior to PI-RADS v2, exhibiting higher total and partial areas under the ROC curve.

CONCLUSIONS

Both scoring systems demonstrated good diagnostic performance, with similar rates of decision to biopsy. Overall, Likert was superior by all definitions of clinically significant prostate cancer. It has the advantages of being flexible, intuitive and allowing inclusion of clinical data. However, its use should only be considered once radiologists have developed sufficient experience in reporting prostate mpMRI.

Erratum: Mesothelioma subtypes of the tunica vaginalis: a rare case report and review of histological criteria

[This corrects the article DOI: 10.1093/jscr/rjz040.].

Mesothelioma subtypes of the tunica vaginalis: a rare case report and review of histological criteria

Well-differentiated papillary mesothelioma (WDPM) is a rare histological subtype of mesothelioma arising from the tunica vaginalis. We present a case of a 23-year-old male with a palpable para-testicular lump of 3 years duration. Scrotal exploration revealed a grossly abnormal cystic appearance of his tunica vaginalis. An excision biopsy confirmed WDPM of the tunica vaginalis. The three subtypes of mesothelial tumours of the tunica vaginalis are described by their distinct histological features, tumour growth and reported prognosis. A summary of immunohistochemistry and the surgical management across the disease spectrum is provided. Recent clarification of the histological criteria of WDPM provides the opportunity for surgeons to offer a limited approach to managing this indolent tumour that mimics malignant mesothelioma. However, the lack of evidence on recurrence and progression rates in WDPM restricts most surgeons to performing a radical orchidectomy, as was performed in this case.

Transition Risk Assessment Score to Stratify Health Care Needs and Interventions in Adolescents with Anorectal Malformations: A Pilot Study

Introduction Anorectal malformations (ARMs) are a complex collection of congenital disorders of the anus, rectum, and genitourinary system with possible active morbidities beyond adolescence. Aims To create the first evidence-based inclusive transition risk assessment score (TRAS) to stratify health care needs and interventions in teenagers with ARM transitioning to adult health care. Method MEDLINE, EMBASE, and the Cochrane Library were searched electronically for original articles containing published scoring systems evaluating children with ARM from January 1, 1990 to December 31, 2013. Current published scoring systems identified were weighted to create a novel score (TRAS) to objectively assess the most common active problems present in teenagers with ARM: fecal, urinary, and sexual functions; quality of life; and psychosocial well-being. The TRAS was applied to patients visiting our tertiary anorectal clinic in the period from January 2014 to March 2016. Patients were rescored on each visit to the clinic. Results Total 21 separate scoring systems were identified in the literature, with 3 scoring systems incorporated into the TRAS. The score divided patients into "low" (0-4), "medium" (5-10), and "high" (11-35) risk categories. The TRAS was used to assess 14 adolescents with ARMs during the study period; 14 patients had a single TRAS, 7 had two TRAS, and 3 had three TRAS assessments. At first visit 14 patients with a median age of 13 were assessed with TRAS ranging from 2 to 13 (M = 5, SD 3.33, 95% CI 3.08-7.68). At second visit seven patients with a median age of 15 were assessed with TRAS ranging from 2 to 12 (M = 6.43, SD 3.51, 95% CI 3.19-9.67). At third visit three patients with a median age of 16 were assessed with TRAS ranging from 6 to 12 (M = 8.33, SD 3.21, 95% CI 0.35-16.32). There was no significant difference (p > 0.05) between a patient's TRAS at different visits. Conclusion Preliminary data suggest that the TRAS is a holistic and effective clinical tool to help to objectively stratify ARM patients, identify active problems, and select those who may require intensive multidisciplinary input and interventions during the transition to adult health care services.

Necrotizing Fasciitis of the Thigh and Calf: A Reminder to Exclude a Perforated Intra-Abdominal Viscus: A Case Report

CASE

Diverticular disease and its associated complications are an increasing problem among Western populations. Perforated diverticulitis results in intra-abdominal sepsis, which rarely causes a life-threatening necrotizing soft-tissue infection. We present the case of a 70-year-old man with a sigmoid diverticulitis perforation presenting as necrotizing fasciitis of the thigh and calf requiring serial debridement and major limb reconstruction.

CONCLUSION

Clinicians should be aware of index presentations of diverticulitis and its recognized complications in this demographic group. For the orthopaedic and the general surgeon, knowledge of the dangers of the concomitant presence of these 2 conditions will substantially reduce morbidity and mortality.

Esophageal atresia and transitional care--step 1: a systematic review and meta-analysis of the literature to define the prevalence of chronic long-term problems

BACKGROUND

Esophageal atresia (EA) is a rare congenital anomaly with high infantile survival rates. The aim of this study was to outline the prevalence of common long-term problems associated with EA repair in patients older than 10 years of age.

DATA SOURCES

Original papers were identified by systematic searching of MEDLINE and EMBASE databases from January 1993 to July 2014. Fifteen articles (907 EA patients) met inclusion criteria.

CONCLUSIONS

This is the first systematic review aiming to quantify the prevalence of the long-term problems associated with EA. The main active medical conditions (pooled estimated prevalence) identified were the following: dysphagia (50.3%), gastroesophageal reflux disease with (40.2%) or without (56.5%) histological esophagitis, recurrent respiratory tract infections (24.1%), doctor-diagnosed asthma (22.3%), persistent cough (14.6%), and wheeze (34.7%). The prevalence of Barrett's esophagus (6.4%) was 4 and 26 times higher than the adult (1.6%) and pediatric (.25%) general populations. Adult and pediatric practitioners should focus on how to develop effective long-term follow-up and transitional care for these patients.

The posterior epidural ligaments: a cadaveric and histological investigation in the lumbar region

Purpose. Incidental durotomy is a relatively common complication for patients undergoing posterior spinal surgery. Delineating anatomical variants in the posterior lumbar spinal canal is crucial in reducing future rates of incidental durotomy. Materials and Methods. The ligamentous attachments between the dura mater and ligamentum flavum in the lumbar region of 17 soft-fixed cadavers were investigated. The lumbar vertebral columns were removed, and cross-sectional dissection was performed at levels L1-S1. Anterior retraction of the dorsal dura mater identified attachments between the dorsal surface of the dura mater and the ligamentum flavum. Histological staining of the ligamentous attachments was carried out with hematoxylin and eosin (H&E) and elastic van Gieson (EVG). Results. Posterior epidural ligaments were present in 9 (52.9%) cadavers. Nine (9) separate ligaments were identified in these cadavers, with 3 (33.3%) at L3/L4, 5 (55.5%) at L4/L5, and 1 (11.1%) at L5/S1. Histology confirmed the presence of poorly differentiated collagen-based connective tissue, distinct from the normal anatomy. Conclusions. This study confirms the presence of multiple dorsomedial posterior epidural ligaments at the main sites for posterior spinal surgery (L3-S1). An intraoperative awareness of the variability of such connections may be an important step in reducing static rates of incidental durotomy.

Detection of mutations in the RB1 gene by single strand conformation polymorphism (SSCP) analysis, amplification mismatch detection (AMD) analysis and polymerase chain reaction sequencing

Mutations of the retinoblastoma gene are known to cause both nonhereditary and hereditary forms of retinoblastoma. Most patients with hereditary retinoblastoma have bilateral disease. Hereditary predisposition to retinoblastoma is caused by a germline mutation at the retinoblastoma gene locus (RB1) and transmitted as an autosomal dominant trait with 90% penetrance. Three quarters of these alterations represent de novo mutations. Since 75% of these cases are new mutations, there is a need for methods which can be used to identify carriers, so that informed genetic counselling will be available to patients and close relatives. In the present study, leukocyte DNA and RNA from 5 patients with sporadic bilateral retinoblastoma. were subjected to single stranded conformation analysis (SSCP) and amplification and mismatch detection (AMD) analysis. SSCP band shifts were found in 3 of the 5 patients. AMD was applied to reverse-transcriptase PCR and exons of the RB1 gene in the patients with bilateral retinoblastoma. Cleavage was found in 2 patients. Neither of these patients corresponded to the 3 with SSCP band shifts. Thus in total, 5 patients with retinoblastoma had mutations detected by a combination of SSCP and AMD analysis, and proof was sought by means of sequencing. This approach has proved to be a useful method for the rapid detection of mutations in the RB1 gene. The five mutations detected in this study were all novel and emphasise the heterogeneity of the molecular pathology in this gene.

Aberrant RNA splicing in the hMSH2 gene: molecular identification of three aberrant RNA in Scottish patients with colorectal cancer in the West of Scotland

Blood samples from 47 unselected patients with colorectal cancer were used as a source of hMSH2 mRNA. We identified three new hMSH2 aberrant mRNAs including: 1) IVS15 +5 G-->C resulting in exon 15 skipping from transcript; 2) an mRNA deletion of exons 2 to 6 inclusive; and 3) an mRNA deletion of exons 2 to 8 inclusive. In order to find out whether or not exon skipping is a natural consequence of alternative mRNA splicing, total RNA from 20 healthy individuals was converted to cDNA by reverse-transcriptase polymerase chain reaction, and our results show that none of the healthy individuals have the above aberrant mRNA. Our results also show that the presence of mutations in colorectal cancer cases, which do not fully meet the hereditary non-polyposis colon cancer criteria, would suggest that all familial cases should be investigated for germ line mutations in the mismatch repair genes.

Pharmacokinetics of chronically administered all-trans-retinoyl-beta-glucuronide in mice

After the subcutaneous injection of retinoyl beta-glucuronide (RAG), both RAG and retinoic acid (RA), formed by the hydrolysis of RAG in vivo, achieved peak plasma concentrations within 1-2 h. Thereafter, RA was rapidly cleared from the plasma whereas RAG was eliminated much more slowly. No significant changes were noted in the peak (2 h) plasma levels of RAG for treatment periods up to 56 days (one injection of RAG/day), in the clearance rate of RAG from plasma, or in plasma retinol concentrations. Similarly, no consistent decrease in plasma levels of the RA hydrolysis product was observed. Mice undergoing these long-term chronic treatments with RAG did not show any clinical manifestations of retinoid toxicity. Taken together, our findings that chronic dosing with RAG produces sustained levels of both the parent compound and the RA hydrolysis product, combined with the apparent low toxicity of RAG, suggest that RAG could be a safe and useful alternative to some retinoids which are presently being utilized in the clinic.

Expanding the dialogue on praxis in nursing research and practice

The intent of this article is twofold: to expand the dialogue on research as praxis in nursing as articulated by Newman and to support the concept of praxis as a catalyst for extending nursing knowledge. The article revisits the concept of research as praxis through examining critiques by other writers. It explores the notion of praxis as practice within the methodology and research protocol developed by Newman and extended by other researcher-practitioners including the author.

Detection of trisomy 12 and centromeric alterations in CLL by interphase- and metaphase-FISH

We have studied trisomy 12 in chronic lymphocytic leukemia (CLL) by fluorescence in situ hybridization (FISH) with an alpha-satellite centromeric probe for chromosome 12 on both dividing and non-dividing cells. Trisomy for chromosome 12 was demonstrated in four of these patients (15.3%) using FISH on interphase cells. The percentage of trisomic cells ranged from 10% to 65% of nuclei. The hybridization signals in the trisomic and disomic nuclei were of a broadly similar size and nature. Interestingly, three of the remaining CLL patients, who exhibited disomy for chromosome 12, showed a marked difference in size of the hybridization signals in interphase nuclei. This was also demonstrated in metaphase spreads. In addition, metaphase FISH studies revealed a supernumerary marker chromosome in three out of 26 patients with CLL.

Philadelphia chromosome in chronic myelogenous leukemia: confirmation of cytogenetic diagnosis in Ph positive and negative cases by fluorescence in situ hybridization

In this study, patients with Philadelphia (Ph) negative and positive chronic myelogenous leukemia (CML) were analyzed by unicolor- and dual color- (DC) fluorescence in situ hybridization (FISH) using abl and bcr cosmid probes. Unicolor- and DC-FISH analysis revealed a BCR-ABL fusion in a Ph-negative patient. DC-FISH to interphase nuclei revealed the BCR-ABL fusion, even though no metaphases were available for metaphase-FISH and conventional cytogenetic analysis. In the remaining cases, the findings of FISH were in agreement with the cytogenetic results.

Retinoic acid synthesis in normal and Alzheimer diseased brain and human neural cells

Retinoids play fundamental roles in CNS development, but their distribution, metabolism, and function within the mature human CNS are unknown. In these studies, extracts of autopsy tissues recovered from histopathologically confirmed control and Alzheimer diseased brains were tested for their ability to synthesize retinoic acid. Retinaldehyde dehydrogenase (RLDH), the enzyme that forms retinoic acid from retinaldehyde, was present in hippocampus, frontal cortex, and parietal cortex. The RLDH activity of hippocampus and parietal cortex from Alzheimer diseased brains was 1.5- to 2-fold higher (p < 0.05) compared to the controls. In contrast, the RLDH activity of frontal cortex was the same for both Alzheimer diseased and control groups. A cultured human glioblastoma (U251) and neuroblastoma (LA-N-5) cell line synthesized retinoic acid from retinaldehyde or retinol, suggesting that a variety of neural cell types possess this activity. LA-N-5 cells grown in vitamin A-depleted medium had higher (p < 0.05) RLDH activity (0.35 +/- 0.04 nmol/mg/h) than LA-N-5 cells grown in vitamin A-replete media (0.15 +/- 0.02 nmol/mg/h). This difference was lost when retinol was added back to the medium, confirming that a reduction in vitamin A supply can induce RLDH activity in neural cells. However, this feedback mechanism does not appear to explain the higher RLDH activity of Alzheimer diseased hippocampus and parietal cortex, because the overall vitamin A status as indicated by serum retinol and carotenoid levels and by hippocampal retinoid content was similar for the Alzheimer diseased and control groups. These studies establish the presence of retinoids and RLDH activity in human brain tissues, and indicate that retinoic acid synthesis is modulated in some regions of Alzheimer diseased brain.

Identification of variant translocations in chronic myeloid leukemia by fluorescence in situ hybridization

We studied two cases of chronic myeloid leukemia (CML) having variant complex translocations detected by trypsin G-banding and fluorescence in situ hybridization (FISH). Application of dual color- (DC-) FISH using abl and bor cosmid probes permitted us to detect the bor-abl fusion event on both interphase nuclei and metaphase spread. Furthermore, FISH using combinatorial hybridization (centromeric-library and library-library probes) demonstrated the content and the position of the translocations in CML patients with variant (complex type) Ph-positive rearrangements. FISH analysis appears to be superior than conventional cytogenetic analysis.

In vivo study of the biosynthesis of long-chain fatty acids using deuterated water

To determine the contributions of preexisting fatty acid, de novo synthesis, and chain elongation in long-chain fatty acid (LCFA) synthesis, the synthesis of LCFAs, palmitate (16:0), stearate (18:0), arachidate (20:0), behenate (22:0), and lignocerate (24:0), in the epidermis, liver, and spinal cord was determined using deuterated water and mass isotopomer distribution analysis in hairless mice and Sprague-Dawley rats. Animals were given 4% deuterated water for 5 days or 8 wk in their drinking water. Blood was withdrawn at the end of these times for the determination of deuterium enrichment, and the animals were killed to isolate the various tissues for lipid extraction for the determination of the mass isotopomer distributions. The mass isotopomer distributions in LCFA were incompatible with synthesis from a single pool of primer. The synthesis of palmitate, stearate, arachidate, behenate, and lignocerate followed the expected biochemical pathways for the synthesis of LCFAs. On average, three deuterium atoms were incorporated for every addition of an acetyl unit. The isotopomer distribution resulting from chain elongation and de novo synthesis can be described by the linear combination of two binomial distributions. The proportions of preexisting, chain elongation, and de novo-synthesized fatty acids as a percentage of the total fatty acids were determined using multiple linear regression analysis. Fractional synthesis was found to vary, depending on the tissue type and the fatty acid, from 47 to 87%. A substantial fraction (24-40%) of the newly synthesized molecules was derived from chain elongation of unlabeled (recycled) palmitate.

Enhanced potency of 9-cis versus all-trans-retinoic acid to induce the differentiation of human neuroblastoma cells

All-trans-retinoic acid (ATRA) has been shown to be one of the most potent chemical inducers of human neuroblastoma differentiation. The recent discovery that the stereoisomer of ATRA, 9-cis-retinoic acid (9-cis-RA), binds to both the retinoic acid and retinoid X series of receptors prompted us to evaluate the ability of this compound to promote differentiation of this cell type. Using the LA-N-5 cell line, we have now determined that 9-cis-RA can induce the differentiation of human neuroblastoma cells as evidenced by dose-dependent inhibition of cell proliferation, neurite outgrowth, increased acetylcholinesterase activity, and reduction of N-myc mRNA expression. In comparing the effects of 9-cis-RA to ATRA, we found that while both compounds induced qualitatively similar cholinergic (versus adrenergic) features in LA-N-5 cells, 9-cis-RA was 5-to-10-fold more potent than ATRA in its antiproliferative and differentiation activity. These results were supported by transient transfection experiments utilizing chloramphenicol acetyltransferase (CAT) plasmid constructs containing a retinoic acid responsive regulatory element which showed a 2-to-3-fold increase in reporter gene activity induced with 9-cis-RA over that seen with ATRA at pharmacologically relevant retinoid concentrations (> 10(-8) M). Furthermore, we have determined that 9-cis-RA can significantly enhance mRNA levels of the nuclear retinoic acid receptors alpha and beta in LA-N-5 cells. Taken together, these findings have established the ability of 9-cis-RA to induce neuroblastoma differentiation and suggest that this retinoic acid isomer may have better therapeutic characteristics than ATRA.

The hr locus and the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in newborn mice

In mice, the recessive mutation hairless (hr) controls the cutaneous response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) but its influence on TCDD's systemic toxicity is unclear. To clarify this, we compared the effects of lactational TCDD exposure on standardized litters of newborn HRS/J mice homozygous for either hr or + that were fostered by haired dams exposed to 0, 6, 8 or 12 micrograms TCDD/kg body weight on postnatal day 0. At 12 micrograms/kg, TCDD was lethal to both haired and hairless pups. At the lower doses (6 and 8 micrograms/kg) the survival of hr/hr pups was significantly lower than +/+ pups. Affected pups succumbed following a 1 to 2-day period of cachexia and wasting. As has been reported for other mouse strains, TCDD exposure impacted on their neonatal development and lessened the time to eye opening for both haired and hairless pups. However, the hairless animals were affected at lower doses than were the haired. The results of this study document that the hr/hr genotype does influence the systemic toxicity of TCDD in mice.

Influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on TNF-alpha levels in the skin of congenic haired and hairless mice

It has been proposed that TNF-alpha mediates TCDD-induced toxicity. TCDD induces a chloracne-like response in the skin of hairless HRS/J mice but not in congenic haired animals. Using an ELISA, we measured TNF-alpha levels in the skin of TCDD-treated haired and hairless HRS/J mice to test the hypothesis that TNF-alpha mediates the cutaneous toxicity of TCDD. TNF-alpha levels in the skin of haired mice were at or below minimal detectable levels and were unchanged by TCDD exposure. In contrast, TNF-alpha levels were significantly higher in the skin of hairless mice after TCDD exposure. The bulk of the induced TNF-alpha was present in the dermis, although detectable amounts were present in the epidermis. To determine if murine skin cells were producing TNF-alpha in direct response to TCDD, cultures of neonatal epidermal keratinocytes and dermal fibroblasts were treated with varying biologically active doses of TCDD or vehicle (DMSO) or with lipopolysaccharide (LPS) as a positive control. Within 24 hr of exposure to LPS, TNF-alpha levels were increased in the culture media of all cells tested. In contrast, TCDD treatment (10(-11) M to 10(-7) M) failed to induce detectable TNF-alpha release from either fibroblasts or keratinocytes over a comparable time frame or when measured for up to 6 days following exposure. The failure of TCDD to stimulate TNF-alpha production by keratinocytes or fibroblasts suggests that the rise in dermal TNF-alpha levels seen in vivo is unlikely to be a primary component of the mechanism of toxicity. We suggest that the source of the dermal TNF-alpha in TCDD-treated hairless mouse skin is probably component cells of the inflammatory response.