Surgery, brachytherapy, and external-beam radiotherapy for early prostate cancer

Advances in localized prostate cancer: A special focus on photothermal therapy

Prostate cancer (PCa) is a high prevalence disease, per 10000 habitants, that tends to increase with age. This pathology is difficult to detect at an early stage due to the absence of symptoms, hence the importance of monitoring signs for early detection. This disease can be detected by various methods, including plasmatic levels of prostate-specific antigen (PSA) and rectal touch, with biopsy being necessary to confirm the diagnosis. Patients affected by prostate cancer can have localized or advanced disease. There are conventional approaches that have been used as a reference in localized cancer, such as active surveillance, surgery, or radiotherapy. However, the adverse effects might vary and, sometimes, they can be permanent. An overview about the innovative therapeutic approaches to improve outcomes in terms of both tumor remission and side effects for localized PCa is presented. In case of emerging light-based treatment strategies, they aimed at ablating tumor tissue by inducing an external light are non-invasive, localized and, considerably, they are able to reduce lesions in peripheral tissues. One is photodynamic therapy (PDT) and it involves the photooxidation of molecules culminating in the formation of reactive oxygen species (ROS), inducing cell death. On the other hand, photothermal therapy (PTT) is based on inducing hyperthermia in cancer cells by irradiating them with beams of light at a specific wavelength. To improve the heat generated, gold nanoparticles (AuNPs) have those desirable characteristics that have drawn attention to PTT. Various studies point to AuNPs as efficient nanomaterials in PTT for the treatment of tumors, including prostate cancer. This review includes the most representative advances in this research field, dated from 1998 to 2023. It is noticed that several advances have been made and the way to find the effective treatment without impacting adverse side effects is shorter.

Experimental study for in vitro prostate cancer treatment with microwave ablation and pulsed electromagnetic field

This paper presents the findings of a comprehensive study exploring the synergistic effects arising from the combination of microwave ablation and pulsed electromagnetic field (PEMF) therapy on prostate cancer cells. The research encompassed five distinct experimental groups, with continuous electric field measurements conducted during the entire treatment process. Group 1 and Group 2, subjected to microwave power below 350 W, exhibited specific electric field values of 72,800 V/m and 56,600 V/m, respectively. In contrast, Group 3 and Group 4, exposed to 80 W microwave power, displayed electric field levels of approximately 1450 V/m, while remaining free from any observable electrical discharges. The migratory and invasive capacities of PC3 cells were assessed through a scratch test in all groups. Notably, cells in Group 3 and Group 4, subjected to the combined treatment of microwave ablation and PEMF, demonstrated significantly accelerated migration in comparison to those in Groups 1 and 2. Additionally, Group 5 cells, receiving PEMF treatment in isolation, exhibited decreased migratory ability. These results strongly suggest that the combined approach of microwave ablation and PEMF holds promise as a potential therapeutic intervention for prostate cancer, as it effectively reduced cell viability, induced apoptosis, and impeded migration ability in PC3 cells. Moreover, the isolated use of PEMF demonstrated potential in limiting migratory capacity, which could hold critical implications in the fight against cancer metastasis.

Precision Interventional Brachytherapy: A Promising Strategy Toward Treatment of Malignant Tumors

Precision interventional brachytherapy is a radiotherapy technique that combines radiation therapy medicine with computer network technology, physics, etc. It can solve the limitations of conventional brachytherapy. Radioactive drugs and their carriers change with each passing day, and major research institutions and enterprises worldwide have conducted extensive research on them. In addition, the capabilities of interventional robotic systems are also rapidly developing to meet clinical needs for the precise delivery of radiopharmaceuticals in interventional radiotherapy. This study reviews the main radiopharmaceuticals, drug carriers, dispensing and fixation technologies, and interventional robotic precision delivery systems used in precision brachytherapy of malignant tumors. We then discuss the current needs in the field and future development prospects in high-precision interventional brachytherapy.

Estimates of over-time trends in incidence and mortality of prostate cancer from 1990 to 2030

Background

This research aims to identify the current and future trends in the incidence and death rate of prostate cancer and to provide the necessary data support for making relevant health decisions.

Methods

This study used the collected data and methodologies to describe the incidence and mortality trends of prostate cancer from 1990 to 2016. Based on the data, this paper projected the future trends in prostate cancer incidence and death rate.

Results

In 2016, prostate cancer cases [1,435,742; 95% uncertainty interval (UI), 1,293,395–1,618,655] were nearly 2.5-fold the number in 1990 (579,457; 95% UI, 521,564–616,107). Deaths increased by 2.0-fold from 191,687 (95% UI, 168,885–209,254) in 1990 to 380,916 (95% UI, 320,808–412,868) in 2016. The global age-standardized incidence rate (ASIR) increased from 17.75 (95% UI, 18.91–15.95) in 1990 to 22.12 (95% UI, 19.92–24.91) in 2016, changing 24.62%. The global change of age-standardized death rate (ASDR) has declined slightly, but in some regions it shows a trend of growth. By sociodemographic index (SDI) sub-types, prostate cancer will frequently occur in high SDI countries from 1990 to 2030. Simultaneously, the highest mortality will present in low SDI countries.

Conclusions

Through projecting and analyzing incidence and mortality rate of prostate cancer, from 1990 to 2030, by different ages, regions and SDI sub-types, this result may reveal the relationship between prostate cancer and financial development. At the same time, the result also showed a sufficiently heavy burden of prostate cancer, but the burden varies greatly in each region. The burden is a challenge and will require attention for all levels of society. The current study is beneficial to formulate more specific and efficient policies.

Brachytherapy Combined With or Without Hormone Therapy for Localized Prostate Cancer: A Meta-Analysis and Systematic Review

Purpose: The purpose of this study was to evaluate the efficacy of brachytherapy combined with or without hormone therapy in patients with localized prostate cancer.

Methods and Materials: We systemically searched the Medline, Web of Science, Cochrane Library and Embase databases for studies published between the databases' dates of inception and February 2019. The primary endpoints were the 5-year overall survival (OS) rates, 5-year biochemical progression-free survival (bPFS) rates and 10-year bPFS rates. The results were expressed as the relative risk (RR) and 95% confidence interval (CI). Based on the heterogeneity evaluated with the I² statistic, a meta-analysis was performed using either a random- or fixed-effects model.

Results: A total of 16 cohort studies including 9,359 patients met all the criteria for inclusion in the analysis. Our data showed that brachytherapy (BT) combined with hormone therapy (HT) increased the patients' 5-year bPFS rates (RR = 1.04, 95% CI: 1.01–1.08, P = 0.005) and 10-year bPFS rates (RR = 1.12, 95% CI: 1.02–1.23, P = 0.001) compared with BT monotherapy. However, BT combined with HT did not increase the patients' 5-year OS rates (RR = 1.02, 95% CI: 0.99–1.095, P = 0.1) compared with BT monotherapy.

Conclusions: BT combined with HT can increase the bPFS rates of patients with localized prostate cancer, but it does not improve patients' OS rates.

The ALERT-B questionnaire: A screening tool for the detection of gastroenterological late effects after radiotherapy for prostate cancer

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ALERT-B provides an effective screening tool for gastroenterological late effects.

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84.4% and 95.7% of patients demonstrated complications at 6 and 12 months post-treatment.

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ROC curves at baseline indicated an AUC of 0.867 compared to the GSRS diarrhoea subscale.

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ROC curves at baseline indicated an AUC of 0.765 compared to the EPIC bowel subscale.

There is an increasing need to measure treatment-related side effects in normal tissues following cancer therapy. The ALERT-B (Assessment of Late Effects of RadioTherapy - Bowel) questionnaire is a screening tool that is composed of four items related specifically to bowel symptoms. Those patients that respond with a “yes” to any of these items are referred on to gastroenterologist in order to improve the long-term consequences of these side effects of radiological treatment. Here we wish to test the ability of this questionnaire to identify these subsequent gastroenterological complications by tracking prostate cancer patients that were positive with respect to ALERT-B. We also carry out receiver-operator curve (ROC) analysis for baseline data for an overall ALERT-B questionnaire score with respect to subscale data for the Gastrointestinal Symptom Rating Scale (GSRS) and the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. 84.4% and 95.7% of patients identified by the ALERT-B questionnaire demonstrated complications diagnosed at 6 and 12 months post-treatment, respectively. ROC curve analysis of baseline data showed that ALERT-B detected clinically relevant levels of side effects established at baseline by the GSRS diarrhoea subscale (AUC = 0.867, 95% CI = 0.795 to 0.926) and at the minimally important level of side effects for the EPIC bowel subscale (AUC = 0.765, 95% CI = 0.617 to 0.913). These results show that ALERT-B provides a simple and effective screening tool for identifying gastroenterological complications after treatment for prostate cancer.

COMP report: CPQR technical quality control guidelines for low-dose-rate permanent seed brachytherapy

The Canadian Organization of Medical Physicists (COMP), in close partnership with the Canadian Partnership for Quality Radiotherapy (CPQR) has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet in order to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities. The development process enables rapid review and update to keep the guidelines current with changes in technology. This article contains detailed performance objectives and safety criteria for low‐dose‐rate (LDR) permanent seed brachytherapy.

The Role of External-Beam Radiation Therapy in the Treatment of Clinically Localized Prostate Cancer

Background

The treatment of clinically localized prostate cancer is controversial. Options include radical prostatectomy, external-beam radiation therapy (EBRT), brachytherapy, cryotherapy, and watchful waiting.

Methods

The author reviews EBRT as treatment for clinically localized prostate cancer, with particular emphasis on the technological advances that have allowed dose escalation and fewer therapy-related side effects.

Results

Technological advances in the last two decades have significantly improved the delivery of EBRT to the prostate. This has resulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest improvements in biochemical outcome. An alternative approach of combining androgen suppression therapy and EBRT has also been successful in improving clinical outcomes. However, establishing the optimal therapy for prostate cancer remains controversial.

Conclusions

Recent progress has led to improvements in clinical outcomes in patients treated with EBRT for prostate cancer. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.

Multifunctional Envelope-Type siRNA Delivery Nanoparticle Platform for Prostate Cancer Therapy

With the capability of specific silencing of target gene expression, RNA interference (RNAi) technology is emerging as a promising therapeutic modality for the treatment of cancer and other diseases. One key challenge for the clinical applications of RNAi is the safe and effective delivery of RNAi agents such as small interfering RNA (siRNA) to a particular nonliver diseased tissue (e.g., tumor) and cell type with sufficient cytosolic transport. In this work, we proposed a multifunctional envelope-type nanoparticle (NP) platform for prostate cancer (PCa)-specific in vivo siRNA delivery. A library of oligoarginine-functionalized and sharp pH-responsive polymers was synthesized and used for self-assembly with siRNA into NPs with the features of long blood circulation and pH-triggered oligoarginine-mediated endosomal membrane penetration. By further modification with ACUPA, a small molecular ligand specifically recognizing prostate-specific membrane antigen (PSMA) receptor, this envelope-type nanoplatform with multifunctional properties can efficiently target PSMA-expressing PCa cells and silence target gene expression. Systemic delivery of the siRNA NPs can efficiently silence the expression of prohibitin 1 (PHB1), which is upregulated in PCa and other cancers, and significantly inhibit PCa tumor growth. These results suggest that this multifunctional envelope-type nanoplatform could become an effective tool for PCa-specific therapy.

Improving the well-being of men by Evaluating and Addressing the Gastrointestinal Late Effects (EAGLE) of radical treatment for prostate cancer: study protocol for a mixed-method implementation project

INTRODUCTION

Radiotherapy treatment for prostate cancer can cause bowel problems, which may lead to severe difficulties for cancer survivors including limiting travel, work or socialising. These symptoms can appear at any time following radiotherapy. This study focuses on the early identification and protocol-based management of effects known to cause long-term, or even permanent, changes to the well-being of prostate cancer survivors. The rationale of this study is to improve the care offered to men and their families following pelvic radiotherapy for prostate cancer.

METHOD AND ANALYSIS

Implementation research methodology will be used to adopt a multicomponent intervention at three UK centres. The intervention package comprises a standardised clinical assessment of relevant symptoms in oncology outpatient clinics and rapid referral to an enhanced gastroenterological service for patients identified with bowel problems. Gastroenterology staff will be trained to use an expert-practice algorithm of targeted gastroenterology investigations and treatments. The evaluation of the intervention and its embedding within local practices will be conducted using a mixed-methods design. The effect of the new service will be measured in terms of the following outcomes: acceptability to staff and patients; quality of life; symptom control and cost-effectiveness. Data collection will take place at baseline, 6 months (±2 months), and 12 months (±2 months) after entry into the study.

ETHICS AND DISSEMINATION

The study has ethical approval from the North West-Liverpool East Research Ethics Committee and the appropriate NHS governance clearance. All participants provide written informed consent. The study team aim to publish the results of the study in peer-reviewed journals as well as at national and international conferences.

TRIAL REGISTRATION NUMBER

UKCRN16974.

Primary radical therapy selection in high-risk non-metastatic prostate cancer

As the incidence of prostate cancer rises, the detection and management of men with high-risk non-metastatic prostate cancer is becoming increasingly important. The benefits of radical treatment have been clearly shown in this group from a number of publications. The current mainstays of treatment are radical prostatectomy (with selective use of adjuvant radiation) and radical radiotherapy with concurrent androgen deprivation. The outcomes from these two approaches seem to be remarkably similar and are considered equally valid options for primary treatment. The choice of therapy is critically dependent on a number of factors, but ultimately left to the decision of the patients with advice from clinicians. Clinicians themselves, however, are known to be biased towards their particular skill set and experiences. Attempts at randomised comparisons between these two modalities have so far failed and are confounded by patient-clinician bias, the continual advances in therapy as well as the long natural history of the disease. In the lack of level 1 comparable evidence, this article explores the existing literature as to the key factors that should be considered in radical treatment selection for high-risk prostate cancer. These factors include disease aggressiveness, comorbidity and life expectancy, functional outcomes and the consequences of therapy failure with regards to salvage treatment. We propose that these factors may be useful in developing a decision guide for rationale radical therapy selection in the light of two apparently equally effective treatments. Ultimately, however, there is an urgent need for added clinical and biological markers that can provide a more precise approach to therapy selection.

Adding intensity-modulated radiotherapy to the pelvis does not worsen the adverse effect profiles compared to limited field radiotherapy in men with prostate cancer at 12-month follow-up

To compare adverse effects and toxicity in men with high-risk or locally advanced prostate cancer when adding intensity-modulated radiotherapy (IMRT) technique to the pelvis.

PATIENTS AND METHODS

In this prospective follow-up study 180 patients treated with conformal radiotherapy (RAD) to the prostate and vesiculae seminales (boost volumes; PV) and long-term androgen deprivation therapy (LADT), were compared to 90 patients managed by LADT, RAD to the PV and additionally pelvic IMRT. Adverse effects were self-reported at baseline, at 3- and 12-month follow-up. At each time point, the patients rated a questionnaire covering urinary, bowel, and sexual function and bother, quality of life, fatigue, and mental distress.

RESULTS

At 3-month follow-up urinary and bowel functions were significantly decreased among IMRT compared to RAD. At 12-month follow-up both groups showed the same reductions within the urinary, bowel and sexual domains. RAD patients had more mental distress than IMRT patients. The scores on quality of life, fatigue and mental distress hardly influenced function or bother within the urinary, bowel or sexual domains.

CONCLUSIONS

Men treated for high-risk or locally advanced prostate cancer with a combination of LADT, RAD and IMRT including PV and pelvic structures had considerably more acute side effects at 3 months than men treated with LADT and RAD to the PV only. However, at 12-month follow-up, the observed genitourinary and gastrointestinal function and bother were similar in both groups.

Five-year potency preservation after iodine-125 prostate brachytherapy

BACKGROUND

We aimed to evaluate long-term erectile function following prostate brachytherapy, based on patient characteristics and treatment factors.

METHODS

Between 2003 and 2006, 665 men with localized prostate cancer were treated with (125)I permanent seed implantation. None was given adjuvant hormone therapy. Erectile function was assessed before treatment, and at 6 months, 1, 2, 3, 4 and 5 years after implantation using the Mount Sinai Erectile Function Score (MSEFS) of 0-3 (0 = no erections, 1 = erections insufficient for intercourse, 2 = suboptimal erections but sufficient for intercourse, 3 = normal erectile function). Potency was defined as score 2 or 3, and 382 men were potent before treatment. Univariate and multivariate analyses were performed on the data from these 382 patients to identify variables associated with potency preservation.

RESULTS

In patients who were potent before treatment, the actuarial potency preservation rate fell to 46.2 % at 6 months after brachytherapy, and then slowly recovered reaching 52.0 % at 5 years after brachytherapy. In multivariate logistic regression analysis, patient age (p = 0.04) and pre-treatment MSEFS (p < 0.001) were predictors of 5-year potency preservation. Neoadjuvant hormone therapy affected potency preservation only at 6 months after brachytherapy.

CONCLUSIONS

Patient age at implantation and pre-treatment erectile function are predictive factors for the development of erectile dysfunction following prostate brachytherapy.

Real-time catheter tracking for high-dose-rate prostate brachytherapy using an electromagnetic 3D-guidance device: a preliminary performance study

PURPOSE

In order to increase the accuracy and speed of catheter reconstruction in a high-dose-rate (HDR) prostate implant procedure, an automatic tracking system has been developed using an electromagnetic (EM) device (trakSTAR, Ascension Technology, VT). The performance of the system, including the accuracy and noise level with various tracking parameters and conditions, were investigated.

METHODS

A direct current (dc) EM transmitter (midrange model) and a sensor with diameter of 1.3 mm (Model 130) were used in the trakSTAR system for tracking catheter position during HDR prostate brachytherapy. Localization accuracy was assessed under both static and dynamic analyses conditions. For the static analysis, a calibration phantom was used to investigate error dependency on operating room (OR) table height (bottom vs midposition vs top), sensor position (distal tip of catheter vs connector end of catheter), direction [left-right (LR) vs anterior-posterior (AP) vs superior-inferior (SI)], sampling frequency (40 vs 80 vs 120 Hz), and interference from OR equipment (present vs absent). The mean and standard deviation of the localization offset in each direction and the corresponding error vectors were calculated. For dynamic analysis, the paths of five straight catheters were tracked to study the effects of directions, sampling frequency, and interference of EM field. Statistical analysis was conducted to compare the results in different configurations.

RESULTS

When interference was present in the static analysis, the error vectors were significantly higher at the top table position (3.3 ± 1.3 vs 1.8 ± 0.9 mm at bottom and 1.7 ± 1.0 mm at middle, p < 0.001), at catheter end position (3.1 ± 1.1 vs 1.4 ± 0.7 mm at the tip position, p < 0.001), and at 40 Hz sampling frequency (2.6 ± 1.1 vs 2.4 ± 1.5 mm at 80 Hz and 1.8 ± 1.1 at 160 Hz, p < 0.001). So did the mean offset errors in the LR direction (-1.7 ± 1.4 vs 0.4 ± 0.5 mm in AP and 0.8 ± 0.8 mm in SI directions, p < 0.001). The error vectors were significantly higher with surrounding interference (2.2 ± 1.3 mm) vs without interference (1.0 ± 0.7 mm, p < 0.001). An accuracy of 1.6 ± 0.2 mm can be reached when using optimum configuration (160 Hz at middle table position). When interference was present in the dynamic tracking, the mean tracking errors in LR direction (1.4 ± 0.5 mm) was significantly higher than that in AP direction (0.3 ± 0.2 mm, p < 0.001). So did the mean vector errors at 40 Hz (2.1 ± 0.2 mm vs 1.3 ± 0.2 mm at 80 Hz and 0.9 ± 0.2 mm at 160 Hz, p < 0.05). However, when interference was absent, they were comparable in the both directions and at all sampling frequencies. An accuracy of 0.9 ± 0.2 mm was obtained for the dynamic tracking when using optimum configuration.

CONCLUSIONS

The performance of an EM tracking system depends highly on the system configuration and surrounding environment. The accuracy of EM tracking for catheter reconstruction in a prostate HDR brachytherapy procedure can be improved by reducing interference from surrounding equipment, decreasing distance from transmitter to tracking area, and choosing appropriated sampling frequency. A calibration scheme is needed to further reduce the tracking error when the interference is high.

Model-based patterns in prostate cancer mortality worldwide

Background:

Prostate cancer mortality has been decreasing in several high income countries and previous studies analysed the trends mostly according to geographical criteria. We aimed to identify patterns in the time trends of prostate cancer mortality across countries using a model-based approach.

Methods:

Model-based clustering was used to identify patterns of variation in prostate cancer mortality (1980–2010) across 37 European, five non-European high-income countries and four leading emerging economies. We characterised the patterns observed regarding the geographical distribution and gross national income of the countries, as well as the trends observed in mortality/incidence ratios.

Results:

We identified three clusters of countries with similar variation in prostate cancer mortality: pattern 1 (‘no mortality decline'), characterised by a continued increase throughout the whole period; patterns 2 (‘later mortality decline') and 3 (‘earlier mortality decline') depict mortality declines, starting in the late and early 1990s, respectively. These clusters are also homogeneous regarding the variation in the prostate cancer mortality/incidence ratios, while are heterogeneous with reference to the geographical region of the countries and distribution of the gross national income.

Conclusion:

We provide a general model for the description and interpretation of the trends in prostate cancer mortality worldwide, based on three main patterns.

Impact of edema and seed movement on the dosimetry of prostate seed implants

This article summarizes current knowledge concerning the characterization of prostatic edema and intra-prostatic seed movement as these relate to dosimetry of permanent prostate implants, and reports the initial application to clinical data of a new edema model used in calculating pre- and post-implant dose distributions. Published edema magnitude and half-life parameters span a broad range depending on implant technique and measurement uncertainty, hence clinically applicable values should be determined locally. Observed intra-prostatic seed movements appear to be associated with particular aspects of implant technique and could be minimized by technique modification. Using an extended AAPM TG-43 formalism incorporating the new edema model, relative dose error RE associated with neglecting edema was calculated for three I-125 seed implants (18.9 cc, 37.6 cc, 60.2 cc) performed at our center. Pre- and post-plan RE average values and ranges in a 50 × 50 × 50 mm(3) calculation volume were similar at ~2% and ~0-3.5%, respectively, for all three implants; however, the spatial distribution of RE varied for different seed configurations. Post-plan values of D90 and V100 for prostate were reduced by ~2% and ~1%, respectively. In cases where RE is not clinically negligible as a consequence of large edema magnitude and / or use of Pd-103 seeds, the dose calculation method demonstrated here can be applied to account for edema explicitly and there by improve the accuracy of clinical dose estimates.

Intra-operative 3D guidance and edema detection in prostate brachytherapy using a non-isocentric C-arm

PURPOSE

Brachytherapy (radioactive seed insertion) has emerged as one of the most effective treatment options for patients with prostate cancer, with the added benefit of a convenient outpatient procedure. The main limitation in contemporary brachytherapy is faulty seed placement, predominantly due to the presence of intra-operative edema (tissue expansion). Though currently not available, the capability to intra-operatively monitor the seed distribution, can make a significant improvement in cancer control. We present such a system here.

METHODS

Intra-operative measurement of edema in prostate brachytherapy requires localization of inserted radioactive seeds relative to the prostate. Seeds were reconstructed using a typical non-isocentric C-arm, and exported to a commercial brachytherapy treatment planning system. Technical obstacles for 3D reconstruction on a non-isocentric C-arm include pose-dependent C-arm calibration; distortion correction; pose estimation of C-arm images; seed reconstruction; and C-arm to TRUS registration.

RESULTS

In precision-machined hard phantoms with 40-100 seeds and soft tissue phantoms with 45-87 seeds, we correctly reconstructed the seed implant shape with an average 3D precision of 0.35 mm and 0.24 mm, respectively. In a DoD Phase-1 clinical trial on six patients with 48-82 planned seeds, we achieved intra-operative monitoring of seed distribution and dosimetry, correcting for dose inhomogeneities by inserting an average of over four additional seeds in the six enrolled patients (minimum 1; maximum 9). Additionally, in each patient, the system automatically detected intra-operative seed migration induced due to edema (mean 3.84 mm, STD 2.13 mm, Max 16.19 mm).

CONCLUSIONS

The proposed system is the first of a kind that makes intra-operative detection of edema (and subsequent re-optimization) possible on any typical non-isocentric C-arm, at negligible additional cost to the existing clinical installation. It achieves a significantly more homogeneous seed distribution, and has the potential to affect a paradigm shift in clinical practice. Large scale studies and commercialization are currently underway.

In vitro and in vivo double-enhanced suicide gene therapy mediated by generation 5 polyamidoamine dendrimers for PC-3 cell line

Background

One of the most frequently used and efficient suicide gene therapies for prostate cancer is HSV-TK/GCV system, but its application has been limited due to lack of favorable gene vector and the reduction of "bystander effect". We investigated the effect of a novel combination of HSV-TK/GCV fused with Cx43 and gemcitabine using non-viral vector generation 5 polyamidoamine dendrimers (G5-PAMAM-D) on PC-3 cells.

Methods

RT-PCR and Western blot were used to detect TK and Cx43 expression. Cell viability and proliferation were measured by using MTT assay. Cell apoptosis was detected with double-staining of Annexin V-FITC and propidium iodide (PI) by flow cytometry. Nude mice models were established to evaluate the therapeutic effect in vivo.

Results

G5-PAMAM-D efficiently delivered recombinant plasmids into PC-3 cells and HSV-TK and Cx43 could be expressed successfully. With gemcitabine, G5-PAMAM-D mediated HSV-TK and Cx43 expression effectively inhibited prostate cancer PC-3 cell proliferation, leading to more cellular apoptosis and inhibiting PC-3 tumor growth in nude mice models.

Conclusions

This study illustrates that this new suicide gene system mediated by G5-PAMAM-D is effective in decreasing PC-3 cell proliferation and inducing cell apoptosis, and inhibiting tumor growth in vivo. In a word, our study could provide a potential approach for gene therapy of prostate cancer.

Intraoperative 3D reconstruction of prostate brachytherapy implants with automatic pose correction

The success of prostate brachytherapy critically depends on delivering adequate dose to the prostate gland, and the capability of intraoperatively localizing implanted seeds provides potential for dose evaluation and optimization during therapy. REDMAPS is a recently reported algorithm that carries out seed localization by detecting, matching and reconstructing seeds in only a few seconds from three acquired x-ray images (Lee et al 2011 IEEE Trans. Med. Imaging 29 38-51). In this paper, we present an automatic pose correction (APC) process that is combined with REDMAPS to allow for both more accurate seed reconstruction and the use of images with relatively large pose errors. APC uses a set of reconstructed seeds as a fiducial and corrects the image pose by minimizing the overall projection error. The seed matching and APC are iteratively computed until a stopping condition is met. Simulations and clinical studies show that APC significantly improves the reconstructions with an overall average matching rate of ⩾99.4%, reconstruction error of ⩽0.5 mm, and the matching solution optimality of ⩾99.8%.

Inhibition of acid ceramidase by a 2-substituted aminoethanol amide synergistically sensitizes prostate cancer cells to N-(4-hydroxyphenyl) retinamide

BACKGROUND

The purpose of this study was to determine whether the therapeutic efficacy of fenretinide (4-HPR), a ceramide-generating anticancer agent, could be enhanced in prostate cancer cells by inclusion of a novel synthetic acid ceramidase (AC) inhibitor, DM102, a pivaloylamide of a 2-substituted aminoethanol. In prostate cancer, AC plays a role in progression and resistance to chemotherapy.

METHODS

PC-3 and DU 145 hormone-refractory human prostate cancer cell lines were used. Cells were exposed to 4-HPR, DM102, and combinations; viability, apoptosis, cell migration, ceramide metabolism, and levels of reactive oxygen species (ROS) were assessed.

RESULTS

Single agent 4-HPR and DM102 (2.5-10 µM) were weakly cytotoxic; however, combinations synergistically decreased cell viably to as low as 1.5% of control. N-oleoylethanolamine (NOE), a frequently employed AC inhibitor, was not effective in producing synergy. The 4-HPR/DM102 regimen enhanced caspase activity and increased [(3) H](dihydro)ceramide and ROS levels 6- and 30-fold over control, respectively. The antioxidant vitamin E, but not the de novo ceramide synthesis inhibitor myriocin, partially rescued cells from 4-HPR/DM102 cytotoxicity. The 4-HPR/DM102 combination also elicited synergistic cytotoxicity in DU 145 cells, another human hormone-refractory prostate cancer cell line.

CONCLUSION

This study shows that 4-HPR cytotoxicity is enhanced in a synergistic fashion by inclusion of the AC inhibitor DM102, by a mechanism that enlists generation of ROS, and thus provides a system to raise 4-HPR therapeutic potential. The role of ceramide however in the cytotoxic response is not clear, as blocking ceramide generation failed to rescue PC-3 cells from 4-HPR/DM102 cytotoxicity.

Predictors in the outcome of 125I brachytherapy as monotherapy for prostate cancer

A number of different prostate cancer treatment modalities exist. Nomograms are used to assist clinicians and patients in choosing the most appropriate treatment. However, the predicted outcome for (125)I brachytherapy is much worse than what would be expected considering the actual survival rates. This underestimation may result in suboptimal treatment decisions. Therefore, better predictors for outcome after (125)I brachytherapy are necessary. The following factors, which may either influence outcome or predict outcome after brachytherapy, are discussed: tumor characteristics and risk stratification, patient age at treatment, obesity, adjuvant androgen-deprivation therapy, prostate-specific antigen bounce, implantation technique and dosimetry. For the prediction of outcome after (125)I brachytherapy, as long as the quality of the implant is optimal, only high-risk prostate cancer was found to have a negative impact on outcome.

Radical prostatectomy versus external-beam radiotherapy for localized prostate cancer: long-term effect on biochemical control-in search of the optimal treatment

BACKGROUND

The optimal management of patients with clinically localized prostate carcinoma remains undefined due in part to the absence of well-designed, randomized trials.

METHODS

This retrospective study comprised 505 patients diagnosed with low- or intermediate- risk prostate cancer in 1998-2005 and treated at Hospital Gregorio Marañón (Spain) with radical prostatectomy (RP) or external-beam radiotherapy (EBRT). No adjuvant therapy was administered. Biochemical relapse was defined as a prostate-specific antigen (PSA) level ≥0.4 ng/ml for RP cases and nadir + 2 for EBRT cases. RP was performed in 271 patients (53.6%) and EBRT in 234 patients (46.4%). The median follow-up was 60 months. The analysis end point was to compare the biochemical recurrence-free survival (bRFS) between the two groups.

RESULTS

The 5-year bRFS rates for RP and EBRT were 79 ± 2% and 86 ± 2%, respectively (P = 0.48). Multivariate analysis indicated that initial PSA (P = 0.00), perineural invasion in the biopsy specimen (P = 0.00), Gleason score (P = 0.04), EBRT dose (P = 0.02), and positive margins (P = 0.00) were independent predictors of relapse. A decision tree model was constructed with these variables. In the EBRT cohort, a nadir PSA of <0.3 ng/ml was associated with the best 5-year bRFS (96.6 vs. 56.5% if nadir PSA > 1.3 ng/ml). Late biochemical failure (>5 years) was more frequent in the RT group and with low-dose EBRT (≤72 Gy).

CONCLUSIONS

The biochemical failure rates were similar between PR and EBRT in low- and intermediate-risk subgroups. Outcome was determined by classic pre-treatment features, perineural invasion, low-dose EBRT (≤72 Gy), and nadir PSA value in the RT cohort.

Short- and long-term HRQOL issues following brachytherapy for prostate cancer

Given the lack of evidence from randomized controlled trials and large prospective studies, controversy exists regarding the optimal treatment strategy for early stage prostate cancer. The impact of various treatments on health-related quality of life has become an increasingly important but controversial issue. The literature on health-related quality of life following brachytherapy, an increasingly used treatment option that can have short- and long-term side effects influencing patient health-related quality of life is reviewed. Urinary, bowel and sexual health-related quality of life issues related to this treatment are addressed. The authors findings suggest that brachytherapy with or without external beam radiotherapy and/or hormonal treatment has a considerable impact on short-term health-related quality of life but this impact diminishes in the long-term. However, in certain subgroups of patients, brachytherapy has long-term effects on bowel, bladder and sexual function. Clinicians should ensure that patients are aware of these consequences on long-term health-related quality of life.

The impact of pretreatment prostate volume on severe acute genitourinary toxicity in prostate cancer patients treated with intensity-modulated radiation therapy

PURPOSE

To assess the impact of pretreatment prostate volume on the development of severe acute genitourinary toxicity in patients undergoing intensity-modulated radiation therapy (IMRT) for prostate cancer.

METHODS AND MATERIALS

Between 2004 and 2007, a consecutive sample of 214 patients who underwent IMRT (75.6 Gy) for prostate cancer at two referral centers was analyzed. Prostate volumes were obtained from computed tomography scans taken during treatment simulation. Genitourinary toxicity was defined using the National Cancer Institute Common Terminology Criteria for Adverse Events Version 3.0 guidelines. Acute toxicity was defined as any toxicity originating within 90 days of the completion of radiation therapy. Patients were characterized as having a small or large prostate depending on whether their prostate volume was less than or greater than 50 cm(3), respectively. Genitourinary toxicity was compared in these groups using the chi-square or Fisher's exact test, as appropriate. Bivariate and multivariate logistic regression analysis was performed to further assess the impact of prostate volume on severe (Grade 3) acute genitourinary toxicity.

RESULTS

Patients with large prostates (>50 cm(3)) had a higher rate of acute Grade 3 genitourinary toxicity (p = .02). Prostate volume was predictive of the likelihood of developing acute Grade 3 genitourinary toxicity on bivariate (p = .004) and multivariate (p = .006) logistic regression. Every 27.0 cm(3) increase in prostate volume doubled the likelihood of acute Grade 3 genitourinary toxicity.

CONCLUSIONS

Patients with larger prostates are at higher risk for the development of severe acute genitourinary toxicity when treated with IMRT for prostate cancer.

Quality of life two years after radical prostatectomy, prostate brachytherapy or external beam radiotherapy for clinically localised prostate cancer: the Catalan Institute of Oncology/Bellvitge Hospital experience

OBJECTIVE

The objective was to compare the short- and long-term impact of 3 different treatment modalities on health-related quality of life (HRQOL) in patients treated for localised prostate cancer at a single centre in Catalonia, Spain.

MATERIAL AND METHODS

This was a longitudinal, prospective study of 304 patients from a single centre in Catalonia, Spain. Patients underwent 1 of 3 treatment procedures: radical prostatectomy (114 patients), external beam radiation (134) or interstitial brachytherapy (56). HRQOL was assessed by both general and specific questionnaires, including the SF-36 health survey and the Expanded Prostate Cancer Index Composite (EPIC). Interviews were administered prior to treatment and at months 1, 3, 6, 12 and 24. One-way analysis of variance and generalised estimating equations models were constructed to assess between group differences in HRQOL.

RESULTS

After initial deterioration, HRQOL scores partially recovered, although significant differences between treatment groups persisted at two years. Worsening of urinary incontinence was especially marked for the radical prostatectomy group (11.45, p=0.005), while deterioration in the urinary irritative/obstructive domain was worse following brachytherapy treatment (4.76, p=0.025). Decline in sexual function was significantly greater for the radical prostatectomy group than for the brachytherapy group (18.74, p<0.001). No significant between-group differences were observed in bowel domain scores.

CONCLUSIONS

Quality of life 2 years after treatment for prostate cancer shows wide variability. Radical prostatectomy had the largest negative impact on the sexual and urinary incontinence domains. Differences between external radiation and brachytherapy were relatively small. Brachytherapy led to a moderate increase in urinary irritation compared to the other 2 groups.

Acid ceramidase upregulation in prostate cancer: role in tumor development and implications for therapy

Bioactive sphingolipids, such as ceramide, sphingosine and sphingosine-1-phosphate are known bio-effector molecules which play important roles in various aspects of cancer biology including cell proliferation, growth arrest, apoptosis, metastasis, senescence and inflammation. Therefore, enzymes involved in ceramide metabolism are gaining recognition as being critical regulators of cancer cell growth and/or survival. We previously observed that the ceramide metabolizing enzyme, acid ceramidase (AC) is upregulated in tumor tissues. Studies have now concluded that this creates a dysfunctional ceramide pathway, which is responsible for tumor progression and resistance to chemotherapy and radiation. This suggests that development of small-molecule drugs that inhibit AC enzyme activity is a promising approach for improving standard cancer therapy and patient's clinical outcomes.

Prostate brachytherapy seed reconstruction with Gaussian blurring and optimal coverage cost

Intraoperative dosimetry in prostate brachytherapy requires localization of the implanted radioactive seeds. A tomosynthesis-based seed reconstruction method is proposed. A three-dimensional volume is reconstructed from Gaussian-blurred projection images and candidate seed locations are computed from the reconstructed volume. A false positive seed removal process, formulated as an optimal coverage problem, iteratively removes "ghost" seeds that are created by tomosynthesis reconstruction. In an effort to minimize pose errors that are common in conventional C-arms, initial pose parameter estimates are iteratively corrected by using the detected candidate seeds as fiducials, which automatically "focuses" the collected images and improves successive reconstructed volumes. Simulation results imply that the implanted seed locations can be estimated with a detection rate of > or = 97.9% and > or = 99.3% from three and four images, respectively, when the C-arm is calibrated and the pose of the C-arm is known. The algorithm was also validated on phantom data sets successfully localizing the implanted seeds from four or five images. In a Phase-1 clinical trial, we were able to localize the implanted seeds from five intraoperative fluoroscopy images with 98.8% (STD=1.6) overall detection rate.

The impact of acute urinary retention after iodine-125 prostate brachytherapy on health-related quality of life

PURPOSE

To evaluate the impact of acute urinary retention (AUR) in patients treated with (125)I prostate brachytherapy on short- and long-term health-related quality of life (HRQOL); and to assess whether pretreatment HRQOL has additional value in the prediction of AUR.

METHODS AND MATERIALS

For 127 patients treated with (125)I brachytherapy for localized prostate cancer between December 2000 and June 2003, toxicity and HRQOL data were prospectively collected. Patients received a HRQOL questionnaire at five time points: before and 1 month, 6 months, 1 year, and 6 years after treatment. The questionnaire included the RAND-36 generic health survey, the cancer-specific European Organization for Research and Treatment of Cancer core questionnaire (EORTC QLQ-C30), the tumor-specific EORTC prostate cancer module (EORTC QLQ-PR25), and the American Urological Association (AUA) symptom index.

RESULTS

Of 127 patients, 13 (10.2%) developed AUR. Patients with AUR had a significantly worse urinary QOL at all time points compared with patients without AUR. The mean difference over time (6 years) between both groups for the EORTC QLQ-PR25 urinary symptom score was 13.0 points (p < 0.001) and for the AUA urinary symptom score was 15.7 points (p = 0.001). Global QOL scores (EORTC QLQ-C30) over time for patients who developed AUR were significantly worse compared with patients without AUR (mean difference 6.7 points; p = 0.043). In multivariate logistic regression analysis, pretreatment International Prostate Symptom Score (p = 0.004) and neoadjuvant hormonal treatment (p = 0.034) were predictors of AUR. Quality of life did not have added predictive value.

CONCLUSION

Acute urinary retention after prostate brachytherapy has a significant negative impact on patient's HRQOL up to 6 years after treatment, in terms of both global QOL measures and urinary symptom scores. Furthermore, our results suggest limited value of pretreatment HRQOL measures for the prediction of AUR.

Personality predicts prostate cancer treatment decision-making difficulty and satisfaction

OBJECTIVE

Prostate cancer (PCa) patients often must decide between several treatment modalities considered equally efficacious, but associated with different benefits and side-effects. For some, the decision-making process can be difficult, but little is known about patient characteristics and cognitive processes that might influence the difficulty of such decisions. This study investigated the roles of dispositional optimism and self-efficacy in PCa treatment decision-making difficulty and satisfaction.

METHODS

One hundred and twenty-five patients with clinically localized PCa completed a mail-in paper-and-pencil survey after they had made their treatment decision, but prior to treatment.

RESULTS

After adjusting for covariates, optimism and treatment decision-making self-efficacy were associated with less difficulty and greater satisfaction with the treatment decision-making process. Effects of optimism on difficulty and satisfaction were partially mediated by self-efficacy for making the treatment decision.

CONCLUSIONS

Men with PCa and who are low in optimism may be at greater risk for treatment decision-making difficulty and lack of treatment decision-making satisfaction, in part, because they have lower confidence in their ability to make the decision compared with those who are more optimistic. As self-efficacy perceptions are modifiable, consideration should be given to including self-efficacy enhancing components as part of PCa treatment decision-making interventions.

Non-surgical treatment of localised prostate cancer

The non-surgical treatment of localised prostate cancer depends on a number of factors including: PSA, stage, Gleason score, age, fitness for treatment and life expectancy, and is individualised depending on risk. Patients who present with early localised (stage T1 or T2) tumours with low risk features (PSA <10 ng/ml, Gleason score 3+4 or below) and who have a life expectancy of more than 10 years may consider radiotherapy or active surveillance. Permanent brachytherapy seed implantation is suitable for low risk patients who have minimal lower urinary tract symptoms, with equivalent results to external beam radiotherapy Conformal high-dose external beam radiotherapy is effective for patients with high risk disease, and consideration should be given to the use of neoadjuvant and adjuvant anti-androgens. Prophylactic pelvic nodal irradiation is indicated for patients with high risk of lymph node disease, followed by a boost to the prostate using either a smaller external beam volume, or brachytherapy. The definitive treatment depends on both clinical parameters such as the clinical staging, prognostic risk, and the likelihood of acute and late toxicity and the patient's personal choice based on their life style.

Acid ceramidase upregulation in prostate cancer cells confers resistance to radiation: AC inhibition, a potential radiosensitizer

Radiation resistance in a subset of prostate tumors remains a challenge to prostate cancer radiotherapy. The current study on the effects of radiation on prostate cancer cells reveals that radiation programs an unpredicted resistance mechanism by upregulating acid ceramidase (AC). Irradiated cells demonstrated limited changes of ceramide levels while elevating levels of sphingosine and sphingosine-1-phosphate. By genetically downregulating AC with small interfering RNA (siRNA), we observed radiosensitization of cells using clonogenic and cytotoxicity assays. Conversely, AC overexpression further decreased sensitivity to radiation. We also observed that radiation-induced AC upregulation was sufficient to create cross-resistance to chemotherapy as demonstrated by decreased sensitivity to Taxol and C(6) ceramide compared to controls. Lower levels of caspase 3/7 activity were detected in cells pretreated with radiation, also indicating increased resistance. Finally, utilization of the small molecule AC inhibitor, LCL385, sensitized PPC-1 cells to radiation and significantly decreased tumor xenograft growth. These data suggest a new mechanism of cancer cell resistance to radiation, through upregulation of AC that is, in part, mediated by application of the therapy itself. An improved understanding of radiotherapy and the application of combination therapy achieved in this study offer new opportunities for the modulation of radiation effects in the treatment of cancer.

Comparison of two treatment approaches for prostate cancer: intensity-modulated radiation therapy combined with 125I seed-implant brachytherapy or 125I seed-implant brachytherapy alone

The purpose of the present study was to assess the results of two different treatment approaches for clinically localized prostate cancer: intensity‐modulated radiation therapy (IMRT) followed by I125 seed‐implant brachytherapy and I125 seed‐implant brachytherapy alone. We studied our 30 most recent consecutive patients. The sample population consisted of 15 cases treated with IMRT (50.4 Gy) followed by I125 seed‐implant boost (95 Gy), and 15 cases treated with I125 seed implant only (144 Gy). We analyzed established dosimetric indices and various clinical parameters. In addition, we also evaluated and compared the acute urinary morbidities of the two treatment approaches, as assessed by the international prostate symptom score (IPSS). In our series, acute urinary morbidity was slightly increased with IMRT followed by I125 seed‐implant brachytherapy as compared with I125 seed‐implant brachytherapy alone. In addition, we observed no statistically significant correlation between the IPSS and the maximum or mean urethral dose. The combination of IMRT and seed‐implant brachytherapy presents an alternative opportunity to treat clinically localized prostate cancer. The full potential of the procedure needs to be further investigated.

PACS number: 87.53.Tf

Chronic genitourinary and gastrointestinal toxicity of prostate cancer patients undergoing pelvic radiotherapy with intensity-modulated versus 4-field technique

PURPOSE

To compare chronic GU and GI toxicity of pelvic radiotherapy delivered using intensity-modulated radiotherapy (IMRT) versus conventional 4-field technique.

METHODS

The records of consecutive prostate cancer patients receiving RT at a single institution with a minimum follow-up of 120 days were reviewed; 48 of these patients received a prostate boost preceded by pelvic radiotherapy (PRT), 14 with IMRT (IM-PRT), and 34 with 4-field (4F-PRT). Dosimetric endpoints for the bladder, rectum, composite, and target for the PRT plans were compared using the 2-tailed t test. Late RTOG GU and GI toxicity were compared using the chi test. Ordered logit regression analyses were performed using all major patient, disease, and treatment factors as covariates.

RESULTS

IM-PRT demonstrated superior bladder and rectum dosimetric endpoints over 4F-PRT for the PRT portion of the treatment and for the composite treatment at the expense of higher target inhomogeneity in the PRT portion of the treatment plan. Late GU toxicity was significantly lower in the IM-PRT group (P < 0.001), whereas late GI toxicity was similar in both groups (P = 0.44). When considering a similar follow-up interval in both groups, however, the difference in GU toxicity only reached a trend (P = 0.10). The regression analyses showed that no factor, including IMRT, reached significance in predicting GU or GI toxicity.

CONCLUSION

Use of pelvic IMRT for prostate cancer patients was not associated with reduction of late GI toxicity but was associated with a small reduction of late GU toxicity. This reduction of late GU toxicity warrants further exploration in consortium studies.

Surgery Versus Implant for Early Prostate Cancer: Results From a Single Institution, 1992–2005

PURPOSE

The aim of this study was to compare the biochemical disease-free survival rates for radical prostatectomy versus transperineal ultrasound-guided prostate implant for patients with early prostate cancer treated at a single institution from 1992 through 2005.

MATERIALS AND METHODS

The charts of 741 patients with early prostate cancer (350 implant and 391 surgery) treated from 1992 through 2005 were retrospectively reviewed. Surgery patients were treated by members of the academic Urology Section at Yale University School of Medicine. Implant patients were treated by a combined team from the Urology Section and the Department of Therapeutic Radiology at Yale Medical School. For the 350 implant patients, 35% were treated with iodine-125 and 65% with palladium-103. Of the implant patients 92% were treated with an implant alone and 8% with combined external beam radiation therapy plus an implant and 25% received short-term hormone therapy to downsize the prostate before the implant. Both surgery and implant patients were analyzed based on a group with favorable cancers (clinical stage T1c or T2, prostate-specific antigen <10, and Gleason score <7), an intermediate group (any 1 factor increased compared with the favorable group), and a poor group (any 2 factors increased compared with the favorable group). The follow-up time varied from 12 to 120 months with a mean/median follow-up time of 44 months/42 months for implant patients and 42 months/40 months for surgery patients. Prostate-specific antigen recurrence for surgery was defined as any detectable prostate-specific antigen after surgery. Prostate-specific antigen recurrence for implant was defined as the prostate-specific antigen nadir plus 2 ng/mL after implant. The biochemical disease-free survival rates were calculated using the life-table method.

RESULTS

The 5-year biochemical disease-free survival rates for radical prostatectomy versus implant were identical for the favorable group (93% versus 92%), intermediate group (70% versus 70%), and poor group (50% versus 52%) patients.

CONCLUSIONS

From 1992 through 2005, implant therapy produced equivalent 5-year biochemical disease-free survival rates compared with surgery in patients with early prostate cancer treated at a single institution.

Recto-urethral fistula following brachytherapy for localized prostate cancer

OBJECTIVE

The use of prostate brachytherapy (BT) in the management of prostate cancer is increasing. BT is often chosen because of its perceived lower toxicity when compared with other radical therapy options. Rarely however serious complications can occur. One such complication is recto-urethral fistula (RUF). We report the incidence of RUF following BT at our centre and review the potential factors in fistula development.

METHOD

A prospectively collected database was used to identify cases of RUF among 1455 patients treated with prostate BT at a single UK centre with at least 2 years of follow up. This included patients treated with BT monotherapy, as well as those treated with BT combined with external beam radiotherapy and BT used as salvage as all these groups have a higher incidence of RUF. Implant dose and volume characteristics for those patients, their co-morbidities and history of endoscopic procedures were recorded.

RESULTS

Recto-urethral fistula was identified in three (0.2%) patients, occurring at 19-27 months following BT. All these patients had BT monotherapy. All three patients had rectal symptoms after their BT and had been investigated with endoscopy and low rectal biopsy. Subsequent surgical management with faecal and/or urinary diversion was required. On review of patients' BT details, radiation dose and volume parameters were higher on the postprocedure CT calculations than had been suggested by the preimplant plan. No other predisposing risk factors for RUF were identified.

CONCLUSION

The incidence of RUF in our population is low. RUF following BT has been associated with rectal biopsy in previous series and this is confirmed in our report. Gastrointestinal specialists should not perform biopsy of the anterior rectum in patients who have had BT unless there is a very high clinical suspicion of malignancy.