Quality-of-life outcomes in metastatic spinal cord compression: findings from the SCORAD trial

PURPOSE

This article reports detailed quality-of-life data including preferred and actual place of care from SCORAD, the only large prospective randomized trial in metastatic spinal cord compression (MSCC).

METHODS

SCORAD compared 2 doses of radiotherapy in patients with MSCC: 8 Gy single fraction and 20 Gy in 5 fractions. In total, 686 patients were randomized, of whom 590 had Health-Related Quality of Life (HRQoL) data collected at baseline and at least 1 later time point. HRQoL was measured using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 supplemented with the QLU-C10D and data on place of care at weeks 1, 4, 8, and 12 postrandomization. Quality-of-Life Adjusted Survival was computed by multiplying Kaplan-Meier survival probabilities with the UK utility weights obtained from the QLU-C10D.

RESULTS

Patients with a baseline physical functioning score of above 50 demonstrated a 28% reduction in the risk of death (hazard ratio [HR] = 0.72, 99% confidence interval [CI] = 0.54 to 0.95; P = .003). An increased risk of death was associated with fatigue (HR = 1.35, 99% CI = 1.03 to 1.76; P = .0040), dyspnea (HR = 1.61, 99% CI = 1.24 to 2.08; P < .001), and appetite loss (HR = 1.25, 99% CI = 0.99 to 1.59; P = .014). The preferred place of care for the majority was at home or with relatives (61%-74% across the 12 weeks) but achieved by only 53% at 8 weeks.

CONCLUSIONS

Prolonged survival in patients with MSCC was associated with better HRQoL. More than 60% of patients preferred to be cared for at home or with relatives, but only half were able to achieve this. There was no difference in HRQoL between the multifraction and single-fraction groups.

TRIAL REGISTRATION

ISRCTN97555949 and ISRCTN97108008.

A hypoxia biomarker does not predict benefit from giving chemotherapy with radiotherapy in the BC2001 randomised controlled trial

BACKGROUND

BC2001 showed combining chemotherapy (5-FU + mitomycin-C) with radiotherapy improves loco-regional disease-free survival in patients with muscle-invasive bladder cancer (MIBC). We previously showed a 24-gene hypoxia-associated signature predicted benefit from hypoxia-modifying radiosensitisation in BCON and hypothesised that only patients with low hypoxia scores (HSs) would benefit from chemotherapy in BC2001. BC2001 allowed conventional (64Gy/32 fractions) or hypofractionated (55Gy/20 fractions) radiotherapy. An exploratory analysis tested an additional hypothesis that hypofractionation reduces reoxygenation and would be detrimental for patients with hypoxic tumours.

METHODS

RNA was extracted from pre-treatment biopsies (298 BC2001 patients), transcriptomic data generated (Affymetrix Clariom-S arrays), HSs calculated (median expression of 24-signature genes) and patients stratified as hypoxia-high or -low (cut-off: cohort median).

PRIMARY ENDPOINT

invasive loco-regional control (ILRC); secondary overall survival.

FINDINGS

Hypoxia affected overall survival (HR = 1.30; 95% CI 0.99-1.70; p = 0.062): more uncertainty for ILRC (HR = 1.29; 95% CI 0.82-2.03; p = 0.264). Benefit from chemotherapy was similar for patients with high or low HSs, with no interaction between HS and treatment arm. High HS associated with poor ILRC following hypofractionated (n = 90, HR 1.69; 95% CI 0.99-2.89 p = 0.057) but not conventional (n = 207, HR 0.70; 95% CI 0.28-1.80, p = 0.461) radiotherapy. The finding was confirmed in an independent cohort (BCON) where hypoxia associated with a poor prognosis for patients receiving hypofractionated (n = 51; HR 14.2; 95% CI 1.7-119; p = 0.015) but not conventional (n = 24, HR 1.04; 95% CI 0.07-15.5, p = 0.978) radiotherapy.

INTERPRETATION

Tumour hypoxia status does not affect benefit from BC2001 chemotherapy. Hypoxia appears to affect fractionation sensitivity. Use of HSs to personalise treatment needs testing in a biomarker-stratified trial.

FUNDING

Cancer Research UK, NIHR, MRC.

Radiotherapy trial quality assurance processes: a systematic review

Quality assurance remains a neglected component of many trials, particularly for technical interventions, such as surgery and radiotherapy, for which quality of treatment is an important component in defining outcomes. We aimed to evaluate evidence for the processes used in radiotherapy quality assurance of clinical trials. A systematic review was undertaken focusing on use of a pre-trial outlining benchmark case and subsequent on-trial individual case reviews of outlining for recruited patients. These pre-trial and on-trial checks are used to ensure consistency and standardisation of treatment for each patient recruited to the trial by confirming protocol compliance. Non-adherence to the trial protocol has been shown to have a negative effect on trial outcomes. 29 studies published between January, 2000, and December, 2022, were identified that reported on either outlining benchmark case results or outlining individual case review results, or both. The trials identified varied in their use of radiotherapy quality assurance practices and reporting of outcomes was inconsistent. Deviations from trial protocols were frequent, particularly regarding outlining. Studies correlating benchmark case results with on-trial individual case reviews provided mixed results, meaning firm conclusions could not be drawn regarding the influence of the pre-trial benchmark case on subsequent on-trial performance. The optimal radiotherapy quality assurance processes were unclear, and there was little evidence available. Improved reporting of outcomes from radiotherapy quality assurance programmes is needed to develop an evidence base for the optimal approach to radiotherapy quality assurance in trials.

Functional Magnetic Resonance Imaging in Cervical Cancer Diagnosis and Treatment

Cervical Cancer is the fourth most common cancer in women worldwide. Treatment with chemoradiotherapy followed by brachytherapy achieves high local control, but recurrence with metastatic disease impacts survival. This highlights the need for predictive and prognostic biomarkers identifying populations at risk of poorer treatment response and survival. Magnetic resonance imaging (MRI) is routinely used in cervical cancer and is a potential source for biomarkers. Functional MRI (fMRI) can characterise tumour beyond anatomical MRI, which is limited to the assessment of morphology. This review summarises fMRI techniques used in cervical cancer and examines the role of fMRI parameters as predictive or prognostic biomarkers. Different techniques characterise different tumour factors, which helps to explain the variation in patient outcomes. These can impact simultaneously on outcomes, making biomarker identification challenging. Most studies are small, focussing on single MRI techniques, which raises the need to investigate combined fMRI approaches for a more holistic characterisation of tumour.

CBCT-based deformable dose accumulation of external beam radiotherapy in cervical cancer

Background: Delivered radiotherapy doses do not exactly match those planned for a course of treatment, largely due to inter-fraction changes in anatomy. In this study, accumulated delivered dose was calculated for a sample of cervical cancer patients, by deformably registering daily cone beam computed tomography (CBCT) images to the planning computed tomography (CT) scan. Planned and accumulated doses were compared for the clinical target volume (CTV), bladder, and rectum.Material and Methods: For 10 patients receiving 45 Gy in 25 fractions of external beam radiotherapy, daily dose distributions were calculated on CBCT. These images were deformed onto the planning CT and the dose was accumulated using Velocity 4.1 (Varian Medical Systems, Palo Alto, USA). The quality of deformable image registration was evaluated visually and by calculating Dice similarity coefficients and mean distance to agreement.Results: V95%>99% was achieved for the primary CTV in 9/10 patients for the planned dose distribution and 7/10 patients for the accumulated dose distribution. Primary CTV coverage by 95% of the prescription dose was reduced in one patient, due to an increase in anterior-posterior separation. Comparison of planned and accumulated dose volume histograms (DVHs) for the bladder and rectum found agreement within 5% at low and intermediate doses, but differences exceeded 20% at higher doses. Direct addition of CBCT DVHs was seen to be a poor estimate for the accumulated DVH at higher doses.Conclusion: Computation of delivered radiotherapy dose that accounts for inter-fraction anatomical changes is important for establishing dose-effect relationships. Updating delivered dose distributions after each fraction would support informed clinical decision making on any potential treatment interventions.

First-in-human technique translation of oxygen-enhanced MRI to an MR Linac system in patients with head and neck cancer

BACKGROUND AND PURPOSE

Tumour hypoxia is prognostic in head and neck cancer (HNC), associated with poor loco-regional control, poor survival and treatment resistance. The advent of hybrid MRI - radiotherapy linear accelerator or 'MR Linac' systems - could permit imaging for treatment adaptation based on hypoxic status. We sought to develop oxygen-enhanced MRI (OE-MRI) in HNC and translate the technique onto an MR Linac system.

MATERIALS AND METHODS

MRI sequences were developed in phantoms and 15 healthy participants. Next, 14 HNC patients (with 21 primary or local nodal tumours) were evaluated. Baseline tissue longitudinal relaxation time (T1) was measured alongside the change in 1/T1 (termed ΔR1) between air and oxygen gas breathing phases. We compared results from 1.5 T diagnostic MR and MR Linac systems.

RESULTS

Baseline T1 had excellent repeatability in phantoms, healthy participants and patients on both systems. Cohort nasal concha oxygen-induced ΔR1 significantly increased (p < 0.0001) in healthy participants demonstrating OE-MRI feasibility. ΔR1 repeatability coefficients (RC) were 0.023-0.040 s-1 across both MR systems. The tumour ΔR1 RC was 0.013 s-1 and the within-subject coefficient of variation (wCV) was 25% on the diagnostic MR. Tumour ΔR1 RC was 0.020 s-1 and wCV was 33% on the MR Linac. ΔR1 magnitude and time-course trends were similar on both systems.

CONCLUSION

We demonstrate first-in-human translation of volumetric, dynamic OE-MRI onto an MR Linac system, yielding repeatable hypoxia biomarkers. Data were equivalent on the diagnostic MR and MR Linac systems. OE-MRI has potential to guide future clinical trials of biology guided adaptive radiotherapy.

A National Referral Service for Paediatric Brachytherapy: An Evolving Practice and Outcomes Over 13 Years

AIMS

Most children requiring radiotherapy receive external beam treatment and few have tumours suitable for brachytherapy. No paediatric radiotherapy centre will treat enough patients from its own normal catchment population for expertise in brachytherapy to be developed and sustained. Following discussion and agreement in the national paediatric radiotherapy group, a service for paediatric brachytherapy in the UK has been developed. We report the process that has evolved over more than 10 years, with survival and functional outcome results.

MATERIALS AND METHODS

Since 2009, potential patients have been referred to the central paediatric oncology multidisciplinary team meeting, where imaging, pathology and treatment options are discussed. Since 2013, the National Soft Tissue Sarcoma Advisory Panel has also reviewed most patients, with the principal aim of advising on the most suitable primary tumour management for complex patients. Clinical assessment and examination under anaesthetic with biopsies may be undertaken to confirm the appropriateness of brachytherapy, either alone or following conservative surgery. Fractionated high dose rate brachytherapy was delivered to a computed tomography planned volume after implantation of catheters under ultrasound imaging guidance. Since 2019, follow-up has been in a dedicated multidisciplinary clinic.

RESULTS

From 2009 to 2021 inclusive, 35 patients (16 female, 19 male, aged 8 months to 17 years 6 months) have been treated. Histology was soft-tissue sarcoma in 33 patients and carcinoma in two. The treated site was pelvic in 31 patients and head and neck in four. With a median follow-up of 5 years, the local control and overall survival rates are 100%. Complications have been few, and functional outcome is good.

CONCLUSION

Brachytherapy is effective for selected paediatric patients, resulting in excellent tumour control and good functional results. It is feasible to deliver paediatric brachytherapy at a single centre within a national referral service.

Comparison of multiple gene expression platforms for measuring a bladder cancer hypoxia signature

Tumour hypoxia status provides prognostic information and predicts response to hypoxia‑modifying treatments. A previous study by our group derived a 24‑gene signature to assess hypoxia in bladder cancer. The objectives of the present study were to compare platforms for generating signature scores, identify cut‑off values for prospective studies, assess intra‑tumour heterogeneity and confirm hypoxia relevance. Briefly, RNA was extracted from prospectively collected diagnostic biopsies of muscle invasive bladder cancer (51 patients), and gene expression was measured using customised Taqman Low Density Array (TLDA) cards, NanoString and Clariom S arrays. Cross‑platform transferability of the gene signature was assessed using regression and concordance analysis. The cut‑off values were the cohort median expression values. Intra‑ and inter‑tumour variability were determined in a retrospective patient cohort (n=51) with multiple blocks (2‑18) from the same tumour. To demonstrate relevance, bladder cancer cell lines were exposed to hypoxia (0.1% oxygen, 24 h), and extracted RNA was run on custom TLDA cards. Hypoxia scores (HS) values showed good agreement between platforms: Clariom S vs. TLDA (r=0.72, P<0.0001; concordance 73%); Clariom S vs. NanoString (r=0.84, P<0.0001; 78%); TLDA vs. NanoString (r=0.80, P<0.0001; 78%). Cut‑off values were 0.047 (TLDA), 7.328 (NanoString) and 6.667 (Clariom S). Intra‑tumour heterogeneity in gene expression and HS (coefficient of variation 3.9%) was less than inter‑tumour (7.9%) variability. HS values were higher in bladder cancer cells exposed to hypoxia compared with normoxia (P<0.02). In conclusion, the present study revealed that application of the 24‑gene bladder cancer hypoxia signature was platform agnostic, cut‑off values determined prospectively can be used in a clinical trial, intra‑tumour heterogeneity was low and the signature was sensitive to changes in oxygen levels in vitro.

Radiotherapy-induced toxicity in prostate cancer patients with hip prostheses

Introduction

Acute and late toxicity was analysed for prostate cancer patients with bilateral hip prostheses, who received fixed field intensity modulated radiotherapy (IMRT). The aims were (1) to establish whether toxicity rates differed from those of a control group with normal hips, (2) to develop a volumetric modulated arc therapy (VMAT) approach for patients with prostheses and (3) to compare doses to bladder and rectum for the control group, prostheses group and VMAT replans for the prostheses group.

Methods

Genitourinary (GU) and gastrointestinal (GI) toxicity was scored using Common Terminology Criteria for Adverse Events version 5.0. The incidence of grade 2 or worse (G2+) toxicity was compared using Fisher’s exact test. Dose volume histograms (DVHs) and mean doses to organs at risk (OARs) were compared using signed rank tests.

Results

There were 17 patients in the prostheses group and 50 in the control group. Acute and late GU toxicity was similar. G2+ late GI toxicity incidence was 31% for the prostheses group and 14% for the control group (p = 0.14). Significant differences (p < 0.05) were seen between the OAR DVHs of the prostheses group who had IMRT and the control group for a range of intermediate doses. The rectum mean dose was significantly different (p < 0.001), but no difference was seen for the bladder mean dose (p = 0.08).

Conclusions

No significant differences were seen in GU and GI toxicity incidence between patients with bilateral hip prostheses and a control group. The DVHs for bladder and rectum were significantly higher for patients with prostheses planned with IMRT. Replanning using a VMAT technique significantly reduced doses to the OARs, whilst maintaining good planning target volume coverage.

Predicted Risks of Cardiovascular Disease Following Chemotherapy and Radiotherapy in the UK NCRI RAPID Trial of Positron Emission Tomography-Directed Therapy for Early-Stage Hodgkin Lymphoma

PURPOSE

The contemporary management of early-stage Hodgkin lymphoma (ES-HL) involves balancing the risk of late adverse effects of radiotherapy against the increased risk of relapse if radiotherapy is omitted. This study provides information on the risk of radiation-related cardiovascular disease to help personalize the delivery of radiotherapy in ES-HL.

METHODS

We predicted 30-year absolute cardiovascular risk from chemotherapy and involved field radiotherapy in patients who were positron emission tomography (PET)-negative following three cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy within a UK randomized trial of PET-directed therapy for ES-HL. Cardiac and carotid radiation doses and chemotherapy exposure were combined with established dose-response relationships and population-based mortality and incidence rates.

RESULTS

Average mean heart dose was 4.0 Gy (range 0.1-24.0 Gy) and average bilateral common carotid artery dose was 21.5 Gy (range 0.6-38.1 Gy), based on individualized cardiovascular dosimetry for 144 PET-negative patients receiving involved field radiotherapy. The average predicted 30-year radiation-related absolute excess overall cardiovascular mortality was 0.56% (range 0.01%-6.79%; < 0.5% in 67% of patients and > 1% in 15%), whereas average predicted 30-year excess incidence was 6.24% (range 0.31%-31.09%; < 5% in 58% of patients and > 10% in 24%). For cardiac disease, the average predicted 30-year radiation-related absolute excess mortality was 0.42% (0.79% with mediastinal involvement and 0.05% without) and for stroke, it was 0.14%.

CONCLUSION

Predicted excess cardiovascular risk is small for most patients, so radiotherapy may provide net benefit. However, for a minority of patients receiving high doses of radiation to cardiovascular structures, it may be preferable to consider advanced radiotherapy techniques to reduce doses or to omit radiotherapy and accept the increased relapse risk. Individual assessment of cardiovascular and other risks before treatment would allow personalized decision making about radiotherapy in ES-HL.

Salvage Reirradiation Options for Locally Recurrent Prostate Cancer: A Systematic Review

BACKGROUND

Reirradiation using brachytherapy (BT) and external beam radiation therapy (EBRT) are salvage strategies with locally radiorecurrent prostate cancer. This systematic review describes the oncologic and toxicity outcomes for salvage BT and EBRT [including Stereotactic Body Radiation Therapy (SBRT)].

METHODS

An International Prospective Register of Systematic Reviews (PROSPERO) registered (#211875) study was conducted using Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. EMBASE and MEDLINE databases were searched from inception to December 2020. For BT, both low dose rate (LDR) and high dose rate (HDR) BT techniques were included. Two authors independently assessed study quality using the 18-item Modified Delphi technique.

RESULTS

A total of 39 eligible studies comprising 1967 patients were included (28 BT and 11 SBRT). In 35 studies (90%), the design was single centre and/or retrospective and no randomised prospective studies were found. Twelve BT studies used LDR only, 11 HDR only, 4 LDR or HDR and 1 pulsed-dose rate only. All EBRT studies used SBRT exclusively, four with Cyberknife alone and 7 using both Cyberknife and conventional linear accelerator treatments. Median (range) modified Delphi quality score was 15 (6-18). Median (range) follow-up was 47.5 months (13-108) (BT) and 25.4 months (21-44) (SBRT). For the LDR-BT studies, the median (range) 2-year and 5-year bRFS rates were 71% (48-89.5) and 52.5% (20-79). For the HDR-BT studies, the median (range) 2-year and 5-year bRFS rates were 74% (63-89) and 51% (45-65). For the SBRT studies, the median (range) 2-year bRFS for the SBRT group was 54.9% (40-80). Mean (range) acute and late grade≥3 GU toxicity rates for LDR-BT/HDR-BT/SBRT were 7.4%(0-14)/2%(0-14)/2.7%(0-8.7) and 13.6%(0-30)/7.9%(0-21.3%)/2.7%(0-8%). Mean (range) acute and late grade≥3 GI toxicity rates for LDR-BT/HDR-BT/SBRT were 6.5%(0-19)/0%/0.5%(0-4%) and 6.4%(0-20)/0.1%(0-0.9)/0.2%(0-1.5). One third of studies included Patient Reported Outcome Measures (PROMs).

CONCLUSIONS

Salvage reirradiation of radiorecurrent prostate cancer using HDR-BT or SBRT provides similar biochemical control and acceptable late toxicity. Salvage LDR-BT is associated with higher late GU/GI toxicity. Challenges exist in comparing BT and SBRT from inconsistencies in reporting with missing data, and prospective randomised trials are needed.

Advances in radiotherapy in bone metastases in the context of new target therapies and ablative alternatives: A critical review

In patients with bone metastases (BM), radiotherapy (RT) is used to alleviate symptoms, reduce the risk of fracture, and improve quality of life (QoL). However, with the emergence of concepts like oligometastases, minimal invasive surgery, ablative therapies such as stereotactic ablative RT (SABR), radiosurgery (SRS), thermal ablation, and new systemic anticancer therapies, there have been a paradigm shift in the multidisciplinary approach to BM with the aim of preserving mobility and function survival. Despite guidelines on using single-dose RT in uncomplicated BM, its use remains relatively low. In uncomplicated BM, single-fraction RT produces similar overall and complete response rates to RT with multiple fractions, although it is associated with a higher retreatment rate of 20% versus 8%. Complicated BM can be characterised as the presence of impending or existing pathologic fracture, a major soft tissue component, existing spinal cord or cauda equina compression and neuropathic pain. The rate of complicated BM is around 35%. Unfortunately, there is a lack of prospective trials on RT in complicated BM and the best dose/fractionation regimen is not yet established. There are contradictory outcomes in studies reporting BM pain control rates and time to pain reduction when comparing SABR with Conventional RT. While some studies showed that SABR produces a faster reduction in pain and higher pain control rates than conventional RT, other studies did not show differences. Moreover, the local control rate for BM treated with SABR is higher than 80% in most studies, and the rate of grade 3 or 4 toxicity is very low. The use of SABR may be preferred in three circumstances: reirradiation, oligometastatic disease, and radioresistant tumours. Local ablative therapies like SABR can delay change or use of systemic therapy, preserve patients' Qol, and improve disease-free survival, progression-free survival and overall survival. Moreover, despite the potential benefit of SABR in oligometastatic disease, there is a need to establish the optial indication, RT dose fractionation, prognostic factors and optimal timing in combination with systemic therapies for SABR. This review evaluates the role of RT in BM considering these recent treatment advances. We consider the definition of complicated BM, use of single and multiple fractions RT for both complicated and uncomplicated BM, reirradiation, new treatment paradigms including local ablative treatments, oligometastatic disease, systemic therapy, physical activity and rehabilitation.

A miRNA signature predicts benefit from addition of hypoxia-modifying therapy to radiation treatment in invasive bladder cancer

BACKGROUND

miRNAs are promising biomarkers in oncology as their small size makes them less susceptible to degradation than mRNA in FFPE tissue. We aimed to derive a hypoxia-associated miRNA signature for bladder cancer.

METHODS

Taqman miRNA array cards identified miRNA seed genes induced under hypoxia in bladder cancer cell lines. A signature was derived using feature selection methods in a TCGA BLCA training data set. miRNA expression data were generated for 190 tumours from the BCON Phase 3 trial and used for independent validation.

RESULTS

A 14-miRNA hypoxia signature was derived, which was prognostic for poorer overall survival in the TCGA BLCA cohort (n = 403, p = 0.001). Univariable analysis showed that the miRNA signature predicted an overall survival benefit from having carbogen-nicotinamide with radiotherapy (HR = 0.30, 95% CI 0.094-0.95, p = 0.030) and performed similarly to a 24-gene mRNA signature (HR = 0.47, 95% CI 0.24-0.92, p = 0.025). Combining the signatures improved performance (HR = 0.26, 95% CI 0.08-0.82, p = 0.014) with borderline significance for an interaction test (p = 0.065). The interaction test was significant for local relapse-free survival LRFS (p = 0.033).

CONCLUSION

A 14-miRNA hypoxia signature can be used with an mRNA hypoxia signature to identify bladder cancer patients benefitting most from having carbogen and nicotinamide with radiotherapy.

Lost in application: Measuring hypoxia for radiotherapy optimisation

The history of radiotherapy is intertwined with research on hypoxia. There is level 1a evidence that giving hypoxia-targeting treatments with radiotherapy improves locoregional control and survival without compromising late side-effects. Despite coming in and out of vogue over decades, there is now an established role for hypoxia in driving molecular alterations promoting tumour progression and metastases. While tumour genomic complexity and immune profiling offer promise, there is a stronger evidence base for personalising radiotherapy based on hypoxia status. Despite this, there is only one phase III trial targeting hypoxia modification with full transcriptomic data available. There are no biomarkers in routine use for patients undergoing radiotherapy to aid management decisions, and a roadmap is needed to ensure consistency and provide a benchmark for progression to application. Gene expression signatures address past limitations of hypoxia biomarkers and could progress biologically optimised radiotherapy. Here, we review recent developments in generating hypoxia gene expression signatures and highlight progress addressing the challenges that must be overcome to pave the way for their clinical application.

Ultra-hypofractionated radiotherapy for low- and intermediate risk prostate cancer: High-dose-rate brachytherapy vs stereotactic ablative radiotherapy

PURPOSE

To compare the biochemical control rates (BCRs), late gastrointestinal (GI) and genitourinary (GU) toxicities in patients with low- and intermediate risk prostate cancer (PCa) treated with high-dose-rate brachytherapy (HDR BT) of 19 Gy/1 fraction, 26 Gy/2 fractions, or stereotactic ablative radiotherapy (SABR) of 36.25 Gy/5 fractions.

METHODS AND MATERIALS

Between August 2008 and December 2017, patients with low- and intermediate risk PCa who received single dose or 2-fraction HDR BT, or 5-fraction SABR at a single institution were included. BCR for the whole population and the individual treatment groups were calculated using the Phoenix definition. Post treatment GI and GU toxicities were evaluated according to the CTCAE v4.0 guidelines.

RESULTS

185 patients with low- and intermediate risk PCa were included in this study with a median follow up of 60.5 months. BCRs at 3 and 5 years were 95% and 85% for all patients. The 5-year BCRs were 69%, 95% and 92% for the 19 Gy/1 fraction, 26 Gy/2 fractions and 36.25 Gy/5 fractions groups respectively. The cumulative 5-year incidence rates of ≥grade 2 GI events in the 19 Gy/1fr, 26 Gy/2fr and 36.25 Gy/5fr groups were 0%, 2% and 4%, respectively. Incidence rates in those treated in the 5-fraction SABR arm were significantly higher (p < 0.05) than those treated in both HDR BT arms where no statistically significant difference between the two HDR BT groups was seen (p = 0.15). The cumulative 5-year incidence rates of ≥grade 2 GU events in the 19 Gy/1fr, 26 Gy/2fr and 36.25 Gy/5fr groups were 30%, 5% and 6%, respectively. No statistically significant difference was found between the 26 Gy/2fr and 36.25 Gy/5fr (p = 0.37) treatment arms but the incidence rate in the 26 Gy/2fr were significantly lower than those seen after 19 Gy/1fr (p < 0.05).

CONCLUSIONS

26 Gy/2 fractions HDR BT provided equivalent BCR with lower toxicity compared to 36.25 Gy/5 fractions SABR. Both 2-fraction HBR BT and 5-fraction SABR achieved better BCRs than single dose 19 Gy HDR BT. The two-fraction HDR BT schedule should be considered as an important comparator in future clinical trials.

Practical brachytherapy solutions to an age-old quandary

•

Age should not be a limiting factor for brachytherapy in patients with localised cancer or for palliation in metastatic disease.

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In tumour streams where brachytherapy forms part of the curative management, it should not be omitted in elderly patients who are medically fit for treatment.

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Treatment decisions should factor in patient preferences, the relative merits of different therapeutic approaches and maintaining minimal impact on quality of life.

Cancer is predominantly a disease of the elderly and as population life expectancy increases, so will the incidence of malignant disease. Elderly patients often have other comorbidities and social complexities, increasing the support required to safely deliver all treatment modalities. Brachytherapy is a relatively simple technique by which radiation therapy can be delivered. It offers dosimetric advantages through a highly conformal dose distribution thereby limiting radiation exposure to normal tissues reducing toxicity. Requiring fewer hospital visits, it also offers practical and logistical advantages to the elderly population and in many cases can be performed without the need for general anaesthesia. In tumour streams where brachytherapy forms part of the curative management, it should not be omitted in elderly patients who are medically fit for treatment. In the palliative setting, brachytherapy often offers an excellent means for achieving either local tumour and/or symptom control and should be actively considered in the therapeutic armamentarium of the oncologist in this context.

Randomised trial of external-beam radiotherapy alone or with high-dose-rate brachytherapy for prostate cancer: Mature 12-year results

BACKGROUND AND PURPOSE

A randomised phase-III trial compared external beam radiotherapy (EBRT) alone with EBRT combined with high-dose-rate brachytherapy boost (HDR-BTb) in localised prostate adenocarcinoma. Previous analysis, at median follow up of 85 months, demonstrated improved relapse free survival (RFS) with EBRT + HDR-BTb. This data has now been updated with a median follow up of 131 months.

MATERIALS AND METHODS

From December 1997 to August 2005, patients were assigned either to EBRT alone delivering 55 Gy in 20 fractions over 4 weeks or EBRT followed by a temporary high-dose-rate implant delivering 2 × 8·5 Gy over 24 h. The primary endpoint was RFS defined by a PSA rise ≥2.0 µg/l above nadir, clinical progression or death. Actuarial survival rates and Hazard Ratios (HRs) were calculated using the Kaplan-Meier method and Cox's Proportional Hazard Model, respectively. Secondary endpoints were overall survival (OS), urinary and bowel toxicity.

RESULTS

One hundred and six patients received EBRT alone and 110 EBRT + HDR-BTb. Median time to relapse was 137 months in the HDR-BTb arm compared to 82 months for EBRT alone (p = 0·01). A 27% risk of recurrence with EBRT alone was observed (p = 0·001), resulting in a 21% improvement in RFS at 12 years with EBRT + HDR-BTb. In multivariate analysis treatment arm, risk category and no androgen deprivation therapy were significant covariates for risk of relapse. Differences in overall survival were not significant.

CONCLUSION

At 12 years there remains a significant improvement in RFS after EBRT + HDR-BTb; both treatments were equitoxic for severe late urinary and bowel events and urethral strictures.

The implementation of an empty bladder filling protocol for localised prostate volumetric modulated arctherapy (VMAT): early results of a single institution service evaluation

OBJECTIVE

To examine the impact of an empty bladder filling protocol on patients receiving radical RT for localised prostate cancer on post RT toxicity and biochemical progression free survival (bPFS).

METHODS AND MATERIALS

Records of patients receiving radical external beam RT (EBRT) for localised prostate cancer with a full or empty bladder were reviewed. These included the bladder size on planning CT, daily online image guided RT (IGRT) setup data, treatment time and post treatment follow up data.These included bPFS, gastrointestinal(GI) and genitourinary(GU) toxicity scoring post RT using the CTCAE v4.0 scoring system. All patients included in the study were planned and treated under the same departmental clinical protocol with VMAT and daily online IGRT corrections.

RESULTS

90 patients were treated with 60 Gy in 20 fractions with a median follow up of 48 months. At 4 years bPFS in the empty bladder group was 100 and 98% in the full bladder group (p = 0.27). There were no statistically significant differences in cumulative ≥Grade 2GU (p = 0.10) and GI (p = 0.27) toxicity rates between the two bladder filling protocols. No statistically significant differences in the IGRT setup between the two groups of patients. Although the median treatment times per fraction were not statistically different between the two groups (p = 0.47), patients in the full bladder filling group were required to spend a longer time in the RT department per treatment session for bladder filling.

CONCLUSION

An empty bladder filling protocol has non-inferior bPFS, GI and GU toxicities at 4 years in patients with localised prostate cancer using advanced RT techniques in comparison to a full bladder filling protocol. A longer follow up with a larger sample size is required to validate this approach.

ADVANCES IN KNOWLEDGE

This study suggests that an empty bladder filling protocol can be used in external beam EBRT for localised prostate cancer with non-inferior treatment outcomes.

Radiobiologically derived biphasic fractionation schemes to overcome the effects of tumour hypoxia

OBJECTIVE

As a fractionated course of radiotherapy proceeds tumour shrinkage leads to resolution of hypoxia and the initiation of accelerated proliferation of radioresistant cancer cells with better repair capacity. We hypothesise that, in tumours with significant hypoxia, improved tumour control could be achieved with biphasic fractionation schedules that either use acceleration after 3-4 weeks of conventional radiotherapy or deliver a higher proportional dose towards the end of a course of treatment. We conducted a modelling study based on the concept of biological effective dose (BED) comparing such novel regimens with conventional fractionation.

METHODS

The comparator conventional fractionation schedule 70 Gy in 35 fractions delivered over 7 weeks was tested against the following novel regimens, both of which were designed to be isoeffective in terms of late normal tissue toxicity.40 Gy in 20 fractions over 4 weeks followed by 22.32 Gy in 6 consecutive daily fractions (delayed acceleration)30.4 Gy in 27 fractions over 4 weeks followed by 40 Gy in 15 fractions over 3 weeks (temporal dose redistribution)The delayed acceleration regimen is exactly identical to that of the comparator schedule over the first 28 days and the BED gains with the novel schedule are achieved during the second phase of treatment when reoxygenation is complete. For the temporal redistribution regimen, it was assumed that the reoxygenation fraction progressively increases during the first 4 weeks of treatment and an iterative approach was used to calculate the final tumour BED for varying hypoxic fractions.

RESULTS

Novel fractionation with delayed acceleration or temporal fractionation results in tumour BED gains equivalent to 3.5-8 Gy when delivered in 2 Gy fractions.

CONCLUSION

In hypoxic tumours, novel fractionation strategies result in significantly higher tumour BED in comparison to conventional fractionation.

ADVANCES IN KNOWLEDGE

We demonstrate that novel biphasic fractionation regimens could overcome the effects of tumour hypoxia resulting in biological dose escalation.

Addition of Androgen-Deprivation Therapy or Brachytherapy Boost to External Beam Radiotherapy for Localized Prostate Cancer: A Network Meta-Analysis of Randomized Trials

PURPOSE

In men with localized prostate cancer, the addition of androgen-deprivation therapy (ADT) or a brachytherapy boost (BT) to external beam radiotherapy (EBRT) have been shown to improve various oncologic end points. Practice patterns indicate that those who receive BT are significantly less likely to receive ADT, and thus we sought to perform a network meta-analysis to compare the predicted outcomes of a randomized trial of EBRT plus ADT versus EBRT plus BT.

MATERIALS AND METHODS

A systematic review identified published randomized trials comparing EBRT with or without ADT, or EBRT (with or without ADT) with or without BT, that reported on overall survival (OS). Standard fixed-effects meta-analyses were performed for each comparison, and a meta-regression was conducted to adjust for use and duration of ADT. Network meta-analyses were performed to compare EBRT plus ADT versus EBRT plus BT. Bayesian analyses were also performed, and a rank was assigned to each treatment after Markov Chain Monte Carlo analyses to create a surface under the cumulative ranking curve.

RESULTS

Six trials compared EBRT with or without ADT (n = 4,663), and 3 compared EBRT with or without BT (n = 718). The addition of ADT to EBRT improved OS (hazard ratio [HR], 0.71 [95% CI, 0.62 to 0.81]), whereas the addition of BT did not significantly improve OS (HR, 1.03 [95% CI, 0.78 to 1.36]). In a network meta-analysis, EBRT plus ADT had improved OS compared with EBRT plus BT (HR, 0.68 [95% CI, 0.52 to 0.89]). Bayesian modeling demonstrated an 88% probability that EBRT plus ADT resulted in superior OS compared with EBRT plus BT.

CONCLUSION

Our findings suggest that current practice patterns of omitting ADT with EBRT plus BT may result in inferior OS compared with EBRT plus ADT in men with intermediate- and high-risk prostate cancer. ADT for these men should remain a critical component of treatment regardless of radiotherapy delivery method until randomized evidence demonstrates otherwise.

Single dose high-dose rate (HDR) brachytherapy (BT) as monotherapy for localised prostate cancer: Early results of a UK national cohort study

BACKGROUND

HDR brachytherapy alone is effective for the treatment of localised prostate cancer when given in 2-4 or more fractions. Single dose treatment has been explored in small cohort studies to date. This paper reports a large patient population with localised prostate cancer treated with single dose HDR brachytherapy delivering 19 Gy providing early outcome data from this approach.

PATIENTS AND METHODS

Seven centres across the UK collaborated in this national protocol to deliver 19 Gy to the PTV defined by the prostate capsule and a 3 mm expansion with clearly defined planning constraints for the urethra and rectum. Entry criteria allowed all risk groups provided PSA ≤40 µg/L and staging investigations were negative for metastases. The primary end point was biochemical relapse free survival (bRFS) defined using the Phoenix definition. Toxicity was measured using CTCAE v4.0.

RESULTS

A total of 441 patients were entered with median follow up 26 months (range 2-56). Median age was 73 (range 54-84) and 10% were low risk, 65% intermediate risk and 25% high risk. ADT was received by 37.6% overall and 90% of high risk patients for a median period of 6 months. Three year bRFS was overall 88%: this was 100% in low risk, 86% in intermediate risk and 75% in high risk. Only Gleason score was an independent predictor of bRFS. Relapse in 25 patients was assessed radiologically and occurred in the prostate in 15 of these, 11 of whom had localised prostate relapse only. Acute toxicity was low with no grade 3 or 4 events; there were two cases of late urinary stricture and two grade 3 late rectal events.

CONCLUSION

This is the largest cohort of single dose HDR brachytherapy patients treated with a single dose published to date. It shows that with 19 Gy there is 100% bRFS at 3 years in low risk patients but results in intermediate and high risk groups are less encouraging falling to 86% and 75% at 3 years with relapse predominantly in the prostate. Limited by the short follow up period of this study, the long-term outcomes of this single dose HDR approach remains uncertain. It is important to have close ongoing surveillance of this cohort as the data matures.

Magnetic resonance-guided radiation therapy: A review

Magnetic resonance-guided radiation therapy (MRgRT) is a promising approach to improving clinical outcomes for patients treated with radiation therapy. The roles of image guidance, adaptive planning and magnetic resonance imaging in radiation therapy have been increasing over the last two decades. Technical advances have led to the feasible combination of magnetic resonance imaging and radiation therapy technologies, leading to improved soft-tissue visualisation, assessment of inter- and intrafraction motion, motion management, online adaptive radiation therapy and the incorporation of functional information into treatment. MRgRT can potentially transform radiation oncology by improving tumour control and quality of life after radiation therapy and increasing convenience of treatment by shortening treatment courses for patients. Multiple groups have developed clinical implementations of MRgRT predominantly in the abdomen and pelvis, with patients having been treated since 2014. While studies of MRgRT have primarily been dosimetric so far, an increasing number of trials are underway examining the potential clinical benefits of MRgRT, with coordinated efforts to rigorously evaluate the benefits of the promising technology. This review discusses the current implementations, studies, potential benefits and challenges of MRgRT.

Effect of Single-Fraction vs Multifraction Radiotherapy on Ambulatory Status Among Patients With Spinal Canal Compression From Metastatic Cancer: The SCORAD Randomized Clinical Trial

IMPORTANCE

Malignant spinal canal compression, a major complication of metastatic cancer, is managed with radiotherapy to maintain mobility and relieve pain, although there is no standard radiotherapy regimen.

OBJECTIVE

To evaluate whether single-fraction radiotherapy is noninferior to 5 fractions of radiotherapy.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter noninferiority randomized clinical trial conducted in 42 UK and 5 Australian radiotherapy centers. Eligible patients (n = 686) had metastatic cancer with spinal cord or cauda equina compression, life expectancy greater than 8 weeks, and no previous radiotherapy to the same area. Patients were recruited between February 2008 and April 2016, with final follow-up in September 2017.

INTERVENTIONS

Patients were randomized to receive external beam single-fraction 8-Gy radiotherapy (n = 345) or 20 Gy of radiotherapy in 5 fractions over 5 consecutive days (n = 341).

MAIN OUTCOMES AND MEASURES

The primary end point was ambulatory status at week 8, based on a 4-point scale and classified as grade 1 (ambulatory without the use of aids and grade 5 of 5 muscle power) or grade 2 (ambulatory using aids or grade 4 of 5 muscle power). The noninferiority margin for the difference in ambulatory status was -11%. Secondary end points included ambulatory status at weeks 1, 4, and 12 and overall survival.

RESULTS

Among 686 randomized patients (median [interquartile range] age, 70 [64-77] years; 503 (73%) men; 44% had prostate cancer, 19% had lung cancer, and 12% had breast cancer), 342 (49.8%) were analyzed for the primary end point (255 patients died before the 8-week assessment). Ambulatory status grade 1 or 2 at week 8 was achieved by 115 of 166 (69.3%) patients in the single-fraction group vs 128 of 176 (72.7%) in the multifraction group (difference, -3.5% [1-sided 95% CI, -11.5% to ∞]; P value for noninferiority = .06). The difference in ambulatory status grade 1 or 2 in the single-fraction vs multifraction group was -0.4% (63.9% vs 64.3%; [1-sided 95% CI, -6.9 to ∞]; P value for noninferiority = .004) at week 1, -0.7% (66.8% vs 67.6%; [1-sided 95% CI, -8.1 to ∞]; P value for noninferiority = .01) at week 4, and 4.1% (71.8% vs 67.7%; [1-sided 95% CI, -4.6 to ∞]; P value for noninferiority = .002) at week 12. Overall survival rates at 12 weeks were 50% in the single-fraction group vs 55% in the multifraction group (stratified hazard ratio, 1.02 [95% CI, 0.74-1.41]). Of the 11 other secondary end points that were analyzed, the between-group differences were not statistically significant or did not meet noninferiority criterion.

CONCLUSIONS AND RELEVANCE

Among patients with malignant metastatic solid tumors and spinal canal compression, a single radiotherapy dose, compared with a multifraction dose delivered over 5 days, did not meet the criterion for noninferiority for the primary outcome (ambulatory at 8 weeks). However, the extent to which the lower bound of the CI overlapped with the noninferiority margin should be considered when interpreting the clinical importance of this finding.

TRIAL REGISTRATION

ISRCTN Identifiers: ISRCTN97555949 and ISRCTN97108008.

MRE11 as a Predictive Biomarker of Outcome After Radiation Therapy in Bladder Cancer

PURPOSE

Organ-confined muscle-invasive bladder cancer is treated with cystectomy or bladder preservation techniques, including radiation therapy. There are currently no biomarkers to inform management decisions and aid patient choice. Previously we showed high levels of MRE11 protein, assessed by immunohistochemistry (IHC), predicted outcome after radiation therapy, but not cystectomy. Therefore, we sought to develop the MRE11 IHC assay for clinical use and define its relationship to clinical outcome in samples from 2 major clinical trials.

METHODS AND MATERIALS

Samples from the BCON and BC2001 randomized controlled trials and a cystectomy cohort were stained using automated IHC methods and scored for MRE11 in 3 centers in the United Kingdom.

RESULTS

Despite step-wise creation of scoring cards and standard operating procedures for staining and interpretation, there was poor intercenter scoring agreement (kappa, 0.32; 95% confidence interval, 0.17-0.47). No significant associations between MRE11 scores and cause-specific survival were identified in BCON (n = 132) and BC2001 (n = 221) samples. Reoptimized staining improved agreement between scores from BCON tissue microarrays (n = 116), but MRE11 expression was not prognostic for cause-specific survival.

CONCLUSIONS

Manual IHC scoring of MRE11 was not validated as a reproducible biomarker of radiation-based bladder preservation success. There is a need for automated quantitative methods or a reassessment of how DNA-damage response relates to clinical outcomes.

Organ preservation in bladder cancer: an opportunity for truly personalized treatment

Radical treatment of many solid tumours has moved from surgery to multimodal organ preservation strategies combining systemic and local treatments. Trimodality bladder-preserving treatment (TMT) comprises maximal transurethral resection of the bladder tumour followed by radiotherapy and concurrent radiosensitizing treatment, thereby sparing the urinary bladder. From the patient's perspective, the choice of maintaining quality of life without a negative effect on the chances of cure and long-term survival is attractive. In muscle-invasive bladder cancer (MIBC), the evidence shows comparable clinical outcomes between patients undergoing radical cystectomy and TMT. Despite this evidence, many patients continue to be offered radical surgery as the standard-of-care treatment. Improvements in radiotherapy techniques with adaptive radiotherapy and advances in imaging translate to increases in the accuracy of treatment delivery and reductions in long-term toxicities. With the advent of novel biomarkers promising improved prediction of treatment response, stratification of patients for different treatments on the basis of tumour biology could soon be a reality. The future of oncological treatment lies in personalized medicine with the combination of technological and biological advances leading to truly bespoke management for patients with MIBC.

Development and Validation of a 28-gene Hypoxia-related Prognostic Signature for Localized Prostate Cancer

BACKGROUND

Hypoxia is associated with a poor prognosis in prostate cancer. This work aimed to derive and validate a hypoxia-related mRNA signature for localized prostate cancer.

METHOD

Hypoxia genes were identified in vitro via RNA-sequencing and combined with in vivo gene co-expression analysis to generate a signature. The signature was independently validated in eleven prostate cancer cohorts and a bladder cancer phase III randomized trial of radiotherapy alone or with carbogen and nicotinamide (CON).

RESULTS

A 28-gene signature was derived. Patients with high signature scores had poorer biochemical recurrence free survivals in six of eight independent cohorts of prostatectomy-treated patients (Log rank test P < .05), with borderline significances achieved in the other two (P < .1). The signature also predicted biochemical recurrence in patients receiving post-prostatectomy radiotherapy (n = 130, P = .007) or definitive radiotherapy alone (n = 248, P = .035). Lastly, the signature predicted metastasis events in a pooled cohort (n = 631, P = .002). Prognostic significance remained after adjusting for clinic-pathological factors and commercially available prognostic signatures. The signature predicted benefit from hypoxia-modifying therapy in bladder cancer patients (intervention-by-signature interaction test P = .0026), where carbogen and nicotinamide was associated with improved survival only in hypoxic tumours.

CONCLUSION

A 28-gene hypoxia signature has strong and independent prognostic value for prostate cancer patients.

A Gene Signature for Selecting Benefit from Hypoxia Modification of Radiotherapy for High-Risk Bladder Cancer Patients

Purpose: Hypoxia modification improves overall survival in muscle-invasive bladder cancer patients who undergo radiotherapy. There is evidence that hypoxic tumors benefit most from hypoxia modification. The study aimed to identify or derive a hypoxia gene signature that predicts benefit from hypoxia-modifying treatment in bladder cancer.Experimental Design: Published hypoxia signatures were tested and a new one derived by analyzing bladder cancer transcriptomic data from public databases. Tumor samples were available from the BCON phase III randomized trial of radiotherapy alone or with carbogen and nicotinamide (CON). Gene expression data were generated for 151 tumors using Affymetrix Human 1.0 Exon ST arrays and used for independent validation.Results: A 24-gene signature was derived, which was prognostic in four of six independent surgical cohorts (n = 679; meta HR, 2.32; 95% CI, 1.73-3.12; P < 0.0001). The signature was also prognostic in BCON patients receiving radiotherapy alone (n = 75; HR for local relapse-free survival, 2.37; 95% CI, 1.26-4.47; P = 0.0076). The signature predicted benefit from CON (n = 76; HR, 0.47; 95% CI, 0.26-0.86; P = 0.015). Prognostic significance (P = 0.017) and predictive significance (P = 0.058) remained after adjusting for clinicopathologic variables. A test for interaction between hypoxia status and treatment arms was significant (P = 0.0094).Conclusions: A 24-gene hypoxia signature has strong and independent prognostic and predictive value for muscle-invasive bladder cancer patients. The signature can aid identification of patients likely to benefit from the addition of carbogen and nicotinamide to radiotherapy. Clin Cancer Res; 23(16); 4761-8. ©2017 AACR.

Abiraterone for Prostate Cancer Not Previously Treated with Hormone Therapy

BACKGROUND

Abiraterone acetate plus prednisolone improves survival in men with relapsed prostate cancer. We assessed the effect of this combination in men starting long-term androgen-deprivation therapy (ADT), using a multigroup, multistage trial design.

METHODS

We randomly assigned patients in a 1:1 ratio to receive ADT alone or ADT plus abiraterone acetate (1000 mg daily) and prednisolone (5 mg daily) (combination therapy). Local radiotherapy was mandated for patients with node-negative, nonmetastatic disease and encouraged for those with positive nodes. For patients with nonmetastatic disease with no radiotherapy planned and for patients with metastatic disease, treatment continued until radiologic, clinical, or prostate-specific antigen (PSA) progression; otherwise, treatment was to continue for 2 years or until any type of progression, whichever came first. The primary outcome measure was overall survival. The intermediate primary outcome was failure-free survival (treatment failure was defined as radiologic, clinical, or PSA progression or death from prostate cancer).

RESULTS

A total of 1917 patients underwent randomization from November 2011 through January 2014. The median age was 67 years, and the median PSA level was 53 ng per milliliter. A total of 52% of the patients had metastatic disease, 20% had node-positive or node-indeterminate nonmetastatic disease, and 28% had node-negative, nonmetastatic disease; 95% had newly diagnosed disease. The median follow-up was 40 months. There were 184 deaths in the combination group as compared with 262 in the ADT-alone group (hazard ratio, 0.63; 95% confidence interval [CI], 0.52 to 0.76; P<0.001); the hazard ratio was 0.75 in patients with nonmetastatic disease and 0.61 in those with metastatic disease. There were 248 treatment-failure events in the combination group as compared with 535 in the ADT-alone group (hazard ratio, 0.29; 95% CI, 0.25 to 0.34; P<0.001); the hazard ratio was 0.21 in patients with nonmetastatic disease and 0.31 in those with metastatic disease. Grade 3 to 5 adverse events occurred in 47% of the patients in the combination group (with nine grade 5 events) and in 33% of the patients in the ADT-alone group (with three grade 5 events).

CONCLUSIONS

Among men with locally advanced or metastatic prostate cancer, ADT plus abiraterone and prednisolone was associated with significantly higher rates of overall and failure-free survival than ADT alone. (Funded by Cancer Research U.K. and others; STAMPEDE ClinicalTrials.gov number, NCT00268476 , and Current Controlled Trials number, ISRCTN78818544 .).

The evolution of brachytherapy for prostate cancer

Brachytherapy (BT), using low-dose-rate (LDR) permanent seed implantation or high-dose-rate (HDR) temporary source implantation, is an acceptable treatment option for select patients with prostate cancer of any risk group. The benefits of HDR-BT over LDR-BT include the ability to use the same source for other cancers, lower operator dependence, and - typically - fewer acute irritative symptoms. By contrast, the benefits of LDR-BT include more favourable scheduling logistics, lower initial capital equipment costs, no need for a shielded room, completion in a single implant, and more robust data from clinical trials. Prospective reports comparing HDR-BT and LDR-BT to each other or to other treatment options (such as external beam radiotherapy (EBRT) or surgery) suggest similar outcomes. The 5-year freedom from biochemical failure rates for patients with low-risk, intermediate-risk, and high-risk disease are >85%, 69-97%, and 63-80%, respectively. Brachytherapy with EBRT (versus brachytherapy alone) is an appropriate approach in select patients with intermediate-risk and high-risk disease. The 10-year rates of overall survival, distant metastasis, and cancer-specific mortality are >85%, <10%, and <5%, respectively. Grade 3-4 toxicities associated with HDR-BT and LDR-BT are rare, at <4% in most series, and quality of life is improved in patients who receive brachytherapy compared with those who undergo surgery.

Expression of miR-210 in relation to other measures of hypoxia and prediction of benefit from hypoxia modification in patients with bladder cancer

BACKGROUND

The addition of hypoxia modifiers carbogen and nicotinamide (CON) to radiotherapy (RT) improved overall survival (OS) in bladder cancer patients in the BCON phase III clinical trial. We investigate whether expression of hsa-miR-210 in BCON patient samples reflects hypoxia and predicts benefit from hypoxia modification.

METHODS

In all, 183 T1-T4a bladder cancer samples were available for miR-210 analysis. A total of 86 received RT+CON and 97 received RT alone. TaqMan qPCR plates were used to assess miR-210 expression. Patients were classified as low (

RESULTS

Patients with high miR-210 had a trend towards improved 5-year OS with RT+CON (53.2%) compared with RT alone (37.8%; hazard ratio (HR) 1.68, 95% CI 0.95-2.95, P=0.07). No benefit was seen with low miR-210 (HR 1.02, 95% CI 0.58-1.79, P=0.97). High miR-210 was significantly associated with high HIF-1α protein (P=0.001), CA9 protein (P=0.0004), Glut-1 protein (P=0.001), 26-gene hypoxia score (P=0.007), tumour necrosis (P=0.02) and concurrent pTis (P=0.03).

CONCLUSIONS

High miR-210 may reflect hypoxia in bladder cancer. However, its ability to predict benefit from hypoxia modification does not improve upon other hypoxia markers. Investigation as part of a miRNA hypoxia signature may reveal the full potential of miR-210.

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Key Words

• bladder cancer
• microrna
• hypoxic modification
• necrosis
• biomarker
• radiotherapy
• carbogen and nicotinamide

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MESH Headings

• Aged
• Aged, 80 and over
• Cell Hypoxia/genetics
• Female
• Humans
• Male
• MicroRNAs/genetics
• Middle Aged
• Urinary Bladder Neoplasms/genetics
• Urinary Bladder Neoplasms/pathology

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Grants

• 11359 Cancer Research UK
• G0300648 Medical Research Council
• 16466 Cancer Research UK
• G0801525 Medical Research Council
• 18974 Cancer Research UK

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Randomized Double-Blind Trial of Pregabalin Versus Placebo in Conjunction With Palliative Radiotherapy for Cancer-Induced Bone Pain

PURPOSE

Cancer-induced bone pain (CIBP) affects one third of patients with cancer. Radiotherapy remains the gold-standard treatment; however, laboratory and clinical work suggest that pregabalin may be useful in treating CIBP. The aim of this study was to examine pregabalin in patients with CIBP receiving radiotherapy.

PATIENTS AND METHODS

A multicenter, double-blind randomized trial of pregabalin versus placebo was conducted. Eligible patients were age ≥ 18 years, had radiologically proven bone metastases, were scheduled to receive radiotherapy, and had pain scores ≥ 4 of 10 (on 0-to-10 numeric rating scale). Before radiotherapy, baseline assessments were completed, followed by random assignment. Doses of pregabalin and placebo were increased over 4 weeks. The primary end point was treatment response, defined as a reduction of ≥ 2 points in worst pain by week 4, accompanied by a stable or reduced opioid dose, compared with baseline. Secondary end points assessed average pain, interference of pain with activity, breakthrough pain, mood, quality of life, and adverse events.

RESULTS

A total of 233 patients were randomly assigned: 117 to placebo and 116 to pregabalin. The most common cancers were prostate (n = 88; 38%), breast (n = 77; 33%), and lung (n = 42; 18%). In the pregabalin arm, 45 patients (38.8%) achieved the primary end point, compared with 47 (40.2%) in the placebo arm (adjusted odds ratio, 1.07; 95% CI, 0.63 to 1.81; P = .816). There were no statistically significant differences in average pain, pain interference, or quality of life between arms. There were differences in mood (P = .031) and breakthrough pain duration (P = .037) between arms. Outcomes were compared at 4 weeks.

CONCLUSION

Our findings do not support the role of pregabalin in patients with CIBP receiving radiotherapy. The role of pregabalin in CIBP with a clinical neuropathic pain component is unknown.

High dose rate brachytherapy for prostate cancer: Standard of care and future direction

High dose rate brachytherapy is a highly conformal method of radiation dose escalation for prostate cancer and one of several treatment options for men with localised disease. The large doses per fraction exploit the low alpha/beta ratio of prostate cancer cells so that biological radiation dose delivered is substantially greater than that achieved with conventional external beam delivery. This review article presents contemporary data on the rationale for high dose rate brachytherapy including treatment technique and future directions.

Dose-effect relationship and risk factors for vaginal stenosis after definitive radio(chemo)therapy with image-guided brachytherapy for locally advanced cervical cancer in the EMBRACE study

BACKGROUND/PURPOSE

To identify risk factors for vaginal stenosis and to establish a dose-effect relationship for image-guided brachytherapy in locally advanced cervical cancer.

MATERIALS/METHODS

Patients from the ongoing EMBRACE study with prospectively assessed morbidity (CTCAEv3.0) at baseline and at least one follow-up were selected. Patient-, disease- and treatment characteristics were tested as risk factors for vaginal stenosis G ⩾ 2 in univariate and multivariable analyses (Cox proportional hazards model) and a dose-effect curve was deduced from the estimates. The ICRU rectum point was used to derive the recto-vaginal reference point dose.

RESULTS

In 630 patients included (median follow-up 24months), 2-year actuarial estimate for vaginal stenosis G ⩾ 2 was 21%. Recto-vaginal reference point dose (HR=1.025, p=0.029), external beam radiotherapy (EBRT) dose >45 Gy/25 fractions (HR=1.770, p=0.056) and tumor extension in the vagina (HR=2.259, p ⩽ 0.001) were risk factors for vaginal stenosis, adjusted for center reporting effects. Based on the model curve, the risk was 20% at 65 Gy, 27% at 75 Gy and 34% at 85 Gy (recto-vaginal reference point dose).

CONCLUSION

Keeping the EBRT dose at 45 Gy/25 fractions and decreasing the dose contribution of brachytherapy to the vagina decrease the risk of stenosis. A planning aim of ⩽65 Gy EQD2 (EBRT+brachytherapy dose) to the recto-vaginal reference point is therefore proposed.

Stereotactic body radiotherapy (SBRT) in the management of extracranial oligometastatic (OM) disease

OBJECTIVE

A review of stereotactic body radiotherapy (SBRT) for oligometastases defined as three or fewer sites of isolated metastatic disease. The aim was to identify local control, overall survival (OS) and progression-free survival (PFS) of patients receiving SBRT for oligometastatic (OM) disease.

METHODS

Data were analysed for SBRT delivered between 01 September 2010 and 31 March 2014. End points included local control, PFS, OS and toxicity.

RESULTS

76 patients received SBRT. The median age was 60 years (31-89 years). 44 were male. Median follow-up was 12.3 months (0.2-36.9 months). Major primary tumour sites included colorectal (38%), the breast (18%) and the prostate (12%). The treatment sites included lymph nodes (42%), the bone and spine (29%) and soft tissue (29%). 42% were previously treated with conventional radiotherapy. 45% were disease free after SBRT. 4% had local relapse, 45% had distant relapse, and 6% had local and distant relapse. Local control was 89%. The OS was 84.4% at 1 year and 63.2% at 2 years. PFS was 49.1% at 1 year and 26.2% at 2 years. Toxicities included duodenal ulcer and biliary stricture formation.

CONCLUSION

SBRT can achieve durable control of OM lesions and results in minimal radiation-induced morbidity.

ADVANCES IN KNOWLEDGE

This cohort is one of the largest reported to date and contributes to the field of SBRT in oligometastases that is emerging as an important research area. It is the only study reported from the UK and uses a uniform technique throughout. The efficacy and low toxicity with durable control of local disease with this approach is shown, setting the foundations for future randomized studies.

Protons and more: state of the art in radiotherapy

The purpose of modern radiotherapy is to deliver a precise high dose of radiation which will result in reproductive death of the cells. Radiation should transverse within the tumour volume whilst minimising damage to surrounding normal tissue. Overall 40% of cancers which are cured will have received radiotherapy. Current state of the art treatment will incorporate cross-sectional imaging and multiple high energy X-ray beams in processes called intensity modulated radiotherapy and image guided radiotherapy. Brachytherapy enables very high radiation doses to be delivered by the direct passage of a radiation source through or within the tumour volume and similar results can be achieved using rotational stereotactic X-ray beam techniques. Protons have the characteristics of particle beams which deposit their energy in a finite fixed peak at depth in tissue with no dose beyond this point - the Bragg peak. This has advantages in certain sites such as the spine adjacent to the spinal cord and particularly in children when the overall volume of tissue receiving radiation can be minimised.

Dosimetric analysis of urethral strictures following HDR (192)Ir brachytherapy as monotherapy for intermediate- and high-risk prostate cancer

BACKGROUND AND PURPOSE

To evaluate dosimetric parameters related to urethral strictures following high dose-rate brachytherapy (HDRBT) alone for prostate cancer.

MATERIAL AND METHODS

Ten strictures were identified in 213 patients treated with HDRBT alone receiving 34Gy in four fractions, 36Gy in four fractions, 31.5Gy in 3 fractions or 26Gy in 2 fractions. A matched-pair analysis used 2 controls for each case matched for dose fractionation schedule, pre-treatment IPSS score, number of needles used and clinical target volume. The urethra was divided into membranous urethra and inferior, mid and superior thirds of the prostatic urethra.

RESULTS

Stricture rates were 3% in the 34Gy group, 4% in the 36Gy group, 6% in the 31.5Gy group and 4% in the 26Gy group. The median time to stricture formation was 26months (range 8-40). The dosimetric parameters investigated were not statistically different between cases and controls. No correlation was seen between stricture rate and fractionation schedule.

CONCLUSIONS

Urethral stricture is an infrequent complication of prostate HDRBT when used to deliver high doses as sole treatment, with an overall incidence in this cohort of 10/213 (4.7%). In a matched pair analysis no association with dose schedule or urethral dosimetry was identified, but the small number of events limits definitive conclusions.

Survival with Newly Diagnosed Metastatic Prostate Cancer in the "Docetaxel Era": Data from 917 Patients in the Control Arm of the STAMPEDE Trial (MRC PR08, CRUK/06/019)

BACKGROUND

Prostate cancer (PCa) is the second most common disease among men worldwide. It is important to know survival outcomes and prognostic factors for this disease. Recruitment for the largest therapeutic randomised controlled trial in PCa--the Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy: A Multi-Stage Multi-Arm Randomised Controlled Trial (STAMPEDE)--includes men with newly diagnosed metastatic PCa who are commencing long-term androgen deprivation therapy (ADT); the control arm provides valuable data for a prospective cohort.

OBJECTIVE

Describe survival outcomes, along with current treatment standards and factors associated with prognosis, to inform future trial design in this patient group.

DESIGN, SETTING, AND PARTICIPANTS

STAMPEDE trial control arm comprising men newly diagnosed with M1 disease who were recruited between October 2005 and January 2014.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall survival (OS) and failure-free survival (FFS) were reported by primary disease characteristics using Kaplan-Meier methods. Hazard ratios and 95% confidence intervals (CIs) were derived from multivariate Cox models.

RESULTS AND LIMITATIONS

A cohort of 917 men with newly diagnosed M1 disease was recruited to the control arm in the specified interval. Median follow-up was 20 mo. Median age at randomisation was 66 yr (interquartile range [IQR]: 61-71), and median prostate-specific antigen level was 112 ng/ml (IQR: 34-373). Most men (n=574; 62%) had bone-only metastases, whereas 237 (26%) had both bone and soft tissue metastases; soft tissue metastasis was found mainly in distant lymph nodes. There were 238 deaths, 202 (85%) from PCa. Median FFS was 11 mo; 2-yr FFS was 29% (95% CI, 25-33). Median OS was 42 mo; 2-yr OS was 72% (95% CI, 68-76). Survival time was influenced by performance status, age, Gleason score, and metastases distribution. Median survival after FFS event was 22 mo. Trial eligibility criteria meant men were younger and fitter than general PCa population.

CONCLUSIONS

Survival remains disappointing in men presenting with M1 disease who are started on only long-term ADT, despite active treatments being available at first failure of ADT. Importantly, men with M1 disease now spend the majority of their remaining life in a state of castration-resistant relapse.

PATIENT SUMMARY

Results from this control arm cohort found survival is relatively short and highly influenced by patient age, fitness, and where prostate cancer has spread in the body.