Randomized Trial of Concomitant Hypofractionated Intensity Modulated Radiation Therapy Boost Versus Conventionally Fractionated Intensity Modulated Radiation Therapy Boost for Localized High-Risk Prostate Cancer (pHART2-RCT)

PURPOSE

The aim of this work is to report on the results of a phase 2 randomized trial of moderately hypofractionated (MH) versus conventionally fractionated (CF) radiation therapy to the prostate with elective nodal irradiation.

METHODS AND MATERIALS

This was a single-center, prospective, phase 2 randomized study. Patients with high-risk disease (cT3, prostate-specific antigen level >20 ng/mL, or Gleason score 8-10) were eligible. Patients were randomized to either MH using a simultaneous integrated boost (68 Gy in 25 fractions to prostate; 48 Gy to pelvis) or CF (46 Gy in 23 fractions with a sequential boost to the prostate of 32 Gy in 16 fractions), with long-term androgen deprivation therapy. The primary endpoint was grade ≥2 acute gastrointestinal (GI) and genitourinary (GU) toxicity (Common Terminology Criteria for Adverse Events version 3.0). Secondary endpoints included late GI and GU toxicity, quality of life, and oncologic outcomes.

RESULTS

One-hundred eighty patients were enrolled; 90 were randomized to and received MH and 90 to CF. The median follow-up was 67.4 months. Seventy-five patients (41.7%) experienced a grade ≥2 acute GI and/or GU toxicity, including 34 (37.8%) in the MH and 41 (45.6%) in the CF arms, respectively (P = .29). Late grade ≥2 GI (P = .07) and GU (P = .25) toxicity was not significantly different between arms; however, late grade ≥3 GI toxicity was worse in the MH group (P = .01). There were no statistically significant quality-of-life differences between the 2 treatments. There were no statistically significant differences observed in cumulative incidence of biochemical failure (P = .71) or distant metastasis (P = .31) and overall survival (P = .46).

CONCLUSIONS

MH to the prostate and pelvis with androgen deprivation therapy for men with high-risk localized prostate cancer was not significantly different than CF with regard to acute toxicity, quality of life, and oncologic efficacy. However, late grade ≥3 GI toxicity was more common in the MH arm.

To Boost or Not to Boost: Pooled Analyses From 2-Fraction SABR Trials for Localized Prostate Cancer

PURPOSE

Focal boost to dominant intraprostatic lesion (DIL) is an approach for dose escalation in prostate radiation therapy. In this study, we aimed to report the outcomes of 2-fraction SABR ± DIL boost.

METHODS AND MATERIALS

We included 60 patients with low- to intermediate-risk prostate cancer enrolled in 2 phase 2 trials (30 patients in each trial). In the 2STAR trial (NCT02031328), 26 Gy (equivalent dose in 2-Gy fractions = 105.4 Gy) was delivered to the prostate. In the 2SMART trial (NCT03588819), 26 Gy was delivered to the prostate, with up to 32 Gy boost to magnetic resonance imaging-defined DIL (equivalent dose in 2-Gy fractions = 156.4 Gy). The reported outcomes included prostate-specific antigen (PSA) response (ie, <0.4 ng/mL) at 4 years (4yrPSARR), biochemical failure (BF), acute and late toxicities, and quality of life (QOL).

RESULTS

In 2SMART, median DIL D99% of 32.3 Gy was delivered. Median follow-up was 72.7 months (range, 69.1-75.) in 2STAR and 43.6 months (range, 38.7-49.5) in 2SMART. The 4yrPSARR was 57% (17/30) in 2STAR and 63% (15/24) in 2SMART (P = 0.7). The 4-year cumulative BF was 0% in 2STAR and 8.3% in 2SMART (P = 0.1). The 6-year BF in 2STAR was 3.5%. For genitourinary toxicities, there were differences in grade ≥1 urinary urgency in the acute (0% vs 47%; P < .001) and late settings (10% vs 67%; P < .001) favoring 2STAR. For urinary QOL, no difference was observed in the acute setting, but lower proportion in 2STAR had minimal clinically important changes in urinary QOL score in the late setting (21% vs 50%; P = .03). There were no significant differences in gastrointestinal and sexual toxicities and QOL in both acute and late settings between the 2 trials.

CONCLUSIONS

This study presents the first prospective data comparing 2-fraction prostate SABR ± DIL boost. The addition of DIL boost resulted in similar medium-term efficacy (in 4yrPSARR and BF), with impact on late urinary QOL outcomes.

Dosimetric correlates of toxicities and quality of life following two-fraction stereotactic ablative radiotherapy (SABR) for prostate cancer

PURPOSE

There is no evidence-based data to guide dose constraints in two-fraction prostate stereotactic ablative radiotherapy (SABR). Using individual patient-data from two prospective trials, we aimed to correlate dosimetric parameters with toxicities and quality of life (QoL) outcomes.

MATERIALS AND METHODS

We included 60 patients who had two-fraction prostate SABR in the 2STAR (NCT02031328) and 2SMART (NCT03588819) trials. The prescribed dose was 26 Gy to the prostate+/-32 Gy boost to the dominant intraprostatic lesions. Toxicities and QoL data were prospectively collected using CTCAEv4 and EPIC-26 questionnaire. The outcomes evaluated were acute and late grade ≥ 2 toxicities, and late minimal clinical important changes (MCIC) in QoL domains. Dosimetric parameters for bladder, urethra, rectum, and penile bulb were evaluated.

RESULTS

The median follow-up was 56 months (range: 39-78 months). The cumulative incidence of grade ≥ 2 genitourinary (GU), gastrointestinal (GI), and sexual toxicities were 62%, 3%, and 17% respectively in the acute setting (<3 months), and 57%, 15%, and 52% respectively in late setting (>6 months). There were 36%, 28%, and 29% patients who had late MCIC in urinary, bowel and sexual QoL outcomes respectively. Bladder 0.5 cc was significant predictor for late grade ≥ 2 GU toxicities, with optimal cut-off of 25.5 Gy. Penile bulb D5cc was associated of late grade ≥ 2 sexual toxicities (no optimal cut-off was identified). No dosimetric parameters were identified to be associated with other outcomes.

CONCLUSION

Using real-life patient data from prospective trials with medium-term follow-up, we identified additional dose constraints that may mitigate the risk of late treatment-related toxicities for two-fraction prostate SABR.

Dosimetric Parameters Predictive of Treatment-Related Toxicity in High Dose-Rate Brachytherapy as Monotherapy for Prostate Cancer

PURPOSE/OBJECTIVE(S)

High dose-rate (HDR) brachytherapy as monotherapy is an effective treatment for patients with low- and intermediate-risk prostate cancer and is increasingly being offered as a 2-fraction protocol. There is a lack of consensus on the optimal dosimetric planning parameters to use, or whether there is any benefit summating dosimetric parameters from more than one implant. Our goal is to determine planning parameters associated with disease control, toxicity and health-related quality of life (HRQOL).

MATERIALS/METHODS

Data were collected on 83 patients with low- and intermediate-risk prostate cancer who received 2 fractions of 13.5 Gy HDR brachytherapy without androgen-deprivation therapy as part of a randomized phase II clinical trial. An in-house deformable, registration algorithm was used to co-register and dose-summate the plans from both implants for each patient. Acute and late GU and GI toxicities were measured using CTCAE 4.0 and HRQOL was measured in urinary, bowel, sexual and hormonal domains using the EPIC scores. Treatment efficacy was assessed through PSA measurement and imaging with or without biopsy where indicated. Covariates included baseline clinical factors, disease characteristics and treatment dosimetric parameters. Cox proportional hazards was performed to evaluate covariates impact on treatment toxicity and efficacy, and logistic regression analysis evaluated covariates impact on HRQOL.

RESULTS

Among the 83 patients, median prostate volume was 46.7cm3. Median summated planning target volume receiving 100% prescription dose (PTV V100%) was 97.4%, median PTV V150% 42.4% and median PTV V200% 15.5%. Median highest dose to the 1cm3 rectum (D1cc) was 66.9% of the prescription dose and median rectum V80% was 0.008cm3. Median urethral D1cc was 99.0% of the prescription dose, median urethral Dmax 121.7% and median urethral D10% 116.2%. Grade ≥2 GI toxicity was uncommon (3.7% acute and 8.5% late), but grade ≥2 GU toxicity was reported in 73.2% (acute) and 46.3% (late) patients. Rectum D1cc and V80% were found to be significantly associated with grade 2 or higher acute GI toxicity, while use of a-blocker at baseline was associated with grade ≥2 acute GU toxicity. Similarly, use of a-blocker was associated with late grade ≥2 GU toxicity, but with no dosimetric associations. No other variables were associated with treatment-related toxicities. Only rectum D1cc was significantly associated with changes in bowel EPIC scores. Estimated 5-year biochemical disease-free survival was 93.9% and 5-year cumulative incidence of local failure was 3.8%.

CONCLUSION

HDR monotherapy with 27 Gy delivered in 2 fractions in treatment of prostate cancer is well tolerated with high rates of disease control and minimal toxicity. Dose summation between 2 fractions of HDR brachytherapy is feasible, with rectal dose predicting acute GI toxicity. The lack of association between dose metrics and urinary toxicity raises the potential for further dose escalation.

Dosimetric Predictors of Toxicities and Quality of Life Following Two-Fraction Stereotactic Body Radiotherapy for Prostate Cancer

PURPOSE/OBJECTIVE(S)

There is emerging interest in two-fraction stereotactic body radiotherapy (2#SBRT) for localized prostate cancer. However, there is limited data to guide organs at risk (OAR) dose constraints in 2#SBRT. We aim to identify dosimetric predictors of toxicities and quality of life (QoL) using real life patient data from two prospective 2#SBRT trials.

MATERIALS/METHODS

We included 60 patients who had 2#SBRT in the 2STAR (NCT02031328) and 2SMART (NCT03588819) phase 2 trials. The prescribed dose was 26Gy to the prostate +/- focal boost of 32Gy to the dominant intraprostatic lesions. Toxicities and QoL data were prospectively collected using CTCAEv4 and EPIC26 questionnaires. For QoL, we reported the minimal clinical important changes (MCIC), defined as changes in QoL score of >0.5 standard deviation from baseline QoL score. We evaluated the bladder, urethra, rectum, and penile bulb dosimetry (urethra dosimetry only available in 30 patients in 2SMART trial). Some of the dosimetric parameters were log-transformed to normalize the distribution. Cox regression was used to identify dosimetric predictors for acute and late grade ≥2 GU toxicities. Logistic regression was used to identify dosimetric predictors for late MCIC in urinary, bowel and sexual QoL domains. Backward stepwise selection was used to identify significant dosimetric parameters. For GU toxicities and urinary QoL, three additional clinical factors (age, prostate volume and IPSS) were included in the final model as confounding factors. Receiver operating characteristics curve was used to identify cut-off for significant dosimetric parameters.

RESULTS

The median follow-up for the cohort was 56 months (range: 39-78 months). The cumulative acute and late grade ³2 GU toxicities were 62% (37/60) and 57% (34/60) respectively. No bladder or urethra dosimetric parameter was associated with acute grade ≥2 GU toxicities. Bladder D0.5cc was significant predictor of late grade ≥2 GU toxicities in univariate model (P = 0.05), but not in multivariate model. Baseline IPSS score was the single strongest predictor for late grade ≥2 GU toxicities (HR = 1.9; 95% CI = 1.1-3.4; P = 0.03). For late QoL outcomes, there were 36% (21/58), 28% (16/58), and 29% (17/58) of patients with MCIC in urinary, bowel and sexual QoL domains respectively. Bladder V10Gy was associated with late urinary MCIC in multivariate model after adjusting for clinical confounders (HR = 2.6, 95% CI = 1.1-6.6; P = 0.04). 48% (14/29) and 24% (7/29) of patients with bladder V10Gy>13.9% and V10Gy≤13.9% respectively had late urinary MCIC. No rectum and penile bulb dosimetry parameters was identified to be associated with late bowel or sexual QoL.

CONCLUSION

Using real life patient data from prospective clinical trials with medium term follow-up, we identified statistically significant bladder dosimetry parameter predictive of late urinary QoL. This finding could be useful to guide OAR dose constraints in prostate 2#SBRT trials.

Impact of Frailty on Health Care Resource Utilization and Costs of Care in Myelodysplastic Syndromes

PURPOSE

The role of frailty in affecting survival in myelodysplastic syndromes (MDS) is increasingly recognized. Despite this, a paucity of data exists on the association between frailty and other clinically meaningful outcomes including health care resource utilization and costs of care.

METHODS

We linked the Ontario subset of the prospective Canadian MDS registry (including baseline patient/disease characteristics) to population-based health system administrative databases. Baseline frailty was calculated from the 15-item MDS-specific frailty scale (FS-15). Primary outcomes were public health care utilization and 30-day standardized costs of care (2019 Canadian dollars) determined for each phase of disease (initial, continuation, and terminal phases). Negative binomial regression was used to assess the association between frailty and health care costs with Poisson regression to explore predictors of hospitalization.

RESULTS

Among 461 patients with complete FS-15 scores, 374 (81.1%) had a hospitalization with a mean length of stay of 10.6 days. Controlling for age, comorbidities, Revised International Prognostic Scoring System, and transfusion dependence, the FS-15 was independently associated with hospitalization during the initial (P = .02) and continuation (P = .01) phases but not the terminal disease phase (P = .09). The mean 30-day standardized cost per patient was $8,499 (median, $6,295; interquartile range, $2,798-$11,996), largely driven by cancer clinic visits and hospitalization. On multivariable analysis, the FS-15 was independently associated with costs of care during the initial disease phase (P = .02).

CONCLUSION

We demonstrate an association between frailty and clinically meaningful outcomes including hospitalization and costs of care in patients with MDS. Our results suggest that baseline frailty may help to inform patients and physicians of expected outcomes.

Two-fraction stereotactic MRI-guided ablative radiotherapy with simultaneous boost to dominant intraprostatic lesion: Results from the 2SMART phase 2 trial

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Background: Prostate stereotactic ablative radiotherapy (SABR) for localised prostate cancer is commonly delivered over 5 fractions. Focal boost to the dominant intraprostatic lesion (DIL) seen on multiparametric magnetic resonance imaging (mpMRI) is an approach for dose-escalation in prostate SABR. This is the first report of the outcomes of the 2SMART trial, a phase 2 single-arm study using 2-fraction prostate SABR with DIL boost. Methods: Men with low to intermediate risk prostate cancer were enrolled in the study. Three gold fiducial markers were inserted for image guidance. The clinical target volume (CTV) included the prostate gland, and the planning target volume (PTV) was a 2mm expansion antero-posterior and laterally, and 2.5mm supero-inferiorly. The DIL was contoured on fused mpMRI. The prescribed dose was 26Gy in 2 fractions (EQD2 110Gy, α/β of 1.4) to the CTV, and up to 32Gy in 2 fractions (EQD2 164Gy) to the DIL as long as the dose constraints for the organs at risks were not exceeded. Each fraction was delivered 1 week apart. Daily image guidance with cone-beam computed tomography was used pre- and post-treatment. The primary endpoint was acute (≤3 months) changes in quality of life (QOL), assessed using the EPIC questionnaire. Minimal clinically important change (MCIC) in QOL was defined as an EPIC score decrease of >0.5 standard deviation of the baseline EPIC score for each domain. Secondary endpoints were acute and late toxicities (assessed using CTCAEv4), and biochemical failure (based on Phoenix criteria). Results: 30 men were enrolled in the study, of which 2 (7%) had low risk and 28 (93%) had intermediate risk prostate cancer. The median follow-up was 44 months (range: 39-49 months). The median PSA nadir was 0.2ng/mL, with median time to nadir of 37 months. One patient (3%) had biochemical failure at 44 months post-treatment. 1 (3%) and 17 (57%) had acute Grade 2 GU and GI toxicities, while 3 (10%) and 15 (50%) had late (>6 months) Grade 2 GU and GI toxicities. No acute or late Grade ≥3 GU or GI was reported. 10 (33%), 6 (20%), and 3 (10%) men had acute MCIC in urinary, bowel and sexual domains respectively. 15 (50%), 9 (30%) and 13 (43%) had late MCIC in urinary, bowel and sexual domain respectively. Conclusions: Two-fraction prostate SABR with DIL boost is a safe approach for dose-escalation for localised prostate cancer, with minimal impact on acute QOL, and no grade 3-4 toxicities. Clinical trial information: NCT03588819 .

A natural history of lower-risk myelodysplastic syndromes with ring sideroblasts: an analysis of the MDS-CAN registry

Patients with lower-risk (LR) myelodysplastic syndromes (MDS) with ring sideroblasts (RS) have better prognosis than those without RS, but how they fare over time is not fully understood. This study's objective was to assess the natural history of LR MDS with RS ≥5% using MDS-CAN registry individual data. Kaplan-Meier estimates and generalized linear mixed models were used to describe time-to-event outcomes and continuous outcomes, respectively. One hundred and thirty-eight patients were enrolled; median times from diagnosis to enrollment and follow-up were 6.6 and 39.6 months, respectively. Within 5 years of enrollment, 65% of patients had ≥1 red blood cell transfusion dependence episode. Within 5 years of diagnosis, 59% developed iron overload, 38% received iron chelation therapy, 14% progressed to acute myeloid leukemia, and 42% died. Patients exhibited inferior health-related quality of life trends. These first real-world data in LR MDS-RS in Canada indicate a high level of morbidity and mortality over a 5-year period. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT02537990.

A machine learning model of response to hypomethylating agents in myelodysplastic syndromes

Hypomethylating agents (HMA) prolong survival and improve cytopenias in individuals with higher-risk myelodysplastic syndrome (MDS). Only 30-40% of patients, however, respond to HMAs, and responses may not occur for more than 6 months after HMA initiation. We developed a model to more rapidly assess HMA response by analyzing early changes in patients’ blood counts. Three institutions’ data were used to develop a model that assessed patients’ response to therapy 90 days after the initiation using serial blood counts. The model was developed with a training cohort of 424 patients from 2 institutions and validated on an independent cohort of 90 patients. The final model achieved an area under the receiver operating characteristic curve (AUROC) of 0.79 in the train/test group and 0.84 in the validation group. The model provides cohort-wide and individual-level explanations for model predictions, and model certainty can be interrogated to gauge the reliability of a given prediction.

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We developed a model to more rapidly assess patients’ response to hypomethylating agents

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The model’s predictions use exclusively routinely collected blood count data

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The model confirmed prior findings and identified potential new prognostic factors

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Model predictions are interpretable on both the individual and cohort-wide level

The impact of oral hypoglycemics and statins on outcomes in myelodysplastic syndromes

Observational studies suggest an anti-neoplastic effect associated with statins, metformin, and dipeptidyl peptidase-4 inhibitors (DPP4i), while sulfonylureas may have a neutral or detrimental effect. We linked the Ontario subset of a prospective Canadian myelodysplastic syndromes (MDS) registry with provincial administrative databases. We assessed the impact of statin/oral hypoglycemic medication exposure on overall survival (OS) using Cox regression analysis, controlling for comorbidities and sociodemographic factors. Five hundred thirty-three patients aged ≥ 66 years were included: 49.3% used statins, 18.9% used metformin, 9.0% used sulfonylureas, and 6.4% used DPP4i. Three hundred ninety-five patients were lower-risk based on the International Prognostic Scoring System. On univariate analysis, we identified a marginal improvement in OS in the lower-risk group using DPP4i (HR 0.98, 95% CI 0.95-1.00, P = 0.05), while there was no impact on mortality for higher-risk DPP4i users (HR 1.03, CI 0.99-1.07, P = 0.21). There was no mortality difference for statins (HR 1.00, CI 1.00-1.01, P = 0.93), metformin (HR 1.00, CI 0.99-1.01, P = 0.81), or sulfonylureas (HR 1.00, CI 0.99-1.02, P = 0.43) in the entire cohort, as well as when stratified into lower/higher-risk groups. On multivariable analysis in the lower-risk group, there was no association between DPP4i and OS (HR 0.98, CI 0.95-1.00, P = 0.06). Prospective studies with larger cohorts of patients and longer follow-up are required to further study the impact of DPP4i in MDS.

Genetic Factors Associated with Prostate Cancer Conversion from Active Surveillance to Treatment

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion (MAST3, p = 6.9×10-7 and GAB2, p = 2.0×10-6). Moreover, increasing values of a previously validated 269-variant genetic risk score (GRS) for PC was positively associated with conversion (e.g., comparing the highest to the two middle deciles gave a hazard ratio [HR] = 1.13; 95% Confidence Interval [CI]= 0.94-1.36); whereas, decreasing values of a 36-variant GRS for prostate-specific antigen (PSA) levels were positively associated with conversion (e.g., comparing the lowest to the two middle deciles gave a HR = 1.25; 95% CI, 1.04-1.50). These results suggest that germline genetics may help inform and individualize the decision of AS-or the intensity of monitoring on AS-versus treatment for the initial management of patients with low-risk PC.

Elective pelvic nodal irradiation with a simultaneous hypofractionated integrated prostate boost for localized high risk prostate cancer: Long term results from a prospective clinical trial

BACKGROUND

To report on long-term results of elective pelvic nodal irradiation (EPNI) and a simultaneous hypofractionated prostate boost for high-risk prostate cancer.

MATERIALS AND METHODS

This was a prospective single-arm study. Patients with high-risk disease (cT3, PSA >20 ng/mL, or Gleason score 8-10) were eligible. Patients received 45 Gy in 25 fractions to the prostate and pelvic lymph nodes with a simultaneous intensity-modulated radiotherapy boost of 22.5 Gy to the prostate (total dose 67.5 Gy in 25 fractions), with androgen deprivation therapy (ADT) for 2-3 years. The primary endpoint was biochemical failure. Secondary endpoints included distant metastases and overall survival. Multivariable analysis was performed to look for predictive factors. Late toxicity was assessed using CTCAE v3.0.

RESULTS

230 patients enrolled. Median follow-up was 11.2 years (IQR 8.1-12.9). At 10 years, cumulative incidence of biochemical failure was 33.4%, distant metastasis was 16.5%, and overall survival was 76.3%. On multivariable analysis, PSA nadir ≥0.05 ng/mL was associated with biochemical failure (HR 6.8, 95% CI 4-11.8, p < 0.001) and distant metastases (HR 7.5, 95% CI 3.9-14.5, p < 0.0001). PSA nadir ≥0.1 ng/mL (HR 5.2, 95% 2.2-12, p = 0.0001) and ADT use ≤12 months (versus >24 months) (HR 2.3, 95% CI 1.3-3.9, p = 0.004) were associated with worse survival. The 5-year cumulative incidence of any late grade ≥3 gastrointestinal and genitourinary toxicity was 2.3% and 7.5%, respectively.

CONCLUSION

EPNI and a simultaneous hypofractionated prostate boost combined with long-term ADT for high-risk prostate cancer resulted in acceptable 10-year biochemical control and survival with low grade ≥3 toxicity.

Using the Movember Foundation's GAP3 cohort to measure the effect of active surveillance on patient-reported urinary and sexual function-a retrospective study in low-risk prostate cancer patients

BACKGROUND

Active surveillance (AS) for low-risk prostate cancer (PCa) is intended to overcome potential side-effects of definitive treatment. Frequent prostate biopsies during AS may, however, impact erectile (EF) and urinary function (UF). The objective of this study was to test the influence of prostate biopsies on patient-reported EF and UF using multicenter data from the largest to-date AS-database.

METHODS

In this retrospective study, data analyses were performed using the Movember GAP3 database (v3.2), containing data from 21,169 AS participants from 27 AS-cohorts worldwide. Participants were included in the study if they had at least one follow-up prostate biopsy and completed at least one patient reported outcome measure (PROM) related to EF [Sexual Health Inventory for Men (SHIM)/five item International Index of Erectile Function (IIEF-5)] or UF [International Prostate Symptom Score (IPSS)] during follow-up. The longitudinal effect of the number of biopsies on either SHIM/IIEF-5 or IPSS were analyzed using linear mixed models to adjust for clustering at patient-level. Analyses were stratified by center; covariates included age and Gleason Grade group at diagnosis, and time on AS.

RESULTS

A total of 696 participants completed the SHIM/IIEF-5 3,175 times, with a median follow-up of 36 months [interquartile range (IQR) 20-55 months]. A total of 845 participants completed the IPSS 4,061 times, with a median follow-up of 35 months (IQR 19-56 months). The intraclass correlation (ICC) was 0.74 for the SHIM/IIEF-5 and 0.68 for the IPSS, indicating substantial differences between participants' PROMs. Limited heterogeneity between cohorts in the estimated effect of the number of biopsies on either PROM were observed. A significant association was observed between the number of biopsies and the SHIM/IIEF-5 score, but not for the IPSS score. Every biopsy was associated with a decrease in the SHIM/IIEF-5 score of an average 0.67 (95% CI, 0.47-0.88) points.

CONCLUSIONS

Repeated prostate biopsy as part of an AS protocol for men with low-risk PCa does not have a significant association with self-reported UF but does impact self-reported sexual function. Further research is, however, needed to understand whether the effect on sexual function implies a negative clinical impact on their quality of life and is meaningful from a patient's perspective. In the meantime, clinicians and patients should anticipate a potential decline in erectile function and hence consider incorporating the risk of this harm into their discussion about opting for AS and also when deciding on the stringency of follow-up biopsy schedules with long-term AS.

Patient-reported fatigue refines prognosis in higher-risk myelodysplastic syndromes (MDS): a MDS-CAN study

The incorporation of patient-reported outcomes with traditional disease risk classification was found to strengthen survival prediction in patients with myelodysplastic syndromes (MDS). In the present Canadian MDS registry analysis, we validate a recently reported prognostic model, the Fatigue-International Prognostic Scoring System among higher-risk patients [FA-IPSS(h)], which incorporates patients' reported fatigue, assessed by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life-Core 30 (QLQ-C30), with a threshold of ≥45 points, in higher IPSS score, stratifying them into distinct subgroups with different survival outcomes. We further validated this concept, using the Revised IPSS >3·5 as cut-off for the definition of higher-risk MDS, and patients' reported fatigue according to Edmonton Symptom Self-Assessment Scale (ESAS) Global Fatigue Scale (GFS), a single-item fatigue rating scale, which is easier to deploy. This emphasises the power of self-reported fatigue at refining overall survival predictions in higher-risk MDS and further bolsters the importance of considering patient-related outcomes in global assessments.

A first step towards a global nomogram to predict disease progression for men on active surveillance

BACKGROUND

Signs of disease progression (28%) and conversion to active treatment without evidence of disease progression (13%) are the main reasons for discontinuation of active surveillance (AS) in men with localised prostate cancer (PCa). We aimed to develop a nomogram to predict disease progression in these patients.

METHODS

As a first step in the development of a nomogram, using data from Movembers' GAP3 Consortium (n=14,380), we assessed heterogeneity between centres in terms of risk of disease progression. We started with assessment of baseline hazards for disease progression based on grouping of centres according to follow-up protocols [high: yearly; intermediate: ~2 yearly; and low: at year 1, 4 & 7 (i.e., PRIAS)]. We conducted cause-specific random effect Cox proportional hazards regression to estimate risk of disease progression by centre in each group.

RESULTS

Disease progression rates varied substantially between centres [median hazard ratio (MHR): 2.5]. After adjustment for various clinical factors (age, year of diagnosis, Gleason grade group, number of positive cores and PSA), substantial heterogeneity in disease progression remained between centres.

CONCLUSIONS

When combining worldwide data on AS, we noted unexplained differences of disease progression rate even after adjustment for various clinical factors. This suggests that when developing a global nomogram, local adjustments for differences in risk of disease progression and competing outcomes such as conversion to active treatment need to be considered.

Prostate high dose-rate brachytherapy as monotherapy for low and intermediate risk prostate cancer: Efficacy results from a randomized phase II clinical trial of one fraction of 19 Gy or two fractions of 13.5 Gy

BACKGROUND AND PURPOSE

High dose-rate (HDR) brachytherapy as monotherapy is a treatment option for localized prostate cancer, but optimal dose and fractionation is unknown. We report efficacy results of a randomized phase II trial of HDR monotherapy delivered as either one or two fractions.

MATERIALS AND METHODS

Eligible patients had low or intermediate risk prostate cancer, prostate volume <60 cc, and no androgen deprivation use. 170 patients were randomized to receive HDR as either a single fraction of 19 Gy or as two fractions of 13.5 Gy one week apart. Median age was 65 years, median PSA was 6.33 ng/ml, and Grade Group 1, 2 and 3 was present in 28%, 60%, and 12%, respectively. There was no difference in baseline factors between arms and 19%, 51% and 30% had low risk, favourable intermediate and unfavourable intermediate risk disease, respectively. The Phoenix definition was used to define biochemical failure, all local failures were confirmed by biopsy and toxicity was assessed using CTCAE v.4.

RESULTS

Median follow-up was 60 months. PSA decreased more quickly in the 2-fraction arm (p = 0.009). Median PSA at 5-years was 0.65 ng/ml in the single fraction and 0.16 ng/ml in the 2-fraction arm. The 5-year biochemical disease-free survival and cumulative incidence of local failure was 73.5% and 29% in the single fraction arm and 95% (p = 0.001) and 3% (p < 0.001) in the 2-fraction arm, respectively. Recurrence was not associated with initial stage, grade group, or risk group. Grade 2 late rectal toxicity occurred in 1% while the incidence of grade 2 and 3 urinary toxicity was 45% and 1%, respectively, with no difference between arms.

CONCLUSIONS

HDR monotherapy delivered as two fraction of 13.5 Gy is well tolerated with a high cancer control rate at 5 years. Single fraction monotherapy is inferior and should not be used.

An MDS-specific frailty index based on cumulative deficits adds independent prognostic information to clinical prognostic scoring

The frailty index (FI) is based on the principle that the more deficits an individual has, the greater their risk of adverse outcomes. It is expressed as a ratio of the number of deficits present to the total number of deficits considered. We developed an MDS-specific FI using a prospective MDS registry and assessed its ability to add prognostic power to conventional prognostic scores in MDS. The 42 deficits included in this FI included measurements of physical performance, comorbidities, laboratory values, instrumental activities of daily living, quality of life and performance status. Of 644 patients, 440 were eligible for FI calculation. The median FI score was 0.25 (range 0.05-0.67), correlated with age and IPSS/IPSS-R risk scores and discriminated overall survival. With a follow-up of 20 months, survival was 27 months (95% CI 24-30.4). By multivariate analysis, age >70, FI, transfusion dependence, and IPSS were significant covariates associated with OS. The incremental discrimination improvement of the frailty index was 37%. We derived a prognostic score with five risk groups and distinct survivals ranging from 7.4 months to not yet reached. If externally validated, the MDS-FI could be used as a tool to refine the risk stratification of current clinical prognostication models.

Prostate-specific Antigen Bounce After Stereotactic Body Radiotherapy for Prostate Cancer: A Pooled Analysis of Four Prospective Trials

AIMS

We conducted a pooled analysis of four prospective stereotactic body radiotherapy (SBRT) trials of low- and intermediate-risk prostate cancer to evaluate the incidence of prostate-specific antigen (PSA) bounce and its correlation with the time-dose-fraction schedule. The correlation between bounce with PSA response at 4 years (nadir PSA < 0.4 ng/ml) and biochemical failure-free survival (BFFS) was also explored.

MATERIALS AND METHODS

The study included four treatment groups: 35 Gy/five fractions once per week (QW) (TG-1; n = 84); 40 Gy/five fractions QW (TG-2; n = 100); 40 Gy/five fractions every other day (TG-3; n = 73); and 26 Gy/two fractions QW (TG-4; n = 30). PSA bounce was defined as a rise in PSA by 0.2 ng/ml (nadir + 0.2) or 2 ng/ml (nadir + 2.0) above nadir followed by a decrease back to nadir. Patients with fewer than three follow-up PSA tests were excluded from the pooled analysis.

RESULTS

In total, 287 patients were included, with a median follow-up of 5.0 years. The pooled 5-year cumulative incidence of bounce by nadir + 2.0 was 8%. The 2-year cumulative incidences of PSA bounce by nadir + 0.2 were 28.9, 21, 19.6 and 16.7% (P = 0.12) and by nadir + 2.0 were 7.2, 8, 2.7 and 6.7% (P = 0.32) for TG-1 to TG-4, respectively. Multivariable analysis revealed that for nadir + 2.0, pre-treatment PSA (odds ratio 0.49; 95% confidence interval 0.26-0.97) correlated with PSA bounce. Although PSA bounce by nadir + 0.2 (odds ratio 0.10; 95% confidence interval 0.04-0.24) and nadir + 2.0 (odds ratio 0.29; 95% confidence interval 0.09-0.93) was associated with a lower probability of PSA response at 4 years, there was no association between bounce by nadir + 0.2 (hazard ratio 0.36; 95% confidence interval 0.08-1.74) or nadir + 2 (hazard ratio 1.77; 95% confidence interval 0.28-11.07) with BFFS.

CONCLUSION

The incidence of PSA bounce was independent of time-dose-fraction schedule for prostate SBRT. One in 13 patients experienced a bounce high enough to be misinterpreted as biochemical failure, and clinicians should avoid early salvage interventions in these patients. There was no association between PSA bounce and BFFS.

5-Year Outcomes of a Prospective Phase 1/2 Study of Accelerated Hypofractionated Radiation Therapy to the Prostate Bed

PURPOSE

To report the 5-year outcomes from a single institution, prospective, phase 1/2 study on hypofractionated, accelerated radiation therapy to the prostate bed after radical prostatectomy.

METHODS AND MATERIALS

Patients enrolled in this study were all eligible for postoperative radiation therapy and received a prescribed dose of 51 Gy in 17 fractions to the prostate bed. On follow-up, gastrointestinal (GI) and genitourinary (GU) toxicity was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0; prostate-specific antigen (PSA) was evaluated and quality of life was assessed using the Expanded Prostate Cancer Index Composite (EPIC) questionnaire.

RESULTS

A total of 30 patients were enrolled between 2008 and 2011. Median age was 65 (52-75) years. Median pretreatment PSA was 0.12 ng/mL (0.01-1.42). Twenty-six (93%) patients had Gleason ≤7 disease, 13 (43%) had pT3 disease, and 20 (67%) had positive margins. Twenty-six patients (87%) underwent radiation therapy as salvage treatment. After a median follow-up of 6.4 (2.1-8.1) years, no patient experienced Common Terminology Criteria for Adverse Events grade 3/4 toxicity. Eleven patients (37%) had grade 2 genitourinary and 2 (7%) had grade 2 gastrointestinal toxicity. At baseline and 5 years after radiation therapy, mean EPIC urinary domain score was 80% (standard deviation, 18%) and 82% (17%). Mean EPIC bowel domain score was 93% (13%) and 93% (15%). One patient (4%) had a minimally clinically important change in urinary domain score and 1 patient (4%) had a minimally clinically important change in bowel domain score. Nelson-Aalen estimated cumulative incidence of biochemical failure was 31% (nadir +0.2) and 18% (nadir +2.0) at 5 years. Four-year PSA ≥0.4 was predictive of subsequent androgen deprivation therapy use (Nelson-Aalen cumulative incidence: 1.45; P < .0001). Five patients (17%) received hormonal therapy for biochemical failure. Nelson-Aalen estimated cumulative incidence of hormone therapy use was 14% at 5 years. All patients who received hormone therapy had PSA >0.4 at 4 years.

CONCLUSIONS

In this phase 1/2 study, hypofractionated postoperative radiation therapy seems to have good clinical efficacy without significant late toxicity. Phase 3 studies are warranted.

Consistent Biopsy Quality and Gleason Grading Within the Global Active Surveillance Global Action Plan 3 Initiative: A Prerequisite for Future Studies

Within the Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative, 25 centers across the globe collaborate to standardize active surveillance (AS) protocols for men with low-risk prostate cancer (PCa). A centralized PCa AS database, comprising data of more than 15000 patients worldwide, was created. Comparability of the histopathology between the different cohorts was assessed by a centralized pathology review of 445 biopsies from 15 GAP3 centers. Grade group 1 (Gleason score 6) in 85% and grade group ≥2 (Gleason score ≥7) in 15% showed 89% concordance at review with moderate agreement (κ=0.56). Average biopsy core length was similar among the analyzed cohorts. Recently established highly adverse pathologies, including cribriform and/or intraductal carcinoma, were observed in 3.6% of the reviewed biopsies. In conclusion, the centralized pathology review of 445 biopsies revealed comparable histopathology among the 15 GAP3 centers with a low frequency of high-risk features. This enables further data analyses-without correction-toward uniform global AS guidelines for men with low-risk PCa. PATIENT SUMMARY: Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative combines data from 15000 men with low-risk prostate cancer (PCa) across the globe to standardize active surveillance protocols. Histopathology review confirmed that the histopathology was consistent with low-risk PCa in most men and comparable between different centers.

Two StereoTactic ablative radiotherapy treatments for localized prostate cancer (2STAR): Results from a prospective clinical trial

PURPOSE

Ultrahypofractionation is appealing for prostate cancer (PCa) due to low α/β, and increasing the dose per fraction could improve the therapeutic index. Here we report the outcomes of a phase II prostate SABR trial using two fractions.

METHODS

Patients had low or intermediate risk prostate cancer. Three gold fiducials were implanted for image guidance. The clinical target volume (CTV) included the prostate only, and the planning target volume (PTV) was a 3 mm expansion enabled through the use of a rectal immobilization device. The dose prescribed was 26 Gy in 2 weekly fractions (EQD2 110 Gy_1.4). The primary endpoint was quality of life using EPIC, and minimal clinically important change (MCIC) was defined as an EPIC QOL decrease >0.5 SD.

RESULTS

30 patients were accrued with a median follow-up of 49.3 months. 10% had low-risk, 33% had favourable intermediate-risk and 57% had unfavourable intermediate-risk PCa. Five patients received a short course of ADT. Median nPSA was 0.2 ng/ml. One patient had BF and is being observed. 56.6% of patients had a 4yPSARR. Six (20.7%) patients had a MCIC in the urinary domain, 6 (21.4%) had a MCIC in the bowel domain, and 3 (20%) had a MCIC in the sexual domain.

CONCLUSIONS

Two-fraction SABR in prostate cancer is safe and feasible, with a minimal change in QOL and a low rate of late grade 3-4 toxicity. The PSA kinetics and biochemical control rates are encouraging given that the majority had unfavourable intermediate-risk disease, although longer follow-up is required.

Impact of compliance on outcomes for patients on active surveillance for prostate cancer

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Background: Active surveillance (AS) is the standard of care for low-risk prostate cancer to reduce the risk of overtreatment. However, the impact of compliance to AS on outcomes has not been well described. We hypothesized that compliance to an AS protocol and to the recommendation for active treatment would affect subsequent treatment failure. Methods: A prospective, single-arm cohort study was initiated in 1995 to assess an AS program. Triggers for intervention included a PSA doubling time of less than three years and histologic upgrade. The AS protocol was defined as PSA measurements every three months for two years and then twice annually, as well as a confirmatory biopsy within 12 months and then every three years. Compliance to the AS protocol was defined as four PSA tests and a confirmatory biopsy by 1.5 years after enrollment. Compliance to treatment was defined as the initiation of any active therapy within 12 months from the time of any trigger described above. Treatment failure was defined as a PSA > 0.2 after surgery, PSA > nadir + 2 for other treatments, or the development of metastases. Statistics were performed using logistic regression analysis and the Fisher exact test. Results: A total of 1282 patients were included in the final analysis, of which 460 received treatment. Median follow up was 7.1 years. The actuarial rate of biochemical control at five and 10 years amongst treated patients was 78% and 59% respectively. The rates of compliance to biopsy at years one, four and seven were 71%, 36% and 13%. The treatment failure rate was lower for patients compliant to the AS protocol (crude rate 28%) than those non-compliant (crude rate 38%) with an odds ratio of 0.64 (95% CI 0.43-0.94, p = 0.03). Patients compliant to the protocol were also less likely to develop metastases (OR 0.42, 95% CI 0.21-0.88, p = 0.02). There was no impact on treatment failure by adherence to active therapy within 12 months (p = 0.25) after reaching a trigger to come off AS. Conclusions: Non-compliance to an AS protocol leads to a higher risk of subsequent treatment failure and development of metastases. Physicians and patients need to work together diligently to ensure enrollment on an AS program is followed by adherence to regular PSA checks and repeat biopsies.

Hypofractionated, accelerated radiotherapy to the prostate bed: Five-year outcomes of a prospective phase I/II study

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Background: There have been few studies to date that examine the role of hypofractionated radiotherapy for prostate cancer in the post-operative setting. This study reports on the 5-year outcomes from a single institution, prospective, phase I/II study on hypofractionated prostate bed radiotherapy. Methods: Patients enrolled in this study were all eligible for post-operative radiotherapy and received a prescribed dose of 51Gy in 17 fractions to the prostate bed. On subsequent follow-up, GI/GU toxicity was assessed using the NCI CTCAE v3.0, PSA was evaluated and quality-of-life was assessed using the EPIC questionnaire. Results: A total of 30 patients were enrolled between 2008 and 2011. Median age was 65 [52-75] years. Median pre-treatment PSA was 0.12 ng/ml [0.01-1.42]. Twenty-four (86%) patients had Gleason 7 disease, 13 (43%) had pT3 disease and 20 (67%) had positive margins. Twenty-six (87%) patients underwent radiotherapy as salvage treatment. No patient experienced CTCAE grade 3/4 toxicity. Two (7%) patients experienced at least one CTCAE grade 2 late GI toxicity and 11 (37%) had at least one late grade 2 GU toxicity. At baseline and 5 years post radiotherapy, mean EPIC urinary domain score were 80 (SD: 18) and 82 (17). Mean EPIC bowel domain score were 93 (13) and 93 (15). One (4%) patient had a minimally clinically important change (MCIC) in urinary domain score and 1 (4%) patient had a MCIC in bowel domain score. Nelson-Aalen estimated cumulative incidence of biochemical failure were 31% (nadir+0.2) and 18% (nadir+2.0) at 5 years. Four-year PSA ≥0.4 was highly predictive of subsequent rise to nadir+2.0 at 5 years (Nelson-Aalen cumulative hazard: 1.45; standard error: 0.701; p < 0.0001). Five (17%) patients received hormonal therapy for biochemical failure. Nelson-Aalen estimated cumulative incidence of hormone therapy use was 14% at 5 years. Conclusions: In this phase I/II study, hypofractionated post-operative radiotherapy appears to have good clinical efficacy without significant late toxicity. Phase III studies are warranted. Clinical trial information: 042-2009.

Dose escalation for prostate stereotactic ablative radiotherapy (SABR): Late outcomes from two prospective clinical trials

PURPOSE

Optimal prostate SABR dose-fractionation is unknown. This study compares long-term outcomes from two prospective trials.

METHODS

Study1 patients had low-risk PCa and received 35 Gy/5. Study2 patients had low/intermediate-risk PCa and received 40 Gy/5. Biochemical failure (BF) was defined as nadir + 2.

RESULTS

114 patients were included (study1, n = 84; study2, n = 30). Median follow-up was 9.6 years and 6.9 years. Median nPSA was 0.4 and 0.1 ng/ml. Nine patients had BF (8 in study1, 1 in study2); two were managed with ADT and four had local salvage. The BF rate was 2.5% and 12.8% at 5 and 10 years for study1 and 3.3% at 5 years for study 2. BF probability was 0% if PSA <0.4 at 4 years, and 20.5% at 10 years if PSA ≥0.4 (p = 0.02). Nine patients died, none of PCa. No patient has metastases or castrate-resistance. At 10 years, OS and CSS were 90.4% (p = 0.25) and 100%.

CONCLUSIONS

Dose-escalated prostate SABR was associated with lower nPSAs but no difference in BF, OS, CSS or MFS. PSA <0.4 at 4 years was a predictor of biochemical control. Half of patients with BF were successfully salvaged. Given that this is a favorable-risk cohort, longer follow-up will be needed to see if the lower nPSA translates into lower BF rates.

Once-weekly versus every-other-day stereotactic body radiotherapy in patients with prostate cancer (PATRIOT): A phase 2 randomized trial

BACKGROUND AND PURPOSE

Prostate stereotactic body radiotherapy (SBRT) regimens differ in time, dose, and fractionation. We completed a multicentre, randomized phase II study to investigate the impact of overall treatment time on quality of life (QOL).

MATERIAL AND METHODS

Men with low and intermediate-risk prostate cancer were randomly assigned to 40 Gy in 5 fractions delivered once per week (QW) vs. every other day (EOD). QOL was assessed using the Expanded Prostate Cancer Index Composite. The primary endpoint was the proportion with a minimum clinically important change (MCIC) in bowel QOL during the acute (≤12 week) period, and analysis was by intention-to-treat. ClinicalTrials.gov NCT01423474.

RESULTS

152 men from 3 centres were randomized with median follow-up of 47 months. Patients treated QW had superior acute bowel QOL with 47/69 (68%) reporting a MCIC compared to 63/70 (90%) treated EOD (p = 0.002). Fewer patients treated QW reported moderate-severe problems with bowel QOL during the acute period compared with EOD (14/70 [20%] vs. 40/70 [57%], p < 0.001). Acute urinary QOL was also better in the QW arm, with 52/67 (78%) vs 65/69 (94%) experiencing a MCIC (p = 0.006). There were no significant differences in late urinary or bowel QOL at 2 years or last follow-up.

CONCLUSION

Prostate SBRT delivered QW improved acute bowel and urinary QOL compared to EOD. Patients should be counselled regarding the potential for reduced short-term toxicity and improved QOL with QW prostate SBRT.

Comparative Analysis of Biopsy Upgrading in Four Prostate Cancer Active Surveillance Cohorts

BACKGROUND

Active surveillance (AS) is increasingly accepted for managing low-risk prostate cancer, yet there is no consensus about implementation. This lack of consensus is due in part to uncertainty about risks for disease progression, which have not been systematically compared or integrated across AS studies with variable surveillance protocols and dropout to active treatment.

OBJECTIVE

To compare risks for upgrading from a Gleason score (GS) of 6 or less to 7 or more across AS studies after accounting for differences in surveillance intervals and competing treatments and to evaluate tradeoffs of more versus less frequent biopsies.

DESIGN

Joint statistical model of longitudinal prostate-specific antigen (PSA) levels and risks for biopsy upgrading.

SETTING

Johns Hopkins University (JHU); Canary Prostate Active Surveillance Study (PASS); University of California, San Francisco (UCSF); and University of Toronto (UT) AS studies.

PATIENTS

2576 men aged 40 to 80 years with a GS between 2 and 6 and clinical stage T1 or T2 prostate cancer enrolled between 1995 and 2014.

MEASUREMENTS

PSA levels and biopsy GSs.

RESULTS

After variable surveillance intervals and competing treatments were accounted for, estimated risks for biopsy upgrading were similar in the PASS and UT studies but higher in UCSF and lower in JHU studies. All cohorts had a delay of 3 to 5 months in detecting upgrading with biennial biopsies starting after a first confirmatory biopsy versus annual biopsies.

LIMITATION

The model does not account for possible misclassification of biopsy GS.

CONCLUSION

Men in different AS studies have different risks for biopsy upgrading after variable surveillance protocols and competing treatments are accounted for. Despite these differences, the consequences of more versus less frequent biopsies seem to be similar across cohorts. Biennial biopsies seem to be an acceptable alternative to annual biopsies.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Overall survival in lower IPSS risk MDS by receipt of iron chelation therapy, adjusting for patient-related factors and measuring from time of first red blood cell transfusion dependence: an MDS-CAN analysis

Analyses suggest iron overload in red blood cell (RBC) transfusion-dependent (TD) patients with myleodysplastic syndrome (MDS) portends inferior overall survival (OS) that is attenuated by iron chelation therapy (ICT) but may be biassed by unbalanced patient-related factors. The Canadian MDS Registry prospectively measures frailty, comorbidity and disability. We analysed OS by receipt of ICT, adjusting for these patient-related factors. TD International Prognostic Scoring System (IPSS) low and intermediate-1 risk MDS, at RBC TD, were included. Predictive factors for OS were determined. A matched pair analysis considering age, revised IPSS, TD severity, time from MDS diagnosis to TD, and receipt of disease-modifying agents was conducted. Of 239 patients, 83 received ICT; frailty, comorbidity and disability did not differ from non-ICT patients. Median OS from TD was superior in ICT patients (5·2 vs. 2·1 years; P < 0·0001). By multivariate analysis, not receiving ICT independently predicted inferior OS, (hazard ratio for death 2·0, P = 0·03). In matched pair analysis, OS remained superior for ICT patients (P = 0·02). In this prospective, non-randomized analysis, receiving ICT was associated with superior OS in lower IPSS risk MDS, adjusting for age, frailty, comorbidity, disability, revised IPSS, TD severity, time to TD and receiving disease-modifying agents. This provides additional evidence that ICT may confer clinical benefit.

Stereotactic ablative radiotherapy in the treatment of low and intermediate risk prostate cancer: Is there an optimal dose?

PURPOSE

To investigate if stereotactic ablative radiotherapy (SABR) dose is associated with PSA at 3years (PSA_3y) in the treatment of localized prostate cancer and to explore predictors of late genitourinary (GU) toxicity.

MATERIALS AND METHODS

Three prospective trials of SABR were undertaken at our institution: 1) 35Gy/5 fractions/29days; 2) 40Gy/5 fractions/29days; 3) 40Gy/5 fractions/11 or 29days. PSA_3y was analyzed as a continuous variable. Toxicity was defined as the worst new toxicity and assessed using the radiation therapy oncology group (RTOG) late morbidity scheme. Univariate and multivariable regression analyses were conducted to assess the association between dose and PSA_3y, and to explore predictors of late grade 2+ GU toxicity.

RESULTS

Median PSA3y was 0.64 (intraquartile range (IQR): 0.41-1.12) and 0.27 (IQR: 0.12-0.55) ng/mL for patients treated with 35 and 40Gy respectively. A dose of 40Gy was an independent predictor of lower PSA_3y on multivariable analysis (p<0.001). Dose of 40Gy (odds ratio (OR): 16.69, 95%CI: 5.78, 48.20, p<0.001) and higher International Prostate Symptom Score (OR: 1.01, 95%CI: 1.04, 1.16, p=0.001) predicted for late grade 2+ GU toxicity on multivariable logistic regression.

CONCLUSIONS

This analysis suggests that higher SABR dose is associated with lower PSA_3y. Strategies to allow safe SABR dose escalation should be further investigated.

Pelvic SABR with HDR boost in intermediate- and high-risk prostate cancer (SPARE): Favorable early toxicity and quality-of-life outcomes

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Background: ASCENDE-RT has provided level 1 evidence supporting the use of androgen deprivation therapy (ADT), external beam radiotherapy and brachytherapy boost in intermediate- and high-risk prostate cancer. The objectives of this study are to report early toxicity and quality of life (QOL) outcomes in patients treated on a hybrid protocol using five-fraction pelvic stereotactic ablative radiotherapy (SABR) with a MRI dose painted HDR brachytherapy boost (HDR-BT). Methods: A phase I/II study was performed where intermediate (IR) and high-risk (HR) prostate cancer patients received HDR-BT 15Gy in single fraction to the prostate and up to 22.5Gy to the MRI nodule. Gantry-based 25Gy SABR was delivered to pelvis, seminal vesicles and prostate in 5 weekly fractions. ADT was used for 6-18 months. Common Terminology Criteria for Adverse Events version 3.0 was used to assess toxicities. QOL was captured using EPIC at every follow-up. A minimally clinically important change (MCIC) definition was triggered if the EPIC QOL score at each time point decreases > 0.5 SD, where SD is the standard deviation of baseline scores. Results: Thirty-three patients (NCCN 6.0% low IR, 45.5% high IR and 48.5% HR) completed this treatment with a median follow-up of 13.8 months (IQR 12.1, 18.8). The incidence of worst toxicities is shown in Table 1.The 3 grade 3 GU patients were due to temporary urinary catheterization in the acute period following HDR-BT. Mean (95% SD) EPIC urinary QOL scores were 82.5 (16.5), 83.2 (12.9) and 83.7 (16.3) at baseline, 3 months and 12 months and the bowel scores were 95.9 (3.8), 92.6 (8.2) and 90.5 (8.3), respectively. Proportion of patients experiencing MCIC at 3 months and 12 months were 20.8% and 14.3% for urinary domain, 47.8% and 53.9% for bowel domain; respectively (see Table). Conclusions: This novel treatment protocol incorporating MRI dose painted HDR brachytherapy boost and SABR pelvic radiation for intermediate- and high-risk prostate cancer in combination with ADT is feasible and well tolerated in the acute setting. Clinical trial information: REB 269-2014. [Table: see text]

Dose-Escalated Stereotactic Body Radiation Therapy for Prostate Cancer: Quality-of-Life Comparison of Two Prospective Trials

Introduction

The optimal prostate stereotactic body radiation therapy (SBRT) dose-fractionation scheme is controversial. This study compares long-term quality of life (QOL) from two prospective trials of prostate SBRT to investigate the effect of increasing dose (NCT01578902 and NCT01146340).

Material and methods

Patients with localized prostate cancer received SBRT 35 or 40 Gy delivered in five fractions, once per week. QOL was measured using the Expanded Prostate Cancer Index Composite at baseline and every 6 months. Fisher’s exact test and generalized estimating equations were used to analyze proportions of patients with clinically significant change and longitudinal changes in QOL.

Results

One hundred fourteen patients were included, 84 treated with 35 Gy and 30 treated with 40 Gy. Median QOL follow-up was 56 months [interquartile range (IQR) 46–60] and 38 months (IQR 32–42), respectively. The proportion of patients reporting clinically significant declines in average urinary, bowel, and sexual scores were not significantly different between dose levels, and were 20.5 vs. 24.1% (p = 0.60), 26.8 vs. 41.4% (p = 0.16), and 42.9 vs. 38.5% (p = 0.82), respectively. Similarly, longitudinal analysis did not identify significant differences in QOL between treatment groups.

Conclusion

Dose-escalated prostate SBRT from 35 to 40 Gy in five fractions was not associated with significant decline in long-term QOL.