[Drastic changes in the treatment of metastatic prostate cancer]. / Behandling av metastaserad prostatacancer.

The treatment of metastatic prostate  cancer has seen drastic changes in the recent years with more intense treatment at initial diagnose. The new standard is combination therapy with castration as the backbone and the addition of new hormonal therapies with or without chemotherapy. For patients with minimal metastatic spread it is also recommended to give radiotherapy to the primary tumour. Since many patients now can look forward to longer survival it is paramount to take care of the side-effects of the treatments, where focus is on cardiovascular disease and bone health management. Precision medicine has started also in prostate cancer; testing of BRCA1/2 mutation is mandatory for treatment with PARP inhibitors.

Socioeconomic inequality in prostate cancer diagnostics, primary treatment, rehabilitation, and mortality in Sweden.

We designed a nationwide study to investigate the association between socioeconomic factors (household income and education) and different aspects of prostate cancer care, considering both individual- and neighbourhood-level variables. Data were obtained from Prostate Cancer data Base Sweden (PCBaSe), a research database with data from several national health care registers including clinical characteristics and treatments for nearly all men diagnosed with prostate cancer in Sweden. Four outcomes were analysed: use of pre-biopsy magnetic resonance imaging (MRI) in 2018-2020 (n = 11,843), primary treatment of high-risk non-metastatic disease in 2016-2020 (n = 6633), rehabilitation (≥2 dispensed prescriptions for erectile dysfunction within 1 year from surgery in 2016-2020, n = 6505), and prostate cancer death in 7770 men with high-risk non-metastatic disease diagnosed in 2010-2016. Unadjusted and adjusted odds and hazard ratios (OR/HRs) with 95% confidence intervals (CIs) were calculated. Adjusted odds ratio (ORs) comparing low versus high individual education were 0.74 (95% CI 0.66-0.83) for pre-biopsy MRI, 0.66 (0.54-0.81) for primary treatment, and 0.82 (0.69-0.97) for rehabilitation. HR gradients for prostate cancer death were significant on unadjusted analysis only (low vs. high individual education HR 1.41, 95% CI 1.17-1.70); co-variate adjustments markedly attenuated the gradients (low vs. high individual education HR 1.10, 95% CI 0.90-1.35). Generally, neighbourhood-level analyses showed weaker gradients over the socioeconomic strata, except for pre-biopsy MRI. Socioeconomic factors influenced how men were diagnosed with prostate cancer in Sweden but had less influence on subsequent specialist care. Neighbourhood-level socioeconomic data are more useful for evaluating inequality in diagnostics than in later specialist care.

Uptake of doublet therapy for de novo metastatic castration sensitive prostate cancer: a population-based drug utilisation study in Sweden.

BACKGROUND: Randomised controlled trials have demonstrated prolonged survival with new upfront treatments in addition to standard androgen deprivation therapy (ADT) in men with de novo metastatic castration-sensitive prostate cancer. We describe patient characteristics, time trends and regional differences in uptake of these new treatment strategies in clinical practice. MATERIAL AND METHODS: This descriptive study consisted of men registered in the National Prostate Cancer Register of Sweden from 1 January 2018 to 31 March 2022 with de novo metastatic castration-sensitive prostate cancer defined by the presence of metastases on imaging at the time of diagnosis. Life expectancy was calculated based on age, Charlson Comorbidity Index and a Drug Comorbidity Index. RESULTS: Within 6 months from diagnosis, 57% (1,677/2,959) of men with de novo metastatic castration-sensitive prostate cancer and more than 3 years of life expectancy had received docetaxel, abiraterone, enzalutamide, apalutamide and/or radiotherapy. Over time, there was a 2-fold increase in uptake of any added treatment, mainly driven by a 6-fold increase in use of abiraterone, enzalutamide or apalutamide, with little change in use of other treatments. CONCLUSIONS: Slightly more than half of men diagnosed with de novo metastatic castration-sensitive prostate cancer and a life expectancy of at least 3 years received additions to standard ADT as recommended by national guidelines in 2019-2022 in Sweden. There was a 2-fold increase in use of these treatments during the study period; however, efforts to further increase adherence to guidelines are warranted.

Ki67 and prostate specific antigen are prognostic in metastatic hormone naïve prostate cancer.

BACKGROUND: For metastatic hormone naïve prostate cancer patients, androgen deprivation therapy (ADT) with escalation therapy including docetaxel and/or androgen targeting drugs is the standard therapy. However, de-escalation is preferable to avoid unnecessary side effects, especially from docetaxel, but markers to identify these patients are lacking. The purpose of the present study was to investigate the potential of PSA and Ki67 immunoreactive scores as prognostic and treatment-predictive markers. MATERIAL AND METHODS: Prostate biopsies from 92 patients with metastatic hormone naïve PC (PSA > 80 ng/mL or clinical metastases) were immunohistochemically evaluated for PSA and Ki67. Gene expression analysis was performed with Clariom D microarrays to identify the phenotypic profile associated with the immunohistochemistry scores of biopsies. Cox regression analysis for progression free survival after ADT adjustment for age, ISUP, and serum PSA and Kaplan-Meier analyses were performed to assess prognostic values of Ki67, PSA, and the Ki67/PSA ratio. RESULTS: The immunohistochemical score for PSA was the strongest prognostic factor for progression-free and overall survival after ADT. Consequently, the ratio between Ki67 and PSA displayed a stronger prognostic value than Ki67 itself. Further, mRNA expression data analysis showed an association between high Ki67/PSA ratio, cell-cycle regulation, and DNA damage repair. In an exploratory sub-analysis of 12 patients treated with early docetaxel as addition to ADT and matched controls, a high Ki67/PSA ratio showed potential to identify those who benefit from docetaxel. CONCLUSION: PSA and Ki67 immunoreactive scores are prognostic in the metastatic hormone-sensitive setting, with PSA being superior. The combination of Ki67 and PSA did not give additional prognostic value. The results suggest immunohistochemical scoring of PSA to have potential to improve identification of patients responding well to ADT alone.

Histopathology-validated lesion detection rates of clinically significant prostate cancer with mpMRI, [ 68 Ga]PSMA-11-PET and [ 11 C]Acetate-PET.

OBJECTIVE: PET/CT and multiparametric MRI (mpMRI) are important diagnostic tools in clinically significant prostate cancer (csPC). The aim of this study was to compare csPC detection rates with [ 68 Ga]PSMA-11-PET (PSMA)-PET, [ 11 C]Acetate (ACE)-PET, and mpMRI with histopathology as reference, to identify the most suitable imaging modalities for subsequent hybrid imaging. An additional aim was to compare inter-reader variability to assess reproducibility. METHODS: During 2016-2019, all study participants were examined with PSMA-PET/mpMRI and ACE-PET/CT prior to radical prostatectomy. PSMA-PET, ACE-PET and mpMRI were evaluated separately by two observers, and were compared with histopathology-defined csPC. Statistical analyses included two-sided McNemar test and index of specific agreement. RESULTS: Fifty-five study participants were included, with 130 histopathological intraprostatic lesions >0.05 cc. Of these, 32% (42/130) were classified as csPC with ISUP grade ≥2 and volume >0.5 cc. PSMA-PET and mpMRI showed no difference in performance ( P  = 0.48), with mean csPC detection rate of 70% (29.5/42) and 74% (31/42), respectively, while with ACE-PET the mean csPC detection rate was 37% (15.5/42). Interobserver agreement was higher with PSMA-PET compared to mpMRI [79% (26/33) vs 67% (24/38)]. Including all detected lesions from each pair of observers, the detection rate increased to 90% (38/42) with mpMRI, and 79% (33/42) with PSMA-PET. CONCLUSION: PSMA-PET and mpMRI showed high csPC detection rates and superior performance compared to ACE-PET. The interobserver agreement indicates higher reproducibility with PSMA-PET. The combined result of all observers in both PSMA-PET and mpMRI showed the highest detection rate, suggesting an added value of a hybrid imaging approach.

A randomised, double-blind, dose-finding, phase II multicentre study of ODX in the treatment of patients with castration-resistant prostate cancer and skeletal metastases.

AIMS: This study aimed to assess the efficacy and safety of ODX, a novel, cytotoxic, bone-targeting drug candidate, in castration-resistant prostate cancer bone metastatic disease. METHODS: Patients with progressive disease were randomised to ten cycles of ODX, intravenous infusion Q2W (3, 6, and 9 mg/kg, respectively). The primary objective was to assess the relative change from baseline in bone alkaline phosphatase (B-ALP) and serum-aminoterminal-propeptide of Type I procollagen (S-P1NP) at 12 weeks. The inclusion criteria selected were broad, and a double-blind design was used to ensure objective recruitment of patients for the assessment of efficacy. None of the patients received bone-protecting agents during the ODX treatment period. RESULTS: Fifty-five 21,20 and 14) patients were randomised to ODX (3, 6 and 9 mg/kg), respectively. The lower number of patients in arm 3 was due to too low a recruitment rate towards the end of the study. The median treatment time were 14, 13 and 14 weeks, respectively. The decrease in B-ALP at 12 weeks in study arms 3, 6 and 9 mg/kg was seen in 6/15 (40%), 8/12 (67%) and 5/12 (42%) patients, respectively, whereas the corresponding numbers for P1NP were 8/15 (53%), 8/12 (67%), and 4/12 (33%), respectively. The median decrease in B-ALP and P1NP at 12 weeks for study arms 3, 6 and 9 mg/kg were 37%, 14% and 43%, respectively, and 51%, 40% and 64%, respectively. The decrease in serum C-terminal telopeptide at 12 weeks was seen in the vast majority of patients and in about one-third of patients in bone scan index. ODX was well tolerated, and no drug-related serious adverse events occurred. There were no significant differences between study arms regarding efficacy and safety. CONCLUSIONS: ODX was well tolerated and demonstrated inhibitory effects on markers related to the vicious cycle in bone at all three doses. The reduction in metastatic burden, assessed with bone scan index, supports this finding. Studies with continued ODX treatment until disease progression are being planned (ClinicalTrials.gov Identifier: NCT02825628).

Hyaluronic acid spacer in prostate cancer radiotherapy: dosimetric effects, spacer stability and long-term toxicity and PRO in a phase II study.

BACKGROUND: Perirectal spacers may be beneficial to reduce rectal side effects from radiotherapy (RT). Here, we present the impact of a hyaluronic acid (HA) perirectal spacer on rectal dose as well as spacer stability, long-term gastrointestinal (GI) and genitourinary (GU) toxicity and patient-reported outcome (PRO). METHODS: In this phase II study 81 patients with low- and intermediate-risk prostate cancer received transrectal injections with HA before external beam RT (78 Gy in 39 fractions). The HA spacer was evaluated with MRI four times; before (MR0) and after HA-injection (MR1), at the middle (MR2) and at the end (MR3) of RT. GI and GU toxicity was assessed by physician for up to five years according to the RTOG scale. PROs were collected using the Swedish National Prostate Cancer Registry and Prostate cancer symptom scale questionnaires. RESULTS: There was a significant reduction in rectal V70% (54.6 Gy) and V90% (70.2 Gy) between MR0 and MR1, as well as between MR0 to MR2 and MR3. From MR1 to MR2/MR3, HA thickness decreased with 28%/32% and CTV-rectum space with 19%/17% in the middle level. The cumulative late grade ≥ 2 GI toxicity at 5 years was 5% and the proportion of PRO moderate or severe overall bowel problems at 5 years follow-up was 12%. Cumulative late grade ≥ 2 GU toxicity at 5 years was 12% and moderate or severe overall urinary problems at 5 years were 10%. CONCLUSION: We show that the HA spacer reduced rectal dose and long-term toxicity.

The Swedish national guidelines on prostate cancer, part 1: early detection, diagnostics, staging, patient support and primary management of non-metastatic disease.

OBJECTIVE: There is now an unprecedented amount of evidence to consider when revising prostate cancer guidelines. We believe that there is a value in publishing summaries of national clinical guidelines in English for others to read and comment on. METHODS: This is part 1 of a summary of the Swedish prostate cancer guidelines that were published in June 2022. It covers the early detection, diagnostics, staging, patient support and management of the non-metastatic disease. Part 2 covers recurrence after local treatment and management of the metastatic disease. RESULTS: The 2022 Swedish guidelines include several new recommendations: rectal iodine-povidone to reduce post-biopsy infections, external beam radiation with focal boost to the tumour, use of a pre-rectal spacer to reduce rectal side effects after external beam radiotherapy in some expert centres, 6 months' concomitant and adjuvant rather than neoadjuvant and concomitant hormonal treatment together with radiotherapy for unfavourable intermediate and high-risk disease, and adjuvant abiraterone plus prednisolone together with a GnRH agonist for a subgroup of men with very high-risk disease. The Swedish guidelines differ from the European by having more restrictive recommendations regarding genetic testing and pelvic lymph node dissection, the risk group classification, recommending ultra-hypofractionated (7 fractions) external radiotherapy for intermediate and selected high-risk cancers, by not recommending any hormonal treatment together with radiotherapy for favourable intermediate-risk disease, and by recommending bicalutamide monotherapy instead of a GnRH agonist for some patient groups. CONCLUSIONS: The 2022 Swedish prostate cancer guidelines include several new recommendations and some that differ from the European guidelines.

Characteristics of Patients in SPCG-15-A Randomized Trial Comparing Radical Prostatectomy with Primary Radiotherapy plus Androgen Deprivation Therapy in Men with Locally Advanced Prostate Cancer.

Background: There is no high-grade evidence for surgery as primary treatment for locally advanced prostate cancer. The SPCG-15 study is the first randomized trial comparing surgical treatment with radiotherapy. Objective: To describe the baseline characteristics of the first 600 randomized men in the SPCG-15 study. The study will compare mortality and functional outcomes. Design setting and participants: This study is a Scandinavian prospective, open, multicenter phase III randomized clinical trial aiming to randomize 1200 men. Intervention: Radical prostatectomy with or without consecutive radiotherapy (experimental) and radiotherapy with neoadjuvant androgen deprivation therapy (standard of care). Outcome measurements and statistical analysis: Cause-specific survival, metastasis-free survival, overall survival, and patient-reported bowel function, sexual health, and lower urinary tract symptoms were measured. Results and limitations: The distribution of characteristics was similar in the two study arms. The median age was 67 yr (range 45-75 yr). Among the operated men, 36% had pT3a stage of disease and 39% had pT3b stage. International Society of Urological Pathology grades 2, 3, 4, and 5 were prevalent in 21%, 35%, 7%, and 27%, respectively. Half of the men (51%) in the surgery arm had no positive lymph nodes. The main limitation is the pragmatic design comparing the best available practice at each study site leading to heterogeneity of treatment regimens within the study arms. Conclusions: We have proved that randomization between surgery and radiotherapy for locally advanced prostate cancer is feasible. The characteristics of the study population demonstrate a high prevalence of advanced disease, well-balanced comparison groups, and a demography mirroring the Scandinavian population of men with prostate cancer at large. Patient summary: This study, which has recruited >600 men, compares radiotherapy with surgery for prostate cancer, and an analysis at the time of randomization indicates that the study will be informative and generalizable to most men with locally advanced but not metastasized prostate cancer.

Risk of severe late toxicity after radiotherapy following radical prostatectomy - a nationwide study.

OBJECTIVE: To estimate the long-term risks of severe late toxicities for radiation therapy (RT) following radical prostatectomy (RP) in an unselected nationwide cohort, as severe side-effects are rare but may occur years later. PATIENTS AND METHODS: The study population comprised all men undergoing RP between 1997 and 2016 in the Prostate Cancer database Sweden (PCBaSe) (n = 40 962). By (1:2) matching, two cohorts were created: 2789 men exposed to postoperative RT and 5578 unexposed men with comparable age, comorbidities, and year of surgery. Cumulative incidences and rate ratios were calculated for the following outcomes: symptoms and interventions of the urinary or intestinal tract demanding inpatient care, secondary malignancies, and non-prostate cancer mortality. RESULTS: The largest differences were seen for late toxicities affecting the urinary tract. The 10-year cumulative incidences among those exposed to postoperative RT vs the RP-only group were: 17.8% vs 10.5% for procedures of the urinary tract (difference 7.3%, 95% confidence interval [CI] 4.4 to 10.3; relative risk [RR] 1.74, 95% CI 1.47 to 2.05); 6.0% vs 1.2% for haematuria (difference 4.8%, 95% CI 3.1 to 6.5; RR 6.50, 95% CI 4.31 to 10.10); and 2.4% vs 1.1% for bladder cancer (difference 1.4%, 95% CI 0.4 to 2.3; RR 2.71, 95% CI 1.72 to 4.33). The groups were similar regarding intestinal toxicity, other secondary malignancies, and non-prostate cancer mortality. Adjustments for preoperative tumour risk factors did not importantly affect the rate ratios. CONCLUSION: Severe late toxicity after postoperative RT following RP predominately affects the bladder and can appear many years after RT.

Health-related Quality of Life in Intermediate- or High-risk Patients Treated With Radical External Radiotherapy and Adjuvant Docetaxel for Localized Prostate Cancer: A Randomized, Phase III SPCG-13 Study.

BACKGROUND/AIM: The goal of this study was to investigate whether health-related quality of life (HRQoL) was affected in patients with high- or intermediate-risk localized prostate cancer treated with docetaxel following radiation therapy (RT). PATIENTS AND METHODS: A total of 376 patients treated with RT and androgen deprivation were randomized to receive 6 cycles of docetaxel 75 mg/m2 (N=188, Arm A) or surveillance (N=188, Arm B). FACT-P HRQoL questionnaires were gathered at baseline, six months and 1, 2 and 4 years after randomization. The data were analysed using analysis of covariance. RESULTS: FACT-P scores decreased in Arm A at the end of treatment and remained unchanged in Arm B (p<0.0001). The HRQoL scores in Arm A matched Arm B in the 1-year follow-up (p=0.0528) and remained similar in further follow-up. CONCLUSION: Docetaxel transiently decreased HRQoL during chemotherapy but not after treatment for up to four years of follow-up.

Clinical and biological relevance of the transcriptomic-based prostate cancer metastasis subtypes MetA-C.

To improve treatment of metastatic prostate cancer, the biology of metastases needs to be understood. We recently described three subtypes of prostate cancer bone metastases (MetA-C), based on differential gene expression. The aim of this study was to verify the clinical relevance of these subtypes and to explore their biology and relations to genetic drivers. Freshly-frozen metastasis samples were obtained as hormone-naive (n = 17), short-term castrated (n = 21), or castration-resistant (n = 65) from a total of 67 patients. Previously published sequencing data from 573 metastasis samples were also analyzed. Through transcriptome profiling and sample classification based on a set of predefined MetA-C-differentiating genes, we found that most metastases were heterogeneous for the MetA-C subtypes. Overall, MetA was the most common subtype, while MetB was significantly enriched in castration-resistant samples and in liver metastases, and consistently associated with poor prognosis. By gene set enrichment analysis, the phenotype of MetA was described by high androgen response, protein secretion and adipogenesis, MetB by high cell cycle activity and DNA repair, and MetC by epithelial-to-mesenchymal transition and inflammation. The MetB subtype demonstrated single nucleotide variants of RB transcriptional corepressor 1 (RB1) and loss of 21 genes at chromosome 13, including RB1, but provided independent prognostic value to those genetic aberrations. In conclusion, a distinct set of gene transcripts can be used to classify prostate cancer metastases into the subtypes MetA-C. The MetA-C subtypes show diverse biology, organ tropism, and prognosis. The MetA-C classification may be used independently, or in combination with genetic markers, primarily to identify MetB patients in need of complementary therapy to conventional androgen receptor-targeting treatments.

Deep learning-based classification and structure name standardization for organ at risk and target delineations in prostate cancer radiotherapy.

Radiotherapy (RT) datasets can suffer from variations in annotation of organ at risk (OAR) and target structures. Annotation standards exist, but their description for prostate targets is limited. This restricts the use of such data for supervised machine learning purposes as it requires properly annotated data. The aim of this work was to develop a modality independent deep learning (DL) model for automatic classification and annotation of prostate RT DICOM structures. Delineated prostate organs at risk (OAR), support- and target structures (gross tumor volume [GTV]/clinical target volume [CTV]/planning target volume [PTV]), along with or without separate vesicles and/or lymph nodes, were extracted as binary masks from 1854 patients. An image modality independent 2D InceptionResNetV2 classification network was trained with varying amounts of training data using four image input channels. Channel 1-3 consisted of orthogonal 2D projections from each individual binary structure. The fourth channel contained a summation of the other available binary structure masks. Structure classification performance was assessed in independent CT (n = 200 pat) and magnetic resonance imaging (MRI) (n = 40 pat) test datasets and an external CT (n = 99 pat) dataset from another clinic. A weighted classification accuracy of 99.4% was achieved during training. The unweighted classification accuracy and the weighted average F1 score among different structures in the CT test dataset were 98.8% and 98.4% and 98.6% and 98.5% for the MRI test dataset, respectively. The external CT dataset yielded the corresponding results 98.4% and 98.7% when analyzed for trained structures only, and results from the full dataset yielded 79.6% and 75.2%. Most misclassifications in the external CT dataset occurred due to multiple CTVs and PTVs being fused together, which was not included in the training data. Our proposed DL-based method for automated renaming and standardization of prostate radiotherapy annotations shows great potential. Clinic specific contouring standards however need to be represented in the training data for successful use. Source code is available at https://github.com/jamtheim/DicomRTStructRenamerPublic.

Registration of histopathology to magnetic resonance imaging of prostate cancer.

BACKGROUND AND PURPOSE: The diagnostic accuracy of new imaging techniques requires validation, preferably by histopathological verification. The aim of this study was to develop and present a registration procedure between histopathology and in-vivo magnetic resonance imaging (MRI) of the prostate, to estimate its uncertainty and to evaluate the benefit of adding a contour-correcting registration. MATERIALS AND METHODS: For twenty-five prostate cancer patients, planned for radical prostatectomy, a 3D-printed prostate mold based on in-vivo MRI was created and an ex-vivo MRI of the specimen, placed inside the mold, was performed. Each histopathology slice was registered to its corresponding ex-vivo MRI slice using a 2D-affine registration. The ex-vivo MRI was rigidly registered to the in-vivo MRI and the resulting transform was applied to the histopathology stack. A 2D deformable registration was used to correct for specimen distortion concerning the specimen's fit inside the mold. We estimated the spatial uncertainty by comparing positions of landmarks in the in-vivo MRI and the corresponding registered histopathology stack. RESULTS: Eighty-four landmarks were identified, located in the urethra (62%), prostatic cysts (33%), and the ejaculatory ducts (5%). The median number of landmarks was 3 per patient. We showed a median in-plane error of 1.8 mm before and 1.7 mm after the contour-correcting deformable registration. In patients with extraprostatic margins, the median in-plane error improved from 2.1 mm to 1.8 mm after the contour-correcting deformable registration. CONCLUSIONS: Our registration procedure accurately registers histopathology to in-vivo MRI, with low uncertainty. The contour-correcting registration was beneficial in patients with extraprostatic surgical margins.

High Monocyte Count and Expression of S100A9 and S100A12 in Peripheral Blood Mononuclear Cells Are Associated with Poor Outcome in Patients with Metastatic Prostate Cancer.

Increasing evidence indicates calcium-binding S100 protein involvement in inflammation and tumor progression. In this prospective study, we evaluated the mRNA levels of two members of this family, S100A9 and S100A12, in peripheral blood mononuclear cells (PBMCs) in a cohort of 121 prostate cancer patients using RT-PCR. Furthermore, monocyte count was determined by flow cytometry. By stratifying patients into different risk groups, according to TNM stage, Gleason score and PSA concentration at diagnosis, expression of S100A9 and S100A12 was found to be significantly higher in patients with metastases compared to patients without clinically detectable metastases. In line with this, we observed that the protein levels of S100A9 and S100A12 in plasma were higher in patients with advanced disease. Importantly, in patients with metastases at diagnosis, high monocyte count and high levels of S100A9 and S100A12 were significantly associated with short progression free survival (PFS) after androgen deprivation therapy (ADT). High monocyte count and S100A9 levels were also associated with short cancer-specific survival, with monocyte count providing independent prognostic information. These findings indicate that circulating levels of monocytes, as well as S100A9 and S100A12, could be biomarkers for metastatic prostate cancer associated with particularly poor prognosis.

Impact of neoadjuvant androgen deprivation therapy on magnetic resonance imaging features in prostate cancer before radiotherapy.

BACKGROUND AND PURPOSE: In locally advanced prostate cancer (PC), androgen deprivation therapy (ADT) in combination with whole prostate radiotherapy (RT) is the standard treatment. ADT affects the prostate as well as the tumour on multiparametric magnetic resonance imaging (MRI) with decreased PC conspicuity and impaired localisation of the prostate lesion. Image texture analysis has been suggested to be of aid in separating tumour from normal tissue. The aim of the study was to investigate the impact of ADT on baseline defined MRI features in prostate cancer with the goal to investigate if it might be of use in radiotherapy planning. MATERIALS AND METHODS: Fifty PC patients were included. Multiparametric MRI was performed before, and three months after ADT. At baseline, a tumour volume was delineated on apparent diffusion coefficient (ADC) maps with suspected tumour content and a reference volume in normal prostatic tissue. These volumes were transferred to MRIs after ADT and were analysed with first-order -and invariant Haralick -features. RESULTS: At baseline, the median value and several of the invariant Haralick features of ADC, showed a significant difference between tumour and reference volumes. After ADT, only ADC median value could significantly differentiate the two volumes. CONCLUSIONS: Invariant Haralick -features could not distinguish between baseline MRI defined PC and normal tissue after ADT. First-order median value remained significantly different in tumour and reference volumes after ADT, but the difference was less pronounced than before ADT.

Ultra-hypofractionated versus conventionally fractionated radiotherapy for prostate cancer (HYPO-RT-PC): patient-reported quality-of-life outcomes of a randomised, controlled, non-inferiority, phase 3 trial.

BACKGROUND: The HYPO-RT-PC trial compared conventionally fractionated radiotherapy with ultra-hypofractionated radiotherapy in patients with localised prostate cancer. Ultra-hypofractionation was non-inferior to conventional fractionation regarding 5-year failure-free survival and toxicity. We aimed to assess whether patient-reported quality of life (QOL) differs between conventional fractionation and ultra-hypofractionation up to 6 years after treatment in the HYPO-RT-PC trial. METHODS: HYPO-RT-PC is a multicentre, open-label, randomised, controlled, non-inferiority, phase 3 trial done in 12 centres (seven university hospitals and five county hospitals) in Sweden and Denmark. Inclusion criteria were histologically verified intermediate-to-high-risk prostate cancer (defined as T1c-T3a with one or two of the following risk factors: stage T3a; Gleason score ≥7; and prostate-specific antigen 10-20 ng/mL with no evidence of lymph node involvement or distant metastases), age up to 75 years, and WHO performance status 0-2. Participants were randomly assigned (1:1) to conventional fractionation (78·0 Gy in 39 fractions, 5 days per week for 8 weeks) or ultra-hypofractionation (42·7 Gy in seven fractions, 3 days per week for 2·5 weeks) via a minimisation algorithm with stratification by trial centre, T-stage, Gleason score, and prostate-specific antigen. QOL was measured using the validated Prostate Cancer Symptom Scale (PCSS) and European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire (EORTC QLQ-C30) at baseline, the end of radiotherapy, months 3, 6, 12, and 24 after radiotherapy, every other year thereafter up to 10 years, and at 15 years. The primary endpoint (failure-free survival) has been reported elsewhere. Here we report QOL, a secondary endpoint analysed in the per-protocol population, up to 6 years after radiotherapy. The HYPO-RT-PC trial is registered with the ISRCTN registry, ISRCTN45905321. FINDINGS: Between July 1, 2005, and Nov 4, 2015, 1200 patients were enrolled and 1180 were randomly assigned (conventional fractionation n=591, ultra-hypofractionation n=589); 1165 patients (conventional fractionation n=582, ultra-hypofractionation n=583) were included in this QOL analysis. 158 (71%) of 223 patients in the conventional fractionation group and 146 (66%) of 220 in the ultra-hypofractionation group completed questionnaires at 6 years. The median follow-up was 48 months (IQR 25-72). In seven of ten bowel symptoms or problems the proportion of patients with clinically relevant deteriorations at the end of radiotherapy was significantly higher in the ultra-hypofractionation group than in the conventional fractionation group (stool frequency [p<0·0001], rush to toilet [p=0·0013], flatulence [p=0·0013], bowel cramp [p<0·0001], mucus [p=0·0014], blood in stool [p<0·0001], and limitation in daily activity [p=0·0014]). There were no statistically significant differences in the proportions of patients with clinically relevant acute urinary symptoms or problems (total 14 items) and sexual functioning between the two treatment groups at end of radiotherapy. Thereafter, there were no clinically relevant differences in urinary, bowel, or sexual functioning between the groups. At the 6-year follow-up there was no difference in the incidence of clinically relevant deterioration between the groups for overall urinary bother (43 [33%] of 132 for conventional fractionation vs 33 [28%] of 120 for ultra-hypofractionation; mean difference 5·1% [95% CI -4·4 to 14·6]; p=0·38), overall bowel bother (43 [33%] of 129 vs 34 [28%] of 123; 5·7% [-3·8 to 15·2]; p=0·33), overall sexual bother (75 [60%] of 126 vs 59 [50%] of 117; 9·1% [-1·4 to 19·6]; p=0·15), or global health/QOL (56 [42%] of 134 vs 46 [37%] of 125; 5·0% [-5·0 to 15·0]; p=0·41). INTERPRETATION: Although acute toxicity was higher for ultra-hypofractionation than conventional fractionation, this long-term patient-reported QOL analysis shows that ultra-hypofractionation was as well tolerated as conventional fractionation up to 6 years after completion of treatment. These findings support the use of ultra-hypofractionation radiotherapy for intermediate-to-high-risk prostate cancer. FUNDING: The Nordic Cancer Union, the Swedish Cancer Society, and the Swedish Research Council.

Marked response to cabazitaxel in prostate cancer xenografts expressing androgen receptor variant 7 and reversion of acquired resistance by anti-androgens.

BACKGROUND: Taxane treatment may be a suitable therapeutic option for patients with castration-resistant prostate cancer and high expression of constitutively active androgen receptor variants (AR-Vs). The aim of the study was to compare the effects of cabazitaxel and androgen deprivation treatments in a prostate tumor xenograft model expressing high levels of constitutively active AR-V7. Furthermore, mechanisms behind acquired cabazitaxel resistance were explored. METHODS: Mice were subcutaneously inoculated with 22Rv1 cells and treated with surgical castration (n = 7), abiraterone (n = 9), cabazitaxel (n = 6), castration plus abiraterone (n = 8), castration plus cabazitaxel (n = 11), or vehicle and/or sham operation (n = 23). Tumor growth was followed for about 2 months or to a volume of approximately 1000 mm3 . Two cabazitaxel resistant cell lines; 22Rv1-CabR1 and 22Rv1-CabR2, were established from xenografts relapsing during cabazitaxel treatment. Differential gene expression between the cabazitaxel resistant and control 22Rv1 cells was examined by whole-genome expression array analysis followed by immunoblotting, immunohistochemistry, and functional pathway analysis. RESULTS: Abiraterone treatment alone or in combination with surgical castration had no major effect on 22Rv1 tumor growth, while cabazitaxel significantly delayed and in some cases totally abolished 22Rv1 tumor growth on its own and in combination with surgical castration. The cabazitaxel resistant cell lines; 22Rv1-CabR1 and 22Rv1-CabR2, both showed upregulation of the ATP-binding cassette sub-family B member 1 (ABCB1) efflux pump. Treatment with ABCB1 inhibitor elacridar completely restored susceptibility to cabazitaxel, while treatment with AR-antagonists bicalutamide and enzalutamide partly restored susceptibility to cabazitaxel in both cell lines. The cholesterol biosynthesis pathway was induced in the 22Rv1-CabR2 cell line, which was confirmed by reduced sensitivity to simvastatin treatment. CONCLUSIONS: Cabazitaxel efficiently inhibits prostate cancer growth despite the high expression of constitutively active AR-V7. Acquired cabazitaxel resistance involving overexpression of efflux transporter ABCB1 can be reverted by bicalutamide or enzalutamide treatment, indicating the great clinical potential for combined treatment with cabazitaxel and anti-androgens.