Dataset Information

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

ABSTRACT:

Purpose

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

Methods and materials

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

Results

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

Conclusions

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

SUBMITTER: Walker AK

PROVIDER: S-EPMC6588678 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

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Publications

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

Walker Alexandra K AK Karaszi Katalin K Valentine Helen H Strauss Victoria Y VY Choudhury Ananya A McGill Shaun S Wen Kaisheng K Brown Michael D MD Ramani Vijay V Bhattarai Selina S Teo Mark T W MTW Yang Lingjian L Myers Kevin A KA Deshmukh Nayneeta N Denley Helen H Browning Lisa L Love Sharon B SB Iyer Gopa G Clarke Noel W NW Hall Emma E Huddart Robert R James Nicholas D ND Hoskin Peter J PJ West Catharine M L CML Kiltie Anne E AE

International journal of radiation oncology, biology, physics 20190315 4

<h4>Purpose</h4>Organ-confined muscle-invasive bladder cancer is treated with cystectomy or bladder preservation techniques, including radiation therapy. There are currently no biomarkers to inform management decisions and aid patient choice. Previously we showed high levels of MRE11 protein, assessed by immunohistochemistry (IHC), predicted outcome after radiation therapy, but not cystectomy. Therefore, we sought to develop the MRE11 IHC assay for clinical use and define its relationship to cli ...[more]

PMID: 30885775

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Project description:ImportanceBladder-preserving trimodality therapy can be an effective alternative to radical cystectomy for treatment of muscle-invasive bladder cancer (MIBC), but biomarkers are needed to guide optimal patient selection. The DNA repair protein MRE11 is a candidate response biomarker that has not been validated in prospective cohorts using standardized measurement approaches.ObjectiveTo evaluate MRE11 expression as a prognostic biomarker in MIBC patients receiving trimodality therapy using automated quantitative image analysis.Design, setting, and participantsThis prognostic study analyzed patients with MIBC pooled from 6 prospective phase I/II, II, or III trials of trimodality therapy (Radiation Therapy Oncology Group [RTOG] 8802, 8903, 9506, 9706, 9906, and 0233) across 37 participating institutions in North America from 1988 to 2007. Eligible patients had nonmetastatic MIBC and were enrolled in 1 of the 6 trimodality therapy clinical trials. Analyses were completed August 2020.ExposuresTrimodality therapy with transurethral bladder tumor resection and cisplatin-based chemoradiation therapy.Main outcomes and measuresMRE11 expression and association with disease-specific (bladder cancer) mortality (DSM), defined as death from bladder cancer. Pretreatment tumor tissues were processed for immunofluorescence with anti-MRE11 antibody and analyzed using automated quantitative image analysis to calculate a normalized score for MRE11 based on nuclear-to-cytoplasmic (NC) signal ratio.ResultsOf 465 patients from 6 trials, 168 patients had available tissue, of which 135 were analyzable for MRE11 expression (median age of 65 years [minimum-maximum, 34-90 years]; 111 [82.2%] men). Median (minimum-maximum) follow-up for alive patients was 5.0 (0.6-11.7) years. Median (Q1-Q3) MRE11 NC signal ratio was 2.41 (1.49-3.34). Patients with an MRE11 NC ratio above 1.49 (ie, above first quartile) had a significantly lower DSM (HR, 0.50; 95% CI, 0.26-0.93; P = .03). The 4-year DSM was 41.0% (95% CI, 23.2%-58.0%) for patients with an MRE11 NC signal ratio of 1.49 or lower vs 21.0% (95% CI, 13.4%-29.8%) for a ratio above 1.49. MRE11 NC signal ratio was not significantly associated with overall survival (HR, 0.84; 95% CI, 0.49-1.44).Conclusions and relevanceHigher MRE11 NC signal ratios were associated with better DSM after trimodality therapy. Lower MRE11 NC signal ratios identified a poor prognosis subgroup that may benefit from intensification of therapy.

Project description:PurposeBladder preservation with trimodal therapy (TMT; maximal tumor resection followed by chemoradiation) is an effective paradigm for select patients with muscle invasive bladder cancer. We report our institutional experience of a TMT protocol using nonadaptive magnetic resonance imaging-guided radiation therapy (MRgRT) for partial bladder boost (PBB).Methods and materialsA retrospective analysis was performed on consecutive patients with nonmetastatic muscle invasive bladder cancer who were treated with TMT using MRgRT between 2019 and 2022. Patients underwent intensity modulated RT-based nonadaptive MRgRT PBB contoured on True fast imaging with steady state precession (FISP) images (full bladder) followed sequentially by computed tomography-based RT to the whole empty bladder and pelvic lymph nodes with concurrent chemotherapy. MRgRT treatment time, table shifts, and dosimetric parameters of target coverage and normal tissue exposure were described. Prospectively assessed acute and late genitourinary and gastrointestinal (GI) toxicity were reported. Two-year local control was assessed with Kaplan-Meier methods.ResultsSeventeen patients were identified for analysis. PBB planning target volume margins were ≤8 mm in 94% (n = 16) of cases. Dosimetric target coverage parameters were favorable and all normal tissue dose constraints were met. For MRgRT PBB fractions, median table shifts were 0.4 cm (range, 0-3.15), 0.45 cm (0-2.65), and 0.75 cm (0-4.8) in the X, Y, and Z planes, respectively. Median treatment time for MRgRT PBB fractions was 9 minutes (range, 6.9-17.4). We identified 32 out of 100 total MRgRT fractions that may have benefitted from online adaptation based on changes in organ position relative to planning target volume, predominantly because of small bowel (13/32, 41%) or rectum (8/32, 25%). Two patients discontinued RT prematurely. The incidence of highest-grade acute genitourinary toxicity was 1 to 2 (69%) and 3 (6%), whereas the incidence of acute GI toxicity was 1 to 2 (81%) and 3 (6%). There were no late grade 3 events; 17.6% had late grade 2 cystitis and none had late GI toxicity. With median follow-up of 18.2 months (95% CI, 12.4-22.5), the local control rate was 92%, and no patient has required salvage cystectomy.ConclusionsNonadaptive MRgRT PBB is feasible with favorable dosimetry and low resource utilization. Larger studies are needed to evaluate for potential benefits in toxicity and local control associated with this approach in comparison to standard treatment techniques.

Project description:PurposeTrimodality therapy for muscle-invasive bladder cancer (MIBC) yields similar oncologic outcomes compared to radical cystectomy in appropriately selected patients; however, data regarding locally advanced MIBC (LA-MIBC) is limited. We explored our experience with LA-MIBC undergoing radiation therapy (RT).MethodsWe retrospectively identified 30 patients from an institutional prospectively collated database with non-metastatic, LA-MIBC. Patients with T3-4 N0 or T2-4 N + treated from 2012 to 2022 with definitive-intent RT, who were not candidates for cystectomy were included. Kaplan-Meier analysis was used to estimate time-to-event outcomes, and multivariate analyses were conducted using Cox proportional hazards modeling.Results43 % had T3N0 disease, 30 % had T4N0 disease, and 27 % had node positive disease.. Neoadjuvant chemotherapy/systemic therapy was administered in 63 % of patients. Median dose and fractionation of RT was 60 Gy in 30 fractions. 23 % of patients received hypofractionated RT, 57 % received nodal RT.At a median follow-up of 20 (range, 1-75) months after RT, estimated 1- and 2-year OS was 73 % and 61 %, respectively. Estimated 1-year progression-free survival was 50 %. Local bladder failure was a component of progression in 17 % of patients, and all local bladder failure events occurred within the first 12 months following RT. Lymph node or distant metastases occurred in 23 % of patients. Estimated 1-year OS was 83 % with pure urothelial histology but only 58 % with variant histology (P = 0.001). Late grade 3 + GU and GI toxicity occurred in 7 % and 5 % of patients, respectively.ConclusionsIn this cohort with LA-MIBC treated with RT, distant failures predominate, local failures are less common, and toxicity was minimal. Survival outcomes remain encouraging for RT in this challenging patient population. Further investigation is warranted to identify biomarkers for patient selection and strategies to improve distant control.

Project description:Bladder cancer therapy relies on aggressive treatments highlighting the need for new, targeted therapies with reduced side effects. SWI/SNF complexes are mutated in ~20% across human cancers and dependency of SWI/SNF-deficient tumors on EZH2 has been uncovered recently. To systematically dissect the frequency of genetic alterations in SWI/SNF complexes potentially contributing to their inactivation, mutations and copy number variations in 25 SWI/SNF subunit genes were analyzed making use of publicly available sequencing data for 408 muscle-invasive bladder carcinoma samples. ARID1A truncating mutations were identified as the by far most common alterations of SWI/SNF complexes in urothelial bladder cancer. As current ARID1A protein expression data in bladder cancer are inconsistent and incomplete we examined if the frequency of truncating ARID1A mutations translates into a similar frequency of cases showing ARID1A protein loss. We applied a validated ARID1A antibody conducting a comprehensive immunohistochemistry-based expression analysis in urothelial bladder cancer (n = 362) including carcinoma in situ (CIS) cases. While observing increased median ARID1A protein levels in all carcinoma subgroups compared to normal urothelial controls (n = 21), the percentage of cases showing ARID1A protein loss was positively correlated with increasing stage and grade culminating in a rate of 14.1% in muscle-invasive disease. ARID1A-depletion did neither increase EZH2 protein or trimethylated H3K27 levels in vitro nor did ARID1A expression correlate with EZH2 or H3K27me3 amounts in human bladder carcinomas. Importantly, ARID1A-deficiency was neither associated with enhanced sensitivity towards inhibition of EZH2 enzymatic activity nor depletion of EZH2 protein. In summary, ARID1A truncating mutations, potentially translating into ARID1A protein loss in a subset of high-grade bladder cancers, are the most common SWI/SNF genetic alterations in bladder cancer. Our data do not support ARID1A-deficiency as predictive biomarker for EZH2-inhibitor treatment response in bladder cancer underlining the need for future bladder cancer-specific, drug screens for successfull discovery of ARID1A-deficiency-based targeted drugs.

Dataset Information

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

Purpose

Methods and materials

Results

Conclusions

Publications

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

Similar Datasets

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