Search

Background: Endometrial cancer can be molecularly classified into POLEmut, mismatch repair deficient (MMRd), p53 abnormal (p53abn), and no specific molecular profile (NSMP) subgroups. We aimed to develop an interpretable deep learning pipeline for whole-slide-image-based prediction of the four molecular classes in endometrial cancer (im4MEC), to identify morpho-molecular correlates, and to refine prognostication. Methods: This combined analysis included diagnostic haematoxylin and eosin-stained slides and molecular and clinicopathological data from 2028 patients with intermediate-to-high-risk endometrial cancer from the PORTEC-1 (n=466), PORTEC-2 (n=375), and PORTEC-3 (n=393) randomised trials and the TransPORTEC pilot study (n=110), the Medisch Spectrum Twente cohort (n=242), a case series of patients with POLEmut endometrial cancer in the Leiden Endometrial Cancer Repository (n=47), and The Cancer Genome Atlas-Uterine Corpus Endometrial Carcinoma cohort (n=395). PORTEC-3 was held out as an independent test set and a four-fold cross validation was performed. Performance was measured with the macro and class-wise area under the receiver operating characteristic curve (AUROC). Whole-slide images were segmented into tiles of 360 μm resized to 224 × 224 pixels. im4MEC was trained to learn tile-level morphological features with self-supervised learning and to molecularly classify whole-slide images with an attention mechanism. The top 20 tiles with the highest attention scores were reviewed to identify morpho-molecular correlates. Predictions of a nuclear classification deep learning model serve to derive interpretable morphological features. We analysed 5-year recurrence-free survival and explored prognostic refinement by molecular class using the Kaplan-Meier method. Findings: im4MEC attained macro-average AUROCs of 0·874 (95% CI 0·856–0·893) on four-fold cross-validation and 0·876 on the independent test set. The class-wise AUROCs were 0·849 for POLEmut (n=51), 0·844 for MMRd (n=134), 0·883 for NSMP (n=120), and 0·928 for p53abn (n=88). POLEmut and MMRd tiles had a high density of lymphocytes, p53abn tiles had strong nuclear atypia, and the morphology of POLEmut and MMRd endometrial cancer overlapped. im4MEC highlighted a low tumour-to-stroma ratio as a potentially novel characteristic feature of the NSMP class. 5-year recurrence-free survival was significantly different between im4MEC predicted molecular classes in PORTEC-3 (log-rank pmut had an excellent prognosis, as do those with true POLEmut endometrial cancer. Interpretation: We present the first interpretable deep learning model, im4MEC, for haematoxylin and eosin-based prediction of molecular endometrial cancer classification. im4MEC robustly identified morpho-molecular correlates and could enable further prognostic refinement of patients with endometrial cancer. Funding: The Hanarth Foundation, the Promedica Foundation, and the Swiss Federal Institutes of Technology.

ObjectiveDrug repurposing is an alternative development pathway that utilizes the properties of drugs approved for other diseases and builds on available safety and pharmacological data to develop the drug as a potential treatment for other diseases. A literature-based approach was performed to identify drug repurposing opportunities in cervical cancer to inform future research and trials.MethodsWe queried PubMed for each drug included in two databases (ReDO_DB and CDcervix_DB, which include 300+ non-cancer drugs and 200+ cancer drugs not used in cervical cancer, respectively) and manually assessed all abstracts for relevance and activity in cervix cancer, and type of evidence. Subsequently, we also performed a search of clinical trial databases where we generated a list of registered trials in cervical cancer with all drugs from our databases.ResultsOf the 534 drugs from both databases, 174 (33%) had at least one relevant abstract or registered trial in cervical cancer. 94 (18%) drugs had at least human data available, and 52 (10%) drugs were evaluated in registered trials. To prioritize drugs to consider for future trials, all 174 drugs were further assessed for strength of scientific rationale, feasibility for integration in cervical cancer standard of care, evidence of radiosensitization, and potential mechanism of action. Out of the 174 drugs, 38 (22%) potential drug candidates were selected.ConclusionThis study resulted in a list of candidate drugs for potential evaluation in cervical cancer. Many drugs might warrant additional (pre)clinical investigation, which could be done in a coordinated manner using platform trials.

Funding Information: The authors thank ESGO, ESTRO, and ESP for their support. The authors also thank the 155 international reviewers (physicians and patient representatives, see Appendix 2 in Online Supplemental File 2) for their valuable comments and suggestions. The authors thank the ESGO office, especially Kamila Macku, Tereza Cicakova, and Kateřina Šibravová, provided invaluable logistical and administrative support throughout the process. The development group (including all authors) is collectively responsible for the decision to submit for publication. DC (chair), JL (chair), MRR (chair) and FP (methodologist) wrote the first draft of the manuscript. All other contributors have actively given personal input, reviewed the manuscript, and have given final approval before submission. DC is responsible for the overall content as the guarantor. Initiated through the ESGO the decision to develop multidisciplinary guidelines was made jointly by the ESGO, ESTRO, and ESP. The ESGO provided administrative support. The ESGO, ESTRO and ESP are nonprofit knowledgeable societies. *These guidelines were developed by ESGO, ESTRO and ESP and are published in the Int J Gynecol Cancer, Radiother Oncol and Virchows Archiv. CCh has reported advisory boards for GSK, MSD and EISAI; SFL has reported advisory boards for MSD, GSK, AstraZeneca and Novartis; DL has reported consultant honoria from AstraZeneca, Clovis Oncology, GSK, MSD, Immunogen, Genmab, Amgen, Seagen and PharmaMar, advisory boards for AstraZeneca, Merck Serono, Seagen, Immunogen, Genmab, Oncoinvest, Corcept and Sutro, research institutional funding from Clovis Oncology, GSK, MSD and PharmaMar, research sponsored by AstraZeneca, Clovis Oncology, Genmab, GSK, Immunogen, Incyte, MSD, Roche, Seagen and Novartis, and speakers’ bureau activities for AstraZeneca, Clovis Oncology, GSK, MSD and PharmaMar; UM has reported advisory boards for AstraZeneca (Steering committee member for CALLA Study); RN has reported research grants from Elekta, Varian, Accuray, Dutch Research Council, and Dutch Cancer Society; AO has reported personal fees for advisory board membersip from Agenus, AstraZeneca, Clovis Oncology, Corcept Therapeutics, Deciphera Pharmaceuticals, Eisai, EMD Serono, F. Hoffmann-La Roche, Genmab/Seagen, GSK, ImmunoGen, Itheos, Merck Sharp & Dohme de Espana, SA, Mersana Thereapeutics, Novocure, PharmaMar, piIME Oncology, Roche, Sattucklabs, Sutro Biopharma and Tesaro, and personal fees for travel/accomodation from AstraZeneca, PharmaMar and Roche; DQ has reported advisory boards for Mimark inc; MPS has reported research grants and personal fees for workshops from Elekta AB; DC, MRR, FP, CC, AF, DF, DJK, FJ, CK, PM, RN, FPec, JP, SR, AS, VS, KT, IZ and JCL have reported no conflicts of interest. Not commissioned; internally peer reviewed. Not applicable. Not applicable. David Cibula, Maria Rosaria Raspollini, François Planchamp, Carlos Centeno, Cyrus Chargari, Ana Felix, Daniela Fischerova, Daniela Jahn-Kuch, Florence Joly, Christhardt Kohler, Sigurd F. Lax, Domenica Lorusso, Umesh Mahantshetty, Patrice Mathevet, Raj Naik, Remi Nout, Ana Oaknin, Fedro Peccatori, Jan Persson, Denis Querleu, Sandra Rubio, Maximilian Paul Schmid, Artem Stepanyan, Valentyn Svintsitskyi, Karl Tamussino, Ignacio Zapardiel, Jacob Christian Lindegaard. All data relevant to the study are included in the article or uploaded as supplementary information. Funding Information: CCh has reported advisory boards for GSK, MSD and EISAI; SFL has reported advisory boards for MSD, GSK, AstraZeneca and Novartis; DL has reported consultant honoria from AstraZeneca, Clovis Oncology, GSK, MSD, Immunogen, Genmab, Amgen, Seagen and PharmaMar, advisory boards for AstraZeneca, Merck Serono, Seagen, Immunogen, Genmab, Oncoinvest, Corcept and Sutro, research institutional funding from Clovis Oncology, GSK, MSD and PharmaMar, research sponsored by AstraZeneca, Clovis Oncology, Genmab, GSK, Immunogen, Incyte, MSD, Roche, Seagen and Novartis, and speakers’ bureau activities for AstraZeneca, Clovis Oncology, GSK, MSD and PharmaMar; UM has reported advisory boards for AstraZeneca (Steering committee member for CALLA Study); RN has reported research grants from Elekta, Varian, Accuray, Dutch Research Council, and Dutch Cancer Society; AO has reported personal fees for advisory board membersip from Agenus, AstraZeneca, Clovis Oncology, Corcept Therapeutics, Deciphera Pharmaceuticals, Eisai, EMD Serono, F. Hoffmann-La Roche, Genmab/Seagen, GSK, ImmunoGen, Itheos, Merck Sharp & Dohme de Espana, SA, Mersana Thereapeutics, Novocure, PharmaMar, piIME Oncology, Roche, Sattucklabs, Sutro Biopharma and Tesaro, and personal fees for travel/accomodation from AstraZeneca, PharmaMar and Roche; DQ has reported advisory boards for Mimark inc; MPS has reported research grants and personal fees for workshops from Elekta AB; DC, MRR, FP, CC, AF, DF, DJK, FJ, CK, PM, RN, FPec, JP, SR, AS, VS, KT, IZ and JCL have reported no conflicts of interest. Publisher Copyright: © 2023 ESGO, ESTRO, ESP In 2018, the European Society of Gynecological Oncology (ESGO) jointly with the European Society for Radiotherapy and Oncology (ESTRO) and the European Society of Pathology (ESP) published evidence-based guidelines for the management of patients with cervical cancer. Given the large body of new evidence addressing the management of cervical cancer, the three sister societies jointly decided to update these evidence-based guidelines. The update includes new topics to provide comprehensive guidelines on all relevant issues of diagnosis and treatment in cervical cancer. To serve on the expert panel (27 experts across Europe) ESGO/ESTRO/ESP nominated practicing clinicians who are involved in managing patients with cervical cancer and have demonstrated leadership through their expertise in clinical care and research, national and international engagement, profile, and dedication to the topics addressed. To ensure the statements were evidence based, new data identified from a systematic search was reviewed and critically appraised. In the absence of any clear scientific evidence, judgment was based on the professional experience and consensus of the international development group. Before publication, the guidelines were reviewed by 155 independent international practitioners in cancer care delivery and patient representatives. These updated guidelines are comprehensive and cover staging, management, follow-up, long-term survivorship, quality of life and palliative care. Management includes fertility sparing treatment, early and locally advanced cervical cancer, invasive cervical cancer diagnosed on a simple hysterectomy specimen, cervical cancer in pregnancy, rare tumors, recurrent and metastatic diseases. The management algorithms and the principles of radiotherapy and pathological evaluation are also defined. publishersversion published

Supplementary Tables 1-14 and Supplementary Figures 1-4

Optimum risk stratification in early-stage endometrial cancer combines clinicopathologic factors and the molecular endometrial cancer classification defined by The Cancer Genome Atlas (TCGA). It is unclear whether analysis of intratumoral immune infiltrate improves this. We developed a machine-learning, image-based algorithm to quantify density of CD8+ and CD103+ immune cells in tumor epithelium and stroma in 695 stage I endometrioid endometrial cancers from the PORTEC-1 and -2 trials. The relationship between immune cell density and clinicopathologic/molecular factors was analyzed by hierarchical clustering and multiple regression. The prognostic value of immune infiltrate by cell type and location was analyzed by univariable and multivariable Cox regression, incorporating the molecular endometrial cancer classification. Tumor-infiltrating immune cell density varied substantially between cases, and more modestly by immune cell type and location. Clustering revealed three groups with high, intermediate, and low densities, with highly significant variation in the proportion of molecular endometrial cancer subgroups between them. Univariable analysis revealed intraepithelial CD8+ cell density as the strongest predictor of endometrial cancer recurrence; multivariable analysis confirmed this was independent of pathologic factors and molecular subgroup. Exploratory analysis suggested this association was not uniform across molecular subgroups, but greatest in tumors with mutant p53 and absent in DNA mismatch repair–deficient cancers. Thus, this work identified that quantification of intraepithelial CD8+ cells improved upon the prognostic utility of the molecular endometrial cancer classification in early-stage endometrial cancer.

Frequency of amplifications, GISTIC q-value and Cox regression P value for all regions in 1q locus for cluster 2, 3 and 4 ECs (n= 268).

Purpose: Molecular classification of endometrial cancer identified distinct molecular subgroups. However, the largest subset of endometrial cancers remains poorly characterized and is referred to as the “nonspecific molecular profile” (NSMP) subgroup. Here, we aimed at refining the classification of this subgroup by profiling somatic copy-number aberrations (SCNAs).Experimental Design: SCNAs were analyzed in 141 endometrial cancers using whole-genome SNP arrays and pooled with 361 endometrial cancers from The Cancer Genome Atlas. Genomic Identification of Significant Targets in Cancer (GISTIC) identified statistically enriched SCNAs and penalized Cox regression assessed survival effects. The prognostic significance of relevant SCNAs was validated using multiplex ligation-dependent probe amplification in 840 endometrial cancers from the PORTEC-1/2 trials. Copy-number status of genes was correlated with gene expression to identify potential cancer drivers. One plausible oncogene was validated in vitro using antisense oligonucleotide-based strategy.Results: SCNAs affecting chromosome 1q32.1 significantly correlated with worse relapse-free survival (RFS) in the NSMP subgroup (HR, 2.12; 95% CI, 1.26–3.59; P = 0.005). This effect was replicated in NSMP endometrial cancers from PORTEC-1/2 (HR, 2.34; 95% CI, 1.17–4.70; P = 0.017). A new molecular classification including the 1q32.1 amplification improved risk prediction of recurrence. MDM4 gene expression strongly correlated with 1q32.1 amplification. Silencing MDM4 inhibited cell growth in cell lines carrying 1q32.1 amplification, but not in those without MDM4 amplification. Vice versa, increasing MDM4 expression in nonamplified cell lines stimulated cell proliferation.Conclusions: 1q32.1 amplification was identified as a prognostic marker for poorly characterized NSMP endometrial cancers, refining the molecular classification of this subgroup. We functionally validated MDM4 as a potential oncogenic driver in the 1q32.1 region. Clin Cancer Res; 23(23); 7232–41. ©2017 AACR.

Fluorescent In Situ Hybridization of Pole on metaphase spreads of Pole-mutant cell line

Supplementary Material and Methods

Multivariable analysis on the prognostic role of the clinicopathological characteristics, molecular subgroups, and potential other classifiers in all cases of early-stage endometrial cancer (n=834) and in the subset of EC without substantial LVSI, >10% L1CAM, p53 and POLE mutation (n=620).

Sensitivity to nucleoside analogs gemcitabine, cladribine and clofarabine conferred by Pole proofreading domain mutations in a cell-based model

Purpose:The elevated levels of somatic copy-number alterations (SCNAs) in a subset of high-risk endometrial cancers are suggestive of defects in pathways governing genome integrity. We sought to assess the prevalence of homologous recombination deficiency (HRD) in endometrial cancers and its association with histopathologic and molecular characteristics.Experimental Design:Fresh tumor tissue was prospectively collected from 36 endometrial cancers, and functional HRD was examined by the ability of replicating tumor cells to accumulate RAD51 protein at DNA double-strand breaks (RAD51 foci) induced by ionizing radiation. Genomic alterations were determined by next-generation sequencing and array comparative genomic hybridization/SNP array. The prevalence of BRCA-associated genomic scars, a surrogate marker for HRD, was determined in the The Cancer Genome Atlas (TCGA) endometrial cancer cohort.Results:Most endometrial cancers included in the final analysis (n = 25) were of non-endometrioid (52%), grade 3 (60%) histology, and FIGO stage I (72%). HRD was observed in 24% (n = 6) of cases and was restricted to non-endometrioid endometrial cancers (NEEC), with 46% of NEECs being HRD compared with none of the endometrioid endometrial cancers (EEC, P = 0.014). All but 1 of the HRD cases harbored either a pathogenic BRCA1 variant or high somatic copy-number (SCN) losses of HR genes. Analysis of TCGA cases supported these results, with BRCA-associated genomic scars present in up to 48% (63/132) of NEEC versus 12% (37/312) of EEC (P < 0.001).Conclusions:HRD occurs in endometrial cancers and is largely restricted to non-endometrioid, TP53-mutant endometrial cancers. Evaluation of HRD may help select patients that could benefit from treatments targeting this defect, including platinum compounds and PARP inhibitors.

Purpose: Recommendations for adjuvant treatment for women with early-stage endometrial carcinoma are based on clinicopathologic features. Comprehensive genomic characterization defined four subgroups: p53-mutant, microsatellite instability (MSI), POLE-mutant, and no specific molecular profile (NSMP). We aimed to confirm the prognostic capacity of these subgroups in large randomized trial populations, investigate potential other prognostic classifiers, and integrate these into an integrated molecular risk assessment guiding adjuvant therapy.Experimental Design: Analysis of MSI, hotspot mutations in 14 genes including POLE, protein expression of p53, ARID1a, β-catenin, L1CAM, PTEN, ER, and PR was undertaken on 947 available early-stage endometrioid endometrial carcinomas from the PORTEC-1 and -2 trials, mostly high-intermediate risk (n = 614). Prognostic value was determined using univariable and multivariable Cox proportional hazard models. AUCs of different risk stratification models were compared.Results: Molecular analyses were feasible in >96% of the patients and confirmed the four molecular subgroups: p53-mutant (9%), MSI (26%), POLE-mutant (6%), and NSMP (59%). Integration of prognostic molecular alterations with established clinicopathologic factors resulted in a stronger model with improved risk prognostication. Approximately 15% of high-intermediate risk patients had unfavorable features (substantial lymphovascular space invasion, p53-mutant, and/or >10% L1CAM), 50% favorable features (POLE-mutant, NSMP being microsatellite stable, and CTNNB1 wild-type), and 35% intermediate features (MSI or CTNNB1-mutant).Conclusions: Integrating clinicopathologic and molecular factors improves the risk assessment of patients with early-stage endometrial carcinoma. Assessment of this integrated risk profile is feasible in daily practice, and holds promise to reduce both overtreatment and undertreatment. Clin Cancer Res; 22(16); 4215–24. ©2016 AACR.

Supplementary table 1. Demographic and clinicopathological characteristics of cases by EC molecular subtype

Supplementary Methods

Purpose: Pathogenic POLE proofreading domain mutations are found in many malignancies where they are associated with ultramutation and favorable prognosis. The extent to which this prognosis depends on their sensitivity to adjuvant treatment is unknown, as is the optimal therapy for advanced-staged or recurrent POLE-mutant cancers.Experimental Design: We examined the recurrence-free survival of women with POLE-mutant and POLE–wild-type endometrial cancers (EC) in the observation arm of the randomized PORTEC-1 endometrial cancer trial (N = 245 patients with stage I endometrial cancer for analysis). Sensitivity to radiotherapy and selected chemotherapeutics was compared between Pole-mutant mouse-derived embryonic stem (mES) cells, generated using CRISPR-Cas9 (Pole mutations D275A/E275A, and cancer-associated P286R, S297F, V411L) and isogenic wild-type cell lines.Results: In the observation arm of the PORTEC-1 trial (N = 245), women with POLE-mutant endometrial cancers (N = 16) had an improved recurrence-free survival (10-year recurrence-free survival 100% vs. 80.1% for POLE–wild-type; HR, 0.143; 95% confidence interval, 0.001–0.996; P = 0.049). Pole mutations did not increase sensitivity to radiotherapy nor to chemotherapeutics in mES cells. In contrast, Pole-mutant cells displayed significantly increased sensitivity to cytarabine and fludarabine (IC50 Pole P286R–mutant vs. wild-type: 0.05 vs. 0.17 μmol/L for cytarabine, 4.62 vs. 11.1 μmol/L for fludarabine; P < 0.001 for both comparisons).Conclusions: The favorable prognosis of POLE-mutant cancers cannot be explained by increased sensitivity to currently used adjuvant treatments. These results support studies exploring minimization of adjuvant therapy for early-stage POLE-mutant cancers, including endometrial and colorectal cancers. Conversely, POLE mutations result in hypersensitivity to nucleoside analogues, suggesting the use of these compounds as a potentially effective targeted treatment for advanced-stage POLE-mutant cancers. Clin Cancer Res; 24(13); 3197–203. ©2018 AACR.

Figure S1 shows that the Oncoscan and CGH agilent platform yield similar results.

Table S1 shows the clinicopathological characteristics of the cases included in final analysis.

Supplementary table 2. Antigen presentation pathway mutations in TCGA POLE proofreading-mutant ECs

Purpose: Recent studies have shown that 7% to 12% of endometrial cancers are ultramutated due to somatic mutation in the proofreading exonuclease domain of the DNA replicase POLE. Interestingly, these tumors have an excellent prognosis. In view of the emerging data linking mutation burden, immune response, and clinical outcome in cancer, we investigated whether POLE-mutant endometrial cancers showed evidence of increased immunogenicity.Experimental Design: We examined immune infiltration and activation according to tumor POLE proofreading mutation in a molecularly defined endometrial cancer cohort including 47 POLE-mutant tumors. We sought to confirm our results by analysis of RNAseq data from the TCGA endometrial cancer series and used the same series to examine whether differences in immune infiltration could be explained by an enrichment of immunogenic neoepitopes in POLE-mutant endometrial cancers.Results: Compared with other endometrial cancers, POLE mutants displayed an enhanced cytotoxic T-cell response, evidenced by increased numbers of CD8+ tumor-infiltrating lymphocytes and CD8A expression, enrichment for a tumor-infiltrating T-cell gene signature, and strong upregulation of the T-cell cytotoxic differentiation and effector markers T-bet, Eomes, IFNG, PRF, and granzyme B. This was accompanied by upregulation of T-cell exhaustion markers, consistent with chronic antigen exposure. In silico analysis confirmed that POLE-mutant cancers are predicted to display more antigenic neoepitopes than other endometrial cancers, providing a potential explanation for our findings.Conclusions: Ultramutated POLE proofreading-mutant endometrial cancers are characterized by a robust intratumoral T-cell response, which correlates with, and may be caused by an enrichment of antigenic neopeptides. Our study provides a plausible mechanism for the excellent prognosis of these cancers. Clin Cancer Res; 21(14); 3347–55. ©2015 AACR.

This file describes additional methodology, Supplementary Tables and Supplementary Figure legends.

Supplementary figure 1. Tumor infiltrating lymphocytes and Crohn's like reaction in POLE- mutant endometrioid endometrial cancers

Supplementary figure 4. CD20+ and FOXP3+ tumor infiltrate according to EC molecular subtype

Legends to supplementary figures and tables

Supplementary figure 2. CD3+ tumor infiltrate according to EC molecular subtype

Supplementary figure 3. Number of TIA-1+ cytolytic T cells according to molecular subtype

Purpose: Radiation therapy techniques have developed from 3-dimensional conformal radiation therapy (3DCRT) to intensity modulated radiation therapy (IMRT), with better sparing of the surrounding normal tissues. The current analysis aimed to investigate whether IMRT, compared to 3DCRT, resulted in fewer adverse events (AEs) and patient-reported symptoms in the randomized PORTEC-3 trial for high-risk endometrial cancer.Methods and materials: Data on AEs and patient-reported quality of life (QoL) of the PORTEC-3 trial were available for analysis. Physician-reported AEs were graded using Common Terminology Criteria for Adverse Events v3.0. QoL was assessed by the European Organisation for Research and Treatment of Cancer QLQC30, CX24, and OV28 questionnaires. Data were compared between 3DCRT and IMRT. A P value of = .01 was considered statistically significant due to the risk of multiple testing. For QoL, combined scores 1 to 2 ("not at all" and "a little") versus 3 to 4 ("quite a bit" and "very much") were compared between the techniques.Results: Of 658 evaluable patients, 559 received 3DCRT and 99 IMRT. Median follow-up was 74.6 months. During treatment no significant differences were observed, with a trend for more grade =3 AEs, mostly hematologic and gastrointestinal, after 3DCRT (37.7% vs 26.3%, P = .03). During follow-up, 15.4% (vs 4%) had grade >= 2 diarrhea, and 26.1% (vs 13.1%) had grade >= 2 hematologic AEs after 3DCRT (vs IMRT) (both P < .01). Among 574 (87%) patients evaluable for QoL, 494 received 3DCRT and 80 IMRT. During treatment, 37.5% (vs 28.6%) reported diarrhea after 3DCRT (vs IMRT) (P = .125); 22.1% (versus 10.0%) bowel urgency (P = 0039), and 18.2% and 8.6% abdominal cramps (P = .058). Other QoL scores showed no differences.Conclusions: IMRT resulted in fewer grade >= 3 AEs during treatment and significantly lower rates of grade >= 2 diarrhea and hematologic AEs during follow-up. Trends toward fewer patient-reported bowel urgency and abdominal cramps were observed after IMRT compared to 3DCRT. (C) 2021 The Authors. Published by Elsevier Inc.

Background: Radiotherapy (RT) is standard of care for most advanced head and neck squamous cell carcinoma (HNSCC) and results in an unfavorable 5-year overall survival of 40%. Despite strong biological rationale, combining RT with immune checkpoint inhibitors does not result in a survival benefit. Our hypothesis is that the combination of these individually effective treatments fails because of radiation-induced immunosuppression and lymphodepletion. By integrating modern radiobiology and innovative radiotherapy concepts, the patient’s immune system could be maximally retained by: (1) increasing the dose per fraction so that the total-dose and number of fractions can be reduced (HYpofractionation), (2) redistributing the radiation dose towards a higher peak dose within the tumor center and a lowered elective lymphatic field dose (Dose-redistribution), and by (3) using RAdiotherapy with protons instead of photons (HYDRA). Methods: The primary aim of this multicenter study is to determine the safety of HYDRA proton- and photon radiotherapy by conducting two parallel phase-I trials. Both HYDRA arms are randomized with standard of care for longitudinal immune profiling. There will be a specific focus on actionable immune targets and their temporal patterns that can be tested in future hypofractionated immuno-radiotherapy trials. The HYDRA dose prescriptions (in 20 fractions) are 40 Gy elective dose and 55 Gy simultaneous integrated boost on the clinical target volume with a 59 Gy focal boost on the tumor center. A total of 100 patients (25 per treatment group) will be recruited, the final analysis will be performed one year after the last patient has been included. Discussion: In the context of HNSCC, hypofractionation has historically only been reserved for small tumors out of fear for late normal tissue toxicity. To date, hypofractionated radiotherapy may also be safe for larger tumors as both the radiation dose and volume can be reduced by the combination of advanced imaging for better target definition, novel accelerated repopulation models and high-precision radiation treatment planning and dose delivery. HYDRA’s expected immune sparing effect may lead to improved outcome by allowing for future effective combination treatment with immunotherapy. Trial registration: The trial is registered at ClinicalTrials.gov; NCT05364411 (registered on May 6th, 2022).

Background Long-term survivors of Hodgkin lymphoma (HL) and mediastinal non-Hodgkin lymphoma experience late adverse effects of radiotherapy and/or anthracycline-containing chemotherapy, leading to premature cardiovascular morbidity and mortality. Objectives The aim of this study was to identify markers for subclinical cardiovascular disease using cardiovascular magnetic resonance (CMR) in survivors of HL and non-Hodgkin lymphoma. Methods CMR was performed in 80 lymphoma survivors treated with mediastinal radiotherapy with or without anthracyclines, and results were compared with those among 40 healthy control subjects matched for age and sex. Results Of the 80 lymphoma survivors, 98% had histories of HL, the mean age was 47 ± 11 years, and 54% were male. Median radiotherapy dose was 36 Gy (interquartile range: 36-40 Gy), and radiotherapy was combined with anthracyclines in 70 lymphoma survivors (88%). Mean time between diagnosis and CMR was 20 ± 8 years. Significantly lower left ventricular (LV) ejection fraction (53% ± 5% vs 60% ± 5%; P < 0.001) and LV mass (47 ± 10 g/m2 vs 56 ± 8 g/m2; P < 0.001) and higher LV end-systolic volume (37 ± 8 mL/m2 vs 33 ± 7 mL/m2; P = 0.013) were found in lymphoma survivors. LV global strain parameters were also significantly worse in lymphoma survivors (P < 0.02 for all). Native myocardial T1 was significantly higher in lymphoma survivors compared with healthy control subjects (980 ± 33 ms vs 964 ± 25 ms; P = 0.007), and late gadolinium enhancement was present in 11% of the survivors. Conclusions Long-term lymphoma survivors have detectable changes in LV function and native myocardial T1 on CMR. Further longitudinal studies are needed to assess the implication of these changes in relation to treatment and clinical outcome., Central Illustration

Patients with locally advanced cervical cancer (LACC) treated with chemoradiation often experience hematologic toxicity (HT), as chemoradiation can induce bone marrow (BM) suppression. Studies on the relationship between BM dosimetric parameters and clinically significant HT might provide relevant indices for developing BM sparing (BMS) radiotherapy techniques. This systematic review studied the relationship between BM dose and HT in patients with LACC treated with primary cisplatin-based chemoradiation. A systematic search was conducted in Embase, Medline, and Web of Science. Eligibility criteria were treatment of LACC-patients with cisplatin-based chemoradiation and report of HT or complete blood cell count (CBC). The search identified 1346 papers, which were screened on title and abstract before two reviewers independently evaluated the full-text. 17 articles were included and scored according to a selection of the TRIPOD criteria. The mean TRIPOD score was 12.1 out of 29. Fourteen studies defining BM as the whole pelvic bone contour (PB) detected significant associations with V10 (3/14), V20 (6/14), and V40 (4/11). Recommended cut-off values were V10 > 95-75%, V20 > 80-65%, and V40 > 37-28%. The studies using lower density marrow spaces (PBM) or active bone marrow (ABM) as a proxy for BM only found limited associations with HT. Our study was the first literature review providing an overview of articles evaluating the correlation between BM and HT for patients with LACC undergoing cisplatin-based chemoradiation. There is a scarcity of studies independently validating developed prediction models between BM dose and HT. Future studies may use PB contouring to develop normal tissue complication probability models. (c) 2021 The Author(s). Published by Elsevier B.V. Radiotherapy and Oncology 164 (2021) 128-137 This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Objective. To evaluate feasibility of chemoradiation as alternative for extensive surgery in patients with locally advanced vulvar cancer and to report on locoregional control, toxicity and survival. Methods. In a multicenter, prospective phase II trial patients with locally advanced vulvar cancer were treated with locoregional radiotherapy combined with sensitizing chemotherapy (capecitabine). Treatment feasibility, percentage locoregional control, survival and toxicity were evaluated. Results. 52 patients with mainly T2/T3 disease were treated according to the study protocol in 10 centers in the Netherlands from 2007 to 2019. Full dose radiotherapy (tumor dose of 64.8Gy) was delivered in 92% and full dose capecitabine in 69% of patients. Most prevalent acute >_ grade 3 toxicities were regarding skin/ mucosa and pain (54% and 37%). Late >_grade 3 toxicity was reported for skin/mucosa (10%), fibrosis (4%), GI incontinence (4%) and stress fracture or osteoradionecrosis (4%). Twelve weeks after treatment, local clinical complete response (cCR) and regional control (RC) rates were 62% and 75%, respectively. After 2 years, local cCR persisted in 22 patients (42%) and RC was 58%. Thirty patients (58%) had no evidence of disease at end of follow-up (median 35 months). In 9 patients (17%) extensive surgery with stoma formation was needed. Progression free survival was 58%, 51% and 45% and overall survival was 76%, 66%, 52% at 1,2, and 5 years. Conclusions. Definitive capecitabine-based chemoradiation as alternative for extensive surgery is feasible in locally advanced vulvar cancer and results in considerable locoregional control with acceptable survival rates with manageable acute and late toxicity. (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Highlights • Converting the ESTRO gyn teaching course to an online version did not affect participant numbers. • Participant satisfaction and engagement remained high despite less direct contact time with faculty. • The number of participants submitting contouring and dose planning homework was higher than for live courses. • Viewing of pre-course lecture content was variable which may reflect self-perceived learning needs based on different levels of experience., Introduction In 2020, the ESTRO course on image-guided radiotherapy and chemotherapy in gynaecological cancer was converted into an online version due to the COVID-19 pandemic. This paper describes the change process and evaluates the impact on participants compared with previous live courses. Methods and materials The 2019 live course contained 41 h of educational content, comprising 33 h of synchronous activities (lectures, interactive activities, videos) and 8 h of homework (contouring, dose planning). For the online course, the lectures were provided as pre-course material (11 mandatory, 22 optional). Contouring/dose planning homework was unchanged. The synchronous sessions were reconfigured as six 2-hour webinars (total educational content ~38 h). Participant numbers/characteristics, engagement and satisfaction for six live courses and the online course were compared. Results Participant numbers for the online and live courses were similar (90 vs. mean 96). There were more participants from outside Europe (28% vs. mean 18%) and more non-doctors (47% vs. mean 33%). Proportion of participants responding to the pre-course questionnaire was similar (77% vs. mean 78%) but post-course questionnaire response was lower (62% vs. mean 92%). 43% participants viewed ≥75% of mandatory lectures before the webinars. 86% viewed the optional lectures. Submissions of contouring and dose planning homework was higher (contouring 77%–90% vs. 56%–69%, dose planning 74%–89% vs. 29%–57%). 96% (47/49) participants rated the online course as Excellent (43%) or Good (53%). Overall satisfaction was similar (4.4 vs. mean 4.6). Conclusion Participant satisfaction and engagement with the online course remained high despite less contact time with faculty.

Serous endometrial cancer represents a relative rare entity accounting for about 10% of all diagnosed endometrial cancer, but it is responsible for 40% of endometrial cancer-related deaths. Patients with serous endometrial cancer are often diagnosed at earlier disease stage, but remain at higher risk of recurrence and poorer prognosis when compared stage-for-stage with endometrioid subtype endometrial cancer. Serous endometrial cancers are characterized by marked nuclear atypia and abnormal p53 staining in immunohistochemistry. The mainstay of treatment for newly diagnosed serous endometrial cancer includes a multi-modal therapy with surgery, chemotherapy and/or radiotherapy. Unfortunately, despite these efforts, survival outcomes still remain poor. Recently, The Cancer Genome Atlas (TCGA) Research Network classified all endometrial cancer types into four categories, of which, serous endometrial cancer mostly is found within the "copy number high" group. This group is characterized by the increased cell cycle deregulation (e.g., CCNE1, MYC, PPP2R1A, PIKCA, ERBB2 and CDKN2A) and TP53 mutations (90%). To date, the combination of pembrolizumab and lenvatinib is an effective treatment modality in second-line therapy, with a response rate of 50% in advanced/recurrent serous endometrial cancer. Owing to the unfavorable outcomes of serous endometrial cancer, clinical trials are a priority. At present, ongoing studies are testing novel combinations of various targeted and immunotherapeutic agents in newly diagnosed and advanced/recurrent endometrial cancer - an important strategy for serous endometrial cancer, whereby tumors are usually p53+ and pMMR, making response to PD-1 inhibitor monotherapy unlikely. Here, the rare tumor working group (including members from the European Society of Gynecologic Oncology (ESGO), Gynecologic Cancer Intergroup (GCIG), and Japanese Gynecologic Oncology Group (JGOG)), performed a narrative review reporting on the current landscape of serous endometrial cancer and focusing on standard and emerging therapeutic options for patients affected by this difficult disease.

Accurate risk prediction of distant recurrence (DR) is crucial for personalized adjuvant systemic therapy of endometrial cancer (EC) stage I-III patients, as DR is associated with a 5-year overall survival of 10-20%. Risk stratification and treatment recommendation are currently based on histopathological and molecular markers, which is challenging due to high inter-observer variability and testing costs respectively. Deep Learning (DL) models can predict prognosis by identifying relevant visual features from H&E whole slide images (WSIs) at different resolutions without prior assumptions. Here, we developed and tested the first interpretable state-of-the-art DL model for WSI-based risk prediction of DR of stage I-III EC (DeREC) from the randomized PORTEC-1/-2/-3 trials and three clinical cohorts with long-term follow-up data. We used one representative H&E WSI each from 1761 EC patients, excluding those who received adjuvant chemotherapy as it lowers the risk of DR. We randomly sampled 20% as a held-out internal test set (N=353 with 62 events; 8.45 year median follow-up) and performed a 5-fold cross-validation on the training set (N=1408). WSIs were partitioned into 360 micron patches at 40x magnification. DeREC combined self-supervised representation learning of patches using a multi-resolution vision transformer and a WSI-level graph attention-based time-to-event prediction model. The model performance of correctly ranking patients by predicted risk scores and true time to DR was measured with the concordance-index and compared with a Cox’ Proportional Hazards (CPH) model fitted on histopathological variables (histotype, grade, lymphovascular space invasion, stage). Discriminative quality of the predicted risk groups was investigated with Kaplan-Meier analysis and the log-rank test. Most predictive patches by predicted risk groups were reviewed by an expert gynecopathologist for identification of prognostic morphological features. DeREC achieved a concordance-index of 0.764 [95%CI 0.754-0.773] on 5-fold cross validation and 0.757 on the test set, as compared to 0.704 [95%CI 0.662-0.746] with CPH. Predicted risk groups around quartiles 1 and 3 accurately stratified patients between low (N=89), intermediate (N=175), high (N=89) risk of DR (p Citation Format: Sarah Fremond, Sonali Andani, Jurriaan Barkey Wolf, Gitte Ørtoft, Estrid Høgdall, Jouke Dijkstra, Jan J. Jobsen, Ina M. Jürgenliemk-Schulz, Ludy CHW Lutgens, Melanie E. Powell, Naveena Singh, Linda R. Mileshkin, Helen J. Mackay, Alexandra Leary, Dionyssios Katsaros, Hans W. Nijman, Stephanie M. de Boer, Remi A. Nout, Vincent T.H.B.M Smit, Carien L. Creutzberg, Nanda Horeweg, Viktor H. Koelzer, Tjalling Bosse. Deep learning risk prediction model of distant recurrence from H&E endometrial cancer slides. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5695.

BackgroundVaginal brachytherapy is currently recommended as adjuvant treatment in patients with high-intermediate risk endometrial cancer to maximize local control and has only mild side effects and no or limited impact on quality of life. However, there is still considerable overtreatment and also some undertreatment, which may be reduced by tailoring adjuvant treatment to the patients’ risk of recurrence based on molecular tumor characteristics.Primary objectivesTo compare the rates of vaginal recurrence in women with high-intermediate risk endometrial cancer, treated after surgery with molecular-integrated risk profile-based recommendations for either observation, vaginal brachytherapy or external pelvic beam radiotherapy or with standard adjuvant vaginal brachytherapyStudy hypothesisAdjuvant treatment based on a molecular-integrated risk profile provides similar local control and recurrence-free survival as current standard adjuvant brachytherapy in patients with high-intermediate risk endometrial cancer, while sparing many patients the morbidity of adjuvant treatment and reducing healthcare costs.Trial designA multicenter, international phase III randomized trial (2:1) of molecular-integrated risk profile-based adjuvant treatment (experimental arm) or adjuvant vaginal brachytherapy (standard arm).Major inclusion/exclusion criteriaWomen aged 18 years and over with a histological diagnosis of high-intermediate risk endometrioid endometrial cancer after total abdominal or laparoscopic hysterectomy and bilateral salpingo-oophorectomy. High-intermediate risk factors are defined as: (i) International Federation of Gynecology and Obstetrics stage IA (with invasion) and grade 3; (ii) stage IB grade 1 or 2 with age ≥60 and/or lymph-vascular space invasion; (iii) stage IB, grade 3 without lymph-vascular space invasion; or (iv) stage II (microscopic and grade 1).EndpointsThe primary endpoint is vaginal recurrence. Secondary endpoints are recurrence-free and overall survival; pelvic and distant recurrence; 5-year vaginal control (including treatment for relapse); adverse events and patient-reported symptoms and quality of life; and endometrial cancer-related healthcare costs.Sample size500 eligible and evaluable patients.Estimated dates for completing accrual and presenting resultsEstimated date for completing accrual will be late 2021. Estimated date for presentation of (first) results is expected in 2023.Trial registrationThe trial is registered at clinicaltrials.gov (NCT03469674) and ISRCTN (11659025).

Randomized controlled trials (RCTs) are considered as the gold standard for testing causal hypotheses in the clinical domain. However, the investigation of prognostic variables of patient outcome in a hypothesized cause-effect route is not feasible using standard statistical methods. Here, we propose a new automated causal inference method (AutoCI) built upon the invariant causal prediction (ICP) framework for the causal re-interpretation of clinical trial data. Compared to existing methods, we show that the proposed AutoCI allows to efficiently determine the causal variables with a clear differentiation on two real-world RCTs of endometrial cancer patients with mature outcome and extensive clinicopathological and molecular data. This is achieved via suppressing the causal probability of non-causal variables by a wide margin. In ablation studies, we further demonstrate that the assignment of causal probabilities by AutoCI remain consistent in the presence of confounders. In conclusion, these results confirm the robustness and feasibility of AutoCI for future applications in real-world clinical analysis., Submitted to Nature Machine Intelligence. The code is publicly available via https://github.com/CTPLab/AutoCI

We investigated whether the addition of adjuvant chemotherapy to chemoradiation improves overall survival (OS) and progression-free survival (PFS) by conducting a systematic review and meta-analysis. Systematic searches in the databases of PubMed, Embase and Web of Science yielded 881 articles. Two reviewer authors independently selected 31 articles for full text review and deemed eight studies eligible for inclusion. Two were randomised controlled trials (RCT), one was a large (n = 609) matched-case study and the remaining were small retrospective cohort studies; in total 2150 patients. Risk of bias assessment showed that the RCTs were at low risk and all other studies were at high risk of bias. Pooled hazard ratios for OS and PFS were 0.78 (95%CI 0.45-1.33, p = 0.36) and 0.85 (95%CI 0.65-1.10, p = 0.22), respectively. Analysis stratified by study design and sensitivity analysis showed similar results. Funnel plots showed significant publication bias due to a lack of small studies with negative outcomes.

Objective: Osteoradionecrosis (ORN) is a severe late complication after radiotherapy but current knowledge on ORN risks in the setting of postoperative radiotherapy (PORT) is limited. We studied the incidence and risk factors of ORN in patients with oral cavity cancers (OCC, treated with PORT.Patients and Methods: A retrospective cohort study was conducted including OCC patients (mainly squamous cell) treated with postoperative intensity modulated radiotherapy between 2010 and 2018 with > 1 year disease-free survival. Cumulative incidences of ORN were computed using the Kaplan Meier method. Clinical and dosimetric risk factors for mandibular ORN were evaluated using Cox regression models.Results: Within our cohort (N = 227, median follow-up 49 months) we observed 46 cases of ORN, mainly in the mandible (n = 41). The cumulative incidence of mandibular ORN was 15.9 % (SE 2.5 %) at three years and 19.8 % (SE 3.0 %) at five years. At univariable analysis, smoking, mandibular mandibulotomy or segment resection, mean dose to the mandible, and mandible volume (%) >= 60 Gy (V60) were significantly associated with increased ORN risks. At multivariable analysis, smoking (HR 2.13, 95 %CI 1.12-4.06) and V60 (HR 1.02 per 1 % increase, 95 %CI 1.01-1.04) remained predictive factors. For active smokers with a high V60 >= 40 % we observed rapid ORN development with a 1-year incidence of 29 % vs 6 % for others (p < 0.01).Conclusion: OCC Patients treated with PORT are at high risk for mandibular ORN. We identified the mandibular volume receiving >= 60 Gy as the dominant risk factor, especially in active smokers. Limiting high-dose volumes at treatment planning may decrease ORN risks.

In 2008, the GEC ESTRO Gyn network launched the first multiinstitutional, observational, and prospective international study on MRI-guided brachytherapy in locally advanced cervical cancer patients (EMBRACE-I). EMBRACE-I was followed by EMBRACE-II from 2016 and ongoing. Among the aims of the EMBRACE studies are to benchmark morbidity outcomes and develop dose-volume effects and predictive models for morbidity. The EMBRACE studies collect both physician (CTCAE v.3) and patient (EORTC QLQ-C30/CX24) reported outcomes, including baseline information, in a regular follow-up schedule. The EMBRACE studies feature high numbers of patients (EMBRACE-I N = 1416, EMBRACE-II N = 1500 expected) enrolled from many institutions worldwide (EMBRACE-I n = 23, EMBRACE-II n = 45). This large-scale multiinstitutional approach offers a unique opportunity to investigate and develop new strategies for improving the quality of assessment and reporting of morbidity. This report presents an overview of the challenges and pitfalls regarding the assessment and reporting of morbidity encountered during more than a decade of development and research activities within the EMBRACE consortium. This includes the recognition and evaluation of inconsistencies in the morbidity assessment, and consequently, the provision of assistance and training in the scoring procedure to reduce systematic assessment bias. In parallel, a variety of methodological approaches were tested to comprehensively summarize morbidity outcomes, and a novel approach was developed to refine dose-effect models and risk factor analyses. The purpose of this report is to present an overview of these findings, describe the learning process, and the strategies that have consequently been implemented regarding educational activities, training, and dissemination.

Human papillomaviruses (HPV)-related gynecological cancers are a major health care issue, and a leading cause of cancer death in low- and middle-income countries (LMIC). In 2020, the World Health Organization launched a program aimed at cervical cancer elimination, by screening and vaccination strategies. Offering the best possible care to women diagnosed with invasive cancer is a complementary objective. Treatment of cervical cancer as per modern standards is complex and multimodal, mainly relying on surgery, external-beam radiotherapy (+/−chemotherapy) and brachytherapy. In parallel with the pivotal role of multidisciplinary discussion, international societies provide guidance to define the most effective and least toxic anti-cancer strategy, homogenize treatment protocols and provide benchmark quality indicators as a basis for accreditation processes. The challenge is to offer the appropriate diagnostic workup and treatment upfront and to avoid non- evidence-based treatment that consumes resources, impairs quality of life (QoL), and compromises oncological outcome. Various strategies may be applied for improving treatment quality: development of surgical mentorship, companion-training programs and international cooperation. The lack of radiotherapy/brachytherapy facilities is a major concern in LMIC. Reinforcing international support in terms of education, training, research and development and technical cooperation with national projects is required to increase access to minimum requirements but also introduce modern techniques, upgrade radiotherapy/brachytherapy services, and expand access to modern systemic treatments. In countries with robust economies, compliance to standards should also be increased. Integrative cancer care and multidisciplinary approaches are needed to tackle the dual challenge of increasing cure rates while minimizing QoL impairment. Appropriate dimensioning of the resources to avoid harmful treatment delays and access to expert referral centers is also a priority.

Simple Summary Chemoradiation with photon radiotherapy is very effective as a locally advanced cervical cancer (LACC) treatment. However, the majority of women with LACC experience treatment-related toxicity involving the gastrointestinal and urogenital tracts and the immune system. Compared to that of photon therapy, proton therapy substantially reduces undesired dose to the organs around the tumor, leading to a decrease in radiotherapy-related side-effects. At present, few studies on proton therapy in patients with LACC will be conducted. The PROTECT trial aims to evaluate the differences in side effects between photon therapy and proton therapy, both combined with chemotherapy, for LACC. Fifteen patients will be enrolled per treatment group. Information will be collected on the differences in dose to the organs around the tumor, treatment-related side effects, and the impact on the immune system. This information will be used to assess the potential of proton therapy as an innovative treatment for LACC. Abstract External beam radiation therapy (EBRT) with concurrent chemotherapy followed by brachytherapy is a very effective treatment for locally advanced cervical cancer (LACC). However, treatment-related toxicity is common and reduces the patient’s quality of life (QoL) and ability to complete treatment or undergo adjuvant therapies. Intensity modulated proton therapy (IMPT) enables a significant dose reduction in organs at risk (OAR), when compared to that of standard intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT). However, clinical studies evaluating whether IMPT consequently reduces side effects for LACC are lacking. The PROTECT trial is a nonrandomized prospective multicenter phase-II-trial comparing clinical outcomes after IMPT or IMRT/VMAT in LACC. Thirty women aged >18 years with a histological diagnosis of LACC will be included in either the IMPT or IMRT/VMAT group. Treatment includes EBRT (45 Gy in 25 fractions of 1.8 Gy), concurrent five weekly cisplatin (40 mg/m2), and 3D image (MRI)-guided adaptive brachytherapy. The primary endpoint is pelvic bones Dmean and mean bowel V15Gy. Secondary endpoints include dosimetric parameters, oncological outcomes, health-related QoL, immune response, safety, and tolerability. This study provides the first data on the potential of IMPT to reduce OAR dose in clinical practice and improve toxicity and QoL for patients with LACC.

Introduction/Background* The TransPORTEC Consortium was established in 2013 by the PIs and translational science representatives of the PORTEC-3 trial groups from the Netherlands, United Kingdom, Australia, Canada and France. Purpose of the collaboration is to improve treatment of endometrial cancer (EC) patients. Here, we evaluate our experience with international collaboration to identify challenges and strengths. Methodology Result(s)*: Since its establishment, TransPORTEC had a strong scientific team of chief investigators, translational leads and core members from participating groups. Twice-yearly TransPORTEC-meetings were organised to build and maintain friendships, share results and discuss new proposals. Over time, the TransPORTEC-biobank has expanded with PORTEC-trial tumour tissues and other cohorts, and is now the world’s largest set of molecularly classified ECs. The research focus has expanded to include molecular cancer immunology and digital pathology. The group’s output include 10 scientific papers and numerous posters and presentations on (inter)national meetings. Their analysis of PORTEC-3 showing differences in chemotherapy effect by molecular group led to initiating an international program with 4 clinical trials on Refining Adjuvant treatment IN endometrial cancer Based On molecular features (RAINBO) to compare personalised to standard treatment in terms of efficacy, toxicity, quality of life and cost-utility (figure 1). Tumour material of all participants will be collected for translational research. To achieve this, the consortium evolved: new talented members were attracted and trial-specific and expertise teams were installed (figure 2). Despite this impacting on group equilibrium, the collaboration is continuously productive. Keys to success were frequent meetings, sharing of draft protocols and experiences with contacting (inter)national research organisations and potential funders. The first of the RAINBO trials is expected to open by the end of 2021 and the program will probably fuel translational research for years to come. Conclusion* International research collaborations are dynamic and demanding. Challenges include: balancing between a stable organisational structure and flexibility to adapt to opportunities; providing all members with a satisfying share; and acquisition of funding for academic-sponsored international trials. Strengths are the profound interaction and trust between members with different expertise and backgrounds and shared ambitions and successes, resulting in unique and innovative academic research projects with leverage.

Introduction/Background* The molecular endometrial cancer (EC) classification has proven prognostic value and can direct adjuvant treatment decisions. Despite this, a relatively large group of EC is still molecularly unclassified (NSMP-EC). In this study we aimed to identify biomarkers among high-risk NSMP-EC patients with prognostic and/or predictive relevance. Methodology Paraffin-embedded tumour material (n=423) from the PORTEC-3 HREC trial were available for analysis. All patients with NSMP-EC were selected, hence those without pathogenic POLE mutations, mismatch repair deficiency and p53-abnormal immunohistochemistry (IHC). Protein expression of L1CAM, ER and PR (ongoing) were analysed by IHC using a 10% threshold for positivity. Tumour DNA was analysed for pathogenic somatic mutations using a next generation sequencing (NGS) cancer hotspot panel. Time to recurrence was analysed using the Kaplan-Meier method, log-rank tests and Cox’s proportional hazard models. Result(s)* In total, 126 NSMP-EC were identified in PORTEC-3, the majority were hormone receptor positive (ER n=106/121, 87.6%, PR will be presented at ESGO2021). L1CAM overexpression was observed in 11.2% (n=14/125) and mutations in CTNNB1-exon-3 were identified in 34.3% (n=36/105). Clustering showed that ER-positive NSMP-EC were predominantly endometrioid EC (n=99, 93.4%), low grade (n=88, 83.0%) and L1CAM-negative (n=102, 97.1%) (figure 1). PIK3CA and KRAS mutations were present in 27.3% (n=24) and 19.3% (n=17), respectively. ER-negative NSMP-EC were frequently non-endometrioid (n=11, 73.3%), L1CAM-positive (n=11, 73.3%) and rarely harboured PTEN and CTNNB1 mutations (n=1, 7.1% and 0%, respectively). ER-positivity was associated with lower risk of recurrence (HR 0.32 [95%CI 0.14-0.70]; figure 2A), while L1CAM-overexpression and CTNNB1-exon-3 mutations were not (HR 2.25 [95%CI 0.93-5.43] and HR 1.20 [95%CI 0.57-2.54], respectively). Multivariable analysis confirmed independent favourable prognostic impact of ER-positivity and LVSI. Figure 2B shows impact of LVSI on time to recurrence among patients with ER-positive NSMP-EC. Conclusion* The vast majority of NSMP-HREC are ER-positive (87.6%) and are likely sensitive to hormonal therapy. Other treatment targets might be found in this subgroup too as 27.3% had PIK3CA and 19.3% had KRAS mutations. NSMP-EC with loss of ER-expression were often of non-endometrioid histology and had a high risk of recurrence. Future studies should investigate whether this subgroup would benefit from other systemic therapies.

Introduction/Background* The molecular endometrial cancer (EC) classification has proven prognostic impact. However, patients included in previous studies were not always staged by lymphadenectomy (LND) and often received adjuvant treatment (AT). This may have moderated the prognostic effect of the molecular classification. We evaluated the prognostic significance of the molecular classification in high-grade EC patients staged by LND and those without AT. Methodology Targeted DNA-sequencing for pathogenic POLE-exonuclease domain mutations and immunohistochemistry for mismatch repair (MMR) proteins and p53 expression were performed on 412 high-grade EC from the Danish Gynecological Cancer Database 2005-2012 to classify them as POLE-ultramutated (POLEmut), MMR-deficient (MMRd), p53-mutant (p53abn), or no specific molecular profile (NSMP). Patients with stage IV or residual disease after surgery were excluded. Analyses were performed on patients staged by LND and on patients without AT. Time to recurrence analyses were performed using the Kaplan-Meier method, log-rank test and Cox proportional hazard’s models. Pre-specified multivariate regression analyses were performed including age, ASA class, stage, lymphovascular space invasion and in the LND subgroup a propensity score to correct for confounding by indication. Result(s)* Molecular analysis was successful in 367 EC; 251 patients had undergone LND, see table 1. Median follow-up was 11 years (range 7.5-15.4). Multivariable analysis showed that molecular subgroup was a strong independent prognostic factor for recurrence: p53abn HR 3.88 (95%CI 1.89-7.94, p Among 264 patients without AT, 247 (94%) had stage I-II disease and 17 (6%) stage III. None of the patients with POLEmut EC (n=26, 10%) had a recurrence (figure 1B). Multivariable analysis showed that the significant prognostic impact of molecular subgroup was independent of clinicopathological factors. Conclusion* The molecular EC classification has strong prognostic value, independent of clinicopathological factors, also among patients staged by LND and those without AT. This implies that the unfavourable prognosis of p53abn EC is not caused by undetected lymph node metastasis. POLEmut EC is inherently associated with an excellent prognosis even in the absence of adjuvant treatment.