VEXAS and Myelodysplastic Syndrome: An Interdisciplinary Challenge

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently recognized systemic autoinflammatory disease caused by somatic mutations in hematopoietic progenitor cells. This case series of four patients with VEXAS syndrome and comorbid myelodysplastic syndrome (MDS) aims to describe clinical, imaging, and hematologic disease presentations as well as response to therapy. Four patients with VEXAS syndrome and MDS are described. A detailed analysis of imaging features, hemato-oncological presentation including bone marrow microscopy and clinical-rheumatological disease features and treatment outcomes is given. All patients were male; ages ranged between 64 and 81 years; all were diagnosed with MDS. CT imaging was available for three patients, all of whom exhibited pulmonary infiltrates of varying severity, resembling COVID-19 or hypersensitivity pneumonitis without traces of scarring. Bone marrow microscopy showed maturation-disordered erythropoiesis and pathognomonic vacuolation. Somatic mutation in the UBA1 codon 41 were found in all patients by next-generation sequencing. Therapy regimes included glucocorticoids, JAK1/2-inhibitors, nucleoside analogues, as well as IL-1 and IL-6 receptor antagonists. No fatalities occurred (observation period from symptom onset: 18-68 months). Given the potential underreporting of VEXAS syndrome, we highly recommend contemporary screening for UBA1 mutations in patients presenting with ambiguous signs of systemic autoinflammatory symptoms which persist over 18 months despite treatment. The emergence of cytopenia, especially macrocytic hyperchromic anemia, should prompt early testing for UBA1 mutations. Notably conspicuous, pulmonary alterations in CT imaging of patients with therapy-resistant systemic autoinflammatory symptoms should be discussed in interdisciplinary medical teams (Rheumatology, Hematology, Radiology and further specialist departments) to facilitate timely diagnosis during the clinical course of the disease.

Tumour mutational burden and survival with molecularly matched therapy

BACKGROUND

The impact of tumour mutational burden (TMB) on outcome with molecularly matched therapy is unknown. Higher TMB could predict resistance to molecularly matched therapy through co-occurring driver mutations.

METHODS

One hundred and four patients with advanced cancers underwent molecular profiling in the DKTK-MASTER program. Fifty-five patients received systemic therapy excluding immunotherapy. Patients with molecularly matched (n = 35) or non-molecularly informed therapy (n = 20) were analysed for TMB and survival. Results were validated in an independent cohort of patients receiving molecularly matched (n = 68) or non-molecularly informed therapy (n = 40). Co-occurring driver mutations and TMB were analysed in the exploratory cohort and The Cancer Genome Atlas (TCGA) datasets.

RESULTS

Patients were stratified by the median TMB of 1.67 mutations per Megabase (mut/Mb) of 35 patients receiving molecularly matched therapy into TMB-high or TMB-low groups. Median overall survival (4 months [95% CI, 3.3-7.6] versus 12.8 months [95% CI, 10-not reached], p < 0.001) and progression-free survival (1.8 months [95% CI, 1.1-3.7] versus 7.9 months [95% CI, 2.8-17.0], p = 0.003) were significantly shorter in the TMB-high group compared to the TMB-low group. In the validation cohort, shorter OS and PFS were identified in the TMB-high group (TMB cut-off of 4 mut/Mb) treated with molecularly matched therapy. No differences were observed in patients receiving non-molecularly informed systemic therapy. A significant correlation between co-occurring driver mutations and TMB (n = 104, r = 0.78 [95% CI, 0.68-0.85], p < 0.001) was found in the exploratory cohort as well as the majority (24/33) of TCGA studies.

CONCLUSION

A high TMB was associated with unfavourable outcome in patients receiving molecularly matched therapy, indicating untargeted resistance pathways. Therefore, TMB should be further investigated as a predictive biomarker in precision oncology programs.

Abstract 926: Genomics-based personalized oncology of advanced thymic epithelial tumors

Introduction: Thymic epithelial tumors (TETs) are very rare. Thymoma A and AB have a better prognosis than more aggressive thymoma B, thymic carcinoma (TC) and neuroendocrine tumors of the thymus (NET). While previous efforts such as TCGA have mainly characterized thymomas (Radovich et al., Cancer Cell 2018), the molecular landscape of TCs and NETs is still elusive.

Patients and Methods: Between 03/2014 and 07/2020, we enrolled 44 TET patients (27 TCs, 11 thymomas, 6 NETs) in a prospective observational study (MASTER) conducted by the National Center for Tumor Diseases (NCT) Heidelberg, NCT Dresden and the German Cancer Consortium (DKTK). MASTER applied whole genome/exome sequencing (WGS, n=22; WES, n=22), transcriptome (n=40) and germline analysis to inform therapy recommendations by a dedicated molecular tumor board (MTB). We systematically gathered follow-up data to evaluate outcome and compared progression-free survival (PFS) of the first treatment according to an MTB recommendation (PFS2) to the last prior systemic treatment (PFS1) in each patient (PFS ratio).

Results: Tumor mutational burden (TMB) was low (median=0.99 mutations/Mb, range 0.08-3.48) but higher than in TCGA (p&lt;0.05). TMB was higher in TCs than in thymoma (p&lt;0.05). Most frequently mutated genes were TP53 (30%), CYLD (16%), SETD2 (14%) and KIT (14%). Germline analysis revealed (likely) pathogenic germline alterations in 25% of patients (MUTYH, n=3; BRCA1, n=2; BRCA2, BAP1, CHEK2, FANCA, TP53, MEN1, n=1). A comprehensive analysis of candidate biomarkers of homologous recombination repair (HRR) defects revealed a subgroup of TET patients with a rationale for PARP inhibitor therapy. Unsupervised clustering of RNA sequencing data mainly revealed clustering that correlated with WHO classification. Additionally, TCs clustered in two subgroups that we identified as immunologically hot and cold tumors using immunohistochemistry validation. Overall survival of patients with hot tumors was significantly longer (p&lt;0.05). The MTB recommended therapies for 42 patients (95%), which were implemented in 24 cases (57%). Five patients had a PFS2 &gt; 6 months and a PFS ratio &gt; 1.3. The best outcome was achieved using imatinib in a patient with a KIT mutation (p.W557R). After progression, the MTB recommended ponatinib based on a secondary KIT mutation (p.V654A). The patient was still on ponatinib when the observation period ended.

Conclusion: We demonstrate that comprehensive molecular analysis provides clinically relevant information in a subgroup of TET patients. Thymoma, TCs, and NETs present with different molecular characteristics. Distinction between immunologically hot and cold TCs may have value for risk stratification and therapeutic strategies. PARP inhibition could be a potential new treatment option in a small subgroup of TETs. Molecular testing of KIT, germline analysis and genetic counseling should be recommended for all patients with advanced TETs.

Citation Format: Lino Möhrmann, Lysann Rostock, Małgorzata Oleś, Arne Jahn, Marie Arlt, Nagarajan Paramasivam, Korinna Jöhrens, Luise Rupp, Marc Schmitz, Daniela Richter, Sebastian Uhrig, Martina Fröhlich, Barbara Hutter, Jennifer Hüllein, Elena E. Wolf, Dorothea Hanf, Laura Gieldon, Simon Kreutzfeldt, Christoph E. Heilig, Veronica Teleanu, Daniel B. Lipka, Andreas Mock, Ivan Jelas, Damian T. Rieke, Marcel Wiesweg, Melanie Boerries, Anna L. Illert, Alexander Desuki, Thomas Kindler, Angela M. Krackhardt, C. Benedikt Westphalen, Heidrun Grosch, Leonidas Apostolidis, Albrecht Stenzinger, Irina A. Kerle, Christoph Heining, Daniel Hübschmann, Evelin Schröck, Stefan Fröhling, Hanno Glimm. Genomics-based personalized oncology of advanced thymic epithelial tumors [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 926.

Feasibility and outcome of reproducible clinical interpretation of high-dimensional molecular data: a comparison of two molecular tumor boards

BACKGROUND

Structured and harmonized implementation of molecular tumor boards (MTB) for the clinical interpretation of molecular data presents a current challenge for precision oncology. Heterogeneity in the interpretation of molecular data was shown for patients even with a limited number of molecular alterations. Integration of high-dimensional molecular data, including RNA- (RNA-Seq) and whole-exome sequencing (WES), is expected to further complicate clinical application. To analyze challenges for MTB harmonization based on complex molecular datasets, we retrospectively compared clinical interpretation of WES and RNA-Seq data by two independent molecular tumor boards.

METHODS

High-dimensional molecular cancer profiling including WES and RNA-Seq was performed for patients with advanced solid tumors, no available standard therapy, ECOG performance status of 0-1, and available fresh-frozen tissue within the DKTK-MASTER Program from 2016 to 2018. Identical molecular profiling data of 40 patients were independently discussed by two molecular tumor boards (MTB) after prior annotation by specialized physicians, following independent, but similar workflows. Identified biomarkers and resulting treatment options were compared between the MTBs and patients were followed up clinically.

RESULTS

A median of 309 molecular aberrations from WES and RNA-Seq (n = 38) and 82 molecular aberrations from WES only (n = 3) were considered for clinical interpretation for 40 patients (one patient sequenced twice). A median of 3 and 2 targeted treatment options were identified per patient, respectively. Most treatment options were identified for receptor tyrosine kinase, PARP, and mTOR inhibitors, as well as immunotherapy. The mean overlap coefficient between both MTB was 66%. Highest agreement rates were observed with the interpretation of single nucleotide variants, clinical evidence levels 1 and 2, and monotherapy whereas the interpretation of gene expression changes, preclinical evidence levels 3 and 4, and combination therapy yielded lower agreement rates. Patients receiving treatment following concordant MTB recommendations had significantly longer overall survival than patients receiving treatment following discrepant recommendations or physician's choice.

CONCLUSIONS

Reproducible clinical interpretation of high-dimensional molecular data is feasible and agreement rates are encouraging, when compared to previous reports. The interpretation of molecular aberrations beyond single nucleotide variants and preclinically validated biomarkers as well as combination therapies were identified as additional difficulties for ongoing harmonization efforts.

Liquid Biopsy in Colorectal Cancer: Quo Vadis? Implementation of Liquid Biopsies in Routine Clinical Patient Care in Two German Comprehensive Cancer Centers

Objectives

The use of liquid biopsies (LB) in patients with solid malignancies enables comprehensive genomic profiling (CGP) of circulating tumor DNA (ctDNA) and has the potential to guide therapy stratification and support disease monitoring. To examine clinical uptake of LB in a real-world setting, LB implementation was analyzed at two German cancer centers (LMU Munich and Charité - Universitätsmedizin Berlin) between 2017 and 2021, with focus on colorectal cancer (CRC) patients.

Methods

In this retrospective analysis, all patients who received a LB between January 2017 and December 2021 as part of routine clinical management were included. To provide adequate context, we collected disease characteristics and technical specifications of the LB methods applied. Additionally, we examined the concordance of RAS status in tumor tissue and LB. Finally, we discuss the potential of LB as a diagnostic tool to drive personalized treatment in CRC patients and how to implement LB in clinical routine.

Results

In total, our cohort included 86 CRC patients and 161 LB conducted in these patients between 2017 and 2021. In 59 patients, comparison between tissue-based and liquid-based molecular diagnostics, revealed a divergence in 23 (39%) of the evaluable samples.

Conclusion

Our real-world data analysis indicates that the possibilities of LB are not yet exploited in everyday clinical practice. Currently, the variety of methods and lack of standardization, as well as restricted reimbursement for liquid based CGP hinder the use of LB in clinical routine. To overcome these issues, prospective clinical trials are needed to provide evidence driving the implementation of LB into the management of CRC patients and to support their implementation into clinical guidelines.

Response and Disease Dynamics in Untreated Metastatic Colorectal Cancer With Bevacizumab-Based Sequential vs. Combination Chemotherapy—Analysis of the Phase 3 XELAVIRI Trial

Introduction

Early tumor shrinkage (ETS), depth of response (DpR), and time to DpR represent exploratory endpoints that may serve as early efficacy parameters and predictors of long-term outcome in metastatic colorectal cancer (mCRC). We analyzed these endpoints in mCRC patients treated with first-line bevacizumab-based sequential (initial fluoropyrimidines) versus combination (initial fluoropyrimidines plus irinotecan) chemotherapy within the phase 3 XELAVIRI trial.

Methods

DpR (change from baseline to smallest tumor diameter), ETS (≥20% reduction in tumor diameter at first reassessment), and time to DpR (study randomization to DpR image) were analyzed. We evaluated progression-free survival and overall survival with ETS as stratification parameter according to treatment arm, molecular subgroup, and sex.

Results

In 370 patients analyzed, a higher rate of ETS (60.9% vs. 43.5%; p = 0.001) and significantly greater DpR (-40.0% vs. -24.7%; p < 0.001) were observed in the initial combination therapy arm. The improvement was pronounced in RAS/BRAF wild-type tumors. ETS correlated with improved survival irrespective of treatment arm (PFS: p < 0.001; OS: p = 0.012) and molecular subgroup (PFS: p < 0.001; OS: p < 0.001). Male patients in contrast to female patients with ETS had survival benefit (PFS: p < 0.001, HR 0.532; OS: p < 0.001, HR 0.574 vs. PFS: p = 0.107; OS: p = 0.965).

Conclusions

Initial irinotecan-based combination therapy with bevacizumab improved ETS and DpR in mCRC patients with a particularly high irinotecan sensitivity of RAS/BRAF wild-type tumors. ETS seems to be a suitable prognostic marker for fluoropyrimidine- and bevacizumab-based combinations in mCRC. This finding was rather driven by male patients, potentially indicating that ETS might be less predictive of long-term outcome in an elderly, female population.

Exact Primary Tumor Location in mCRC: Prognostic Value and Predictive Impact on Anti-EGFR mAb Efficacy

Simple Summary

Sidedness of primary tumor is a well-established prognostic marker and is predictive for anti-EGFR efficacy in RAS/BRAF wild-type metastatic colorectal cancer (mCRC) patients. As molecular markers change rather continuously throughout the colon, we ask whether the exact primary tumor location (PTL) is a better prognostic marker than sidedness and predictive for anti-EGFR efficacy in RAS/BRAF wild-type mCRC. We retrospectively analyzed five studies containing various therapy protocols concerning primary tumor location, dividing the colorectal frame into six segments. In our cohort, PTL has a prognostic impact on disease spread and overall survival. Only distal segments benefitted when receiving anti-EGFR containing therapy regarding overall survival. Intermediate segments were indifferent and caecal primaries had a detrimental effect receiving anti-EGFR based therapy. Being a retrospective analysis and challenging the standard of basing anti-EGFR treatment on sidedness in RAS/BRAF wild-type mCRC, future studies are necessary to confirm and further investigate our hypothesis-generating results.

Abstract

Primary tumor sidedness (left vs. right) has prognostic and predictive impact on anti-EGFR agent efficacy and thus management of metastatic colorectal cancer (mCRC). This analysis evaluates the relevance of primary tumor location (PTL) in RAS/BRAF wild-type mCRC patients, when dividing the colorectal frame into six segments. This pooled analysis, performed on a single-patient basis of five randomized first-line therapy trials, evaluates the impact of exact PTL classification on baseline characteristics, prognosis and prediction of anti-EGFR antibody efficacy by chi-square and log-rank tests, the Kaplan–Meier method, Cox and logistic regressions. The PTL was significantly associated with metastatic spread: liver (p = 0.001), lung (p = 0.047), peritoneal (p < 0.001) and lymph nodes (p = 0.048). A multivariate analysis indicated an impact on anti-EGFR agent efficacy in terms of overall survival depending on the exact primary tumor location: from detrimental in caecal (HR 2.63), rather neutral effects in the ascending colon (HR 1.24), right flexure/transverse colon (HR 0.99) and left flexure/descending colon (HR 0.91) to clear benefit in sigmoid (HR 0.71) and rectal (HR 0.58) primaries. Exact primary tumor location affects anti-EGFR antibody efficacy in a rather continuous than a dichotomous fashion in RAS/BRAF wild-type mCRC patients. This perspective might help to support clinical decisions when anti-EGFR antibodies are considered.

Survey of Long-Term Experiences of Sperm Cryopreservation in Oncological and Non-Oncological Patients: Usage and Reproductive Outcomes of a Large Monocentric Cohort

Progress in oncological treatment has led to an improved long-term survival of young male cancer patients over the last decades. However, standard cancer treatments frequently implicate fertility-damaging potential. Cryopreservation of sperm is the current standard option to preserve patient’s fertility after treatment, yet long-term data on usage and reproductive experiences is still limited. Natural fertility after treatment and especially in relation to the type of treatment has been poorly analyzed so far. Therefore, we performed a retrospective survey including male patients with an indication for gonadotoxic treatment who cryopreserved reproductive material at our institution between 1994 and 2017. Study questionnaires regarding treatment, material usage, and reproductive outcomes were sent to eligible patients. Additionally, semen analyses of study participants from the time of cryopreservation were evaluated. A total of 99 patients were included in the study. Respondents’ median age was 38.0 years. Most frequent diagnoses were testicular cancer (29.3%) and lymphoma (26.3%). A further 8.1% suffered from autoimmune diseases. Testicular cancer patients had a significantly lower pre-treatment median sperm concentration (18.0 million/ml) compared to non-testicular cancer patients (54.2 million/ml). Until November 2020, the determined sperm usage and cumulative live-birth rate per couple were 17.2% and 58.8%, respectively. Most sperm users received treatments with high (40.0%) or intermediate (33.3%) gonadotoxic potential. 20.7% of all patients reported to had fathered at least one naturally conceived child after treatment, this being the case especially if they had been treated with less or potentially gonadotoxic therapies. In conclusion, our findings emphasize the importance of sperm cryopreservation in the context of male fertility preservation. Furthermore, they indicate that the gonadotoxic potential of patients’ treatments could represent a predictive factor for sperm usage.

Complete Pathological Response After Neoadjuvant Short-Course Immunotherapy with Ipilimumab and Nivolumab in Locally Advanced MSI-H/dMMR Rectal Cancer

Background

Patients with colorectal carcinoma and high‐grade microsatellite instability (MSI‐H) or deficiency in mismatch repair (dMMR) exceptionally respond to immune checkpoint inhibitors (ICIs). ICIs are more active in treatment‐naïve patients than in patients with refractory MSI‐H/dMMR metastatic colorectal cancer and even more active in patients with locally advanced tumors.

Material and Methods

A 33‐year‐old male patient with Lynch syndrome was diagnosed with a locally advanced rectal cancer and refused standard neoadjuvant chemoradiation because of the potential harm of sexual dysfunction. MMR and microsatellite instability status were analyzed by immunohistochemistry and fragment length polymerase chain reaction followed by capillary electrophoresis.

Results

After MSI‐H/dMMR was confirmed, the patient was treated with ICIs (1 mg/kg ipilimumab at day 1 and 3 mg/kg nivolumab at day 1 and 15). A complete clinical response was documented at day 21 after start of treatment. The patient underwent a total mesorectal excision at day 30. In the extirpated tissue, a complete pathological response was confirmed.

Conclusion

In MSI‐H/dMMR locally advanced rectal cancer short‐course ICI treatment is highly effective and may be discussed in patients with dMMR locally advanced rectal cancer.

Key Points

Immune checkpoint inhibitors are more active in treatment‐naïve patients than in patients with refractory high‐grade microsatellite instability (MSI‐H)/deficiency in mismatch repair (dMMR) colorectal cancer.

Standard neoadjuvant chemoradiation is less effective in MSI‐H/dMMR rectal cancer patients than in patients with proficient mismatch repair.

A young patient with Lynch syndrome and MSI‐H/dMMR locally advanced rectal cancer refused chemoradiation in order to preserve his fertility.

After neoadjuvant treatment with one dose of ipilimumab and two doses of nivolumab a complete clinical and pathological response was documented.

Clinical trials are needed to first establish neoadjuvant treatment with immune checkpoint inhibitors in patients with locally advanced MSI‐H/dMMR rectal cancer and thereafter to evaluate organ‐preservation strategies.

This report describes the case of a 33‐year‐old male patient with Lynch syndrome who was diagnosed with locally advanced rectal cancer. Instead of chemoradiation, neoadjuvant treatment with immune checkpoint inhibitors was given.

Mutational profiles of metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab before and after secondary resection (AIO KRK 0306; FIRE-3)

Secondary resection of metastases is recommended in metastatic colorectal cancer (mCRC). Data describing changes in mutational profiles of corresponding primary tumor and metastatic tissue after conversion treatment are limited. Next generation sequencing was performed in formalin-fixed mCRC samples from patients of the FIRE-3 trial (FOLFIRI plus cetuximab or bevacizumab) before treatment start (baseline) and after secondary resection of metastases (post baseline). Changes of mutational profiles and tumor mutational burden (TMB) were assessed within a post-hoc analysis. Median overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) were compared between treatment arms. Paired tumor samples were obtained from 25 patients (19 RAS wild-type, 6 RAS mutant by pyrosequencing). ORR (92.0% vs 58.0%) and OS (60.8 vs 35.4 months, hazard ratio = 0.39 [95% CI 0.14-1.12], P = .08) were higher for patients receiving cetuximab. After conversion therapy, 56 alterations (42 in the cetuximab and 14 in the bevacizumab arm) were newly observed in 18 patients (9 each treated with cetuximab or bevacizumab). Gains (n = 21) and losses (n = 21) of alterations occurred during cetuximab-based treatment, while mainly gains of alterations occurred during bevacizumab (n = 10). Three of nine patients treated with cetuximab that presented a change of mutational profiles, developed resistance to cetuximab. Mutational profiles were largely comparable before and after treatment with anti-VEGF or anti-EGFR directed monoclonal antibodies after secondary resection. Mutations associated with resistance to anti-EGFR antibodies were observed in only one-third of patients.

NeoRAS wild-type in metastatic colorectal cancer: Myth or truth?-Case series and review of the literature

Upfront KRAS and NRAS gene testing ('RAS') is the standard of care for metastatic colorectal cancer (mCRC), to guide first-line treatment. The presence of RAS mutation (MT) is a negative predictor for the efficacy of anti-EGFR antibodies and the use of cetuximab and panitumumab is restricted to RAS wild-type (WT) mCRC. Conversion from RAS WT to RAS MT mCRC after treatment with anti-EGFR antibodies is a known and well-described acquired resistance mechanism. The by far less frequent 'NeoRAS wild-type' phenomenon (reversion from RAS MT to RAS WT) has recently drawn attention. The proposed effect of chemotherapy on RAS status in mCRC patients is not fully understood. Because of the intriguing biological consequence of a RAS MT to RAS WT reversion, subsequent treatment of NeoRAS WT patients with anti-EGFR antibodies is increasingly being discussed. Here, we report three clinical cases of NeoRAS WT mCRC patients, which received standard-of-care regimens for RAS MT mCRC. Anti-EGFR antibodies were used in two out of three patients after progression of the disease. One of the patients had a long-term response. In line with our observations, NeoRAS WT phenomenon occurs in clinical practice. Retesting of RAS status during treatment should be discussed in patients with unusual long-term clinical courses of RAS MT mCRC to optimise treatment strategy and to evaluate the use of anti-EGFR antibodies.

Treatment responses and disease dynamics in patients with untreated metastatic colorectal cancer receiving bevacizumab-based sequential versus combination chemotherapy: Analysis of a phase 3 trial (AIO KRK0110, XELAVIRI study)

3571

Background: Early response parameters such as early tumor shrinkage (ETS), depth of response (DpR), and time to DpR represent exploratory endpoints that may serve as early efficacy endpoints and potential predictors of long-term outcome. We analyzed the association of these endpoints with bevacizumab-based sequential (initial fluoropyrimidines) versus combination (initial fluoropyrimidines plus irinotecan) chemotherapy within a randomized phase III trial. Methods: DpR (change from baseline to smallest tumor diameter), ETS (≥20% reduction in tumor diameter at first reassessment), and time to DpR (study randomization to DpR-image) were analyzed in the XELAVIRI-trial. Moreover, progression-free survival (PFS) and overall survival (OS) were evaluated with ETS as stratification parameter (ETS vs. no ETS) according to treatment arm, molecular subgroup, and sex. Results: 370 patients were available for analysis of early treatment response parameters. A higher rate of ETS (60.9% vs. 43.5%; p = 0.001) and significantly greater DpR (-40.0% vs. -24.7%; p < 0.001) were observed in the initial combination compared to the sequential therapy arm, respectively. The improvement of ETS and DpR was pronounced in the subpopulation of RAS/ BRAF wildtype patients. Male in contrast to female patients significantly benefitted from initial combination treatment in terms of median DpR (male: -40.0% vs. -22.2%; p < 0.001; female: -34.0% vs. -24.4%; p = 0.13) and rate of ETS (male: 64.8% vs. 40.2%; p < 0.001; female: 52.5% vs. 49.3%; p = 0.73). Achievement of ETS correlated with improved survival irrespective of treatment arm (PFS: p < 0.001; OS: p = 0.012) and molecular subgroup (PFS: p < 0.001; OS: p < 0.001). Whereas the survival benefit in male patients achieving ETS was statistically significant (PFS: p < 0.001, HR 0.532 (0.409-0.692); OS: p < 0.001, HR 0.574 (0.437-0.756)), there were no significant differences in PFS (p = 0.107) and OS (p = 0.965) of female patients depending on ETS. Conclusions: In the XELAVIRI trial, initial irinotecan-based combination therapy with bevacizumab improves ETS and DpR in mCRC patients. Improvement in early response parameters appears pronounced in patients with RAS/ BRAF wildtype tumors suggesting a high sensitivity to irinotecan-based treatment. ETS was predictive of PFS and OS regardless of treatment arm. This finding was rather driven by male than female patients, potentially indicating that ETS might be less predictive of long-term outcome in an elderly, female population.

Consensus molecular subtypes and RAS status as biomarker of treatment intensity with fluoropyrimidine, bevacizumab, and irinotecan in metastatic colorectal cancer (XELAVIRI, AIO KRK 0110)

3552

Background: Prognostic biomarkers beside RAS/BRAF status are necessary to identify metastatic colorectal cancer (mCRC) patients who benefit from combined (COMB) versus sequential (SEQ) treatment with fluoropyrimidine, bevacizumab and irinotecan (randomized phase III XELAVIRI trial). Methods: mRNA was extracted from formalin-fixed paraffin embedded (FFPE) tumor tissue of 337 patients, gene expression was measured by the Nanostring PanCancer Progression Panel. Consensus molecular subtypes (CMS) classification was re-derived using a multinomial regression model. Data of Guinney et al. (Nat. Med. 2015. 21:1350-6) and FIRE-3 served as training and validation set. RAS/BRAF MUT were assessed by pyrosequencing. Median overall (OS) and progression free survival (PFS), hazard ratios (HR) and 95% confidence interval (CI) were estimated by Kaplan-Meier method and univariate Cox regression. Results: The multinomial regression model employed in the present analysis correctly predicted CMS labels in 98.3 % of the original Guinney- and 100.0 % of FIRE-3 population. In XELAVIRI, CMS subgroups were predicted as follows: CMS1: n = 62 (18.4 %); CMS2: n = 174 (51.6 %); CMS3: n = 9 (2.7 %); CMS4: n = 92 (27.3 %). A general prognostic impact of CMS was not observed when all patients were analysed. In RAS/BRAF WT mCRC patients, substantial benefit of COMB versus SEQ treatment was shown for OS and PFS in CMS2 and CMS4, but not in CMS1. Conversely, OS was significantly longer for COMB treatment in patients with RAS MUT and CMS1 mCRC, while SEQ treatment was not inferior in RAS MUT and CMS2 or CMS4 subgroups (see TABLE). Additional data for overall response rates, early tumor shrinkage and sidedness might be presented at the meeting. Conclusions: This retrospective analysis of XELAVIRI suggests that CMS may serve as biomarker that predicts response to initially combined versus less intensive sequential chemotherapy in patients with RAS/BRAF WT mCRC.[Table: see text]

Annotation and initial evaluation of a large annotated German oncological corpus

OBJECTIVE

We present the Berlin-Tübingen-Oncology corpus (BRONCO), a large and freely available corpus of shuffled sentences from German oncological discharge summaries annotated with diagnosis, treatments, medications, and further attributes including negation and speculation. The aim of BRONCO is to foster reproducible and openly available research on Information Extraction from German medical texts.

MATERIALS AND METHODS

BRONCO consists of 200 manually deidentified discharge summaries of cancer patients. Annotation followed a structured and quality-controlled process involving 2 groups of medical experts to ensure consistency, comprehensiveness, and high quality of annotations. We present results of several state-of-the-art techniques for different IE tasks as baselines for subsequent research.

RESULTS

The annotated corpus consists of 11 434 sentences and 89 942 tokens, annotated with 11 124 annotations for medical entities and 3118 annotations of related attributes. We publish 75% of the corpus as a set of shuffled sentences, and keep 25% as held-out data set for unbiased evaluation of future IE tools. On this held-out dataset, our baselines reach depending on the specific entity types F1-scores of 0.72-0.90 for named entity recognition, 0.10-0.68 for entity normalization, 0.55 for negation detection, and 0.33 for speculation detection.

DISCUSSION

Medical corpus annotation is a complex and time-consuming task. This makes sharing of such resources even more important.

CONCLUSION

To our knowledge, BRONCO is the first sizable and freely available German medical corpus. Our baseline results show that more research efforts are necessary to lift the quality of information extraction in German medical texts to the level already possible for English.

Identification of BCL-XL as highly active survival factor and promising therapeutic target in colorectal cancer

Since metastatic colorectal cancer (CRC) is a leading cause of cancer-related death, therapeutic approaches overcoming primary and acquired therapy resistance are an urgent medical need. In this study, the efficacy and toxicity of high-affinity inhibitors targeting antiapoptotic BCL-2 proteins (BCL-2, BCL-XL, and MCL-1) were evaluated. By RNA sequencing analysis of a pan-cancer cohort comprising >1500 patients and subsequent prediction of protein activity, BCL-XL was identified as the only antiapoptotic BCL-2 protein that is overactivated in CRC. Consistently, pharmacologic and genetic inhibition of BCL-XL induced apoptosis in human CRC cell lines. In a combined treatment approach, targeting BCL-XL augmented the efficacy of chemotherapy in vitro, in a murine CRC model, and in human ex vivo derived CRC tissue cultures. Collectively, these data show that targeting of BCL-XL is efficient and safe in preclinical CRC models, observations that pave the way for clinical translation.

Abstract 820: Genomics based personalized oncology of cancer of unknown primary

Cancers of unknown primary site (CUPs) represent a heterogeneous group of metastatic tumors, which accounts for 3-5% of malignancies. Due to the poor prognosis and limited local and systemic treatment options, there is an urgent need for improvement of molecularly driven treatment strategies. We investigated the molecular profile and clinical course of 70 patients enrolled in a prospective precision oncology registry trial conducted by the National Center for Tumor Diseases (NCT) Heidelberg/Dresden and the German Cancer Consortium (DKTK) that addresses younger adults with advanced-stage cancer across histologies as well as patients with rare tumors (NCT/DKTK MASTER). Molecular analyses included whole genome sequencing (WGS, n=29), whole exome sequencing (WES, n=41) and transcriptome analysis (n=55). All patients were diagnosed with CUP-syndrome, 61/70 (87.1%) of diagnoses fulfilled the ESMO Clinical Practice Guidelines. Progression free survival (PFS) of the first treatment based on MASTER (PFS2) was compared to the PFS of the last prior systemic treatment (PFS1) in each individual patient. Within the coding sequence, we identified 0 to 1386 nonsynonymous point mutations (SNVs, median=41) and 0 to 38 insertions/deletions (indels, median=3) per sample. Hypermutation (≥100 SNVs and indels) was observed in 14 samples. Mutations of TP53 and KRAS were significantly enriched. Analysis of copy-number changes (CNVs) was performed in 51 samples (27 WGS and 24 WES) and revealed complex CNV profiles in most cases. Gains and losses involved single arms or whole chromosomes. Gains in chromosome 8q, 1q and 7 and losses in chromosome 6q and 17p occurred in more than 40% of the patients. Fusions of EML4-ALK and FGFR2 were found in three and six cases, respectively. In one case, pathological reevaluation for NUT midline carcinoma was recommended based on a NUTM1-MXI1 fusion. In total, pathological reevaluation based on characteristic genetic events was recommended in five cases. Germline analysis of 70 cases revealed five pathogenic variants (ACMG Class 5) in CHEK2, BRCA1, CDKN2A, NBN and ERCC3. In addition, one likely pathogenic variant (ACMG Class 4) was found in FH. The molecular tumor board recommended targeted therapy in 56/70 (80.0%) patients which could be applied in 20/56 (35.7%) cases. The molecularly driven treatment approaches translated into a median PFS2/1 ratio of 2.25 (n=17). Median PFS1 was 89 days (range 31-304, n=17) compared to a median PFS2 of 180 days (range 50-805, n=17). For three patients in which PFS1 could not be determined median PFS2 was 305 days (range 182-336). We demonstrate that a comprehensive molecular analysis of CUPs provides clinically relevant information and additional, molecularly stratified treatment approaches in many cases. These targeted therapies can be highly beneficial even in heavily pretreated patients.

Citation Format: Maximilian Werner, Lino Möhrmann, Małgorzata Oleś, Andreas Mock, Arne Jahn, Simon Kreutzfeldt, Sebastian Uhrig, Martina Fröhlich, Barbara Hutter, Daniela Richter, Gina Rüter, Ivan Jelas, Rainer Hamacher, Johanna Falkenhorst, Sebastian Wagner, Christian Brandts, Melanie Börries, Anna Illert, Klaus Metzeler, Benedikt Westphalen, Alexander Desuki, Thomas Kindler, Albrecht Stenzinger, Evelin Schröck, Benedikt Brors, Peter Horak, Christoph Heining, Stefan Fröhling, Hanno Glimm. Genomics based personalized oncology of cancer of unknown primary [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 820.

Current treatment options in RAS mutant metastatic colorectal cancer patients: a meta-analysis of 14 randomized phase III trials

PURPOSE

Although biomarkers for patients with metastatic colorectal cancer exist, the benefit patients with RAS mutated tumors derive from established regimens is unclear.

METHODS

Efficacy of therapeutic strategies available for RAS mutated patients (addition of chemotherapeutic agents and/or anti angiogenic agents) were investigated in fourteen randomized controlled phase III trials at trial level by meta-analysing individual study hazard ratios and 95% confidence intervals (95% CI) for overall survival (OS) and progression free survival (PFS).

RESULTS

6810 of 10,748 patients (63.3%) were available (48.5% RAS wildtype, 51.5% RAS mutated). Across all treatment lines, additional treatment efficacy (chemotherapy and/or anti angiogenic agents) was significantly smaller in RAS mutated compared to wildtype tumors for OS and PFS. In detail, patients with RAS mutated metastatic colorectal cancer derived significant benefit in PFS but not in OS by the addition of either chemotherapy or anti angiogenic agents to the respective comparator. In patients with RAS wildtype metastatic colorectal cancer, PFS and OS were improved by the addition of chemotherapy or anti angiogenic agent.

CONCLUSION

The therapeutic benefit of additional substances is less distinct in patients with RAS mutated as compared to RAS wildtype metastatic colorectal cancer, especially with regard to OS.

Comparison of the clinical interpretation of high-dimensional molecular data by two molecular tumor boards

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Background: The clinical interpretation of molecular data is a bottleneck of precision oncology. High-dimensional molecular data, such as RNA sequencing (RNA-seq) and whole-exome sequencing (WES), will likely increase the complexity of clinical interpretation. We compared the recommendations by two molecular tumor boards (MTBs) that independently interpreted the same high-dimensional molecular profiles. Methods: Patients with advanced solid tumors, no available standard therapy, an ECOG performance status of 0-1, and available fresh-frozen tissue underwent WES of tumor tissue and normal blood as well as RNA-seq of tumor tissue within the MASTER (Molecularly Aided Stratification for Tumor Eradication Research) precision oncology program of the German Cancer Consortium (DKTK). Data from 46 patients (WES and RNA-seq, n = 41; WES alone, n = 5) were independently discussed by two MTBs. Treatment recommendations were compared with regard to levels of evidence, therapeutic baskets, and types of biomarkers. Results: A total of 51,610 aberrations (median, 393 per patient) were considered for clinical interpretation (34,314 mutations/single-nucleotide variants, 7,115 mRNA expression changes, 6,144 DNA copy number variations, 4,037 gene fusions). 110 and 132 treatment options were identified by the two MTBs, respectively, with an overall agreement rate of 44.1%. The highest agreement rates were identified for treatment options based on clinical levels of evidence (Level 1, 60%; Level 2, 49.6%) and for poly(ADP-ribose)-polymerase inhibition (57.1%). The lowest agreement rates were identified when MTBs opted for traditional chemotherapy (0%), combination therapies (6.9%), therapies based on preclinical levels of evidence (Level 3, 35.9%; Level 4, 32%), and MAPK inhibition (35%). Similar agreement rates, ranging from 39% (gene fusions) to 54% (loss of heterozygosity), were observed for different types of biomarkers. Conclusions: Reproducible, evidence-based annotation of high-dimensional molecular data is feasible. Our experience provides a basis for ongoing harmonization and standardization efforts within the MTBs of the DKTK.

Association of MAPK signaling subtypes with prognostic benefit for bevacizumab in left-sided metastatic colorectal cancer (mCRC) patients treated with FOLFIRI + cetuximab / bevacizumab (FIRE-3 trial)

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Background: We investigated the role of the MAPK pathway by mRNA expression profiles in microarrays of the FIRE-3 trial as it was formerly associated with prognosis. Methods: 451 patients provided eligible mRNA material for subsequent analyses of the MAPK pathway (295 genes). Non-negative matrix factorized (NMF) clustering for normalized mRNA microarray data (Almac Inc, Xcel Array) was performed for 2 to 6 ranks against randomized controls. Linear models with adjustment for multiple testing showed differential gene expression between groups. Single sample gene set enrichment analysis (ssGSEA) was used to compare differentially enriched hallmarks of cancer gene sets. Kaplan Meier method, log rank test and Cox regression analyses were performed to estimate overall (OS) and progression free survival (PFS) between MAPK subtypes. Results: NMF clustering built two groups of MAPK mRNA expression (coph: 0.91, silh: 1.00) without cohort-based bias in principal component analysis. Group MAPK1 (n = 238) was significantly associated with CMS2 (66.4 %), group MAPK2 (n = 213) with CMS4 (67.6 %, p < 0.0001). 5.551 of 23.561 genes were significantly differentially expressed between MAPK subtypes. 49 cancer hallmark gene sets were significantly differentially enriched in ssGSEA ( MAPK1: myc targets, DNA repair, cell cycle, PI3K- AKT- mTOR pathway upregulation; MAPK2: EMT-related signatures, TGFß pathway, angiogenesis upregulation among others). In overall analysis, MAPK1 showed slightly better outcome than MAPK2 (OS: HR: 0.80, 95% CI: 0.65 – 0.99, p = 0.049; PFS: HR: 0.81, 95% CI: 0.66 – 1.00, p = 0.05). However, MAPK1 was significantly more favourable for bevacizumab treatment in OS ( MAPK1: 30.8 m, MAPK2: 19.4 m, HR: 0.56, 95% CI: 0.39 – 0.81, p = 0.002) and PFS ( MAPK1: 11.7 m, MAPK2: 9.8 m, HR: 0.68, 95% CI: 0.48 – 0.98, p = 0.038) in left sided tumors, while no difference was seen for cetuximab treatment, RAS and BRAF status. Conclusions: mCRC subtypes by MAPK mRNA expression might contain prognostic information for the treatment with bevacizumab beyond mutational status in patients with left sided tumors of the FIRE-3 trial.

Relevance of baseline carcinoembryonic antigen for first-line treatment against metastatic colorectal cancer with FOLFIRI plus cetuximab or bevacizumab (FIRE-3 trial)

PURPOSE

Increased baseline carcinoembryonic antigen (CEA) serum level is associated with inferior overall survival (OS) in metastatic colorectal cancer (mCRC). However, limited data exist on its predictive relevance for targeted therapies. Therefore, we analysed its relevance in FIRE-3, a randomised phase III study.

EXPERIMENTAL DESIGN

FIRE-3 evaluated first-line FOLFIRI plus cetuximab (FOLFIRI/Cet) versus FOLFIRI plus bevacizumab (FOLFIRI/Bev) in mCRC patients with RAS-WT tumour (i.e. wild-type in KRAS and NRAS exons 2-4). Herein, the impact of CEA on patient outcome was investigated.

RESULTS

Of 400 patients, 356 (89.0%) were evaluable for CEA. High CEA (>10 ng/ml; N = 237) compared to low CEA (≤10 ng/ml; N = 119) was associated with shorter OS in the FOLFIRI/Bev arm (hazard ratio [HR] = 1.50; P = 0.036), while no significant OS difference was observed in the FOLFIRI/Cet arm (HR = 1.07; P = 0.74). In patients with high CEA, FOLFIRI/Cet compared to FOLFIRI/Bev showed a greater OS benefit (HR = 0.56; P < 0.001) than in patients with low CEA (HR = 0.78; P = 0.30). Furthermore, FOLFIRI/Cet exhibited significantly superior objective response rate in patients with high CEA (odds ratio = 2.21; P = 0.006) in contrast to patients with low CEA (odds ratio = 0.90; P = 0.85).

CONCLUSION

In patients with RAS-WT mCRC receiving first-line chemotherapy with FOLFIRI/Cet versus FOLFIRI/Bev, elevated CEA was associated with inferior survival in the bevacizumab arm, while this was not the case when cetuximab was applied. Comparison of OS and objective response rate according to treatment arms indicated that cetuximab was greatly superior to bevacizumab in patients with elevated CEA, while this effect was markedly lower and lost statistical significance in patients with low CEA.

Association Between Height and Clinical Outcome in Metastatic Colorectal Cancer Patients Enrolled Onto a Randomized Phase 3 Clinical Trial: Data From the FIRE-3 Study

BACKGROUND

Previous studies have found significant relationships between height and colorectal cancer (CRC) risk. Increased growth has been associated with activated pathways such as insulin-like growth factor 1. This study examined the impact of height on outcomes in metastatic CRC patients enrolled onto the FIRE-3 study, a randomized phase 3 clinical trial.

PATIENTS AND METHODS

A total of 695 patients with metastatic CRC were studied and height was measured in centimeters. Male patients were grouped as ≤ 165, 166-175, 176-185, and ≥ 186 cm in height; female patients were grouped as ≤ 154, 155-164, 165-174, and ≥ 175 cm in height. Primary end point was overall survival (OS); secondary end point was progression-free survival.

RESULTS

When patients' heights were categorized into 4 groups, the tallest group showed a worse OS compared to the shortest group; however, there was no linear relationship between height and OS. To investigate this, we showed the association between height as a continuous variable and OS. Patients shorter than 172 cm had a worse OS as their height decreased. Patients taller than 172 cm had a worse OS as their height increased. Moreover, patients with heights between 165 and 179 cm had a better OS compared to other patients (P = .05). This effect was independent of treatment arm and gender.

CONCLUSION

Patients shorter than 165 cm and taller than 179 cm have a worse OS, while those between 165 and 179 cm have a better OS. Hence, clinicians should consider height as an important prognostic factor when treating metastatic CRC patients. Future prospective studies are warranted to shed light on the mechanisms underlying the worse OS in taller patients.

Tumor-targeted IL-12 combined with local irradiation leads to systemic tumor control via abscopal effects in vivo

NHS-IL12 is an immunocytokine, a fusion protein of IL12's functional domains and a necrosis-targeting antibody, which has shown significant effects against human rhabdomyosarcoma xenografts in a humanized tumor model, including terminal growth arrest and differentiation of the tumor cells. Here, we locally irradiated the tumors, increasing necrosis and consequently intratumoral immune cytokine availability, and asked whether this effect may surmount efficacy of single treatment modality. Humanized mice bearing bilateral rhabdomyosarcoma xenografts were evaluated for tumor burden and survival after irradiation, systemic NHS-IL12 therapy or a combination of both. Intratumoral immune compartments were characterized by immunohistochemistry and molecular methods. T_H1-cytokine dependency of underlying effector mechanisms were investigated in vitro in several human tumor cell lines. NHS-IL12 when combined with irradiation terminally arrested tumor growth and significantly improved survival. Combination treatment induced dense intratumoral T-cell infiltrates, clonal epitope-specific T-cell expansions, expression of cytotoxins, decreased pro-tumorigenic cytokines and induced senescence and differentiation in the cancer cells. Senescence and differentiation were reproduced in vitro and confirmed to be dependent on T_H1 cytokines IFNγ and TNF-α. NHS-IL12 and irradiation together induced broad intratumoral T_H1 biased NK and T-cell compartments, established antitumoral cytokine profiles and irreversibly growth arrested tumor cells, leading to systemic cancer control and improved survival. For the first time, we describe immune-induced senescence as a novel mechanism resulting from a treatment regimen combining irradiation with immunotherapy.

[Physical activity for primary prevention of prostate cancer. Possible mechanisms]

BACKGROUND

An explanation of the possible connection between physical activity and prevention of prostate cancer was sought by reviewing the controversial data from prospective and case-control studies. Possible preventive mechanisms are to be described.

METHOD

Scientific publications mainly from the past 10 years were reviewed.

RESULTS

Because of the postulated dependence of prostate carcinoma on testosterone, lowering the testosterone concentration by physical activity is of importance and seems to be a possible explanation. According to many studies there is a speculative connection between prostate carcinoma and calcium concentration in blood, parathormone and vitamin D(3), and the possibly preventive modulation by physical activity results in another beneficial mechanism. Less specific is the possible increase of the antioxidant capacity of the organism by physical activity. Strength training seems to have adverse effects on testosterone, while possibly yielding a beneficial effect on the immune system.

CONCLUSION

High intensive physical activity may contribute to the prevention of prostate carcinoma.