ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 patient groups and the control group that were identified to have a reported association with nystagmus. Post Hoc evaluation showed that the identified genes from all of the patient groups were signifi- cantly under-expressed compared to the control group (p<0.001). The genes that were identified can be divided into those involved in protein synthesis, cell cycle regulation, gap junction formation, transcription regulation, signal transduction, and synaptic function. Conclusion: The relationship illustrated that the common genomic changes may indicate how the pathways that have been altered due to the diseases have intersecting gene expression alteration that lead to visual motor control pathology. Perform- ing differential gene expression studies in the brain samples of post-mortem cases illustrates how autopsy pathology and compu- tation pathology can elucidate the common genomic changes and molecular mechanisms that can present across different diseases which may be significant in the field of both neuro- and ophthal- mic pathology. PS-15-003 Determination of Ly6E and Ly6K gene expression levels in soft tissue tumours and investigation of their correlation of these levels with tumour aggression Ç. Yildirim*, T.D. Kökenek Ünal, O. Kandemir *Dr. A.Y. Oncology Research and Education Hospital, Ankara, Turkey Background & objectives: Soft tissue tumours are rare heterogene- ous group of tumours. In recent years, cancer research has gained a different approach with the discovery of cancer stem cells. We aimed to evaluate the expression of Ly6E and Ly6K genes in these tumours. Methods: The study was performed with 45 patients, aged between 20-80, diagnosed with soft tissue tumours. In the study, there were patients diagnosed with dermatofibroma and leiomyoma; leiomyo- sarcoma, pleomorphic sarcoma and synovial sarcoma. Paraffin blocks sections were taken and deparaffinised, total RNA isolation and cDNA were obtained. Ly6E and Ly6K expression levels were determined by PCR, the results were compared. Results: When all groups are evaluated together; there was a statistically significant increase in Ly6E and Ly6K gene expres- sion in the benign and malignant tumour groups compared to the control group. However, the increase in Ly6K was statistically insignificant. Especially in leimyosarcomas, there was a statisti- cally significant increase of Ly6E gene expression. In synovial sarcoma and pleomorphic sarcomas, it was observed that Ly6E expression increased compared to the control group, but it was insignificant. A statistically significant increase in Ly6K gene expression level was found in malignant tumours originating from smooth muscle compared to the control group. There was no sta- tistically significant difference between other tumour groups in Ly6K expression levels. Conclusion: The expressions of Ly6E and Ly6K in human soft tissue tumours were discussed for the first time in the literature. Especially in well-differentiated malignant soft tissue tumours, the aforementioned markers were found to be elevated and tumour aggressiveness is related with them. Therefore, with more compre- hensive studies, the importance of Ly6E and Ly6K genes in cancer development and their potential roles in the therapy will be better understood and our study will make an important contribution to the literature. PS-15-004 Setting up an ultra-fast next-generation sequencing approach as a reflex testing at diagnosis in non-squamous non-small cell lung cancer C. Bontoux*, S. Heeke, V. Hofman, L. Virginie, B. Olivier, S. Las- salle, E. Long-Mira, S. Lalvée, V. Tanga, M. Allégra, M. Salah, J. Benzaquen, C. Marquette, M. Ilié, P. Hofman *Laboratoire de pathologie Clinique et experimentale, CHU de Nice, Université Côte d’Azur, Nice, France Background & objectives: The number of targetable genomic altera- tions in non-squamous non-small cell lung cancer (NS-NSCLC) patients increased these last few years, while the tissue material reduced in size. Therefore, molecular pathologists are facing challenges to maintain a strategy allowing a rapid diagnosis. Methods: We report here our experience (LPCE, Nice, France) between September 20, 2021 and December 31, 2021 for the development of an optimal workflow for genomic alteration assessment as a reflex testing in routine clinical practice at diag- nosis in patients with NS-NSCLC using an ultra-fast next gen- eration sequencing approach (Genexus OPA DNA RNA panel, Thermo-Fisher). Results: 325 patients were included in the study. 74% of patients had stage IIIB-IV NS-NSCLC, and 26% were stage I-IIIA. Ultra-fast NGS was performed in 182 bronchial biopsies, in 68 transthoracic biopsies, in 50 surgical specimens and in 25 cellblocks from 16 pleural effusion and 9 EBUS with a short mean turnaround time of 72h. Mean tumour cell was 40% (ranging from 5% to 95%). The analytical validation of the Genexus OPA workflow, performed on 30 NS-NSCLC cases, demonstrated 100% concordance with the gold standard methods. Conclusion: We demonstrate that molecular targets accessible to personalized medicine in NS-NSCL were identified using the Genexus system in a rapid turnaround time. Ultra-fast NGS integration as a reflex testing can be an optimal option for genomic alteration assessment at diagnosis for all stage NS- NSLC. This approach enables for a sensitive and a specific identification of mutations, CNVs, and fusion variants types across 50 key genes, on tumour material with a low amount of nucleic acids. PS-15-005 KRAS mutations in 1355 Italian patients with lung adenocarcinoma P. Paliogiannis*, R. Lobrano, M. Colombino, M.C. Sini, A. Fara, M.A. Fedeli, G. Palmieri, A. Cossu *Unit of Anatomic Pathology, Italy Background & objectives: Targeted therapies against KRAS muta- tions in patients with non-small cell lung cancer (NSCLC) were recently introduced in clinical practice. The aim of this study was to investigate the molecular landscape of KRAS mutations in Italian patients with lung adenocarcinoma. Methods: Consecutive Italian patients with histologically diagnosed lung adenocarcinoma who underwent molecular analysis for KRAS mutations were enrolled into the study. Mutation analysis was carried out initially by quantitative measurements of mutations with pyrosequencing (PyroMark Q24 system, Qiagen Inc., USA), replaced in 2021 by next generation sequencing (NGS) techniques on Ion S5 GeneStudio (Life Thermofisher) platform. Results: 1355 patients were enrolled. Among them 850 (62.73%) were males, and the mean age was 67 (±10.3) years. A KRAS mutation was detected in 324 patients (23.9%); most of them were males (238, 73.46%). Considering the male population, KRAS mutations were found in 238 out of 850 (28%), while they were detected in 86 out of 505 (17.03%) women (p<0,0001). No statisti- cally significant difference in the age of mutated and non-mutated patients (68, 95% CI: 67 – 70 vs 68, 95% CI: 67 – 68.5 years) was S141