ECP 2023 Abstracts

S316 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 is formed. MET gene amplification (copy number: 4.45) was also identified. According to NCCN Guidelines MET exon 14 skipping mutation is associated with response with MET TKIs. Classification in high-level MET amplification is evolving and may differ according to the assay used for testing. According to the same Guidelines, for results obtained by NGS, a copy number greater than 10 is consistent with the classifi- cation of high-level MET amplification. Conclusion: Patient started systemic chemotherapy in February with Carboplatin and Pemetrexed, and since March with Pemetrexed. The emergence of complex cases is more and more frequent, with the use of more advanced and informative technologies. It becomes essen- tial to have multidisciplinary therapeutic decision meetings, where the mutations found can be discussed with information on the general condition of the patient and with the drugs/clinical trials in progress. E-PS-15-043 MET exon 14 skipping and EML4-ALK fusion in a NSCLC meta- static case – case report V. Sousa*, A. Alarcão, A.F. Ladeirinha, M.R. Silva, T. Ferreira, C. Eliseu, M. Viseu, V. Almeida, R. Almeida, G. Fontinha, A.L. Alves, L. Carvalho *IAP-PM - Universidade de Coimbra, CHUC, Portugal Background & objectives: Gene alterations are increasingly found in bronchopulmonary carcinomas using NGS for researching thera- peutic targets. Fusions in ALK, RET and MET genes has been very successful targets for therapies in lung adenocarcinomas. Mutations have been found whose meaning is unknown. Methods: We present a case of a woman with a right intracranial tem- poral brain NSCLC metastasis. It was performed mutation research by next-generation sequencing (Genexus, Oncomine Precision Assay Panel, Thermo Fisher Plataform). Manual macrodissection was per- formed and nucleic acid extraction was carried out with the MagMAX FFPE DNA/RNA Ultra Kit. Results: Several alterations have been detected. The MET-MET. M13M15.1 variant was identified which corresponds to MET exon 14 skipping. In the ALK gene, the following alterations were identified: Fusion with the partner being the gene EML4 (EML4-ALK.E13A20) and ALK expression imbalance. In the RET gene, the nonsense muta- tion c.2689C>T;p.(Arg897*) was identified. According to the NSCLC NCCN Guidelines, MET exon 14 skipping is associated with response with MET TKIs. ALK gene fusion is associated with response to ALK tyrosine kinase inhibitor therapy. There is no reference to the ALK expression imbalance. The mutation c.2689C>T;p.(Arg897*) in the RET gene lacks relevant evidence in public data sources included in relevant therapies: EMA, ESMO, NCCN. Conclusion: The patient started Brigatinib therapy for ALK rear- rangement in October 2022. No other therapy was registered prior to the study. The patient is clinically well with a good Performance Status (PS=0). We are increasingly finding concomitant actionable mutations for therapy, making it important to understand how we should proceed in terms of therapy to promote a better patient response, and Molecular Tumour Board might be of great importance in these cases. E-PS-15-044 MYB gene rearrangement in adenoid cystic carcinoma: a multi institutional study from Turkey M.H. Toper*, L. Cinel, F. Bir, K. Başak, Ö. Saraydaroğlu, A. Uğuz, İ.H. Özbudak, A. Tan, S. Altınay, Ü. Han, Ü. Küçük, D. Etit, F. Çakalağaoğlu, A.N. İhvan, S. Sarioglu *Dokuz Eylul University, Turkey Background & objectives: Adenoid cystic carcinoma (ACC) is a com- mon salivary gland malignancy and many ACCs have been reported to have MYB rearrangement. This study aims to analyse the frequency of MYC rearrangement in the region and its relationship with clinical/ pathological parameters. Methods: 122 ACC cases were selected retrospectively from thirteen institutions between 2008-2022. If available, clinical and pathological characteristics of cases including age, gender, tumour size, stage, grade, lymphovascular/perineural invasion were obtained from the original reports. FISH analysis for MYB gene rearrangement was carried out and >10% of cells with break-apart signals were accepted as the thresh- old for a positive result. Results: The study comprised cases aged 22–86 years (median 55 years) and 66% of cases were female. 36% cases were located at major salivary glands, while rest of tumours were at other sites of head and neck, mostly minor salivary glands. Tumour size ranged from 5 to 80 mm. FISH analysis of MYB gene was found 77 cases (63.1%). MYB FISH status was not significantly associated with other parameters, includ- ing gender, age, tumour stage and grade, lymphovascular or perineural invasion, and lymph node or distant metastasis. MYB status also were not associated with statistically significant differences in overall sur- vival (p=0.8). Conclusion: These findings suggest that rearrangement involving MYB is a frequent event in ACC and does not seem to have associa- tion with survival and pathological parameters. The identification of this significant molecular alteration may demonstrate that it can be used for differential diagnosis in routine clinical practice and also might be target of specific therapy in molecularly-defined patient subgroups in future clinical studies. E-PS-15-045 MAML2 gene rearrangement in mucoepidermoid carcinoma: a multi institutional study from Turkey M.H. Toper*, F. Bir, Ö. Saraydaroğlu, L. Cinel, K. Başak, A. Uğuz, S. Altınay, Ü. Han, A.N. İhvan, İ.H. Özbudak, A. Tan, Ü. Küçük, D. Etit, F. Döger, S. Sarioglu *Dokuz Eylul University, Turkey Background & objectives: Mucoepidermoid carcinoma (MEC) is a common salivary gland malignancy. A major subset of MECs have been reported to have a specific MAML2-NFIB gene rearrangement. This study aims to analyse the frequency of MAML2 rearrangement and its relationship with clinical/pathological parameters. Methods: 119 MEC cases were selected retrospectively from thirteen institutions between 2007-2022. If available, clinical and pathological characteristics of cases including age, gender, tumour size, stage, grade, lymphovascular/perineural invasion were obtained from the pathology reports. FISH analysis for MAML2 gene rearrangement was carried out and >10% of cells with break-apart signals were accepted as the threshold for a positive result. Results: The study sample comprised aged 8–92 years (median 48 years) and 55% of cases were female. 60% cases were located at major salivary glands, and rest of cases were at other sites of head and neck. Tumour size ranged from 5 to 105 mm. FISH analysis of MAML2 gene was found 74 case (62.2%). MAML2 positive result was significantly associated with better overall survival, absence of lymphovascular invasion and absence of distant metastasis (p<0.05). MAML2 FISH status was not significantly associated with other parameters, including gender, age, tumour stage and grade, peri- neural invasion, and lymph node metastasis. Conclusion: These findings suggest that MAML2 rearrangement is a frequent event in MEC and does seem to have association with favourable clinical outcome and absence of lymphovascular invasion