Next generation sequencing (NGS) allows parallel sequencing of multiple genes at a very high depth of coverage. The need to analyze a variety of targets for diagnostic/prognostic/predictive purposes requires multi-gene characterization. Multi-gene panels are becoming standard approaches for the molecular analysis of solid lesions. We report a custom-designed 128 multi-gene panel engineered to cover the relevant targets in 22 oncogene/oncosuppressor genes for the analysis of the solid tumors most frequently subjected to routine genotyping. A total of 1695 solid tumors were analyzed for panel validation. The analytical sensitivity is 5%. Analytical validation: (i) Accuracy: sequencing results obtained using the multi-gene panel are concordant using two different NGS platforms and single-gene approach sequencing (100% of 83 cases); (ii) Precision: consistent results are obtained in the samples analyzed twice with the same platform (100% of 20 cases). Clinical validation: the frequency of mutations identified in different tumor types is consistent with the published literature. This custom-designed multi-gene panel allows to analyze with high sensitivity and throughput 22 oncogenes/oncosuppressor genes involved in diagnostic/prognostic/predictive characterization of central nervous system tumors, non-small-cell lung carcinomas, colorectal carcinomas, thyroid nodules, pancreatic lesions, melanoma, oral squamous carcinomas and gastrointestinal stromal tumors.

BRAF exon 15 mutations are the most common molecular alterations found in papillary thyroid carcinoma (PTC). To date, there is no information regarding BRAF alterations in the thyroid parenchyma surrounding the tumor. To explore the early events associated with the development of PTC, we used massively parallel sequencing to investigate BRAF exon 15 in 30 PTCs and in 100 samples from the thyroid parenchyma surrounding the tumor. BRAF p.V600E was identified in 19/30 PTCs (63.3%). BRAF p.V600E mutations were identified in the tissue adjacent the PTC only in samples containing psammoma bodies. The other samples were either BRAF wild type (WT) or carried BRAF non p.V600E mutations. Specifically, BRAF p.G593D, -p.A598T, -p.V600M, -p.R603Q, -p.S607F, and -p.S607P were identified in 4 of 36 (11.1%) samples with follicular cell atypia, in 2 of 16 (12.5%) with follicular cell hyperplasia, and in 1 of 33 (3.0%) histologically normal samples—Only in tissue surrounding BRAF p.V600E mutated PTCs. These mutations are predicted to affect protein function in silico but, in vitro, have kinase activity and BRAF phosphorylation levels similar to BRAF WT. No BRAF exon 15 mutations were identified in samples adjacent to PTCs that were BRAF WT. A mutagenic process affecting BRAF exon 15 occurs in a subset of thyroid glands that develop BRAF p.V600E mutated PTCs.

Aim: European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) criteria are used to choose treatment in low-grade gliomas. However, no data ...

2028 Background: According to the 2016 WHO classification of Central Nervous System tumors, the assessment of exon 4 mutations in IDH1 or IDH2 genes is an essential step in the characterization of gliomas. The R132H mutation is the most frequent alteration in IDH1 gene, however other non-canonical IDH mutations have been identified. The aim of this study was to evaluate the prognostic role of IDH non-canonical mutations. Methods: We analyzed our institutional data warehouse for all consecutive patients (pts) with newly diagnosed, histologically proven grade II – IV IDH mutant gliomas. IDH sequencing was performed using the 454 GS-Junior next generation sequencer (NGS) (Roche Diagnostic, Mannheim, Germany). All analyses were performed on DNA from formalin fixed and paraffin embedded (FFPE) specimens. Results: The analysis included 493 pts with IDH mutations. We found 279 (56.6%) grade 2, 173 grade 3 (35.1%) gliomas, and 41 (8.3%) IDH mutant glioblastoma. Canonical IDH1 R132H mutation was found in 428 pts (86.8%). The remaining pts showed IDH2 (3.9%) or IDH 1 non-canonical mutations (mainly R132C, R132G, R132S – 9.3%). Median follow-up time was 80.5 months. Pts with non-canonical mutations showed a younger median age (32 vs 39 years, p < 0.001). Other clinical characteristics and treatments were similar across IDH groups. Median survival was 145 months (95%CI: 137.7 - 152.9) and 198.6 (95%CI 155.2– 242.1) in patients with IDH R132H and non-canonical mutations, respectively (p = 0.013). In multivariate analysis grading (p < 0.001), extent of surgery (p < 0.001), 1p19q codeletion (p = 0.003) and presence of non-canonical mutations (p = 0.022) showed a significant role for improved survival. Conclusions: Detecting non-canonical IDH1 mutations is essential for diagnosis and for prognosis in patients with gliomas. Differential enzymatic activity of non-canonical IDH1 mutations, resulting in different levels 2-hydroxyglutaratecould be the reason of improved survival.

BackgroundGlioblastoma (GBM) is an aggressive brain tumor with poor survival despite multimodal treatment. The impact of socioeconomic status (SES) and financial toxicity (FT) in GBM remains poorly defined.Patients and methodsThis prospective observational study involved 19 Italian centers and evaluated the association between SES, financial toxicity (FT), biological and clinical variables, and outcomes in newly diagnosed GBM patients within the Italian universal healthcare system. SES and FT data were collected at the start of radiochemotherapy and after 6 months using structured questionnaires, including the Patient Reported Outcome for Fighting FInancial Toxicity (PROFFIT) questionnaire for FT assessment.ResultsBetween March 2021 and September 2024, 405 patients were enrolled; 385 had evaluable baseline questionnaires and 374 histologically confirmed GBM were included in survival analyses. Mean (SD) PROFFIT score was 32.8 (24.2). Higher FT was associated with younger age (p <0.001), foreign birth (p <0.001), dependent family members (p=0.046), unemployment/work disability (p <0.001), work discontinuation (p=0.005), and lower income (p <0.001). FT was also strongly associated with worsening physical appearance and sexual activity (both p<0.001). Caregiver burden was substantial, with 52.2% reducing working hours and 11.6% leaving work due to the patient’s illness. PROFFIT score was not associated with PFS or OS.Conclusions The study showed that FT is a significant issue in GBM, particularly among vulnerable patients, even within a universal healthcare system. The high caregiver burden supports routine FT assessment and health policies aimed at reducing the economic and psychosocial impact of the disease.

E14734 Background: IDH mutational status is required for diagnosis according to the 2016 WHO criteria. The single nucleotide polymorphism (SNP) rs11554137 ( IDH1^105GGT) at codon 105 of IDH1 has been reported in patients with several tumor types, including glioma. The aim of this study is to investigate the prognostic role of IDH1^105GGT Methods: We analyzed our institutional data warehouse for consecutive patients (pts) with newly diagnosed, histologically proven grade II or Grade III gliomas. IDH sequencing was performed using the 454 GS-Junior next generation sequencer (NGS) (Roche Diagnostic, Mannheim, Germany). All analyses were performed on DNA from formalin fixed and paraffin embedded (FFPE) specimens. Results: The analysis included 77 pts with grade II (n = 51, 66.2%) or grade III glioma (n = 26, 33.8%). Median follow up of this study was 91 months. Patients received biopsy/partial resection/complete resection in 7.8%, 70.1% and 22.1%, respectively. Postsurgical RT and/or chemotherapy was delivered in 64.9% of pts. IDH mutations affecting codons 132 (for IDH1) and 172 (for IDH2) were found in 71 pts (92.2%). IDH1^105GGTwas found in 11 pts (14.3%), mainly harboring also IDH mutations (81.8%), and was more frequent in grade 3 (30.8%) than in grade 2 gliomas (5.9%, P = 0.006). Pts harboring both IDH mutations and IDH1^105GGTshowed a significantly longer progression-free survival compared with pts with IDH mutation alone (78.7 months vs 49.9 months, p = 0.041). Conclusions: IDH1^105GGT represents a promising novel biomarker in IDH mutated grade 2 and 3 gliomas and warrants further investigations.