CDKN2A

Homozygous MTAP loss is frequently observed in oncogene-driven non-small-cell lung cancers (NSCLC), particularly in EGFR, ALK, and RET altered subtypes. While this loss did not significantly impact the response to first-line targeted therapies, it creates a selective vulnerability to PRMT5 inhibitors. Preclinical studies demonstrated that the PRMT5 inhibitor BMS-986504 is active in MTAP-deleted NSCLC models and can enhance the efficacy of existing targeted therapies. These findings suggest a novel combined therapeutic strategy for NSCLC patients with MTAP loss.

This study investigates histologic transformation to lung squamous cell carcinoma (LUSC) in EGFR-mutant lung adenocarcinoma (LUAD) patients, an underrecognized resistance mechanism. Multiomic analyses revealed that patients with transforming or adenosquamous (LUAS) phenotypes experienced shorter overall survival on first-line osimertinib. Inactivation of the retinoblastoma (Rb) pathway, particularly via CDKN2A/B deletions, was identified as a key driver of this transformation. Furthermore, MET pathway upregulation was observed, and combined EGFR and MET inhibition demonstrated efficacy in preclinical models. These findings suggest novel strategies to counteract this aggressive form of resistance.

The prospective, multicenter ELIOS study characterized acquired resistance mechanisms to first-line osimertinib in patients with advanced EGFR-mutant non-small cell lung cancer (NSCLC). By analyzing paired tumor biopsies taken pre-treatment and post-progression, the study identified frequent alterations including MET amplification, CDKN2A/CDKN2B and MTAP deletions, and the EGFR C797S mutation. Proteogenomic analysis also revealed high TROP2 expression, irrespective of genetic alterations. The findings highlight the heterogeneous nature of resistance and the complementary utility of tissue and liquid biopsies for alteration detection. This study emphasizes the need for therapeutic strategies targeting multiple resistance pathways.

This study investigates the impact of next-generation sequencing (NGS) on the diagnosis of BAP1 inactivated melanocytic tumors (BIMTs), which often exhibit significant morphological atypia, complicating their classification. A survey among dermatopathologists revealed that incorporating NGS results significantly improved diagnostic accuracy and interobserver agreement. Specific genomic aberrations, including pathogenic variants in TERT-p, CDKN2A, PTEN, and MYC amplification, were found exclusively in malignant cases. These findings suggest that NGS could refine melanoma diagnosis, which is critical for guiding access to effective therapies.

This study analyzed the genomic profile of 480 patients with metastatic adenocarcinoma of unknown primary (ACUP) using the FoundationOne CDx platform. The most frequent mutations included TP53, KRAS, and CDKN2A. Results showed that GNAS and PIK3CA mutations were associated with better overall survival. Conversely, ARID1A and NOTCH1 alterations were linked to a worse prognosis. These findings highlight the significance of specific genomic alterations as prognostic markers in ACUP.