Genomic profile by liquid biopsy of Peruvian patients with lung cancer.

e15027 Background: The optimal treatment of advanced NSCLC patients is currently led by genomic profiling with the goal of detecting actionable mutations with an approved targeted therapy. However, tissue DNA samples are not always available to perform this assays. In this context, liquid biopsy has emerged as a valuable tool for providing the best treatment option. Methods: Retrospective study held at Instituto Nacional de Enfermedades Neoplasicas (INEN), Lima - Peru, between January 2019 and September 2021 to assess the genomic profile of 190 newly diagnosed advanced NSCLC patients through liquid biopsy. Blood samples were profiled with the FoundationOne Liquid Biopsy assay. We describe frequency of pathogenic and targetable genetic alterations, as well as the survival outcomes. Genomic and clinical data were recorded from clinical files. Results: The median age was 63 years (26-90), 66.3% were women, 15.3% smokers, 26.3% had exposure to biomass, 22.6% had a first-degree family history of cancer. The most frequent histological type was adenocarcinoma (86.8%). Regarding genomic profile, 183 patients (96.3%) had at least one pathogenic genetic alteration, the most frequent altered genes were TP53 (54.7%), EGFR (50.5%), DNMT3A (17.9%), KRAS (9.5%) and NF1 (6.8%). 116 patients (61%) had a targetable mutation: EGFR Ex19del/ins (27.4%), EGFR L858R/L861Q (17.9%), ALK rearrangements (5.8%), BRAF V600E (3.2%), RET fusions (1.6%), METex14 skipping (1.6%), KRAS G12C (1.6%), ROS 1 (1.1%), and NTRK (0.5%). Of these, 71 patients (65.5%) were able to access target therapy. For the latter, estimated median PFS and OS were 14.0 months (9.3 – 18.6) and 17.8 months (8.2 – 27.4), respectively. Conclusions: Peruvian NSCLC patients represent a population with a high frequency of pathogenic and targetable mutations, being EGFR mutations and ALK rearrangements the most prevalent ones. Despite limited access, a great proportion of patients received target therapy, achieving remarkable survival.