e20565 Background: Non-small cell lung cancer (NSCLC) accounts for approximately 80% of lung cancer cases globally. Targeted therapies for patients harboring epidermal growth factor receptor (EGFR) mutations have revolutionized survival; however, ethnic and geographic variability in mutation prevalence remains understudied in Latin America. This study represents a decade-long effort to characterize the EGFR mutational landscape in a large Colombian cohort, addressing a critical regional data gap and providing a baseline for precision oncology. Methods: A retrospective observational study was conducted on 1,782 patients with NSCLC whose samples were centralized and analyzed at a national reference laboratory (UDHO) in Cali, Colombia (2014–2023). EGFR status was determined via real-time PCR (qPCR) using IVD/CE certified kits capable of detecting 42 mutations across exons 18–21. Testing utilized formalin-fixed paraffin-embedded (FFPE) tissue (n = 1,555) and plasma (n = 227, implemented in 2016). Strict quality protocols, including a minimum 10% neoplastic content and automated software analysis (LSR), ensured technical reproducibility. Results: The cohort showed a balanced sex distribution (50.5% female, 49.5% male) with ages ranging from 16 to 95 years. A total of 474 mutations were identified. Mutational prevalence was significantly higher in plasma (42%) compared to FFPE tissue (28%). Key findings include: Predominant Mutations: Exon 19 deletions (51.9%–60.8%) and L858R (19.9%–31.8%) were the most frequent. Resistance Profile: Identification of T790M co-mutations, most notably Exon 19 del + T790M (4.5% female; 6% male). Healthcare Barrier: 92.9% of studies were industry-sponsored, with only 7.1% covered by public health entities. The invalid result rate remained low, reflecting high pre-analytical standards. Conclusions: This longitudinal study—one of the most robust in the Andean region—confirms a high prevalence of actionable EGFR mutations in Colombian NSCLC patients. The data underscore that liquid biopsy is a vital diagnostic tool for increasing mutation detection rates in Latin America. These results highlight a critical "access gap," where precision diagnostics rely almost exclusively on pharmaceutical sponsorship, necessitating urgent public health policy shifts to ensure sustainable oncology care and health equity in the region.
Ordoñez et al. (Thu,) studied this question.