EGFR variant profiles in lung adenocarcinoma from different regions of Brazil: A multi- institutional study using a rapid RT‒PCR platform

Background Lung cancer is the second most diagnosed cancer and activating EGFR variants are involved in the pathogenesis of a significant subset of lung adenocarcinomas. Given that Brazil is the largest and most populous country in South America with high ancestry’s admixture, this study aimed to evaluate the frequency of the EGFR variant and its subtypes in lung adenocarcinoma in three distinct Brazilian regions and to correlate these findings with clinicopathological features. Methods A retrospective electronic search was performed to select patients with lung adenocarcinoma who underwent EGFR profiling via a rapid RT‒PCR molecular platform from different regions of Brazil. Results The EGFR variant was present in 21% of the patients, with the highest mutation frequency observed in the northeastern region (NE), followed by the southeastern (SE) and southern (S) regions. Compared with male patients, female patients presented a greater EGFR variant frequency, except in S. Exon 19 deletion (exon 19 del) and p.Leu858Arg were the most common variants found. In addition, the NE had a greater frequency of exon 19 del, whereas the SE had p.Gly719Ala/Cys/Ser. Conclusion The highest frequency of the EGFR variant was observed in the NE, whereas the lowest rate was observed in the S. Furthermore, the NE presented the highest frequency of exon 19 del, whereas the SE presented p.Gly719Ala/Cys/Ser, regardless of gender.