Abstract
Background/Objectives: Late diagnosis and inefficient treatment regimens lead to poor prognosis, with a low 5-year survival rate for both non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). New targeted therapeutic agents can be developed and introduced only by first discovering new driver oncogenes and with a thorough investigation of the known driver genes. The aim of the current study is to investigate the prevalence of alterations in the eight most frequently altered genes in lung cancer-BRAF, EGFR, KRAS, ALK, ROS1, HER2, PD-L1 and PIK3CA. Methods: Real-time polymerase chain reaction (RT-PCR) was used to detect KRAS and EGFR mutations, multiplex PCR and microarray hybridization for KRAS/BRAF/PIK3CA mutations. Immunohistochemical analysis was performed for the detection of ALK, HER2/NEU, ROS-1 and PD-L1 alterations. Results: Overall, 221/603 patients (36.65%) had at least one genetic alteration, of which 22 patients (3.65%) had two genetic alterations and two patients had more than two genetic alterations. Additionally, 50 patients were identified with one or more KRAS mutations (8.29%), 45 patients with EGFR mutations (7.46%), and 1.82% with PIK3CA mutations and 0.66% with BRAF mutations. Furthermore, 50% of the co-occurring alterations were either on KRAS and PIK3CA genes (3/6), on KRAS and BRAF genes (2/6, 33.33%) or on EGFR and PIK3CA genes (1/6, 16.67%), and 10.45% of the patients exhibited PD-L1 overexpression, 5.31% ALK rearrangements, and 2.36% HER2/NEU expression, with no ROS-1 rearrangements detected. Conclusions: Comprehensive testing for somatic alterations in EGFR, BRAF, KRAS, and PIK3CA is significant in guiding therapeutic decisions in lung cancer management. Such testing should be routinely conducted to establish a thorough genetic profile of lung cancers in a manner that is both time-efficient and cost-effective.