ANALYSIS OF PREDICTIVE BIOMARKERS IN PATIENTS WITH LUNG CANCER FROM A BRAZILIAN NORTHEAST CANCER CENTER: AN EXPLORATORY STUDY

Background: Lung cancer is one of the most prevalent malignancies, with high morbidity and mortality rates. The adenocarcinoma subtype may be related to somatic mutations in EGFR, KRAS, and ALK or PDL-1 expression, among other genetic alterations. Aim: To investigate the frequency of EGFR, KRAS, ALK, and PD-L1 biomarkers in lung cancer patients in the Rio Grande do Norte that presented at least one of these genetic alterations. Methods: This is an observational and retrospective study, realized with data from a reference center for oncology and a pathology laboratory, both in the State of Rio Grande do Norte, where most oncological molecular exams are in the state. EGFR, KRAS, ALK, and PDL-1 were analyzed by the Next-Generation Sequencing technique (NGS), and the EGFR mutation was also evaluated by polymerase chain reaction (PCR) and KRAS and PDL1 by immunohistochemistry. The study population was composed of patients aged 18 years or older and diagnosed with lung adenocarcinoma who underwent research for these genetic alterations in these two centers between the years 2020 and 2022. The frequency of biomarkers was calculated by the proportion between the number of mutations found for each biomarker and the number of mutations identified in patients who had at least one of the four mutations screened. Results: The analysis showed the following frequencies for each biomarker: 22.9% for EGFR, 10% for KRAS, 5.2% for ALK, and 61 .6% for PD-L1. Conclusion: This study was essential to know the predictive biomarkers most commonly found in patients with lung adenocarcinoma in the State of Rio Grande do Norte. Since the presence of these biomarkers directs the choice of systemic therapy, whether with target drug or immunotherapy, this type of therapy provides a gain in patient survival. The results presented here can help in the context of public policies of health.