Exploring histopathological and serum biomarkers in lung adenocarcinoma: Clinical applications and translational opportunities (Review)

Lung cancer represents one of the most common neoplasms and the main cause of cancer‑associated death worldwide. Its relationship with different risk factors such as tobacco, which is its main etiological factor, has been clearly established and despite the numerous advances achieved in the diagnosis, treatment and follow‑up of these patients, the life expectancy of these patients is notably limited. Furthermore, its treatment is not exempt from comorbidities and frequently it neither provides optimal control of the disease nor improve the quality of life of these patients. Despite the possibility of performing screening tests in patients at risk, their implementation in daily clinical practice is complex and most of them are diagnosed at an advanced stage of their disease where systemic radiotherapy or chemotherapy treatments slightly improve their prognosis. Lung adenocarcinoma is the most representative type of lung cancer, with specific epidemiological, molecular and clinical features. Thus, a growing number of studies are being conducted to find potential therapeutic targets based on the study of different molecular pathways, improving the outcome for these patients. In addition, a broad spectrum of serological, immunohistochemical and genetic markers are being evaluated for use in the screening and follow‑up of these patients in daily clinical practice, but unlike for other tumors, they are currently not implemented in the early diagnosis of the disease. Therefore, the aim of the present review was to summarize the main advances that have occurred in the development of serological and histological markers and their therapeutic implications in patients diagnosed with lung adenocarcinoma, explaining the limitations that have been observed and analyzing the future perspectives in the clinical management of this disease.