HE4 as a potential tumor-associated marker in lung cancer

The aim of the study was to systematize current data on the use of human epididymis protein 4 (HE4) as a tumor-associated marker for lung cancer (LC) diagnosis, prognosis of treatment response, and monitoring of this category of patients. Material and Methods. A search and analysis of available Russian and Englishlanguage sources was performed in the RSCI and PubMed databases using keywords “lung cancer” and “HE4”. The review includes 44 papers published between 2006 and 2024. Results. HE4 is involved in gynecological cancer progression, but its role in the development of LC remains poorly studied despite its high expression in tumor tissue. Modern studies demonstrate that diagnostic characteristics of serum HE4 are comparable to or slightly superior to other markers used in the diagnosis of LC (CYFRA21-1, CEA, NSE, ProGRP, etc.). Several studies report that the HE4 serum level can serve as a predictor of response to chemotherapy and the duration of the relapse-free interval in LC. Some studies indicate the feasibility of HE4 as a marker for monitoring patients for early detection of lung cancer relapse. The indicators of the diagnostic and prognostic signifcance of serum HE4 vary signifcantly in different studies due to the heterogeneity of the included groups, differences in the reference values and methods for assessing the HE4 levels. This does not allow us to adopt a unifed diagnostic algorithm for using HE4. Conclusion. The accumulated data indicate the feasibility of using HE4 as a tumor-associated marker in LC. However, some aspects that are important for the practical application of HE4 remain unclear. Thus, the introduction of this marker into clinical practice requires further systematic and in-depth studies.