Serum cancer testis antigen MAGEA3-IgG serves as a diagnostic biomarker in lung adenocarcinoma.

OBJECTIVES

This study aims to identify novel biomarkers for the early diagnosis of lung adenocarcinoma (LUAD), with the goal of facilitating early intervention to improve patient prognosis.

METHODS

A pilot cohort was established by collecting serum samples from 55 LUAD patients and 24 healthy controls. Based on the pilot cohort, the sample size was subsequently increased to 107 LUAD patients and 60 healthy controls, forming an expanded validation cohort. Enzyme-linked immunosorbent assay (ELISA) was employed to evaluate the expression levels of IgG and IgM autoantibodies targeting melanoma antigen gene family A (MAGEA) proteins in the pilot cohort. The autoantibody exhibiting the highest diagnostic efficacy was selected for further analysis in the expanded cohort to validate its expression in LUAD serum. Receiver operating characteristic (ROC) curve analysis was utilized to assess its potential for early diagnosis and monitoring of surgical treatment outcomes in LUAD patients.

RESULTS

In the pilot cohort, serum expression levels of MAGEA3-IgG, MAGEA6-IgG, MAGEA8-IgG, MAGEA9-IgG, MAGEA10-IgG, MAGEA11-IgG, and MAGEA10-IgM were significantly elevated in LUAD patients compared with healthy controls (P < 0.05), demonstrating favorable diagnostic efficacy. MAGEA3-IgG, which demonstrated the highest diagnostic efficiency in the pilot cohort, was chosen for validation in the expanded cohort. The results confirmed that the expression of MAGEA3-IgG was significantly upregulated in the serum of LUAD patients compared with healthy controls (P < 0.001), and significant differences were observed across different N stage groups (P < 0.001). Further ROC curve analysis indicated that the diagnostic performance of serum MAGEA3-IgG was marginally superior to that of CEA alone in the LUAD expanded cohort. The AUC for the combination of MAGEA3-IgG and CEA was 0.787 (95% CI 0.716-0.859), significantly enhancing the diagnostic performance. The study also demonstrated that serum levels of MAGEA3-IgG in patients with early LUAD were significantly higher than in healthy controls (P < 0.001), and the combination of MAGEA3-IgG and CEA improved the diagnostic efficacy for early LUAD (AUC = 0.748, 95% CI 0.666-0.83). In addition, serum MAGEA3-IgG exhibited strong potential for monitoring the effects of surgical treatment (AUC = 0.875, 95% CI 0.725-1).

CONCLUSION

Serum MAGEA3-IgG levels are significantly elevated in LUAD patients, and this autoantibody is anticipated to serve as a critical biomarker for early diagnosis, treatment monitoring, and prognostic evaluation in LUAD.