Evaluating the comprehensive diagnosis efficiency of lung cancer, including measurement of SHOX2 and RASSF1A gene methylation

Abstract

Methylation of the promoters of SHOX2 and RASSF1A (LungMe®) exhibits promise as a potential molecular biomarker for diagnosing lung cancer. This study sought to assess the aberrant methylation of SHOX2 and RASSF1A in broncho-exfoliated cells (BEC) and compare it with conventional cytology, histology examination, immunohistochemistry, and serum tumor markers to evaluate the overall diagnostic efficiency for lung cancer. This study recruited 240 patients, including 185 malignant cases and 55 benign cases. In our observation, we noted a slight reduction in the detection sensitivity, however, the ΔCt method exhibited a significant enhancement in specificity when compared to Ct judgment. Consequently, the ΔCt method proves to be a more appropriate approach for interpreting methylation results. The diagnostic sensitivity of cytology and histology was in ranged from 20.0%-35.1% and 42.9%-80%, respectively, while the positive detection rate of LungMe® methylation ranged from 70.0% to 100%. Additionally, our findings indicate a higher prevalence of SHOX2( +) among patients exhibiting medium and high expression of Ki67 (P < 0.01), as opposed to those with low expression of Ki67, but RASSF1A methylation did not show this phenomenon (P = 0.35). Furthermore, CEA, SCCA, and CYFRA21-1 showed positive detection rates of 48.8%, 26.2%, and 55.8%, respectively. Finally, we present a comprehensive lung cancer diagnostic work-up, including LumgMe® methylation. The combined analysis of SHOX2 and RASSF1A methylation serves as a powerful complement and extension to conventional methods, enhancing the accuracy of a lung cancer diagnosis with satisfactory sensitivity and specificity.

Keywords: DNA methylation; Diagnosis; Lung cancer; RASSF1A; SHOX2.

Fig. 1

A Correlation between sex and pathological classification of lung cancer. B Correlation between nodule location and pathological classification of lung cancer

Fig. 2

ROC curve determines the cutoff values of SHOX2 and RASSF1A methylation. A ROC curves of SHOX2 and RASSF1A methylation in diagnosing lung cancer. B ROC curve of combined methylation of SHOX2 and RASSF1A in diagnosing lung cancer

Fig. 3

Quantitative analysis of SHOX2 and RASSF1A DNA methylation in lung cancer (n = 185) and benign lung disease (n = 55) specimens. ΔCt = 20 means Noct

Fig. 4

The complementary role of methylation in cytological and histological diagnosis

Fig. 5

The comprehensive lung cancer diagnostic work-up, including LumgMe® methylation

Fig. 6

The patient's diagnosis process at the Affiliated Hospital of Nantong University