Abstract 3299: Usefulness of protocadherin GA12 and cysteine ​​dioxygenase type 1 methylation biomarkers in the diagnosis of lung cancer

Rationale: The use of bronchoscopy is key to the diagnosis of lung cancer. However, the sensitivity of bronchoscopy is low. In addition, bronchial washing cytology, a routine auxiliary test, does not significantly improve the performance of bronchoscopy due to its low sensitivity. To improve the diagnostic performance of bronchoscopy, protocadherin GA12 (PCDHGA12) and Cysteine ​​Dioxygenase Type 1 (CDO1) methylation biomarkers in bronchial washing fluid have been introduced as novel adjunctive diagnostic tests. Methods: A total of 161 patients with suspected lung cancer who underwent bronchoscopy were analyzed. Cytological examination of bronchial washing fluid and testing for PCDHGA12 and CDO1 methylation biomarkers were performed. Results: The final diagnosis was lung cancer in 114 patients, and benign disease in 49 patients. PCDHGA12 methylation biomarker showed sensitivity of 80.4% and specificity of 87.8%. CDO1 methylation biomarker showed sensitivity of 66.1% and specificity of 98.0%, whereas cytological evaluation showed sensitivity of 43.8% and specificity of 100%. The combined analysis of PCDHGA12 and CDO1 methylation showed sensitivity of 84.8% and specificity of 85.7%. The combined analysis of the methylation biomarkers and cytology tests resulted in a slightly increased sensitivity of 86.6% and specificity of 85.7%. The specificity and sensitivity of the methylation biomarkers were also high in peripheral lung cancer. Conclusion: The results of this study demonstrated that PCDHGA12 and CDO1 methylation as lung cancer biomarkers of bronchial washing may be used as adjunctive tests for bronchoscopy. Keywords: biomarker; bronchoscopy; lung cancer; protocadherin GA12: CDO1, methylation Citation Format: Ji Woong Son, Minhyeok Lee, In Beom Jeong, Sun Jung Kwon, Daeun Kang, Moon Jun Na. Usefulness of protocadherin GA12 and cysteine ​​dioxygenase type 1 methylation biomarkers in the diagnosis of lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3299.