Abstract 6491: Prognostic potential of carcinoembryonic antigen expression patterns in lung adenocarcinoma

Abstract

Abstract Carcinoembryonic antigen (CEA) is one of the most commonly used tumor markers. Although the suitability of CEA as an effective marker for lung cancer remains debatable, characteristics such as noninvasiveness and lack of other reliable markers make CEA an attractive option in lung cancer. Divergent CEA expression patterns before and after EGFR-tyrosine kinase inhibitor (TKI) treatment have been reported. However, whether these patterns are associated with tumor progression remain elusive. We hypothesized that divergent patterns of serum carcinoembryonic antigen at initial diagnosis (CEAIn) and disease progression (CEAPd) may reflect the diversity of lung cancer cells selected by TKI, conferring distinct progression profiles in patients. Our objective was to verify the prognostic potential of divergent CEA patterns before and after TKI treatment in lung cancer patients with wild-type or mutant EGFR. Of the 1736 lung cancer patients identified from the cancer registry group between 2011 to 2016, we selected 517 patients with advanced stage adenocarcinoma, data on EGFR mutation status and CEAIn, among whom were 288 patients with data on CEAPd, eligible for inclusion in the correlation analysis of clinical characteristics and survival. EGFR wild-type lung adenocarcinoma patients displayed lower CEAIn level than those with EGFR mutations. Multivariable analysis revealed that CEAIn expression was associated with poor progression-free survival in patients harboring mutant EGFR but not in those with wild-type EGFR. Moreover, CEAIn and CEAPd were associated with the good and poor post-progression survival, respectively, only in the EGFR-mutant and not in the wild-type group. In vitro cell line experiments revealed that CEA expression, cancer dissemination, and chemoresistant properties can be affected by EGFR-TKI selection. EGFR-mutant patients, exhibiting high CEAIn (≥ 5 ng/mL) and low CEAPd (< 5 ng/mL), showed a potential toward displaying new metastasis. Our findings support the notion that EGFR mutation status is a critical factor in determining prognostic potential of CEAIn and CEAPd in patients under EGFR-TKI treatment, and divergent CEAIn and CEAPd patterns are associated with distinct cancer progression profiles. Citation Format: Ming-Yi Zheng, Yen-Shou Kuo, Yu-Ting Chou. Prognostic potential of carcinoembryonic antigen expression patterns in lung adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6491.