Influence of age and gender on the diagnostic accuracy of pleural fluid carcinoembryonic antigen for malignant pleural effusion: a post hoc analysis

Dan-Ni Yang¹Jian-Xun Wen²Yan Niu²Ling Hai¹Qian Yang¹Su-Na Cha¹Cheng Yan¹Hong-Zhe Zhu¹Tingwang Jiang³Li Yan¹Jinhong Huang³Hong Chen³Xin-Ru Zuo¹Wenqi Zheng¹Zhi-De Hu^1*

• ¹Affiliated Hospital, Inner Mongolia Medical University, Hohhot, China
• ²Inner Mongolia Medical University, Hohhot, Inner Mongolia Autonomous Region, China
• ³the Changshu Hospital of Nantong University, Changshu, China

The diagnostic value of pleural fluid carcinoembryonic antigen (CEA) for malignant pleural effusion (MPE) has been well recognized. However, whether age and gender affect its diagnostic accuracy remains unknown. This study aimed to investigate the influence of age and gender on the accuracy of CEA for differentiating MPE and benign pleural effusion (BPE).We enrolled participants from a prospective cohort (SIMPLE) and a retrospective cohort (BUFF). All participants were pleural effusion patients with undetermined causes. The clinical characteristics were extracted from the medical records of participants. The area under receiver operating characteristics (ROC) curve (AUC) was used to estimate the diagnostic accuracy of CEA.The effects of gender and age on the diagnostic accuracy of CEA for MPE were analyzed using subgroup analysis. A method characterized by resampling participants with different upper limits was also used to investigate the effect of age.The SIMPLE cohort included 210 participants (91 MPEs and 119 BPEs), and the BUFF cohort included 235 participants (50 MPEs and 185 BPEs). Gender did not significantly affect the diagnostic accuracy of CEA. Subgroup analyses with both cohorts revealed the decreased AUC in older patients. The resampling method revealed decreased AUC with the advancement of age.Conclusions: Age should be considered when interpreting the diagnostic accuracy of pleural fluid CEA for MPE, while the effects of gender can be ignored.