Carcinoembryonic antigen (CEA) is not only used to aid the diagnosis of lung cancer, but also help monitor recurrence and determine the prognosis of lung cancer as well as evaluate the therapeutic efficacy for lung cancer. However, studies have also shown that CEA is present at low levels in the serum of patients with benign lung diseases (BLD), which will interfere with the accurate judgment of the disease. Due to difference in sample size, detection methods, cutoff values and sources of BLD, the positive rate of CEA in BLD is different with different literature. Therefore, it is necessary to define CEA levels in patients of different BLD in a large sample study. 4796 patients with BLD were included in this study. The results showed that the CEA levels of 3.1% (149/4796) patients with BLD were elevated, with three cases exceeds 20 ng/mL (0.06%, 3/4796). The results from the literature showed that BLD had a mean positive rate of 5.99% (53/885) and only two cases had CEA above 20 ng/mL. The CEA elevations mainly distributed in chronic obstructive pulmonary disease (COPD), pneumonitis and interstitial lung disease and significantly correlated with age of patients (OR 2.69, 95% CI 1.94–3.73, p < 0.001). Pulmonary tuberculosis (7/1311, 0.53%) had the lowest positive rate of CEA elevations while pulmonary alveolar proteinosis (6/27, 22.22%) had the highest positive rate. The majority of patients with abnormally elevated CEA levels had multiple underlying diseases, mainly diseases of the circulatory system (42.28% [63/149]), endocrine diseases (26.85% [40/149]), and respiratory or heart failure (24.16% [36/149]. In endocrine diseases, 87.5% (35/40) of patients had diabetes. In conclusion, CEA is present at a low positive rate in the serum of patients with BLD, but few exceed 20 ng/mL. For lung disease patients, if CEA levels rise, we should carry out comprehensive analysis of types of lung diseases, age of patients, and comorbid diseases.

癌胚抗原（CEA）不仅用于辅助肺癌的诊断，还有助于监测肺癌的复发情况、判断肺癌的预后以及评估肺癌的治疗效果。但也有研究表明，良性肺病（BLD）患者血清中CEA含量较低，会干扰对疾病的准确判断。由于BLD的样本量、检测方法、临界值和来源的不同，不同文献的BLD中CEA阳性率存在差异。因此，有必要在大样本研究中确定不同 BLD 患者的 CEA 水平。4796 名 BLD 患者被纳入本研究。结果显示3.1%（149/4796）的BLD患者CEA水平升高，3例超过20 ng/mL（0.06%，3/4796）。文献结果显示，BLD 的平均阳性率为 5.99% (53/885)，只有 2 例 CEA 高于 20 ng/mL。CEA升高主要分布于慢性阻塞性肺病（COPD）、肺炎和间质性肺病，且与患者年龄显着相关（OR 2.69, 95% CI 1.94-3.73, p < 0.001）。肺结核（7/1311，0.53%）CEA升高阳性率最低，肺泡蛋白沉积症（6/27，22.22%）阳性率最高。CEA水平异常升高的患者多数有多种基础疾病，主要是循环系统疾病（42.28% [63/149]）、内分泌疾病（26.85% [40/149]）、呼吸或心力衰竭（24.16%） [36/149].内分泌疾病中，87.5%（35/40）的患者有糖尿病。CEA 在 BLD 患者血清中的阳性率很低，但很少超过 20 ng/mL。对于肺部疾病患者，如果CEA水平升高，应综合分析肺部疾病类型、患者年龄、合并症等。