Combining serum CDK1 with tumor markers for the diagnosis of small cell lung cancer.

Objective: An investigation of the diagnostic and clinical value of cell cycle-dependent kinase 1 (CDK1) in small cell lung cancer (SCLC).

Methods: A large tertiary hospital in Jiangxi Province enrolled 80 SCLC cases, 105 cases of non-small cell lung cancer (NSCLC), 114 cases of pulmonary nodule (PN) and 60 control cases from December 2022 to December 2023. ELISA was used to measure CDK1 levels in serum. The expression levers of neuron-specific enolase (NSE), Pro gastrin-releasing peptide (ProGRP), squamous cell carcinoma antigen (SCCA), carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199) and cytokeratin 19 fragment (YFRA21-1) were detected by electrochemiluminescence immunoassay.

Results: ①CDK1, ProGRP, NSE, and CA199 expressions were significantly higher in the SCLC group compared to the NSCLC, PN and Control groups (P < 0.01). ②Spearman correlation analysis showed that serum levels of CDK1, NSE, and ProGRP were associated with clinical staging and lymph node metastasis in SCLC patients (P < 0.05). ③The serum levels of CDK1, NSE, and ProGRP in patients with extensive-disease (ED) SCLC were higher than those in patients with limited-disease (LD) SCLC (P < 0.05), and the serum levels of CDK1, NSE, and ProGRP in SCLC patients with lymph node metastasis were higher than those without lymph node metastasis (P < 0.05). ④Compared with the NSCLC group, the AUC of subjects diagnosed with SCLC by CDK1 was the largest and the sensitivity was the highest, 0.831 and 72.50%, the specificity of ProGRP in diagnosing SCLC is the highest, at 95.20% (P < 0.01). Compared with the PN group, CDK1 had the highest AUC, sensitivity, and specificity in diagnosing SCLC, with values of 0.93%, 88.80%, and 94.70%, respectively (P < 0.01). ⑤The combination of CDK1, ProGRP and NSE had the highest AUC and sensitivity of 0.903 and 86.30% for the diagnosis of SCLC (P < 0.01).

Conclusion: CDK1 not only plays an important role in assisting the diagnosis of SCLC but also in the differential diagnosis between SCLC and NSCLC. The combination of CDK1 and NSE and ProGRP can significantly improve the diagnostic performance and provide new ideas for the clinical diagnosis of SCLC.