Combining 18F-FDG PET/CT and Serum Lactate Dehydrogenase for Prognostic Evaluation of Small Cell Lung Cancer

Xiaoping Lin; Zizheng Xiao; Yingying Hu; Xu Zhang; Wei Fan

doi:10.3389/fphar.2020.592768

Combining ¹⁸F-FDG PET/CT and Serum Lactate Dehydrogenase for Prognostic Evaluation of Small Cell Lung Cancer

Front Pharmacol. 2020 Oct 28:11:592768. doi: 10.3389/fphar.2020.592768. eCollection 2020.

Authors

Xiaoping Lin^{1

2}, Zizheng Xiao^{1

2}, Yingying Hu^{1

2}, Xu Zhang^{1

2}, Wei Fan^{1

2}

Affiliations

¹ Department of Nuclear Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
² State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.

Abstract

Objective: To investigate the value of using ¹⁸F-FDG PET/CT in combination with serum lactate dehydrogenase (LDH) for prognostic evaluation of newly diagnosed small cell lung cancer (SCLC). Methods: We reviewed 118 patients with pathologically proven SCLC who underwent ¹⁸F-FDG PET/CT imaging evaluation in our hospital. Among these patients, 64 patients had extensive disease (ED) and 54 patients had limited disease (LD). The maximum standardized uptake value (SUV_max) of primary tumor was measured. A Cox proportional hazards model was used to evaluate age, sex, performance status, serum LDH, tumor stage and SUV_max on the prediction of overall survival (OS) and median survival time (MST) of patients. Subgroup analysis was performed based on the SUV_max in combination with serum LDH. Results: According to the Receiver Operating Characteristic (ROC) curve, the optimal cut-off value of SUV_max was 10.95. The AUC was 0.535 (95% CI: 0.407-0.663). The patients were divided into four groups according to the SUV_max (higher or lower than 10.95) and LDH (higher or lower than 245 U/L). The univariate and multivariate analyses showed that curative thoracic radiotherapy, Prophylactic Cranial Irradiation (PCI) and the combination of primary tumor SUV_max ≤ 10.95 and LDH ≤ 245 U/L were prognostic factors of OS in patients with all patients (p < 0.05). Smoking status, PCI, the combination of primary tumor SUV_max ≤ 10.95 and LDH ≤ 245 U/L were prognostic factors of OS in patients with LD (p < 0.05). N stage and PCI were significant predictors in both of univariate and multivariate analysis of OS for ED SCLC (p < 0.05). Among all patients, 27 had low SUV_max and normal LDH, and their MST was 36 months (95% CI: 12.98-59.02). Ninety-one patients had high SUV_max and/or high LDH, and their MST was 20 months (95% CI: 15.47-24.53). The difference between these two groups was significant (p = 0.045). In patients with LD, 16 patients had low SUV_max and normal LDH, and their MST was 72 months (95% CI: 26.00-118.0). Thirty-eight patients had high SUV_max and/or high LDH, and their MST was 27 months (95% CI: 20.80-33.21). The difference between these two groups was significant (p = 0.012). In patients with ED SCLC, 10 patients had low SUV_max and normal LDH, with an MST of 18 months (95% CI: 13.69-22.32. Fifty-four patients had high SUV_max and/or high LDH, and their MST was 12 months (95% CI: 10.61-13.39). The difference of MST between these two groups was not statistically significant (p = 0.686). Conclusion: ¹⁸F-FDG PET/CT in combination with serum LDH were prognostic factors of overall survival in patients with SCLC. The prognosis of patients with LD SCLC who had low SUV_max of primary tumor and normal LDH was better than those with high SUV_max and/or high LDH.

Keywords: PET/CT; glycolysis; lactate dehydrogenase; maximum standardized uptake value; prognosis; small cell lung cancer.