Impact of radiotherapy-related factors on survival in non-small cell lung cancer complicated with malignant pleural effusion based on propensity score matching / 中华放射肿瘤学杂志

ABSTRACT

Objective:To analyze the radiotherapy-related factors affecting the survival of non-small cell lung cancer (NSCLC) patients complicated with malignant pleural effusion (MPE)(MPE-NSCLC).Methods:From 2007 to 2019, 256 patients pathologically diagnosed with MPE-NSCLC received primary treatment. Among them, 117 cases were enrolled in this study. All patients were divided into two groups according to the radiation dose (<63 Gy and≥63 Gy). Propensity score matching (PSM) was performed to further adjust the confounding factors (Calipers value=0.1). The impact of radiotherapy-related factors on the overall survival (OS) was analyzed by Kaplan—Meier method, log-rank test and Cox’s regression model. Results:Primary tumor radiotherapy significantly prolonged the OS ( P<0.001). The radiation dose escalation (36.0-44.1 Gy, 45.0-62.1 Gy, 63.0-71.1 Gy) of primary tumor significantly prolonged the OS ( P<0.001). The corresponding median OS were 5, 13 and 18 months, respectively. Before the PSM, univariate analysis suggested that radiation dose ≥63 Gy, gross tumor volume (GTV)<157.7 cm 3 and stations of metastatic lymph node (S-mlN)≤5 were significantly associated with better OS (all P<0.05) and T 4N 3 was significantly associated with worse OS ( P=0.018). After the PSM, univariate analysis indicated that radiation dose ≥63 Gy was significantly associated with better OS ( P=0.013) and S-mlN ≤5 had a tendency to prolong the OS ( P=0.098). Prior to the PSM, multivariate analysis showed that radiation dose ≥63 Gy was an independent favorable factor of OS ( HR=0.566, 95% CI 0.368-0.871, P=0.010) and GTV<157.7 cm 3 had a tendency to prolong the OS ( HR=0.679, 95% CI 0.450-1.024, P=0.065). After the PSM, multivariate analysis revealed that radiation dose ≥63 Gy was still an independent favorable factor of OS ( HR=0.547, 95% CI 0.333~0.899, P=0.017). No ≥grade 4 radiation toxicity occurred. The incidence rates of grade 3 radiation esophagitis and pneumonitis were 9.4% and 5.1%, respectively. Conclusion:For MPE-NSCLC, radiotherapy dose of primary tumor may play a key role in improving OS on the basis of controllable MPE.