Prognostic nomogram for overall survival in patients with stage IV non-small cell lung cancer treated with chemotherapy combined with high-dose thoracic radiotherapy.
Authors: YiChao Geng, Shengfa Su, Weiwei Ouyang, Yinxiang Hu, Qingsong Li, Zhu Ma, Daxian Luo, Wengang Yang, Xiaxia Chen, Cheng Hu, Bing Lu
Journal: Journal of Clinical Oncology (2024)

e20607 Background: Although the targeted therapy and immunotherapy have become the first line options for selected stage IV non-small cell lung cancer (NSCLC) patients. However, there are instances where certain patients are not administered targeted therapy or immunotherapy due to a variety of factors, chemotherapy and radiotherapy remain the main way to treat such patients. This study aimed to construct a prognostic nomogram for patients with stage IV NSCLC treated with chemotherapy combined with high-dose (≥ 60 Gy) thoracic radiotherapy. Methods: The nomogram was based on a retrospective study of 335 patients with stage IV NSCLC who treated with chemotherapy combined with high-dose (≥ 60 Gy) thoracic radiotherapy were hospitalized between January 2010 and January 2018(patient did not receive TKI therapy or immunotherapy). The patients were randomly assigned to either a primary cohort (n = 234) or a validation cohort (n = 101) at a ratio of 7 : 3. In the primary cohort, a univariate analysis of the clinical or therapeutic factors that may predict OS was performed using a Cox regression model, with P &lt; 0.05 indicating statistical significance. The variables from the univariate analysis that affected OS significantly were included in the Cox regression model for the multivariate analysis. A nomogram was then created based on the results of multivariate analysis and using the “rms,” “foreign,” and “survival” R version 4.0.3 software packages. The discriminatory ability of the nomogram was measured using the area under the curve (AUC) of a receiver operating curve (ROC). Results: Multivariate logistic regression analysis revealed that malignant pericardial effusion, adrenal metastasis, elevated lactate dehydrogenase levels, and excessive planning target volume were independent risk factors for poorer 1–3 year overall survival (OS), while a higher radiotherapy dose for the primary lesion was associated with better OS. Nomogram prediction models were constructed using these five variables. The AUC of the ROC for 1-year, 2-year, and 3-year OS in the primary cohort were 0.685, 0.729, and 0.816, respectively. In the validation cohort, the AUC of the ROC for 1-year, 2-year, and 3-year OS were 0.706, 0.749, and 0.797, respectively. The Kaplan-Meier survival analysis showed that differentiation between the high-risk group and low-risk group using the prediction model had a direct, significant effect on survival in both the primary cohort ( P &lt; 0.001) and validation cohort ( P = 0.004). Conclusions: The nomogram model constructed in this study may be used to objectively predict the prognosis and OS of patients with stage IV NSCLC treated with chemotherapy and high-dose thoracic radiotherapy. Identify patients who may not benefit from high-dose thoracic radiotherapy prior to treatment to avoid overtreatment.