Efficacy of chemotherapy combined with local therapy in patients with oligometastatic non-small cell lung cancer: a SEER-based study

Background & Aims: Localized therapy (LCT) is becoming increasingly important in the treatment of patients with oligometastatic non-small cell lung cancer (OM-NSCLC). However, the optimal timing of LCTin relation to systemic treatment remains unclear. This study aimed to develop a novel predictive nomogram to identify specific OM-NSCLC populations who could benefit from LCT. Methods: 14,920 OM-NSCLC patients between 2010 and 2015 were extracted from the Surveillance, Epidemiology and End Results (SEER) database. Propensity score matching (PSM) and Kaplan-Meier Survival Curve were conducted to evaluate the influence of chemotherapy combined with local therapy(CCLCT) on the prognosis. Univariate and multivariate Cox regression models were utilized to determine potential risk factors, and a nomogram of overall survival (OS) at different times was formulated. The area under the receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA) and a risk stratification system were used to validate the nomograms. Results: The most favorable prognostic survival was observed in patients receiving a combination of chemotherapy and surgery, followed by those undergoing chemotherapy, surgery and radiotherapy. Conversely, patients receiving only chemotherapy or a combination of chemotherapy and radiotherapy had the lowest and comparably similar prognostic survival outcomes. Specifically, chemotherapy combined with surgery is an effective treatment option to improve prognostic survival among OM-NSCLC patients, with a 19-month prolongation of median survival compared to chemotherapy alone. Independent prognostic risk factors utilized in the nomogram for predicting overall survival (OS) include therapy type, age, sex, race, primary tumor site, tumor size, presence of metastases (in the bone, brain, and liver), N stage, and tumor grade. The AUC demonstrated the good performance of the nomogram. A favorable consistency between the predicted and actual survival probabilities was demonstrated by adopting calibration curves. Finally, The DCA and the risk classification system further supported that the prediction model was clinically effective. Conclusions: Chemotherapy combined with surgery is a highly effective treatment strategy for OM-NSCLC patients, significantly enhancing their prognostic survival. We constructed a novel nomogram to predict OS in OM-NSCLC patients, aiding both patients and healthcare professionals in assessing prognosis and facilitating informed clinical decisions.