Patients With Stage III PLCNEC Advocated for Radiotherapy Combined With Chemotherapy While With Stage IV Focus on...

PLCNEC is a rare and highly aggressive lung cancer with a poor prognosis. Multimodal therapy, primarily chemotherapy-based, is the standard for advanced PLCNEC, but the role of radiotherapy remains unclear.

We analyzed 1086 PLCNEC patients receiving chemotherapy from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Propensity score matching (PSM) was applied to adjust baseline confounding variables. Kaplan-Meier survival curves were constructed and compared to assess survival differences. Cox proportional hazards regression models were employed to evaluate prognostic factors. Predictive nomograms were developed and validated to predict individual survival probabilities and facilitate clinical decision-making.

Chemotherapy combined with radiotherapy was associated with improved OS and CSS compared with chemotherapy alone in stage III-IV PLCNEC patients (p < 0.05). Sex, N stage, M stage, surgical treatment, and radiotherapy were identified as independent prognostic factors. Nomograms developed demonstrated strong predictive performance, with areas under the curve (AUCs) for OS of 0.720, 0.821, and 0.847 at 1, 3, and 5 years, respectively, and for CSS of 0.733, 0.800, and 0.810 at the corresponding time points. Subgroup analyses suggested that selected patients may derive differential benefit from chemoradiotherapy.

Radiotherapy is associated with improved survival outcomes in stage III PLCNEC patients receiving chemotherapy, whereas its role in stage IV disease appears more context-dependent and warrants individualized consideration. The proposed nomograms provide complementary prognostic information to support individualized clinical decision-making.