The prognosis of clinical stage <scp>IIIa</scp> non‐small cell lung cancer in Taiwan

<jats:title>Abstract</jats:title><jats:p>Lung cancer is the leading cause of cancer death. The treatment of stage IIIa remained the most controversial of all stages of non‐small cell lung cancer (NSCLC). We reported on the heterogenicity and current treatment strategies of stage IIIa NSCLC in Taiwan. This study is a retrospective analysis using data from the Taiwan Society of Cancer Registry between January 2010 and December 2018. 4232 patients with stage IIIa NSCLC were included. Based on cell type, the best 5‐year OS (40.40%) occurred among adenocarcinoma victims. The heterogenicity of T1N2 had the best 5‐year OS (47.62%), followed by T4N0 (39.82%), and the others. Patients who underwent operations had better 5‐year OS (over 50%) than those who did not (less than 30%). Segmentectomy (75.28%) and lobectomy (54.06%) showed better 5‐year OS than other surgical methods (less than 50%). In multivariable analysis, young age, female, lower Charlson Comorbidity Index score, adenocarcinoma cell type, well differentiated, T1N2/T4N0 heterogenicity, treatment with operation, and segmentectomy/lobectomy/bilobectomy were significant factors. In conclusions, the heterogenicity of T1N2 had the best outcomes followed by T4N0. Patients received surgical treatment revealed much better outcomes than those did not. As always, multimodal therapies with individualized treatment tend to provide better survival outcomes.</jats:p>