The clinical-histological and prognostic characteristics in patients with second primary non-small cell lung cancer after lobectomy.

Abstract

This study aimed to investigate whether operation can bring survival benefits to patients with second primary non-small cell lung cancer (NSCLC) after lobectomy for first primary NSCLC and analyze the characteristics affecting the survival of those patients. We performed survival analysis of patients with the second primary NSCLC based on the Surveillance, Epidemiology, and End Results program and used propensity-score matching (PSM) method to reduce the potential bias and analyze the data. Besides, the primary observational endpoint was overall survival (OS), and the secondary observational endpoint was histology migration. The data from 944 patients was used to perform the main analysis. 36.2% of patients experienced a shift in tumor histological type between two diagnoses of primary NSCLC, and this shift significantly effected on OS (p = 0.0065). The median survival time in patients with surgical resection and those without operation was 52.0 months vs. 33.0 months, respectively. Patients with surgical resection at secondary diagnosis had better survival than cases without surgery (5-year OS rate: 48.0% vs. 34.0%, p < 0.001). Besides, compared with pneumonectomy and sublobar resection, lobectomy was the optimal surgical procedure for patients diagnosed with second primary NSCLC after adjusting for other confounders (adjusted hazard ratio: 0.68, p < 0.01). However, in the subgroup analysis, lobar and sublobar resection could provide similar survival benefits for patients with tumor size ≤20mm (p = 0.5). The surgery, especially lobectomy, can prolong OS in patients with the second primary NSCLC. Besides, sublobar resection can be performed in selected patients with tumor size ≤20mm. Moreover, histology migration may impact the survival of those patients with a secondary primary NSCLC.