Risk factors associated with a second primary lung cancer (SPLC) in patients (pts) with a previous initial primary lung cancer (IPLC).

Abstract

e13166 Background: The risk for development of a SPLC after treatment of an IPLC is around 1% to 2% per pt per year. The aim of this study was to characterize the risk factors associated with the development of a SPLC. Methods: Pts registered in the Karmanos Cancer Institute Tumor Registry diagnosed with an IPLC between 2000 and 2017 were included in this study. Pts with an IPLC who later developed a SPLC were matched for age, histology and stage to pts with an IPLC who did not develop a SPLC. SPLC was defined as a second lung cancer with a different pathology or if the same pathology, anatomically, molecularly, or chronologically distinct. Six variables including: stage at IPLC, histology, family history, surgery as a primary treatment for IPLC, and smoking history (determined by pack years, and continued tobacco use after first diagnosis) were reviewed. Logistic and Cox regression analyses were performed to determine the relationship of these characteristics with the development of a SPLC, and their association with overall survival (OS). Results: 121 pts with IPLC who later developed an SPLC were identified and compared to 120 pts with IPLC who did not develop a SPLC. Logistic analyses did not show that stage at first diagnosis, histology, family history, smoking history, and continued tobacco use after first diagnosis to be relevant for increased risk of SPLC. Pts who were primarily treated with surgical resection had a significantly higher probability of developing a SPLC (Odds Ratio: 0.24, 95% CI: 0.12 to 0.48, p < 0.001). Pts who did not have surgical resection as their primary mode of treatment for IPLC had a significantly higher risk of death than those who received surgical resection (HR 3.02, 95% CI: 1.99 to 4.57; p < 0.001). Conclusions: Based on our findings, pts who had surgical resection for an IPLC were found to have improved OS and a higher possibility of developing a SPLC. Stage at first diagnosis of IPLC, histology, family history, smoking history and continued use of tobacco after first diagnosis did not correlate with increased risk for SPLC. These results warrant further investigation and if confirmed could have an impact on surveillance recommendations post resection of initial lung cancers.