The Risk of Second Primary Malignancies in Patients With Lung Neuroendocrine Tumors: A Population-Based Study on SEER Database.

Abstract Purpose We investigated the at-risk sites of second primary malignancies (SPMs) and evaluate the risk factors of SPMs among lung neuroendocrine tumors (LNETs) survivors by using the surveillance, epidemiology, and end results database. Methods Propensity-score matching was performed to conduct a case-control study from the surveillance, epidemiology, and end results database. Cox regression analysis and multiple primary standardized incidence ratios were performed to investigate the risk factors of occurrence of SPMs among patients with LNETs. Results Of 3,206 patients with LNETs after matching, 539 developed SPMs. The risk of developing SPMs was higher in older patients (55–74 vs ≦54: hazard ratios [HR] 1.875; age ≧75 vs ≦54: HR 2.713), higher-stage of LNETs (regional vs localized: HR 1.387; distant vs localized: HR 2.732) and recent periods of diagnosis (2004–2014 vs 1984–1993: HR 1.735). Patients with SCLC, TC and LENEC had a higher risk for SPMs compared to general population. Lung and bronchus, larynx and some digestive organs had higher risk for SPMs while some sex hormone related organs like prostate, breast, and female reproductive system had a lower incidence of SPMs. Conclusions Patients with LNETs had overall higher risks of SPMs than general population. Different types of second primary malignancies occurred in different periods after LNETs were diagnosed. Further investigations are required to screen different second primary malignancies for those with primary LNETs.