Clinical characteristics and risk of second primary lung cancer after cervical cancer: A population-based study

Background Lung cancer is increasingly common as a second primary malignancy. However, the clinical characteristics of second primary non-small cell lung cancer after cervical cancer (CC-NSCLC) compared with first primary non-small cell lung cancer (NSCLC1) is unknown. Methods The Surveillance, Epidemiology, and End Results (SEER) cancer registry between 1998 and 2010 was used to conduct a large population-based cohort analysis. The demographic and clinical characteristics, as well as prognostic data, were systematically analyzed. The overall survival (OS) in the two cohorts was further compared. The risk factors of second primary lung cancer in patients with cervical cancer were also analyzed. Results A total of 557 patients (3.52%) developed second primary lung cancer after cervical cancer, and 451 were eligible for inclusion in the final analyses. Compared with NSCLC1, patients with CC-NSCLC had a higher rate of squamous cell carcinoma (SCC) (36.59% vs 19.07%,P< 0.01). The median OS was longer for CC-NSCLC than for NSCLC1 before propensity score matching (PSM) (16 months vs. 13 months) but with no significant difference after PSM (16 months vs. 17 months). The high-risk factors for the development of cervical cancer to CC-NSCLC include age 50-79 years, black race [odds ratio (OR) 1.417; 95% confidence interval (CI) 1.095-1.834;P< 0.05], and history of radiotherapy (OR 1.392; 95% CI 1.053-1.841;P< 0.05). Conclusion Age 50-79 years, black race, and history of radiotherapy were independent risk factors for second primary lung cancer in patients with cervical cancer. Patients with CC-NSCLC had distinctive clinical characteristics and better prognosis compared with patients with NSCLC1.