Disease Recurrence and Second Tumors in Long-term Survivors of Lung Cancer

Abstract Introduction and objectives As cancer survival improves, the appearance of multiple tumors in a single patient is becoming more common. The aim of this study was to analyze long-term evolution, focusing particularly on disease recurrence and second primary tumors, in patients with lung cancer (LC) and ≥3 years overall survival. Materials and methods Retrospective study of 1769 patients with LC. A total of 218 (136 treated with surgery and 82 with other treatments), followed up for between 5 and 23 years were enrolled. LC progress and intercurrent diseases were recorded. Results A total of 65 patients presented tumor relapse, of which 60.9% occurred in the first 3 years; 26 patients developed secondary primary tumors (84.6% after 5 years) and 24 developed 2 or more second extrapulmonary tumors (66.6% after 5 years), most of which were smoking-related. The incidence of second primaries was greater than the expected incidence of cancer in the general population matched for age and sex. Conclusion The multiple carcinogenic effect of smoking persists and manifests in various organs, more than 5 years after the diagnosis of LC, even in patients with long survival. After 5 years, a second tumor is more likely than a relapse of the primary disease, and the lung is the most common site of development of a second tumor.