ABSTRACT
BACKGROUND: Lung cancer is one of the most common cancers worldwide. Patients with early stage lung cancer have improved long-term survival. With the introduction of low-dose CT scan, more patients are going to be diagnosed at an early stage. However, there is limited data on the risk of second primary malignancies (SPMs) in these subsets of patients in the United States. METHODS: We utilized SEER-13 (Surveillance, Epidemiology and End Results) registry to obtain Multiple Primary- Standardized Incidence Ratio and an Absolute Excess Risk between January 2004 and December 2010 for patients with Stage Ia non-small cell lung cancer. RESULTS: The database comprised of 12,246 patients. A total of 1431 (11.68%) patients developed 1563 SPMs with an observed to expected (O/E) ratio of 2.07 (95% CI = 1.92-2.23, p < .001) in patients with adenocarcinoma and 2.05 (95% CI = 1.92-2.19, p < .001) in squamous cell carcinoma group. CONCLUSIONS: This study showed an excess risk of SPMs in patients with early stage non-small cell lung cancer. We recommend a close follow-up, paying attention to concerning symptoms or examination findings and judicious use of age-appropriate cancer screening.
