Abstract
OBJECTIVE: To study the surgical outcomes of patients with a second primary lung cancer after the extrapulmonary malignancy. MATERIALS AND METHODS: Patients who underwent surgical resection for lung cancers between January 2005 and December 2014 were reviewed. Clinical data, imaging characteristics of tumors, surgical approaches, and outcomes were analyzed with a mean follow-up of 97 months. RESULTS: Of 1075 patients, 166 (15.4%) had a second primary lung cancer after extrapulmonary malignancy. There were no differences in overall 5-year survival rates (81.8% for the group of lung cancer vs. 72.9% for the second primary lung cancer group, p = 0.069) and 5-year disease-free survival (70.1% for the lung cancer group vs. 70.3% for the second primary lung cancer group, p = 0.863) between the two groups. Gender, performance status, tumor size, and maximum standard uptake value (SUVmax) were significantly different between the two groups. After propensity-score matching analysis, patients in the group with lung cancers had better 5-year overall survival (88.1% vs. 72.1% for the group with second primary lung cancers, p = 0.016) and 5-year disease-free survival (80.6% vs. 70.3% for the group with second primary lung cancers; p = 0.054). In the second primary lung cancer group, the patients with preceding breast or thyroid cancers had better prognoses than did those with other extrapulmonary malignancy. CONCLUSIONS: Second primary lung cancers following extrapulmonary malignancies were not uncommon. Surgical resection is considered for early stage secondary primary lung cancer after meticulous work up and result in fair outcome.