Surgical treatment of metachronous second primary lung cancer.

Background: Many studies have demonstrated that patients with metachronous second primary lung cancer (MSPLC) benefit from surgery. Owing to the lack of uniform criteria and prospective randomized trials, the extent of resection remains controversial, and prognostic factors are still not fully clear. The present study aimed to assess surgical treatment of MSPLC and identify prognostic factors of outcome.

Methods: This retrospective analysis included 143 patients who underwent surgical resection of MSPLC in our department from January 2006 to December 2011. Predictors of postoperative complications were analyzed with the binary logistic regression method. Survival was analyzed with Kaplan-Meier and Cox regression methods.

Results: Operative mortality was 1.4%, and the complication rate was 34.3%. Age more than 70 years was an independent risk factor for postoperative complications. The overall 5-year survival after resection of MSPLC was 54.5%. TNM stage II or higher (p = 0.025), 20 or more pack-years of smoking (p = 0.037), and tumor size greater than 2 cm (p = 0.033) were independent negative prognostic factors for survival. For stage I disease, completion pneumonectomy had a lower 5-year survival rate than others, 44.8% and 65.9, respectively (p = 0.039); lobectomy and sublobar resection have a 5-year survival of 77.1% and 56.7%, respectively (p = 0.203).

Conclusions: Surgical treatment of MSPLC is safe and effective. TNM stage I, tumor size 2 cm or less, or less than 20 pack-years smoking are predictors of improved survival. Sublobar resection is acceptable. For stage I disease, lobectomy tends to be associated with better survival than sublobar resection, although the difference is not significant, and completion pneumonectomy is not recommended. Long-term follow-up is necessary even after curative resection of lung cancer.