Impact of Previous Malignancy on Outcome in Surgically Resected Non-Small Cell Lung Cancer

Patients with lung cancer with a history of treatment often undergo curative surgical resection. However, the impact of previous cancer treatment on the outcome of lung cancer remains unclear. We conducted a retrospective study of patients who underwent curative resection for non-small cell lung cancer between 1998 and 2011. We collected clinicopathologic data and patients were divided into groups by previous history of cancer treatment. Comparisons between groups, estimation of survival rates, and multivariate analyses were performed. Propensity score matching was used to create cohorts with reduced bias. Of 878 patients, 196 (22.3%) had previous extrathoracic malignancies, and stage I lung cancer was more frequent in this group (P < .001). In multivariate analysis of the whole cohort, older patients, men, non-adenocarcinoma histologic type, more advanced pathologic stage of lung cancer, interstitial pneumonia, and previous extrathoracic malignancies were associated with appreciably worse prognosis. When propensity score matched cohorts were compared, prognosis was significantly worse in patients with previous extrathoracic malignancies than patients without (5-year survival rates, 75.3% vs 82.7%; P = .009), although recurrence was not frequently seen (5-year recurrence-free rates, 78.7% vs 83.0%; P = .491). Because treatment history of extrathoracic malignancy was not associated with postsurgical lung cancer recurrence, proposing curative resection could be justifiable if the previous cancer is deemed cured or controlled. However, the results showing that patients with previous cancer history have a worse survival rate than patients without should be taken into account when curative surgery is considered.