BACKGROUND Idiopathic pulmonary fibrosis (IPF) is an independent risk factor for lung cancer (LC) development; however, its effect on recurrence after curative surgery remains unclear.

OBJECTIVES This study aimed to determine the impact of IPF on recurrence-free survival following curative surgical resection of stage I-III non-small cell lung cancer (NSCLC) and investigate the effects of patient and surgical factors on the risk of recurrence.

METHODS We reviewed retrospectively collected data of patients with surgically resected stage I-III NSCLC from two tertiary care hospitals in South Korea. By propensity score matching, patients with IPF (LC with IPF) were matched to those without IPF (LC without IPF).

RESULTS In total, 3416 patients underwent surgical resection, and 96 were diagnosed with underlying IPF. In the LC with IPF group, 89.6% patients were men, and the average age was 69.7 years. Sublobar resection was performed more frequently in the LC with IPF group than in the LC without IPF group, while the rate of mediastinal lymph node dissection and dissected node number were lower in the former group. The 5-year recurrence-free survival rate was significantly lower in the LC with IPF group (49.2%) than in the LC without IPF group (69.1%; P<0.001). Multivariable Cox regression analysis revealed that IPF and postoperative stage III were independent risk factors for recurrence.

CONCLUSIONS IPF may increase the risk of recurrence after curative surgical treatment for NSCLC. Close surveillance for recurrence is mandatory for patients with underlying IPF.