Clinicopathological characteristics of surgically resected lung cancer associated with idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVES: Idiopathic pulmonary fibrosis (IPF) is well known to be associated with lung cancer. It is important to clarify the clinical and pathological features of lung cancer with IPF in understanding the pathogenesis of lung cancer in IPF patients. We compared clinicopathological factors of lung cancer in patients with and without IPF.

METHODS: A retrospective study was conducted in 711 surgically resected lung cancer patients. Medical records were compared of IPF and non-IPF patients.

RESULTS: Of the 711 patients, 53 (7.5%) were IPF patients. Lung cancer in IPF patients was more frequent in elderly male smokers. Most lung cancers in IPF (79%) arose in peripheral areas involving fibrosis (P < 0.01). The incidence of squamous cell carcinoma in the IPF patients (46%) was significantly higher than that in non-IPF patients (22%) (P < 0.01). The incidence of multiple lung cancer in IPF cases (17%) was also significantly higher.

CONCLUSIONS: These results suggest that IPF has the potential to develop into lung cancer, especially peripheral squamous cell carcinoma. Further molecular analyses are necessary to clarify the relationship between IPF and lung cancer.