Frequency of lung cancer in idiopathic pulmonary fibrosis

<bold>Introduction:</bold> Lung cancer is 5-7 times more common in cases with IPF than the normal population. <bold>Aims:</bold> We aimed to investigate the frequency, subtypes, risk factors of lung cancer and effect on survival in IPF. <bold>Methods:</bold> Demographics, GAP index, spirometry and carbon monoxide diffusion capacity (DLCO) measurements, subtype and detection time of lung cancer were recorded. <bold>Results:</bold> Totally 177 cases with IPF (128 male, 49 female, mean age: 65.5±9.6 years) were included. Most of the cases were active (12.1%) or former (52.9%) smokers. There was asbestos exposure in 10.7% of them, a family history of lung cancer in 6.2%. At diagnosis, average forced vital capacity (FVC) was 76.6±21.2% and DLCO was 55.7±19.2%. Of the cases 59.9% were GAP stage 1, 32.9% were stage 2, and 7.2% were stage 3. More than 5% decrease in FVC and/or 10% decrease in DLCO was detected in 33.3% at the first year. Antifibrotic use rate was 73.4% (n=130) [58.1% (n=103) pirfenidone, 29.3% (n=52) nintedanib]. Solitary pulmonary nodule (SPN) was detected in 29.3% (n=52) of the cases. Lung cancer developed in 11.5% of these cases (n=6) after an average of 16.5 months (3 adenocancer, 2 squamous cell cancer 1 small cell cancer). Average survival time after diagnosis of cancer was 25.6 months and 3 cases were lost in follow-up. A 5% decrease in FVC and/or a 10% decrease in DLCO at 1 year was more common than in cases who developed lung cancer (p = 0.042). <bold>Conclusions:</bold> According to our findings, malignancy development is more common in patients with disease progression during follow-up.