MS10.06 Interstitial Lung Diseases

Abstract

Patients with a history of smoking are enriched population for studying pulmonary fibrosis and as patients are living longer with fibrosis, they are becoming an enriched population for studying lung cancer (1). Usual interstitial Pneumonitis is the most frequent pattern of pulmonary fibrosis in the United States. There are 48,000 new patients with IPF each year in the US and 40,000 die (2). Ozawa found that the cumulative incidence of lung cancer is 3.3%, 15.4%, and 54.7% at 1, 5, and 10 years of IPF (3). Adenocarcinoma is most common lung cancer in the general population. Kawasaki found that of 53 patients with IPF and lung cancer, there was no predominant histology. There are similarities between lung cancer and fibrosis, which include invasion of normal tissue, lack of monoclonality, mutation of tumor suppressor genes and epithelial mesenchymal transformation (4). The tumor microenvironment often causes cancers in fibrosis to have shorter doubling times. The survival of patients with lung fibrosis and cancer is poor with up to 93% 5-year mortality (5). Screening for lung cancer in patients with fibrosis is different from screening in non-fibrotic patients because of the potential rapid growth of some cancers. Lung cancer occurring in a patient with fibrosis are different from lung cancer occurring in a patient with emphysema. The patients are often not candidates for surgery. If they have surgery, it should be as limited as possible to decrease the risk of exacerbation (6). Chemotherapy increase risk of an exacerbation as does immunotherapy (7). Radiation has an increased risk of exacerbation as well; perhaps proton therapy may have better outcomes (8). In summary as patients are living longer with fibrosis the incidence of lung cancer is increasing however the treatments for early cancer in patients with lung cancer increase the risk of fibrosis exacerbation and further study is necessary in this area to make recommendations for best practices.