Association between idiopathic pulmonary fibrosis and lung cancer

The morbidity of lung cancer in patients with Idiopathic Pulmonary Fibrosis (IPF) ranges from 3% to 22%, significantly shortening the lifespan. However, the mechanisms by which IPF increases morbidity and mortality in lung cancer are not well understood. Lung cancer with IPF is more frequently observed in the peripheral regions of the lungs and in honeycomb areas. Squamous cell carcinoma is the most common cell type in lung fibrosis. Mechanisms such as proliferation, metastasis, angiogenesis, cancer stem cells, immunology, epigenetics, and metabolism may contribute to the initiation and progression of lung cancer in IPF patients. 2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) combined with computed tomography (CT) can assist in reliably detecting cancer. Surgery, chemotherapy, and radiation may trigger exacerbations of fibrosis. The increased use of wedge resection, proton therapy, and immunotherapy may reduce the risk of exacerbations, thereby improving survival.