Does pulmonary fibrosis increase lung cancer risk?

Background The concepts in lung fibrosis and increased lung cancer risk have arisen from clinical observations of the concurrent findings during the autopsy of lung cancer and pulmonary fibrosis. Scar carcinoma attributes the origin of carcinomas to abutting areas of scarring. The association between fibrosis and lung cancer risk immediately raises a query: whether lung fibrosis induces lung cancer? Aim The study was done to elucidate the incidence, risk factors, and clinical characteristics of lung cancer in diffuse lung fibrosis. Patients and methods A cohort study was done based on a prospective group of 50 patients with diffuse lung fibrosis to evaluate the incidence of lung cancer, as well as a retrospective group of 50 patients with lung cancer to search for background of pulmonary fibrosis between 2019 and 2020. Demographic, radiographic, and histologic characteristics were reviewed for both groups. Results Among 50 patients with interstitial lung disease, lung cancer developed in 2/50 (4%) during the follow-up, whereas in the retrospective group, 8/50 (16%) were diagnosed as having lung cancer with diffused lung fibrosis between 2019 and 2020. Lung cancer risk factors were male sex, smoking, and occupational dust exposure. Squamous carcinoma followed by adenocarcinoma was the commonest histologic form. Conclusion Evidence shows an association between interstitial lung diseases and lung cancer emergence. Epidemiological evidence differs owing to the various study designs and populations.