To analyze the pathological types and clinical characteristics of idiopathic pulmonary fibrosis-lung cancer (IPF-LC) patients, the protection and risk factors of IPF-LC.

From November 2014 to October 2022, 190 IPF patients admitted to our hospital were divided into simple IPF group (n=144) and IPF-LC group (n=46) according to whether the patients were complicated with lung cancer. The clinical data, blood gas analysis, imaging examination, erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) levels of the two groups were collected.

Among the 144 cases in the simple IPF group, there were 95 males (65.97%) and 49 females (34.03), with an average age of (58.10±11.57) years; among the 46 cases in the IPF-LC group, there were 41 males (89.13%) and 5 females (10.87%), with an average age of (63.91±10.12) years, with a statistically significant difference in gender and age between the two groups (P<0.05). The average smoking index of the simple IPF group was 250 years, and the average smoking index of the IPF-LC group was 700 years, with a statistically significant difference (P<0.05); there were statistically significant differences in hemoptysis, chest pain, weight loss and clubbing between the simple IPF group and the IPF-LC group (P<0.05); in the IPF-LC group, there were 13 cases (28.26%) of nodular mass shadows in the upper lobe, 24 cases (52.17%) in the lower lobe, and 37 cases (80.43%) in the periphery. There were statistically significant differences in arterial oxygen partial pressure (PaO₂), CRP and ESR levels between the two groups (P<0.05); decreased PaO₂ was a risk factor for IPF patients with LC (P<0.05).

Male IPF patients over 65 years old with high smoking index are more likely to be complicated with LC; The IPF-LC group is more likely to have clubbing, hemoptysis, chest pain, and weight loss than the IPF group alone; the levels of CRP and ESR in the IPF-LC group are higher than those in the IPF group alone, suggesting that chronic inflammatory mediators play a role in the pathogenesis of IPF-LC; the imaging examination of IPF-LC shows that the masses often occur in the area of obvious fibrosis, peripheral lung and lower lobe; PaO₂ is a protective factor for IPF-LC.