Assessing the diagnostic utility of serum tumor markers for lung cancer detection in patients with interstitial pneumonia.

Background: The prevalence of lung cancer among individuals afflicted with interstitial pneumonia (IP) stands at approximately 20%. The early detection of lung cancer via chest computed tomography (CT) surveillance proves challenging in IP patients. Our investigation sought to identify a potential biomarker capable of providing early indications of the presence of lung tumors in such patients.

Materials and methods: We examined the attributes of serum tumor markers, imaging characteristics, and histological findings in individuals diagnosed with IP, both with and without concurrent lung cancer.

Results: 106 patients diagnosed with IP were included in the study, comprising 36 individuals with concurrent lung cancer and 70 patients solely diagnosed with IP. Serum concentrations of CEA and CA12-5 were notably elevated in IP patients with lung cancer, compared to those with IP alone. Logistic regression analyses revealed that, in comparison to IP patients within the first quartile of CEA levels, the relative risk of developing lung cancer associated with IP escalated by 4.0-fold, 3.1-fold, 11.0-fold, and 13.3-fold in the second, third, fourth, and fifth quartiles, respectively. Upon controlling for gender and age, statistical significance in risk was observed solely for the fourth and fifth quartiles. Receiver operating characteristic (ROC) curve analysis conducted in patients diagnosed with ILD-CA identified a CEA cutoff point of 6.9 ng/mL, demonstrating sensitivities of 61.1% and specificities of 78.5%. The area under the curve was calculated as 0.7(95% CI: 0.63-0.81).

Conclusion: The serum levels of CEA were notably elevated in IP patients with concurrent lung cancer in contrast to those who were just suffering from IP. The heightened serum CEA levels correlate with an escalated risk of cancer occurrence among IP patients, suggesting that serum CEA levels could potentially serve as an indicative marker for the presence of cancer in IP patients.