Diagnostic performance of CYFRA 21 − 1 and ProGRP in serum and bronchoalveolar lavage fluid for differentiating lung cancer from benign pulmonary diseases: a case–control study

Abstract Background Late presentation of lung cancer remains a major contributor to its poor prognosis. Identifying simple, minimally invasive biomarkers for differentiation between malignant and benign Pulmonary lesions is of significant clinical importance. Objective To evaluate the discriminatory performance of cytokeratin 19 fragment (CYFRA 21 − 1) and pro–gastrin-releasing peptide (proGRP) in both serum and bronchoalveolar lavage fluid (BALF) for differentiating lung cancer from selected benign pulmonary diseases. Methods This case–control study included 44 participants recruited from the Chest Department, Faculty of Medicine, Cairo University. Twenty-two patients with confirmed lung cancer were compared with 22 patients with benign pulmonary diseases. Serum and BALF levels of CYFRA 21 − 1 and proGRP were measured using enzyme-linked immunosorbent assay (ELISA). Results Patients with lung cancer demonstrated significantly elevated levels of CYFRA 21 − 1 in serum, as well as significantly higher levels of proGRP in both serum and BALF, compared with the control group ( p < 0.05). Combined assessment of CYFRA 21 − 1 and proGRP showed higher discriminatory performance than the individual biomarkers. Conclusion Serum CYFRA 21 − 1 and proGRP, together with BALF proGRP, demonstrated discriminatory ability for differentiating lung cancer from selected benign pulmonary diseases. Combined biomarker assessment showed higher discriminatory performance than individual markers; However, these findings require validation in larger prospective cohorts.