Serum squamous cell carcinoma antigen showed its strongest diagnostic performance for pulmonary squamous cell carcinoma among the pulmonary diseases evaluated in men. Researchers found the biomarker showed its greatest diagnostic performance in pulmonary squamous cell carcinoma, although elevations also occurred in nonmalignant pulmonary diseases, supporting its use alongside established diagnostic methods rather than as a standalone test.
In a retrospective, single-center cohort study, researchers evaluated serum squamous cell carcinoma antigen (SCCA) concentrations in 533 male patients treated at the Affiliated Hospital of Putian University, China, between January 2017 and November 2021 and compared them with those of 80 healthy male controls. The cohort included patients with pulmonary squamous cell carcinoma, pneumonia, chronic obstructive pulmonary disease (COPD), and benign pulmonary nodules. Serum SCCA concentrations were measured using a chemiluminescence immunoassay, and receiver operating characteristic analyses were used to assess diagnostic performance across the disease groups.
The researchers evaluated the diagnostic performance of SCCA across the pulmonary disease groups, compared serum SCCA concentrations among groups, and assessed associations between SCCA and inflammatory markers, including serum amyloid A (SAA), high-sensitivity C-reactive protein (hsCRP), and white blood cell (WBC) count.
Serum SCCA concentrations differed across the pulmonary diseases studied. Patients with pulmonary squamous cell carcinoma had the highest mean SCCA concentration at 7.14 ng/mL, compared with 2.49 ng/mL among patients with COPD, 2.12 ng/mL among patients with pneumonia, 1.45 ng/mL among patients with pulmonary nodules, and 1.03 ng/mL among healthy controls. SCCA concentrations were significantly higher in the lung cancer group than in healthy controls.
SCCA also demonstrated its strongest diagnostic performance for pulmonary squamous cell carcinoma, with an area under the receiver operating characteristic curve of 0.792. Diagnostic performance was lower for COPD (0.769), pneumonia (0.716), and pulmonary nodules (0.651), with the highest AUC observed for pulmonary squamous cell carcinoma among the groups evaluated.
Higher SCCA concentrations were positively associated with SAA, hsCRP, and WBC count, suggesting that systemic inflammation may contribute to elevated SCCA concentrations. The researchers noted that epithelial injury and repair in nonmalignant pulmonary diseases may also increase circulating SCCA, highlighting the importance of interpreting the biomarker in conjunction with clinical, radiologic, and histopathologic findings. They further suggested that combining SCCA with other biomarkers may improve diagnostic performance because SCCA alone has limited sensitivity and specificity.
The study was limited by its retrospective, cross-sectional design, conduct at a single center, relatively modest sample size, and inclusion of only male patients. The researchers also acknowledged that they did not perform multivariable analyses to adjust for potential confounding factors such as smoking history and inflammatory status, and they called for larger prospective studies that include both men and women to validate the findings and clarify the broader clinical utility of SCCA.
Overall, the findings suggest that serum SCCA may complement established diagnostic evaluation of pulmonary squamous cell carcinoma, but it should be interpreted alongside clinical, radiologic, and histopathologic assessments until further validation is available.
“Although SCCA should not be considered a standalone diagnostic marker, its noninvasive, rapid, and cost-effective characteristics support its potential role as an adjunctive tool for early detection, differential diagnosis, and disease monitoring in pulmonary disease evaluation,” wrote Lin Lirong, of the Affiliated Hospital of Putian University, and Wang Kangying.
Disclosures: The authors reported no conflicts of interest. No funding was received for the study.
Source: Diagnostic Pathology
