Technical and Clinical Performance of Two Methods to Detect Squamous Cell Carcinoma Antigen Levels for Comparing Pathological Diagnosis Coincidence Rates in Lung, Cervical, and Head and Neck Cancers.

Background: Detection of serum squamous cell carcinoma (SCC) antigen (SCCA) contributes to the diagnosis and therapeutic monitoring of SCC. However, the results obtained from different detection systems are not always consistent.

Methods: In this study, we compared the performance of electrochemiluminescence assays (ECLIAs) and flow fluorescence immunoassays (FFIAs) (e.g. using a Luminex 200/xMap) in the detection of SCCA for the diagnosis of SCC of the lung (LSCC), cervix (CSCC), and head and neck (HANSCC) in serum samples from 154 healthy individuals and 236 patients with SCC. We also evaluated the consistency of the SCCA results with the pathological diagnosis for both methods.

Results: SCCA levels obtained from ECLIAs were significantly higher than those obtained from FFIAs for all groups. However, the results from the two methods were well correlated (r = 0.918). The diagnostic coincidence rates (FFIA versus ECLIA) for SCCA results in patients with LSCC, CSCC, and HANSCC were 40.82% versus 52.04%, 36.14% versus 57.14%, and 16.36% versus 23.64%, respectively, and the negative coincidence rate (FFIA versus ECLIA) in healthy individuals was 98.05% versus 98.70%. The cutoff value, sensitivity, specificity, and area under the receiver operating characteristic curve of SCCA diagnosis (FFIA versus ECLIA) in LSCC, CSCC, and HANSCC were 1.12, 77.55%, 85.34%, and 0.87 versus 3.07, 85.71%, 91.52%, and 0.91, respectively; 1.21, 81.93%, 90.2%, and 0.90 versus 3.84, 89.16%, 95.24%, and 0.95, respectively; and 1.01, 62.27%, 82%, and 0.81 versus 3.35, 58.18%, 89.65%, and 0.85, respectively.

Conclusions: Serum SCCA levels detected by ECLIAs were significantly higher than those detected by FFIAs, with higher detection performance and pathological diagnosis coincidence rate in the patients with LSCC and CSCC simultaneously.