[Clinical significance of serum SCC Ag in patients with squamous cell carcinoma of the lung].

To evaluate its clinical significance as a tumor marker, the serum level of squamous cell carcinoma associated antigen (SCC Ag) was studied by immunoradiometric assay in 59 patients with histologically proved lung cancer (32 squamous cell carcinomas, 23 adenocarcinomas and 4 small cell carcinomas). Carcinoembryonic antigen (CEA) was measured by radioimmunoassay simultaneously. The serum levels of SCC Ag and CEA were found above the normal range in 71.9% and 28.1% of squamous cell carcinomas, 26.1% and 34.8% of adenocarcinomas and 0% and 25% of small cell carcinomas respectively. In squamous cell carcinomas, the positive rate of SCC Ag increased with progression of clinical stage. With regard to the preoperative serum level dropped dramatically after surgery (P < 0.05). The change would be more outstanding after radical surgery (P < 0.001). The serum level of SCC Ag can be used to effectively monitor the course of disease, and could be used as an important item during the postoperative follow-up.