Prognostic significance of serum squamous cell carcinoma antigen in surgically treated lung cancer.

The serum concentrations of squamous cell carcinoma antigen (SCC-Ag) obtained from 124 surgically treated primary non-small cell lung cancer patients, including 75 adenocarcinomas (AD) and 49 squamous cell carcinomas (SQ), were studied. The changes in the SCC-Ag concentration, which were obtained before and one month after surgery, were analyzed. The 5-year survival rate of the patients with AD who were positive for SCC-Ag preoperatively (32%) was lower than that for those who were negative for SCC-Ag preoperatively (57%, p<0.05). Meanwhile, in those with SQ, the 5-year survival rate of those who were positive for SCC-Ag preoperatively (59%) was not different when compared with those who were negative for SCC-Ag preoperatively (73%). The 5-year survival rate of patients with AD who were positive for SCC-Ag preoperatively and negative postoperatively was 53% versus 17% for those who remained positive postoperatively (p<0.05). In those with SQ, the 5-year survival rate of those who were positive for SCC-Ag preoperatively and negative postoperatively was 76% while it was 0% for those who remained positive postoperatively (p<0.01). In patients with negative SCC-Ag postoperatively, 5-year survival rates were not different between the patients who had positive antigen preoperatively and the patients who had negative antigen preoperatively both in AD (53% and 57%, respectively) and SQ (76% and 75%, respectively). In conclusion, though SCC-Ag is widely used for SQ, preoperative SCC-Ag did not reflect the prognosis. In AD, the survival rate was lower in antigen-positive than antigen-negative patients. Survival rate was higher in antigen-positive patients who became antigen-negative following resection than in patients who remained antigen-positive for both AD and SQ. In the patients who were negative for SCC-Ag postoperatively, survival was the same regardless of the preoperative SCC-Ag positivity in both AD and SQ.