Squamous cell carcinoma-antigen for detection of squamous cell and mucoepidermoid carcinoma after primary treatment: a preliminary report. This study evaluated the efficacy of using the periodic measurement of the serum level of squamous cell carcinoma antigen (SCC-antigen) for determining the local recurrence and/or metastasis of squamous cell and mucoepidermoid carcinomas after primary treatment. It was found that at the time of clinical recognition of recurrence, the SCC-antigen level was normal, but metastasis to regional lymph nodes or to remote organs generally was accompanied by an increase of SCC-antigen. Changes in the SCC-antigen level with mucoepidermoid carcinoma seemed to be less sensitive than with squamous cell carcinoma. 