RESUMO
A human squamous cell carcinoma (SCC) of oral origin was transplanted into athymic mice that were then divided into six groups. The mice were killed at 1 to 6 weeks after tumor transplantation; the sixth group was killed 1 week after excision of SCC grafts. Plasma samples were obtained from each mouse at the time of death for the determination of SCC-associated antigen (SCCAA), a cytoskeletal protein fraction of about 48,000 daltons originally derived from SCC of the uterine cervix. The plasma SCCAA level rose gradually and proportionately to the growth of SCC xenografts from a baseline of 0.66 ng/ml [standard error (SE) + 0.12] to the preoperative peak of 8.44 ng/ml (SE + 1.86) at 5 weeks, to fall precipitously to the postoperative level of 1.05 ng/ml (SE + 0.27) at 6 weeks. No rise in plasma SCCAA level was observed in mice bearing a human malignant melanoma, and only modest rises were observed in mice bearing human adenocarcinomas and oat cell carcinoma. In this experimental model rising plasma SCCAA levels were found to be dependable indicators of SCC tumor growth. These observations and preliminary data on SCCAA levels in patients with or without SCC of the head and neck lend support to the clinical usefulness of serial plasma SCCAA determinations in monitoring patients with SCC of the oral cavity.
