An in vivo model for squamous cell carcinoma of the head and neck.

In recent years, the successful grafting of human tumors into immune deprived animals has spurred the hopes of developing a reliable in vivo model for evaluation of human cancer. The nude mouse has created new perspectives in many different areas of cancer research, and has proved to be the most useful recipient of any animal system for tumor heterotransplantation. This study determined which of several squamous cell carcinoma (SCC) cell lines would reproducibly grow as heterotransplants in nude mice, and allowed an opportunity to determine whether characteristics of the tumor changed as a result of propagation in tissue culture. Sixteen (76%) of the 21 SCC lines heterotransplanted in nude mice remained as viable tumor nodules. Nine (43%) of these lines reproducibly produced progressively enlarging tumor masses. Five (24%) SCC lines failed to grow as heterotransplants. The average lag phase between implantation and the beginning of growth for all SCC lines tested was approximately 7 weeks and emphasizes the need for prolonged observation of nude mice following SCC heterotransplantation. The rate and pattern of growth of SCC in nude mice appears to be related specifically to the tumorigenic factors of a given cell line. The concurrent presence of other SCC or non-SCC tumors in a given mouse do not appear to influence the growth of a specific cell line. In addition, specific host factors that might vary from one mouse to another did not alter the growth patterns of SCC. Histological examination of the SCC lines successfully heterotransplanted in nude mice showed similar histological appearances to the original tumor in the human host.