Human muscle: a model for the study of human neoplasia.

Human muscle (HM) was used in an organ culture system to study the growth of human tumor cells and to test an antitumor drug. The HM system mimicked the in vivo situation regarding the behavior of neoplastic versus normal cells in that tumor cells proliferated extensively and invaded, while normal cells showed only a limited proliferative potential and a limited invasion was observed with fibroblasts but not with epithelial cells. In addition, when human plasma (HP) was used in place of fetal bovine serum (FBS) and cell culture medium as a source of nutrients, the tumor cells displayed a more aggressive histopathologic pattern. The HM system, as illustrated by the 5-FU results, allows the direct visualization of the effect to an antitumor agent not only on tumor cell growth but also on a range of histopathologically evaluable characteristics of the interaction of tumor cells with the host tissue. The HM system provides for the first time an in vitro experimental model using easily accessible adult human tissue to study cancer and its treatment.