Growth regulation in carcinoid tumors.

In hormone-producing tumors such as the carcinoids, overproduction of certain hormones may activate proto-oncogenes. Hormones, or growth factors, thus can be of importance for growth regulation. Information is presented on some growth factors and their receptors in this respect and on the involvement of gastrin and its receptor on tumor development in the experimental Mastomys model. The relevance of differential expression of cell adhesion molecules in endocrine tumors is discussed also.