ABSTRACT
Cancer is a very complex disease, however, if we want to make a simple and clear-cut statement about the molecular
pathomechanism of cancer we can state that cancer is a communication disorder, the result of an intracellular, intercellular (and to some extent even inter-personal) communication disorder, in which a series of genomic changes can be the cause and the consequence of these communication disorders. Communication in this sense means a message which induces or results in a response. In a healthy organism normal cells do not proliferate without an external message. Cancer cells – for various reasons discussed below – generate a false, mimicked proliferation signal for themselves via oncogenes and other genomic changes. Whether this communication failure is the result of environmental factors and/or external messages (generating changes at the genomic level), or comes from the genetic program, is a question which can be answered only on a case by case basis. However, we have to consider that cells, like human beings, live in a well organized society and in a given ecosystem, which, to a certain extent, determines their receptivity and responsiveness as well as the system-response for the various carcinogenic agents and effects. In other words carcinogenic compounds can be carcinogenic in a given in vitro system or in a given organism but the same agent can have different effects in different systems, depending on the circumstances. Clearly, during carcinogenesis changes at the genomic level are critical steps, however the manifestation of these genomic changes and the system response very much depends on the communication state and responsivity of the system (1) (Figure 21.1).
