Complementarity and contradiction in cancer research: The role of hierarchies in carcinogenesis

The essays on carcinogenesis in this volume tend to fall into groups accord ing to the level of complexity at which the theories focus. Many investigat ors focus on events and processes involving genetic mutations. Others, howe ver, identify events ol processes at the chromosomal, cellular; tissue, or organsimal level as being of primary importance. While such different appro aches to carcinogenesis may, nt first, seem to be contradictory, they may b e seen to be complementary in light of the general theory of hierarchical o rganization Hierarchy theory which is a development of general systems theo ry, describes the manner in which organized processes ale formed by subunit s that have unique properties of their own but which can acquire new proper ties through their interactions. Hierarchy theory suggests that carcinogene sis cart only be understood as a set of interactions between organizational processes at every level from genetic to organismal.