Pathobiology of Human Neoplasia: Introduction and Overview

The word “cancer” is perhaps the most feared word in our language. This is largely due to the aggressive nature of this disease, but also because so much is yet unknown about this disease. This lecture will provide an overview of our current understanding of cancer, or more generally, neoplasia. Neoplasia can be defined as a clonal proliferation of cells with somatic genetic alterations and aberrant regulation of growth. Some neoplasms do not seriously threaten the life of the individual, and these are commonly called “benign” neoplasms. On the other hand, malignant neoplasms (i.e., cancers) are characterized by the ability to invade into adjacent normal tissues and metastasize to distant tissues. Many neoplasms form masses (i.e., “tumors”), but some neoplasms, particularly pre-invasive (or in situ) neoplasms do not.