The book is intended for cell and molecular biologists, practitioners and students. It examines the relationship between age and the development of cancer from different angles, with a comprehensive approach that has not been used previously. The multiple pathways at the cellular and tissue levels that can lead to a neoplastic growth are described in detail, explaining the variable delay between cancer initiation and the clinical manifestations. The time that elapses between exposure to the carcinogen and the clinical incidence of different neoplasiae is exemplified through a review of epidemiological studies with atomic bomb survivors and environment-related cancers. The developmental phenomena and the genetic determinants that may lead to or retard the progression of cancer through the life span of the organism are emphasized, illustrating the very dynamic processes that involve neoplastic growth where new variables are continuously created. The incidence of some particular cancers is reported, as well as progression and prognosis as a function of age. The book is organized so that the reader can understand the many different phenomena that intervene in the cancer-age relationship. It also focuses on the compelling lack of evidence supporting the long held view that aging favors overall cancer development.