Molecular interactions of aging and cancer.

The increased incidence of cancer as a function of age has long been interpreted to suggest that multiple genetic changes are required for tumorigenesis. Cancer cells differ from normal cells in many characteristics, including loss of differentiation, increased invasiveness, and decreased drug sensitivity. Although recent molecular advances have helped to clarify the possible relationships between carcinogenesis and aging, it remains unclear whether genetic markers may be common to all cancer types or which markers may be associated with increased age of cancer patients. Fundamental aspects of cancer development for older people are not well understood. Further insight into the genetic factors that may be responsible for the initiation and progression of cancer and their connections to the aging process may be gained in part by studying in vitro cellular or replicative senescence.