Growing old can rob a person of hair, strength, agility, clear vision, and mental sharpness. It also raises one's chance of getting cancer. Cancer rates go up exponentially in the final decades of life.
"Age is the most important of all carcinogens," notes Ronald A. DePinho of the Dana-Farber Cancer Institute in Boston.
Offering a link between aging and cancer, a research team has found that cells in a nondividing state called senescence can stimulate cancer-prone cells to grow into tumors. The finding is unexpected because scientists suspect that senescence evolved as a mechanism to prevent cancer in the early years of long-lived animals.
Decades ago, investigators noted the tendency of aging human cells in laboratory dishes to eventually stop dividing and alter their shape and genetic activity. This led researchers to suggest that a buildup of these senescent cells in the body contributes to age-related deterioration. They also proposed that senescence helps che