As illustrated by the reliability theory of aging, we are complex machines, and our life expectancy is a function of the pace at which we accumulate damage. For example, one contribution to rising life spans over the past century was the elimination of much of the burden of chronic disease throughout early life and middle age. Here, however, is an example of another, less common form of damage that nonetheless has the expected end result: "Although more children today are surviving cancer than ever before, young patients successfully treated in the 1970s and 80s may live a decade less, on average, than the general population ... The study, based on a computer model, is the first to estimate the lifetime toll of childhood cancer and the grueling but increasingly successful treatments for diseases such as kidney and bone cancers, leukemia, and brain tumors. About 10,000 children and adolescents are diagnosed with cancer annually, and the five-year survival rate has risen to about 80 percent overall. ... The study is based on how children were treated in the 1970s and early 1980s. It is our hope that when we see data from more recent cohorts of patients, there will be improved life expectancy as a result of some changes that pediatric oncologists have made."