Delayed Consequences of Therapy

Abstract

Some years ago, we estimated that one in every thousand young adults arriving at the age of 20 years would be a survivor of childhood cancer by the year 1990 [1]. This estimate was based on the risk of developing cancer between birth and 15 years (one in 600), a cure rate of 60% which began in the early 1970s and the average age of children with cancer. There are already beginning to be large numbers of young people who have discontinued therapy, are likely to be cured and who have received treatment which had, and may continue to have, expected and unexpected toxicities. The late consequences already known to us from case reports and multi-institution studies constitute the material of this chapter. It is not meant to be exhaustive, and we are not yet able to quantitate each of the potential long-term disabilities reported. The modern treatment era began in the late 1960s and early 1970s and our experience in children is therefore particularly limited with regard to very late disabilities arising as a result of treatment given 20–40 years earlier. It is our responsibility as paediatric oncologists to prepare the way now for the acquisition of future knowledge regarding any such adverse effects. We need to devise ways of tracking our children and of establishing registries and procedures which will be useful to the paediatric oncologists who plan therapy and counsel patients in the future. It is our hope that large institutions and cooperative groups treating children with cancer will take note of the gaps in our current knowledge and devise methods of collecting the information necessary to fill them.