Cancer and ageing.

Tissue culture and transplantation techniques can be used to analyse the relationship between ageing and cancer. In vitro transformation experiments show that the transformation frequency in mesenchymal cells and salivary gland epithelium does not seem to be age-associated but in the bladder old epithelium can be transformed much more frequently than young. Preliminary transplantation experiments confirm this relationship. These experiments suggest that the increased age susceptibility is tissue dependent.