Creating a virtual cancer  by Rachel Thomas   Chemotherapy drugs
Can a virtual cancer help design better treatments? [Image NCI]
A tumour initially starts when a DNA failure leads to
uncontrolled division of a cell, with the growing tumour
absorbing nutrients and expelling waste through its surface.
However the requirements of a tumour depends on its volume —that
is, its width to the power of three — while the amount that can
be transported through its surface depends on surface area —
that is, its width squared. So once the tumour grows over a
certain size these requirements can no longer be met, leading
some tumours to become a more dangerous, invasive form of
cancer. Cells on the surface of the tumour release chemicals to
degrade surrounding tissue to encourage movement of cancer
cells, and securing a blood supply to the tumour.  Mathematics
is already used to study tumour growth, the pre-invasive stage
is fairly well modelled mathematically. In contrast, Chaplain
and his team want to create a complete