Carcinogenesis is an evolutionary process; establishing the prognosis for a cancer therefore requires predicting the future course of cancer evolution.  The same is true in pre-cancerous conditions: the risk of developing cancer is determined by how the pre-cancerous lesion is evolving.

The level of diversity within a population largely determines how fast that population will evolve. If there is no diversity natural selection cannot operate, whereas diverse populations are likely to contain well-adapted individuals that can prosper in changing environments.  Consequently, quantification of within-tumour diversity is likely to be a proxy-measure of the rate of the underlying evolutionary process that drives carcinogenesis.

In this talk, I will describe how we have measured within-tumour diversity, both genetically and phenotypically, and used these measures to successfully determine prognosis in both established cancers and in premalignant lesions.  I will focus particularly on lung cancer and the premalignant condition Barrett’s Oesophagus.  I will also describe how we have modelled the accrual of genetic diversity during cancer development.  Building upon this work, I will present the case for the quantification of within-tumour diversity as a universal biomarker for cancer prognosis.