Cancer is a major health burden in New Zealand and accounts for one in three deaths. Cancer-related deaths are mainly due to spread of the disease (metastasis) and resistance to treatment. These features are a result of tumour evolution, which is driven by continuous changes in the DNA called chromosomal instability (CIN). Our study aims to understand how CIN contributes to the tumour cell’s ability to manipulate the patient’s immune response, spread to distant organs and develop resistance to treatment. This study will enable us to identify individuals whose tumours have acquired the ability to evolve and are more likely to have a poor outcome, while provide information on novel ways of targeting pathways that promote CIN in tumours.