Circulating tumour DNA (ctDNA) is DNA released by a tumour into the bloodstream and represents a novel class of blood marker for cancer detection. ctDNA can potentially change how cancer is diagnosed and how patients are monitored during and after treatment. Before ctDNA can be integrated into the New Zealand healthcare system, we must test the technology’s clinical utility and determine its best application for reducing health inequities, particularly amongst Māori and rural communities. In this proposed PhD research, I will analyse ctDNA testing for surveillance of stage 2-3 colorectal cancer patients on the West Coast of the South Island. Māori health providers will co-design this study, which will add personalised ctDNA testing to patient’s post-treatment surveillance plan for approximately 1-2 years. Māori co-design and integration in this project will ensure ethical issues are identified, benefits to Māori are optimised, and tikanga is retained in future ctDNA use.