New Zealand has the highest rate of colorectal cancer in the world, resulting in approximately 1200 deaths per year. Two key ways that we can reduce colorectal cancer related deaths are by earlier diagnosis of the disease and through optimising treatment plans for patients. Tumour cells release small RNA molecules that circulate in the blood plasma and have recently been identified as novel biomarkers for colorectal cancer. This study will employ cutting-edge RNA sequencing technology to discover potential RNA biomarkers for early diagnosis of colorectal cancer and for prediction of response to radiation therapy before surgical removal of the tumour. RNA markers identified will also be investigated in tumour cells to determine how they affect the behaviour of cancerous cells and the response to radiation treatment.