Colomid: Midkine as a predictive marker in colorectal cancer

Interventions: Participants will be allowed to receive whichever chemotherapy regimen thier oncologist recommends. They will be studied for 6 months, or until their cancer progresses, and will have blood tests at 2 weeks and then every 3-4 weeks, whilst receiving chemotherapy for their colorectal cancer. The blood test for midkine involves an extra 12mL (2-3 teaspoons) of blood to be taken, which can be done at the same time as the usual blood tests for monitoring the effects of the chemotherapy. The blood tests can be taken at any Hunter Area Pathology Service (HAPS) collection centre, and will be taken using the same procedure as normal blood tests. There is no need to fast prior to collection. The only extra blood test for midkine is 2 weeks after the first dose of chemotherapy. The interval between blood tests depends on when blood tests are required for the chemotherapy regimen that is being used.
Participants will also receive standard monitoring tests: carcino-embryonic antigen (CEA) every 3-4 weeks and computed tomography (CT) scans every 8 weeks.
Primary outcome(s): Response rate to chemotherapy, measured by RECIST 1.1 criteria.[6 months];Progression on chemotherapy, as measured by CT scan (RECIST 1.1), CEA or investigator assessment.[6 months]
Study Design: Purpose: ;Duration: ;Selection: ;Timing: