31st December 2024

Diagnosis of colorectal cancer

Colonoscopy is the first-line investigation. Double-contrast barium enema and CT colonoscopy are alternative investigations for if a patient is not fit for colonoscopy.

Once a diagnosis of colorectal cancer is made, a CT chest, abdomen and pelvis is required for staging.

CEA is a tumour marker associated with colorectal cancer. However not all tumours secrete this, and it is not specific (may be raised in conditions such as IBD). It is mainly used for disease monitoring, as levels correlate with disease burden.