Understanding this cancer
This page covers cancers of the colon and rectum. These usually begin as changes in the inner lining and can develop from some polyps over time. Tumour location, stage, pathology and molecular findings influence treatment.
Signs to discuss with a doctor
Blood in stool, a lasting change in bowel habit, abdominal pain, unexplained anaemia, fatigue or weight loss should be assessed. Bowel obstruction, severe pain or heavy bleeding needs urgent care.
Risk factors
Age, family history, inherited syndromes, inflammatory bowel disease, tobacco, harmful alcohol use, excess body weight, low activity and diets high in processed meat can affect risk.
Tests and diagnosis
Colonoscopy with biopsy confirms most diagnoses. CT and, for rectal cancer, pelvic MRI are commonly used for staging. Mismatch-repair or microsatellite testing is important and broader molecular tests may guide advanced-disease treatment.
Treatment approaches
Surgery is central for many localized cancers. Chemotherapy, radiotherapy for selected rectal cancers, targeted medicines, immunotherapy and symptom-focused procedures may be used according to stage and biomarkers.
Prevention and screening
Screening can find precancerous polyps or early cancer. Starting age and method depend on national guidance and personal risk. Physical activity, healthy weight, avoiding tobacco and limiting processed meat and alcohol may reduce risk.
Questions for your care team
Where exactly is the tumour and what is the stage? Is there obstruction? Were mismatch-repair and relevant molecular tests done? Will I need a stoma, and is it expected to be temporary or permanent?