Rectal Cancer
Understanding Rectal Cancer

Rectal cancer occurs when abnormal cells grow uncontrollably in the rectum, the last portion of the large intestine. It often starts as small, benign polyps that can become cancerous over time. Because the rectum is close to other structures within the pelvis, rectal cancer has a higher risk of spreading locally. Treatment depends on the extent of the cancer at diagnosis, and can include either up-front surgery or initial radiotherapy with chemotherapy.

An Insight into Colorectal Cancer

  • Rectal bleeding or blood in the stool – Often a sign of polyps or cancer
  • Persistent changes in bowel habits – Including diarrhoea, constipation, or narrowing of stool
  • Unexplained weight loss – Cancer can affect metabolism, digestion and appetite
  • Abdominal pain, bloating, or cramping – Caused by tumour growth obstructing the digestive tract
  • Fatigue or anaemia – Caused by chronic blood loss

Rectal cancer typically develops due to genetic mutations in the bowel tissue that cause uncontrolled cell growth. Many people with rectal cancer do not have any risk factors. Possible risk factors include:

  • Genetics and family history – Some inherited syndromes increase risk
  • Age over 50 – Risk increases with age, though “early-onset” disease is increasing
  • Diet – Low fibre, high-fat, and high-processed-meat diets contribute
  • Smoking and alcohol consumption – Linked to higher cancer rates
  • Obesity and lack of exercise – Raises overall cancer risk

  • Colonoscopy – A flexible tube with a camera inspects the rectum and colon for abnormalities
  • Biopsy – A sample of tissue is taken during a colonoscopy to confirm cancer
  • Imaging – CT, MRI, or PET scans help determine the stage
  • Blood tests – Detect tumour markers that may indicate cancer

Early-Stage Disease

  • Surgery – Local excision for small tumours; total mesorectal excision (TME) for larger ones.
  • Radiation Therapy – Used to shrink tumours and reduce recurrence risk, often given with chemotherapy as a “radio-sensitising” drug.
  • Chemotherapy – Might be used before or after surgery, or with radiotherapy.

Metastatic Disease

  • Systemic Treatments:
    • Chemotherapy
    • Targeted Therapy
    • Immunotherapy (in select cases)
  • Surgery or Radiation – Often to relieve obstruction or pain.
  • Clinical Trials – Investigating novel targeted agents, immunotherapies, and combination treatments.