2 Indications and current treatments
2.1 Rectal cancer is a common form of bowel cancer. The likelihood of developing it rises sharply with age. Symptoms include rectal bleeding and change in bowel habit, although the early stages may be asymptomatic.
2.2 Surgery is the main treatment for patients with rectal cancer who are treated with curative intent. It involves resection of the affected part of the rectum and the mesorectum. The anal sphincter is preserved whenever possible; a colostomy is formed when this is not possible.
2.3 In some patients, radiotherapy or chemotherapy or both are used before, during or after surgery to decrease the chances of local recurrence and metastatic disease. Radiotherapy may take the form of external‑beam radiotherapy (EBRT) or radioisotope brachytherapy. EBRT uses radiation from outside the body, which is focused on the cancer and surrounding lymph nodes. Radioisotope brachytherapy involves inserting radioactive pellets or seeds directly into the tumour (interstitial brachytherapy), or placing an endorectal treatment applicator near the tumour to deliver radiation from within the rectum (endorectal high dose rate brachytherapy).