Malignant bowel obstruction

Evidence summary

Malignant bowel obstruction is a frequent complication of intra-abdominal or pelvic cancers, occurring in up to 50 per cent of patients with ovarian cancer and up to 28 per cent in colorectal cancer. [1]

Conservative management of malignant bowel obstruction is well-established in palliative care practice, using a combination of medications including:

• analgesics
• anti-inflammatories (corticosteroids)
• antisecretory agents (including hyoscine butylbromide, glycopyrrolate, ranitidine, and octreotide), and
• antiemetics.

The evidence base to support these practices is not extensive, due to the methodological challenges involved in doing high quality studies in these patients. A systematic review suggests that corticosteroids may speed the resolution of malignant bowel obstruction, [2] and that (at least in the short term) octreotide is more effective at relieving symptoms of bowel obstruction than hyoscine butylbromide. [3,4]

The options for surgical management for malignant bowel obstruction (open procedures to bypass or resect the site of obstruction, with or without a stoma) are of very limited value in advanced cancer and need to be considered against the risks associated with surgery. [5,6] Recent reviews have been able to establish that surgery increased survival time when compared to non-surgical interventions but older age was associated with poorer prognosis. [6,7]

The less invasive option of stenting has also been compared to surgical treatment options. It appears to be safe in appropriate patients, and has the potential to offer good palliation, including the ability to continue oral intake. [6,8,9] Stenting and surgery had similar survival time, but in a recent review patients undergoing stenting had shorter length of stay in hospital and slightly fewer complications. [10]

The use of parental nutrition (PN) in patients with malignant bowel obstruction has been controversial. [1] Recent guidelines recommend artificial nutrition in patients who are unable to eat. [11] So all patients who are nil by mouth due to their malignant bowel obstruction should be considered for parental nutrition. [1] The use of this therapy, therefore could be considered in selected patients who are expected to remain nil by mouth for weeks or months. [1]

Practice implications

Clinical practice recommendations for managing bowel obstruction in patients with end-stage cancer have been developed by the European Association of Palliative Care, [12] based on a systematic review of the available evidence and consensus of expert opinion where evidence was lacking. The recommendations are:

• Surgery should not be undertaken routinely in patients with poor prognostic criteria, such as intra-abdominal carcinomatosis, poor performance status, and massive ascites, older age. [7]
• Medical measures such as analgesics, anti-secretory drugs and antiemetics should be used alone or in combination to relieve symptoms.
• A venting gastrostomy should be considered if drugs fail to reduce vomiting to an acceptable level.
• PN should be considered only for select patients who are required to be nil by mouth for weeks or months to manage their malignant bowel obstruction. [1]
• Parenteral hydration is sometimes indicated to correct nausea, whereas regular mouth care is the treatment of choice for a dry mouth.
• A collaborative approach involving both surgeons and physicians can offer patients an individualised and appropriate symptom management plan.