Medical Management of Inoperable Malignant Bowel Obstruction

Comprehensive Diagnosis and Management of Malignant Bowel Obstruction: A Review

Malignant bowel obstruction is a common complication of advanced gastrointestinal, gynecologic, and genitourinary tumors. Patients present with nausea, vomiting, abdominal pain, and constipation. Cross-sectional imaging is essential to make a diagnosis of bowel obstruction. Initial management is conservative with fluid replacement, electrolyte replacement, bowel rest and sometimes nasogastric decompression. Numerous advanced options exist for definitive management, though none are overly promising but nevertheless may improve quality and quantity of life. Surgical bypass, endoscopic stenting, and endoscopic decompression are some of the options with variable efficacy and are employed in select patients. Chemotherapy may be utilized if the bowel obstruction resolves to reduce tumor burden in a limited number of patients. Parenteral nutrition is an option and should typically be used in surgical patients with good functional and nutritional status with limited tumor burden or curative intent. Palliative care and hospice should be discussed in patients with advanced malignancy who present with peritoneal carcinomatosis or multiple levels of obstruction. Overall prognosis of malignant bowel obstruction is poor, and median survival ranges from 26 to 192 days.

Inoperable Bowel Obstruction in Ovarian Cancer: Prevalence, Impact and Management Challenges

Malignant bowel obstruction (MBO) is one of the most severe complications in patients with advanced ovarian cancer, with an estimated incidence up to 50%. Its presence is related to poor prognosis and a life expectancy measured in weeks for inoperable cases. Symptoms are usually difficult to manage and often require hospitalization, which carries a high burden on patients, caregivers and the healthcare system. Management is complex and requires a multidisciplinary approach to improve clinical outcomes. Patients with inoperable MBO are treated medically with analgesics, antiemetics, steroids and antisecretory agents. Parenteral nutrition and gut decompression with nasogastric tube, venting gastrostomy or stenting may be used as supportive therapy. Treatment decision-making is challenging and often based on clinical expertise and local policies, with lack of high-quality evidence to optimally standardize management. The present review summarizes current literature on inoperable bowel obstruction in ovarian cancer, focusing on epidemiology, prognostic factors, clinical outcomes, medical management, multidisciplinary interventions and quality of life.

Medical management of malignant bowel obstruction in patients with advanced cancer: 2021 MASCC guideline update

BACKGROUND

Malignant bowel obstruction (MBO) is a frequent complication in patients with advanced cancer, particularly colon or gynecological malignancies. MASCC previously published a guideline for symptom management of MBO in 2017. This is a 5-year update.

METHOD

A systematic search and review of relevant literature includes a review published in 2010 and 2017. The guideline update used the same literature search process as followed in 2015. The dates of the new search included 2015 up to February 2, 2021. The guidelines involved the pharmacologic management of nausea and vomiting in malignant bowel obstruction (MBO) only. Only randomized trials were included in the updated guideline as evidence. The evidence was reviewed by the panel and the MASCC criteria for establishing a guideline were followed using MASCC level of grading and category of evidence.

RESULTS

There was one systematic review and 3 randomized trials accepted as evidence from 257 abstracts. Octreotide is effective in reducing gastrointestinal secretions and colic and thereby reduces nausea and vomiting caused by MBO. Scopolamine butylbromide is inferior to octreotide in the doses used in the comparison study. Olanzapine or metoclopramide may be effective in reducing nausea and vomiting secondary to partial bowel obstructions. The panel suggests using either drug. Additional studies are needed to clarify benefits. Haloperidol has been used by convention as an antiemetic but has not been subjected to a randomized comparison. Ranitidine plus dexamethasone may be effective in reducing nausea and vomiting from MBO but cannot be recommended until there is a comparison with octreotide.

DISCUSSION

Octreotide remains the drug of choice in managing MBO. Ranitidine was used in one randomized trial in all participants and so its effectiveness as a single drug is not known until there is a randomized comparison with octreotide. Antiemetics such as metoclopramide and olanzapine may be effective, but we have very few randomized trials of antiemetics in MBO.

CONCLUSION

The panel recommends octreotide in non-operable MBO. Randomized trials are needed to clarify ranitidine and antiemetic choices.