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

Introduction

Malignant bowel obstruction (MBO) represents one of the most severe complications of advanced intraabdominal and intraperitoneal malignancies. It was defined in the International Conference on MBO and Clinical Protocol Committee as (a) clinical evidence of bowel obstruction via history, physical and radiographic examination, (b) bowel obstruction beyond the ligament of Treitz, (c) intraabdominal primary cancer with incurable disease, and (d) non-intraabdominal primary cancer with clear intraperitoneal disease.¹

Methods

We conducted a narrative literature review on inoperable malignant bowel obstruction in ovarian cancer, including epidemiology, clinical outcomes, complications, medical management, multidisciplinary interventions, quality of life and healthcare cost.

Search was performed through MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Embase. The search was limited to human studies and English publications, with a timeframe of 20 years (from 2002 to July 2022). Conferences, case reports, comments, editorials, letters and personal narratives were excluded. A PubMed targeted search using same criteria was conducted by one author and reviewed by another author for articles between 1980 and 2002.

Prevalence

Epidemiology of malignant bowel obstruction is not well established; retrospective and autopsy studies have reported an incidence up to 50% in ovarian cancer and between 10 and 28% in gastrointestinal cancers.² It is associated with a poor prognosis, with survival estimates of 3–8 months for those with operable disease and 4–5 weeks in inoperable cases.^3,4

Classification and Etiology

Obstruction may originate in the small bowel, large bowel, or in both simultaneously. MBO can be classified as partial or complete, according to the presence or absence of residual air and fluid in the collapsed distal bowel segments.⁵ A closed-loop obstruction indicates a complete blockage distally and proximally in a given segment of the intestine.⁶

The etiology is multifactorial and can be divided into two main groups: mechanical and functional. Mechanical causes include extrinsic obstruction due to mesenteric/omental masses or malignant adhesions, intramural, and intraluminal occlusions. Functional obstruction includes motility disorders caused by tumor infiltration of the mesentery, bowel muscle or enteric plexuses.²

Here, we focus on malignant bowel obstruction due to ovarian cancer, where peritoneal disease frequently leads to extrinsic compression of the bowel.

Pathophysiology

Pathophysiology of MBO is multifactorial. An occlusion of the lumen prevents the propulsion of the intestinal contents, causing accumulation of intestinal secretions and malabsorption of water and electrolytes in the obstructed segment. Bowel distension stimulates intestinal fluid secretion, creating a vicious cycle⁷ (Figure 1).

Figure 1 Pathophysiology of MBO. Occlusion of the lumen and accumulation of intestinal content triggers an inflammatory response leading to fluid redistribution, intestinal ischemia and bacterial translocation. Abbreviations: PGs, prostaglandins; VIP, vasoactive intestinal peptide.

Damage in the bowel triggers an inflammatory response, with release of potent secretagogues such as prostaglandins (PGs) and vasoactive intestinal peptide (VIP). This leads to local and systemic alterations such as hyperemia, edema of the intestinal wall and accumulation of fluid in the lumen.^4,8

High portal levels of VIP cause splanchnic vasodilatation leading to blood flow redistribution and fluid sequestration in the third space, which can cause hypotension and multiple organ failure. Increased endoluminal pressure, stasis and ischemia promote bacterial translocation from the intestinal wall into the lymphatic and systemic circulation, which may result in sepsis, gangrene and perforation.^8,9

Diagnosis and Prognostic Factors

MBO manifests insidiously and results in variety of symptoms such as nausea, vomiting, abdominal cramping, distension, bloating, and decreased passage of flatus or stool elimination.^4,8,9

MBO is diagnosed clinically and confirmed radiologically. Typically, erect abdominal X-rays demonstrate bowel-loop distention with air-fluid levels proximal to the point of obstruction and potentially diminution of gas and fecal material distally.^10–12 Such signs are detected in around 40–80% of cases and, therefore, absence of those signs with high clinical index of suspicion should prompt further investigation. Small bowel follow-through (SBFT) has proven useful to confirm suspected small-bowel obstruction in 68% to 100% of cases;¹³ however, the ability to diagnose complications is limited. Computed tomography (CT) scan is the most sensitive study (100%), with a predictive value of 83–94%; it provides detailed information on obstruction level, tumor extension and potential complications such as superimposed ischemia and intestinal perforation.^6,14,15

Many clinical, radiologic, and treatment factors contribute to prognosis of ovarian cancer patients with MBO. Several studies showed that presence of poor performance status, pain, exertional shortness of breath, cognitive impairment, ascites, palpable masses in abdomen and pelvis, poor nutritional status, low albumin, liver failure, multifocal obstruction, and proximal MBO correlated with dismal survival.^16–23 Moreover, a recent retrospective review identified CT findings of ascites, mesenteric disease, and dilated bowel loop wall thinning as poor prognostic indicators.²⁴

Retrospective analyses have shown that systemic chemotherapy after the development of MBO is associated with superior survival, irrespective of whether patients were treated medically or surgically for MBO.^25–27 In advanced ovarian cancer, disease status is an important prognostic factor of treatment response and thus MBO outcome. For example, patients newly diagnosed or with platinum-sensitive recurrence have a high likelihood of response to platinum-based chemotherapy (around 80 and 50% respectively), whereas those with platinum-resistant disease have a lower response rate of 10–15%.²⁸ Selection is key, and chemotherapy may be useful to improve MBO in a subset of patients.

Studies comparing surgical interventions and medical management have reported mixed results; this can be explained at least partially by the diverse definitions of clinical outcome, heterogeneous clinical practice, and selection bias within these studies.^6,27 Daniele et al demonstrated that surgical palliation was associated with longer survival (p=0.025), when compared to medical management.²³ Nonetheless, Yu et al showed no significant difference in survival between surgical and non-surgical patients, albeit their cohort included a minority of ovarian cancer patients;²⁷ this was consistent with a population-based analysis that showed similar overall survival outcome between surgical and medical patients (median 6.5 vs 6.4 months).²⁵

General Management

Patients with MBO should be managed by a multi-disciplinary team, and several approaches can be considered. The focus of this review is on medical management of inoperable bowel obstruction; key publications are summarized in Table 1.

Table 1 Summary of Key Publications in the Management of Inoperable MBO

Diet

To alleviate symptoms like nausea and vomiting, patients admitted with acute MBO are put on a strict nil-by-mouth (NPO) and subjected to decompressive procedures.^29,30 Due to a lack of consensus and few published evidence, the management of the nutritional needs of patients presenting with advanced malignancies and MBO is controversial and ethically demanding.^30–32

The Multinational Association of Supportive Care in Cancer (MASCC) recommends that patients are initially kept NPO and, with guidance from a dietitian, gradually transitioned in stages of oral diets if their MBO symptoms are resolving: from 1) clear fluids to, 2) full fluids to, 3) minced/pureed low fiber diet and then, 4) low fiber diet.²⁹

The terms low residue/fiber are used interchangeably, and neither term has a clear definition. Essentially, residue is undigested food in the intestinal tract that adds bulk to the stool, and 10 grams of fiber a day equates to a low fiber diet.³³ The purpose of a low residue/fiber diet is to decrease the size/bulk of the stool to help ease passage as patients can have tumors and/or adhesions that interrupt normal bowel flow. A low residue/fiber diet assists to alleviate abdominal discomfort, such as bloating, pain, and nausea/vomiting.^23,29,33,34 It is recommended that patients and their caregivers receive nutrition instructions to help them adjust their diet in response to their symptoms.³²

Hydration

Parenteral hydration (PH) is the administration of fluids via the parenteral route, alternative to oral or enteral administration (ie, intravenously or subcutaneously).³⁵ PH is a component of palliative care and should adhere to predetermined, realistic therapeutic objectives. A small prospective randomized trial evaluating inoperable MBO patients, the amount of parenterally administered fluids did not correlate with thirst, dry mouth intensity, or abdominal distention; however, a volume of more than 500 mL/day may improve nausea and drowsiness.³⁷ PH may seem effective in management of dehydration, a common cause of delirium; yet, in the dying phase, even moderate quantities of parenteral hydration may be hazardous. Fluid overload, peripheral swelling, ascites, and pulmonary edema are all conditions that could be exacerbated by PH in the terminal phase of life.³⁸ Subcutaneous infusion of 1000 mL daily did not alleviate dehydration symptoms (fatigue, myoclonus, drowsiness, and hallucinations) in a multicenter, double-blind, randomized study with a placebo control group.³⁹

Clinically assisted hydration at end of life is controversial; a feasibility study showed that a definitive trial to address its utility can be done but will require standardization of the administration methods.⁴⁰ In general, parenteral hydration is an important component of acute management of patients with MBO; however, it is not recommended at the end of life.^29,41

Total Parenteral Nutrition (TPN)

Along with pharmacological management of MBO, care must be taken to ensure that hydration and nutritional needs are met, as oral intake is significantly impaired in patients with MBO. Based on the goals of care, this may range from comfort feeding alone to TPN to maintain adequate calorie intake.²⁹ While deciding upon TPN, it is of prime importance to understand its role, cost, logistics and potential complications and also to discuss in detail goals of care and disease prognosis.²⁹

The various terms used to describe parenteral nutrition include “total parenteral nutrition” (TPN) which is nutrition administered exclusively intravenously and “supplemental parenteral nutrition” (SPN) in which the patient receives nutrition via a combination of intravenous and enteral routes. However, the enteral route is not used in inoperable MBO due to ovarian cancer.²⁹ Any type of parenteral nutrition administered at home is defined as “home parenteral nutrition” (HPN).²⁹ Here, we focus on TPN. Central venous access devices such as a chemoport or a peripherally inserted central catheter are the main modes of TPN administration, as the use of peripheral veins is associated with phlebitis.

Before recommending TPN, risks and benefits must be carefully measured, including the predicted cancer-related survival.^42–44 As our understanding of the evolution and biology of MBO evolves, various ways of patient selection for TPN have been devised.^43,45 TPN can be considered in a selective group of patients, including ECOG performance status 0 to 1, extensive peritoneal carcinomatosis in the absence of distant metastases (such as lung and liver metastases), patients not amenable for diverting stoma and interventional radiological procedures such as insertion of self-expanding metal stents and those with certain histology such as low grade serous ovarian carcinoma.⁶ Patients should be reassessed periodically based on clinical assessment and radiology as we know that ultimately, most patients may not benefit due to functional decline resulting from cancer progression, chronic cancer treatment,⁴⁶ latent infections,⁴⁷ depression,^48,49 and suboptimal nutritional treatment.⁵⁰

TPN is associated with metabolic and catheter-related complications.²⁹ In the study by Sowerbutts et al, 6 to 21% of patients with MBO developed a central venous catheter infection or were hospitalized because of complications related to parenteral nutrition.⁵¹ The risk of potential complications can be minimized with the help of nutrition support teams.⁵²

TPN is also initiated on an inpatient basis given that refeeding syndrome, which can be seen in severely malnourished patients, usually occurs within the first few days after initiation of TPN.^52,53 Refeeding syndrome includes acute beriberi due to Vitamin B1 deficiency, acute volume overload leading to anasarca and pulmonary edema, dyselectrolytemia including hypophosphatemia, hypokalemia and hypomagnesemia, arrhythmias including bradycardia and ventricular arrhythmia, hyperglycemia which if left untreated can lead to hyperosmolar coma.⁵²

Malnutrition and cachexia are usually irreversible and treatment-resistant,⁵⁴ especially in those patients who are heavily pre-treated and have platinum-resistant disease. The European Society for Clinical Nutrition and Metabolism (ESPEN) practical guidelines for clinical nutrition reported that parenteral hydration and nutrition are unlikely to provide any benefit for most patients at the end of life.³¹ A randomized Phase II clinical trial by Oh et al also showed that though patients and families are concerned about starvation at the end of life, parenteral nutrition fails to add meaningful survival benefit.⁵⁵

Surgical Management/Inoperability

A surgical consultation should be obtained at the time of MBO diagnosis; surgery can be beneficial in restoring bowel function in a subset of MBO patients with a good performance status and viable cancer therapy choices.^23,56 Obstruction of the large bowel carries a high risk of morbidity, perforation, and mortality, and expectant management is typically inappropriate in this scenario. Rather than initial resection and anastomosis or bypass, stoma diversion is the most common surgical treatment for large intestinal blockage.^57,58 Unstrangulated small intestinal obstruction is closely linked to widespread peritoneal carcinomatosis and therefore is generally treated conservatively.^57–59 Small bowel resection with anastomosis or internal bypass is reserved for a minority of patients.

Furnes et al reviewed 868 patients with MBO and showed that surgery might ameliorate obstructive symptoms, allow the reintroduction of diet and promote earlier patient discharge to home.⁵⁷ Helyer et al found that surgical intervention in MBO patients may facilitate palliative chemotherapy and this was correlated with better survival.²⁶

Furthermore, a prospective study including 26 with MBO due to ovarian cancer evaluated outcomes of palliative surgical (bowel diversion or bypass/resection) and endoscopic interventions. The majority (88%) of patients reported symptomatic improvement or MBO resolution by 30 days, and 16 patients achieved continued symptom control at 60 days.⁶⁰

These studies support the idea of palliative surgery in patients with specific clinical criteria, including excellent performance capacity, longer treatment-free interval, utter lack of ascites, disease uni-focality, and adequate albumin levels.^61,62 This also reflects on results of a recent bicentric analysis of 87 patients with ovarian cancer and MBO, where regression analysis revealed that better Eastern Cooperative Oncology Group (ECOG) status, platinum sensitivity, and no or volume ascites of <500 mL were associated with a better prognosis.⁶³

At this juncture, there is a well-recognized correlation between MBO palliative surgery and higher morbidity and mortality rates, thus, it should be considered with caution in this cohort of patients.^64,65 De Boer et al found that 58.1% of the patients suffered postoperative complications, and 8.8% of the patients died in the hospital.⁶⁶ Olson’s systematic review revealed that fatalities are rather high (6–32%) and that significant complications are frequent (7–44%).⁵⁸ Counter-intuitively, Yu et al showed no significant difference in terms of survival between surgical and non-surgical management in patients with MBO, albeit the cohort of the study included a minority of ovarian cancer patients.²⁷ A population-based analysis also demonstrated a similar outcome as overall survival was similar between surgical and medical patients (median 6.5 vs 6.4 months).²⁵ Therefore, selection of patients for surgery requires detailed consideration of overall prognosis, performance status, as well as the risk of perioperative complications.

Non-Surgical Interventions

Temporary decompression via nasogastric tube is often used to evacuate a large amount of pooled gastric secretions to improve symptoms during acute MBO episodes.⁶⁷ Nasogastric tubes are not well tolerated for a prolonged time and are associated with complications such as occlusion and displacement, nasal cartilage erosions, aspiration pneumoniae, esophagitis and bleeding.⁶⁸

Percutaneous transesophageal gastro-tubing (PTEG) has shown to be superior to nasogastric tube in terms of symptomatic improvement and quality of life, with no differences in survival between both interventions.⁶⁹

Percutaneous gastrostomy tube, also called venting gastrostomy, can also be used as a more permanent measure for gastric decompression and are associated with reduction of nausea and vomiting.²⁹ Complications include wound infection or leakage of fluid around the tube. In a systematic review that included 25 studies and 1194 patients, Thampy et al summarized a variety of outcomes related to venting gastrostomy insertion, including successful insertion at first attempt in 91%, major complication in 2% and minor complication in 20%.⁷⁰ Patients with malignant ascites, frequently associated with advanced gynecologic cancers, have an increased likelihood of complications or unsuccessful gastrostomy tube insertion, although this is not considered a contraindication.⁷¹

Endoscopic stents have been used to improve symptoms from MBO related to a single point of obstruction mainly in patients with colorectal cancer, but few data support its use in extracolonic malignancies. Small studies evaluated the use of stents in extraluminal narrowing secondary to genitourinary, gynecologic and non-colorectal GI malignancies, with technical success ranging from 20 to 87%.^72,73 Extrinsic compression is associated with higher likelihood of technical and clinical failure, and higher likelihood of requiring surgical diversion for persistent obstructive symptoms despite stent insertion. Risk of stent insertion includes bowel perforation, migration and re-obstruction.⁷⁴

Patient selection is critical when choosing the most appropriate intervention. Patients with single-level obstruction may benefit from local treatment such as stenting or surgery.⁷⁵ However, most patients with ovarian cancer and MBO have multifocal sites of obstruction and are not considered good candidates for the aforementioned procedures, thus managed conservatively.

Pharmacologic Management

In MBO, medical treatment aims to relieve pain and uncomfortable symptoms by lowering inflammation, luminal pressure, and secretions.²⁹ Effective symptomatic management for MBO can be achieved with medical therapy that combines steroids, opioids, antiemetics, and antisecretory medications in addition to intravenous (IV) hydration and bowel decompression (if required).^29,65,76,77 As MBO patients tend not to tolerate medications orally, alternative routes of administration can be pursued (eg, intravenous, subcutaneous, sublingual, or transdermal).^65,77 Periodically adjusting the pharmacological regimen based on the course of MBO and treatment response is of paramount importance.²⁹

Corticosteroids can relieve acute symptoms of MBO, likely due to an anti-inflammatory and anti-secretory effect, which decrease intestinal wall edema and promote salt and water absorption.⁷⁸

In a small clinical trial, 35 patients with MBO mostly due to ovarian cancer were randomized to dexamethasone 4 mg every 6 hours or placebo for 5 days; all patients received standardized medical management with fluids, analgesia antiemetics and laxatives. In the dexamethasone group, 62% of patients showed resolution of obstruction at day 5, compared to 57% in the placebo group; numbers were too small to allow a formal statistical analysis.⁷⁹ In separate study including 52 patients, the administration of methylprednisolone (240 mg or 40 mg versus placebo for 3 days) was associated with a tendency toward symptom improvement in the methylprednisolone group (59% versus 33.5%, p = 0.08).⁸⁰ Finally, in a recent retrospective analysis evaluating 91 ovarian cancer patients with small bowel MBO who received dexamethasone during 154 hospitalizations, 89% of women had initial partial or total symptom control; platinum-sensitive patients were more likely to respond to dexamethasone than platinum-resistant patients (p = 0.04).⁸¹ Duration of treatment is not well established; doses ranging from 4 to 16 mg equivalent of dexamethasone daily for 3 to 5 days are usually used.²⁹ It is recommended to use the lowest effective dose for the shortest period of time to avoid long-term toxicity days.⁸² Concerns about extended glucocorticoid therapy include increased susceptibility to infections, peptic ulcers, impaired mood, and insomnia; consequently, if limited response is noted, glucocorticoids should be discontinued.⁸³

Somatostatin analogues reduce intestinal and pancreatic secretion, modulate gastrointestinal motility, decrease biliary contraction and intestinal edema.³⁷ Although a systematic review of these agents in the treatment of MBO revealed no observable benefit based on the broadly diverse main outcomes defined by the seven eligible trials (427 patients in total) included,⁸⁴ a recent multicenter prospective phase II study of Lanreotide proved benefit in patient with MBO secondary to ovarian and GI malignancies.⁸⁵ Another randomized Phase III study confirmed effectiveness of octreotide and dexamethasone over traditional medical treatment in patients with inoperable MBO.⁸⁶ Moreover, as described in the randomized controlled trials (RCTs), somatostatin analogues proved to be well tolerated, with no withdrawals owing to toxicity.^86,87

The anticholinergic drug hyoscine (scopolamine) butylbromide can be used to alleviate spasmodic abdominal discomfort. In addition to decreasing gastrointestinal secretions, it slows propulsive peristalsis and relaxes the smooth muscles of the gastrointestinal tract. Hyoscine butylbromide may be used for the treatment of inoperable MBO, but there is less evidence to support its use.⁹ Obita et al concluded in their systematic review that somatostatin analogues (eg, octreotide) are more effective than hyoscine butylbromide in decreasing continuous pain in 2 studies with high Cochrane risk of bias.^37,84,87 Another study, however, did not show the same findings.⁸⁸ In contrast, colicky discomfort was not significantly different between octreotide and hyoscine butylbromide in all three studies.^37,84,87,88

Laxatives are not recommended for complete MBO. Patients with incomplete MBO may utilize oral osmotic laxatives (eg, polyethylene glycol 3350) with caution. Osmotic laxatives pull water into the lumen of the intestine to soften feces and increase peristalsis. Bulk-forming laxatives (eg, psyllium) are contraindicated because they increase stool consistency and may aggravate MBO.²⁹ If a digital rectal examination reveals a full rectum or fecal impaction, suppositories and fecal disimpaction may be explored for partial MBO.⁸⁹ Due to the danger of intestinal perforation, enemas are typically contraindicated in complete MBO. It is possible to employ stool softeners (eg, docusate), although their effect on bowel movements is poorly studied.²⁹

As recognized by the WHO recommendations, opioid analgesia is a frequent and effective method for pain control in advanced malignancies.⁹⁰ Pain associated with MBO may be colicky (cramping and intermittent) or persistent. Experts recommend opioid analgesia because it may be supplied bypassing the oral route (intravenous, subcutaneous, sublingual, or trans dermal) and because the depressed impact on intestinal motility may decrease colicky pain.^1,29,64 Evidence supporting its use in MBO is lacking and further investigation is warranted, given that opioids are known to impair gastrointestinal motility and can cause nausea, vomiting and constipation.²⁹

Prokinetics (eg, metoclopramide) boost gastric and small bowel movement, enhance gastric peristalsis and emptying, and promote the transit of intestinal contents through the digestive tract. Metoclopramide is generally regarded as a potential option for first-line therapy in patients with partial MBO (ie, intermittent vomiting as opposed to continuous vomiting), and it mediates myenteric cholinergic action^91,92 However, it is contraindicated for complete MBO as it might exacerbate abdominal cramping, nausea, and vomiting.^93,94 A small study by Mercadante et al analyzed the effects of combining metoclopramide, octreotide, dexamethasone, and diatrizoate in 15 consecutive advanced cancer patients with MBO and found that the therapeutic effect of the combination was better than that of any single drug; additionally, the patients who persisted on this treatment did not have recurrent symptoms until death.⁹³

Role Chemotherapy

The underlying cause of bowel obstruction in patients with advanced ovarian cancer is peritoneal carcinomatosis involving the mesentery and the various folds of peritoneum. This can be seen at the time of presentation in patients with newly diagnosed ovarian cancer as well as at the time of recurrence. The main aim of administering chemotherapy is to treat the underlying peritoneal carcinomatosis. Careful attention must be paid while choosing the drug, keeping in mind the nature and extent of disease, anticipated response, for example, newly diagnosed or platinum-sensitive versus bulky, platinum-resistant disease and tolerability.⁶

Evidence of chemotherapy in MBO is scarce as these patients are generally not included in clinical trials. Most of the patients with MBO have already received multiple lines of treatment, are chemo-resistant and may not have a response that is significant enough to result in resolution of obstruction.^95,96 Yet, chemotherapy with or without surgery may improve survival in ovarian cancer.²⁵ A retrospective study included 2983 patients with advanced cancer from several disease subsites with MBO, of whom 1472 were medically managed. In the entire study population, there were 406 patients (13.6%) with ovarian cancer of whom 244 (60%) were medically managed. More than half of these patients received chemotherapy (with or without surgery) after the diagnosis of MBO; however, there are no details regarding number of lines of treatment or platinum sensitivity.²⁵ The single center, retrospective study by Chouhan et al,⁹⁷ evaluated 82 patients with malignant small bowel obstruction (16 patients with ovarian cancer) who were managed with a combination of systemic chemotherapy and total parenteral nutrition. In the ovarian cancer cohort, 4 patients (25%) had resolution of the small bowel obstruction; however, details on number of lines and chemotherapy protocols for these patients specifically were not reported.⁹⁷

Patients with MBO are often malnourished and may be unable to tolerate standard chemotherapy protocols; hence, dose-modification and weekly protocols can be considered. Based on where the patients with MBO are in their disease trajectory and clinical assessment, including ECOG performance status, tempo of disease progression and their bone marrow reserve, weekly carboplatin-paclitaxel or weekly paclitaxel are some of the suggested regimens.⁹⁷

Treatment needs to be tailored based on goals of care on a case-by-case basis. While patients who are heavily pre-treated and have bulky chemo-resistant peritoneal deposits would benefit from a conservative approach focused on de-escalation of care and symptom management to avoid therapeutic morbidity, it is important to avoid under-treatment of carefully selected patients who are newly diagnosed, healthier or have a good performance status.^98,99 Overall, the evidence to support the use of chemotherapy in patients with advanced gynecologic cancers who developed MBO is still limited, and decisions must be tailored on a case-by-case basis, preferable after multi-disciplinary discussion.

Role of Multi-Disciplinary Management

Every patient with a diagnosis of MBO should be assessed by the palliative care team. Multi-disciplinary team approach for the management of patients with MBO has shown to be associated with improved outcomes such as shorter hospital stays and better survival.⁹⁸ The team generally includes the expertise of surgeons specializing in gastro-intestinal and gynecologic oncology, medical oncologists, specialists in TPN, nurses or nurse-practitioners with special interest in MBO, interventional radiologists, palliative care, and wherever needed, radiation oncologists and infectious disease specialists.

A retrospective analysis from a tertiary care center in Toronto, Canada, which included 107 patients with gynecologic cancer admitted for malignant bowel obstruction, showed that patients who received active management with a dedicated team had improved outcome.¹⁰⁰ A well-planned and coordinated inter-professional team approach ideally includes nurse-led outpatient management, a well devised, easily accessible and implementable inpatient treatment algorithm, patient-directed bowel management educational material and multi-disciplinary case conferences (MCCs).¹⁰¹

Supported Self-Management

Given the complexity in managing MBO, several studies assert the importance of a multidisciplinary approach to care and engaging patients on self-management strategies.^{23,29,34,100–102} Castro et al conducted a retrospective cohort study of ovarian cancer patients with MBO using a protocol management tool developed by their multidisciplinary team, to ascertain patient’s clinical progression. They found patients can experience recurrent episodes of MBO prior to death and suggest engaging in a multidisciplinary team approach using evidence-based care pathways to improve the management of patients with MBO.¹⁰²

The development of an outpatient interprofessional MBO program for gynecologic patients is feasible and was established in a tertiary cancer centre by some authors of this review.¹⁰¹ Patients enrolled in the program receive teaching and educational materials from the nurse on how to (1) recognize MBO symptoms; (2) manage with diet and laxatives; (3) and when to seek support and receive nursing proactive bowel management calls. Lee et al conducted a retrospective analysis pre/post MBO program implementation and found patients had a decrease in length of stay and increase in overall survival validating an improvement in clinical outcomes using this model of care (MOC).¹⁰¹

To evaluate the patient’s perspective on the impact of this outpatient MBO MOC program in their ability to self-manage bowel function and the physical and psychological supports received, Cusimano et al conducted a qualitative descriptive study using semi-structured interviews patients enrolled in the study. The results showed that patients felt empowered to self-manage their bowel function through the education they received on nutritional and laxative management, in addition to understanding symptoms and causes of MBO.³⁴ Most importantly, patients with MBO expressed fear and anxiety related to worsening symptoms but felt that the proactive management with nursing calls and physician interventions decreased their degree of distress and provided a sense of security when seeking support.³⁴

These data highlight the importance of pro-active management of MBO and patient education regarding bowel management and risk of MBO.

Impact

Patient and Family: Quality of Life (QOL)

As discussed, MBO can involve surgical and/or medical management and is considered a pre-terminal event.^23,34,100 The physical burden compounded by the psychological distress that both patients and their caregivers endure impacts their QOL. Considering the severity of this disease and complication with MBO, it is imperative that clinicians establish goals of care with their patients to optimize QOL.^{6,29,34,103,104} Sun et al and Lowe et al refer to QOL as a personal evaluation of one’s life’s challenges and achievements and their psychological, physical, and social well-being following treatment of a medical condition.^105,106 A few studies report several quantitative QOL measurement tools such as the European Organization for Research Quality of Life Core Questionnaire 30 (EORTC-QLQ-C30); the Functional Assessment of Cancer Therapy (FACT-G), which also has an ovarian cancer subscale (FACT-O).^105–107 According to Shariff et al, research on the impact of MBO using these QOL tools is lacking.¹⁰⁷

The qualitative studies reviewed found that despite physical symptom improvement through surgical and/or medical management, the psychological burden remains high.^{34,103,104,106} Patients with MBO reported significant anxiety, fear and powerlessness during and after an MBO episode.^36,105,106

Patients also reported a sense of social and emotional loss/isolation among family and friends with regard to nutritional intake. Food can impact an individual’s QOL as it serves as a source of socialization bringing family and friends together in daily living. A restricted diet, particularly for those with a venting gastrostomy tube or TPN, contributed to disengagement in mealtimes leading to isolation and loss.^34,103,104 Although some patients reported TPN improved their QOL as they were able to spend more time at home with their families, they still faced challenges with body image and felt they were a burden to their families.^{6,29,34,103,104}

The American Society of Clinical Oncology (ASCO) supports introducing palliative care early on with guidelines for patients with advanced metastatic cancer.^108,109 Miller et al reviewed initiation of palliative care in ovarian cancer patients and found a need to standardize screening to optimize care as research indicates that most patients are diagnosed at an advanced stage and have a high recurrence rate.¹¹⁰

Establishing goals of care and timely discussion of palliative care has been the consensus among several authors.^{6,29,74,105,111–113} Communication with patients that an MBO diagnosis is considered a pre-terminal event, particularly at the time of platinum-resistant ovarian cancer, is imperative to alleviate any misperceptions. For instance, Shariff et al conducted a literature review on the management of MBO and found that patients who received interventions improving their symptoms perceived they had a better overall survival rate.¹⁰⁷ In addition, Frey et al found that patients with recurrent disease prioritize survival before QOL and 27% would accept an MBO episode if it meant they would eventually be cured.¹¹¹ These misperceptions may be attributed to a gap in communication.

One qualitative study specifically assessing patient-physician communication found that patients admitted with MBO were frustrated at the paucity of information provided on their prognosis and management and that physicians were too negative in their communication. Interestingly, physicians felt they could not communicate an effective response to the patient’s prognosis given the complexity in management with MBO and conveying realistic expectations without being negative.¹¹³ Clinicians must be transparent that treatment in this setting is not curative, and the importance of balancing treatment-related toxicities and the associated risks with interventions must be considered and discussed to optimize their QOL.^111,112,114

Palliative care is a sensitive discussion, and patients have attested that it is considered a death sentence.³⁴ Communicating with patients that a referral to palliative care in advance will aid in prioritizing goals of care, improve symptom relief, QOL and provide support for caregivers. Furthermore, patients should be made aware that palliative care provides a holistic approach, encompassing all aspects of the patient not just physical and psychosocial but spiritual and cultural as well.^{29,110–112,114} Patients with an MBO diagnosis would greatly benefit from the support, knowledge and expertise that palliative care teams can provide through their disease trajectory.

Impact of MBO on Health Care Expenditure

A retrospective analysis by Lee et al showed that implementation of systematic interprofessional management of MBO and patient education significantly reduced the duration of inpatient admission, thereby reducing the expenditure per hospital admission as well as the cost per patient (including multiple hospital admissions).^101,115

Conclusion

While MBO is a common and significant complication for patients with gynecological cancers, especially advanced and recurrent ovarian cancer, there is a lack of evidence-based management protocols, which stresses upon the need for clinical research initiatives.

Patients with inoperable MBO are treated medically with analgesics, antiemetics, steroids and antisecretory agents. Gut decompression with nasogastric tube, venting gastrostomy or stenting are used as supportive therapy. Intravenous hydration, parenteral nutrition and palliative chemotherapy may derive benefit in a subgroup of patients; careful selection is critical to ensure the best possible clinical outcome.

Timely, systematic multidisciplinary and pro-active approach alongside patient education have been shown to add clarity to the management of complex cases. Efforts are needed to help optimize outcomes in this unique patient population.