Hematology/Oncology




Cancer survivors and their families face myriad challenges related to their disease and its treatment. This life-changing journey begins the moment they hear “cancer.” Palliative care of the oncology patient involves the assessment and treatment of the multidimensional experience of cancer: the physical, emotional, and spiritual. Although each of these elements is important in the total care of patients, this chapter focuses on the physical manifestations of advanced disease and specific approaches to supportive care of the oncology patient. We present a practical approach to the presentation, evaluation, and supportive management of several common oncologic problems: brain, liver, and bone metastases; bowel obstruction; and malignant effusions.


Approach to Brain Metastases


Incidence


Brain metastasis, a common complication of systemic cancer, is present in 98,000 to 170,000 new patients each year, approximately 30% of all patients with malignancy. The frequency may be rising because of the use of more sensitive detection techniques and the prolonged survival of patients with metastatic disease from common malignant tumors. Most recently reported in a large population study, the incidence percentage for patients with primary lung (19.9%), melanoma (6.9%), renal (6.5%), breast (5.1%), and colorectal (1.8%) cancers account for the majority of individuals with brain metastases. The prognosis is dependent on several factors: brain as the only site of metastasis, performance status, age, primary lesion (controlled versus uncontrolled), and number of lesions (single vs. multiple).


Presentation


Brain metastases may manifest with the rapid onset of symptoms or with subacute but progressive neurologic dysfunction. Common presenting symptoms include headache (49%), a focal neurologic deficit (30%), cognitive disturbance (32%), ataxia (21%) seizures (18%), dysarthria (12%), visual disturbances (6%), sensory disturbance (6%), and limb ataxia (6%).


Evaluation


Imaging studies are recommended for any patient with a history of cancer and new neurologic symptoms. Both contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are appropriate evaluation tools, although gadolinium-enhanced magnetic resonance imaging is more sensitive and specific for the detection of central nervous system metastases. Of patients with enhancing metastatic lesions, approximately one third present with solitary lesions and two thirds present with multiple lesions. Metastatic lesions to the brain are commonly well circumscribed and associated with vasogenic edema. A biopsy is generally not necessary in patients with multiple metastatic lesions and known malignant disease, particularly if the primary tumor commonly metastasizes to the brain. If there is clinical uncertainty about the origin of brain lesions, a stereotactic biopsy can differentiate metastatic disease from a primary brain tumor or a nonmalignant cause, such as infection. A solitary brain metastasis in the setting of a patient with good performance status and otherwise well-controlled disease should be considered for resection. A biopsy should be considered in patients with acquired immunodeficiency syndrome, even when patients have multiple lesions, if Toxoplasma titers are negative, to differentiate cancer, particularly lymphoma, from infectious causes.


Management


Medical


The goal of medical therapy for patients with newly diagnosed symptomatic brain metastases is to control edema and to minimize symptoms while evaluating for more definitive therapeutic options. Treatment options include surgical resection, radiosurgery, whole-brain radiation therapy (WBRT), and medical therapy. Untreated, patients with multiple brain metastases have a median survival of approximately 1 month. Corticosteroids reduce vasoedema and double the median survival to 2 months. These agents are an important first step in the management of patients with brain metastases because nearly 70% of patients will experience significant relief of symptoms in the first 48 hours with corticosteroids. Patients who do not improve in the first 2 days generally have a very limited life expectancy of days to weeks and face significant progressive neurologic disability. Although there is no evidence-based consensus on the optimal corticosteroid dose, dexamethasone at 16 to 24 mg/day in divided doses every 4 to 12 hours is a reasonable recommendation. Dexamethasone is the preferred corticosteroid because of its reduced mineralocorticoid effects and relatively long half-life. In patients with symptomatic brain lesions who are near the end of life, corticosteroids may be continued for the remainder of the patient’s life or until he or she can no longer swallow.


Patients receiving high doses of corticosteroids experience several predictable acute side effects, including hyperglycemia, oral candidiasis, leukocytosis, and increased energy; subacute and chronic toxicity includes gastritis, central adiposity, and proximal myopathy. When steroid therapy is initiated, patients should simultaneously start prophylactic antifungal therapy, antacids, and regular blood glucose monitoring.


Interventional


Surgical resection of metastatic brain lesions is indicated for patients with a good performance status, a single lesion in a surgically accessible field, good neurologic function, and well-controlled systemic cancer. Surgery should be followed by WBRT to reduce the risk of central nervous system recurrence. In a recent meta-analysis comparing surgery with surgery plus WBRT, survival was equivalent, but patients treated with combined-modality therapy tended to have greater improvement in function and a reduction in death from neurologic causes.


For patients who are not surgical candidates or for those who present with multiple brain metastases, palliative WBRT is the standard of care. WBRT improves median survival over dexamethasone alone to 3 to 7 months. The best candidates for WBRT are younger than 65 years, with good performance status (KPS ≥70) and absent or controlled extra-cranial disease and have a median survival of 7.1 months. WBRT may be administered as 10 to 15 fractions and is generally well tolerated. The most common side effects include fatigue, alopecia, and cognitive deficits, particularly problems with short-term memory.


Radiosurgery uses either y -radiation or a linear accelerator to deliver a high dose of radiation to a defined target. It is a noninvasive alternative to surgery that can be administered quickly and can access regions of the brain not amenable to surgical resection. The median survival after radiosurgery appears to be equivalent to that after surgery, ranging from 7.4 to 12.9 months. Selection criteria for radiosurgery are similar to those for surgery: limited systemic disease, good performance status (Karnofsky Performance Scale [KPS] >70), and the presence of fewer than three metastatic lesions. Lesions amenable to radiosurgery should be well circumscribed, less than 4 cm, and without invasion deep into the brain tissue. Although single-institution studies are subject to significant selection bias, researchers have reported local control rates of 88% for patients treated with radiosurgery. Compared with WBRT alone, radiosurgery in combination with WBRT offers a survival advantage for patients with a single brain metastasis. In addition, patients with solitary metastasis treated with combined therapy were more likely to achieve a stable or improved KPS score than patients receiving WBRT alone.




Approach to Liver Metastases


Presentation


Patients with liver metastases may be asymptomatic or present with a range of abdominal or constitutional symptoms depending on the volume and location of disease in the liver. For many patients, liver metastases manifest with vague abdominal symptoms followed by increasing gastrointestinal and constitutional symptoms if left untreated. Liver metastases are routinely uncovered with routine surveillance imaging in patients with a history of cancer even before symptoms develop (e.g., lung cancer). Patients with extensive liver metastases may present with signs (ascites, jaundice, coagulopathy, encephalopathy) or symptoms (pain, fever, night sweats, early satiety, anorexia) of advanced liver disease. Liver metastases historically confer a poor prognosis, often less than a year. However, there is significant variability based on tumor type (e.g., colon vs. lung), treatment options, and comorbid disease.


Evaluation


After a careful history and physical examination, evaluation includes imaging studies, typically a contrast-enhanced abdominal CT scan, to assess for the presence and extent of liver disease, biliary or hepatic obstruction, portal vein thrombosis, ascites, and peritoneal disease. Abdominal ultrasound is helpful in patients who cannot tolerate enhanced CT scan. Ultrasound can identify and characterize liver lesions and diagnose biliary obstruction but does not provide the same degree of diagnostic information as CT. Laboratory studies should include liver function tests, albumin, coagulation studies, chemistry profile, and complete blood cell count. If ascites is present, diagnostic paracentesis may be indicated to confirm the diagnosis or evaluate for infection with ascitic fluid analysis for cell count, culture, differential, albumen, and cytology.


Management


Medical


After a clear discussion of the goals of care, treatment may be directed at the tumor in concert with symptom management, or it may be focused on symptoms alone. Early satiety, pain, fever, sweats, anorexia, weight loss, pruritus, nausea, abdominal fullness, and confusion are all common symptoms attributable to bulky liver metastases.


Right upper quadrant pain or discomfort secondary to liver capsular stretch, distention, or bulky disease is common. Opioids are the mainstay of management for malignant pain. Even in patients with liver failure and impaired metabolism, opioids can be used safely and effectively when titrated to effect (see Chapter 7 ). Capsular distention is thought to produce pain, in part from a local inflammatory reaction, and corticosteroids are commonly used as adjuvant pain relievers. In addition, for patients with very advanced disease and multiple symptoms, corticosteroids may transiently ameliorate fatigue and nausea, stimulate appetite, reduce fever and sweats, and improve a patient’s general sense of well-being. Evidence-based dosing recommendations are not available, although clinical experience suggests that modest doses of dexamethasone (6–10 mg/day) given orally or intravenously in the morning are often effective.


Fever and sweats associated with malignant liver disease are difficult to control. The treatment of choice is control of the cancer if possible. Palliative treatment options include antipyretics (nonsteroidal anti-inflammatory drugs, corticosteroids, and acetaminophen), sponging with cool water or an isopropyl alcohol solution, and hypothermic agents (chlorpromazine) that act by directly lower the core body temperature. Therapies for malignancy-associated sweats are not well studied, and reports of successful agents are largely anecdotal: low-dose thioridazine (10–30 mg), the H 2 receptor blocker cimetidine, and thalidomide (100 mg at bedtime) have been reported to improve sweats in patients with advanced cancer.


Pruritus is a disruptive and troublesome symptom for patients. Pruritus secondary to liver disease is most often observed in the setting of obstructive jaundice; the severity of the pruritus, however, does not directly correlate with the degree of bilirubin elevation. Decompression or even partial decompression of the biliary tree, either through percutaneous or endoscopic approach, can provide significant and often permanent relief of the itching.


Interventional


Liver-directed treatment strategies now provide additional options for the treatment of liver metastases. Currently available liver-directed approaches include surgical resection, radiofrequency ablation (RFA), chemoembolization, cryotherapy, and brachytherapy with radiation-impregnated glass beads. The risks, benefits, and patient characteristics leading to a recommendation for one technique or another are highlighted in Table 25-1 . In particular, patients with colorectal cancer and hepatic metastases, without evidence of other metastatic disease, have dramatically improved survival if their lesions are surgically resected (55%–80% survival at 1 year and 25%–50% at 5 years) compared with best supportive care (survival < 1 year). Liver-directed therapies minimize systemic toxicity and spare most normal liver tissue. Patients with a good performance status (KPS > 70), fewer than four metastatic liver lesions, lesions 5 cm or smaller, and minimal systemic metastases are potential candidates for liver-directed therapy.



Table 25-1

Liver-Directed Therapy








































Modality Technique Patient Factors Risks Benefits
Surgical resection Open or laparoscopic approach Good performance status, able to tolerate major surgery, no other distant disease Operative morbidity and mortality; post-procedure pain, prolonged recovery Possibility for cure, best survival outcomes, complete resection
Radiofrequency ablation Percutaneous friction heat ablation Unresectable, fewer than 5 lesions, <4 cm in size, surrounded by liver parenchyma, >1 cm from vessels Post-procedure pain, tract seeding of tumor Outpatient procedure, no general anesthesia, improved 5-year survival rates for metastatic colon cancer
Cryotherapy Cold temperature ablation, –190° C Unresectable, fewer than 5 lesions, <4 cm in size, surrounded by liver parenchyma, >1 cm from vessels Post-procedure pain, less effective than radiofrequency ablation Modest survival benefit when combined with systemic therapy
Chemoembolization Chemotherapy directed into the tumor blood supply Unresectable primary liver tumors, better outcome with normal hepatic function pre-treatment Post-procedure pain, fever, nausea, fatigue, acute hepatitis Minimal systemic toxicity, prolonged survival
Therasphere Radioactive glass beads May have multiple liver lesions, fair hepatic reserve, no hepatopulmonary or gastroduodenal shunting Acute liver toxicity or failure, gastritis or ulcers, pulmonary toxicity if hepatopulmonary shunting exists Easily administered, minimal discomfort, effective, sparing of normal liver, survival similar to chemoembolization




Approach to Bone Metastases


Presentation


Patients with bone metastases commonly present with pain, usually localized to the site of the metastasis. The growth of malignant tumors creates pressure inside the bone and stimulates nociceptors sensitive to pressure. Locally active substances, such as prostaglandin E 2 and osteoclast-activating factor, are secreted, leading to necrosis. Malignant bone pain is classically insidious, with progressive severity over weeks to months. The pain is often described as a focal, constant, deep ache or boring pain without significant radiation. Patients occasionally present with the acute onset of moderate to severe pain after a pathologic fracture. Bone metastases can occur secondary to any solid tumor but are most common in patients with prostate, breast, and lung cancers. In an autopsy series, 85% of patients with these three malignant diseases have bone metastases at the time of death.


Evaluation


The initial evaluation of bone pain begins with a good pain history and physical examination focused on the sites of pain: Percussion over the bones often identifies areas of point tenderness, a red flag for the diagnosis of a metastatic bone lesion. Particular attention should be paid to patients with pain over a vertebral body because it could be a potential sign of vertebral involvement. Localized back pain is the most common presenting symptom of spinal cord compression and should be evaluated in an expedited fashion. Patients with extensive bone metastases may have myelophthisic anemia secondary to tumor infiltration of the bone marrow, characterized by a leukoerythroblastic peripheral blood smear, or elevated markers of bone turnover such as a high serum alkaline phosphatase.


The initial laboratory evaluation should include a chemistry profile with calcium level, complete blood cell count, and alkaline phosphatase. A clinical suspicion of bone metastases dictates an initial evaluation of the affected area by a plain film. Radiographs often identify a patient at risk for pathologic fracture. Lesions with an axial cortical involvement greater than 30 mm indicate an increased risk for fracture, and prophylactic surgical stabilization followed by local radiation therapy should be considered for weight-bearing bones. The most sensitive test to determine the extent of metastatic disease and to characterize (osteolytic or osteoblastic) the lesions is a radionuclide bone scan, although it does not visualize the lesions of multiple myeloma clearly. If a plain film is nondiagnostic, then a bone scan should be performed in most patients at high risk for bone metastases who are experiencing bone pain.


Management


Medical


The treatment of metastatic bone pain lesions is palliative, directed at the patient’s tumor and presenting symptoms and the prevention of skeletal complications. Pain secondary to bone metastases is initially treated with medical therapy. First-line analgesic agents for mild skeletal pain include nonsteroidal anti-inflammatory drugs and acetaminophen. If pain control is inadequate, opioids are added to achieve optimal pain control. Antitumor therapy, directed either at the site of metastasis or systemically, may reduce pain and allow dose reductions or discontinuation of analgesics.


The medical management of malignant bone lesions has changed in the era of oral and intravenous bisphosphonates, a class of agents with a variety of actions, most importantly a multifaceted inhibition of osteoclast activity. These agents may improve pain control and delay skeletal complications of metastatic disease, but they do not affect survival. Zoledronic acid is often used because of its potency and ease of infusion (4 mg over 15 minutes). Bisphosphonates are generally well tolerated with unusual acute toxicities of flulike symptoms and bone pain. Patients on prolonged therapy should be monitored for a number of toxicities, including renal impairment, nephrotic syndrome, hypocalcemia, and osteonecrosis of the jaw (ONJ). Patients should be advised to identify and correct dental problems before beginning therapy and avoid dental procedures while receiving intravenous bisphosphonate therapy. A new approach to managing metastatic bone disease recently approved for use by the FDA is the fully humanized monoclonal antibody against RANK-L (Receptor Activator of Nuclear factor κ B ligand), Denosumab, which results in inhibition of osteoclast activity. The drug is administered by subcutaneous injection and was tested in three phase III trials treating over 5,500 patients with multiple myeloma, breast, and prostate cancers with metastatic bone disease. Denosumab proved to be statistically non-inferior to zoledronic acid in delaying the time to the first skeletal related event (SRE) while overall survival, disease progression, and adverse events were similar in the two arms including equal—though rare—risk for osteonecrosis of the jaw. Because SREs influence morbidity and possibly mortality, delaying such events also appears to improve health related quality of life.


Additional interventions for the treatment of bone metastases include systemic antineoplastic therapy, radiation therapy, RFA, and surgical fixation. Systemic chemotherapeutic options may exist for some patients with highly responsive cancers, such as breast cancer and testicular cancer. Patients with pathologic fractures of weight-bearing bones may benefit from surgical stabilization, whereas vertebral fractures may be stabilize with vertebroplasty or kyphoplasty.


Radiation


External-beam radiation therapy relieves pain, minimizes further tumor destruction, and prevents or delays pathologic fractures. Although most commonly delivered as multiple fractions, a single, higher-dose fraction (generally 800 Gy) reduces the treatment time necessary and minimizes the overall treatment burden for the patient. A meta-analysis (12 trials, 3508 patients) comparing single-fraction with multifraction radiation treatment of bone metastases demonstrated equivalent reduction in pain (60%), complete pain relief (34%), and toxicity. The necessity for repeated treatment, however, was higher for patients treated with a single-fraction versus multiple fractions, 21.5% versus 7.4%, respectively. The choice of therapy depends on the goals of care and life expectancy.


RFA, an emerging technique for the treatment of bone metastases, introduces a high-frequency current into the tumor bed that induces frictional heating and necrosis. There is significant experience using this technique for the treatment of liver metastases, but data evaluating the effectiveness of RFA for reducing pain from bone metastases are limited. Goetz and colleagues, in a multicenter trial, treated 43 patients with painful osteolytic bone metastases with RFA. Eligible patients were without risk for pathologic fracture, and their lesions were not adjacent to large vessels or the spinal cord. Sustained pain relief was achieved in 95% of patients, with mean pain scores falling from 7.9 to 1.4 ( P < .0005) over the 24 weeks following treatment. Other small studies confirm these findings, but prospective, randomized data comparing radiation therapy and RFA for more durable outcomes of pain relief, mobility, and post-treatment pathologic fractures are not available.


Surgery


Surgical stabilization can relieve pain and preserve function in patients with unstable vertebral fractures and spinal cord compression and in those with or at risk for pathologic fracture of a weight-bearing or other long bone. Although there are no established criteria, surgical stabilization is generally considered in patients with good functional status (KPS >70), life expectancy longer than 3 to 6 months, and the ability to tolerate major surgery. Surgical risk depends on a variety of patient-related factors, including comorbid cardiopulmonary disease and relative difficulty of the surgical fixation. Prophylactic stabilization procedures are generally less invasive and better tolerated than fixation procedures after a fracture has already occurred. Surgery provides an opportunity to prevent fracture and to preserve ambulation, but it comes with significant potential morbidity and mortality.


Vertebroplasty offers a nonsurgical approach to stabilize a vertebral fracture. The procedure is performed with the patient under conscious sedation with radiographic guidance. Cement is injected into the fractured vertebra to stabilize it, maintain column height, and prevent future nerve impingement. Although data are limited, case reports and a small case series suggest that vertebroplasty can reduce pain rapidly and is safe in conjunction with radiation therapy. Vertebroplasty is contraindicated in patients with spinal cord compression or with a compression fracture with retropulsed fragments.


Radiopharmaceuticals are indicated for the treatment of multiple painful bone metastases in patients with predominantly osteoblastic metastases. These agents work by tracking to binding sites in the bone matrix at the tumor-bone interface and then delivering a therapeutic radiation dose to the local area ( Table 25-2 ). Because these agents are administered systemically, they are appropriate only for patients with multiple painful lesions who are without other options for systemic antineoplastic agents. A Cochrane meta-analysis to evaluate the efficacy of radiopharmaceuticals for metastatic bone pain identified four trials (325 patients with prostate or breast cancer) and demonstrated a small benefit from radioisotopes for the control of bone pain for 1 to 6 months after treatment, without improvement in survival or reduction in the incidence of spinal cord compression. These agents are associated with significant myelosuppression and cost.



Table 25-2

Bone-Seeking Radiopharmaceuticals




















Drug Mechanism of Action Indication Contraindication
Strontium-89 Calcium homologue tracks to deposition of calcium


  • Similar for all agents:




    • Positive bone scan



    • Bone pain due to cancer



    • Multifocal disease





  • Similar for all agents:




    • Mainly soft-tissue disease



    • Unifocal bone lesion



    • Negative bone scan



    • Significant myelosuppression


Phosphorous-32 (rarely used) Tracks inorganic phosphorous in the body
Samarium-153 EDTMP Phosphonic acid group on carrier molecule, EDTMP, carries agent to areas of newly deposited bone

EDTMP, ethylene diamine tetramethylene phosphonate.

Other agents include 186-rhenium, 188-rhenium, and radium-223, but these are not currently approved for use in the United States.




Approach to Bowel Obstruction


Presentation


In the majority of patients, the diagnosis of malignant bowel obstruction can be made by history and physical examination. Abdominal distention, nausea, vomiting, crampy abdominal pain, and an absence of flatus and bowel movements are typical presenting symptoms. The colon may take as long as 12 to 24 hours to empty completely; thus, patients with small-bowel obstruction may continue to pass flatus and stool even after the obstruction occurs. The classic complaint is of periumbilical, paroxysmal, crampy abdominal pain. Obstruction should be differentiated from perforation: Peritonitis is suggested by symptoms of focal or diffuse abdominal pain, fever, hemodynamic instability, or peritoneal signs (severe pain with movement, firm abdomen, rebound tenderness, involuntary guarding).


The most common tumors causing malignant bowel obstruction are metastatic ovarian and colon cancers, although any patient with advanced cancer can develop an obstruction, particularly a patient with a history of multiple prior abdominal surgeries or abdominal radiation therapy. In as many as one third of patients, the cause of the obstruction is nonmalignant—that is, secondary to adhesions or other causes. Patients with advanced cancer and malignant bowel obstruction have a short life expectancy, generally measured in weeks.


Evaluation


The physical examination in patients with obstruction is highly variable: Fever and tachycardia may be signs of a strangulating obstruction or perforation; auscultation may reveal high-pitched, tinkling, or hypoactive bowel sounds and is not generally diagnostic; oliguria and dry mucous membranes are signs of dehydration; tympany on abdominal percussion suggests dilated loops of bowel; rebound tenderness, guarding, pain with light percussion, and abdominal rigidity suggest peritonitis. A rectal examination often detects an empty vault but may demonstrate an obstructing rectal mass or blood.


Plain radiographs of the abdomen and an upright chest radiograph will detect free peritoneal air if perforation is present and the classic dilated loops of bowel with air-fluid levels when obstruction is the cause of the patient’s symptoms. The presence of air in the colon or rectum makes a complete obstruction unlikely. In patients with malignant disease, an abdominal CT scan helps to define the extent of the underlying disease and may identify the site of the obstruction. An isolated point of obstruction is potentially reversible with surgical resection. Laboratory evaluation, including chemistry panel and complete blood cell count, will illuminate electrolyte imbalances, dehydration, anemia, acid-base disorders, or signs of secondary infection.


Management


Medical


The management goals for a patient with bowel obstruction in the setting of advanced cancer are to minimize bowel wall edema, to treat and prevent nausea and vomiting, to control pain, to decrease intestinal secretions, and to address end-of-life issues. The initial intervention for patients with a bowel obstruction is nasogastric tube drainage to prevent emesis and to relieve the nausea caused by gastric distention. Occasionally, obstructions remit spontaneously with conservative management: nothing-by-mouth, nasogastric suction, intravenous fluids, and analgesics. Intravenous corticosteroids may minimize bowel wall edema and may partially reverse an obstruction. A Cochrane meta-analysis evaluating dexamethasone, 6 to 16 mg/day, for the treatment of malignant bowel obstruction revealed a trend toward resolution of the obstruction with steroids but no survival advantage.


Pain management is vital for patients with a malignant bowel obstruction. Opioid analgesics are recommended. Patients with a nonfunctioning intestinal tract rely on alternate routes of analgesic administration. Fentanyl transdermal patches, rectal administration of long-acting opioids, and subcutaneous or intravenous opioid administration provide predictable analgesic delivery in the absence of a functioning upper gastrointestinal tract.


Somatostatin analogues, such as octreotide, may provide significant relief of symptoms associated with small bowel obstruction and may be used as first-line therapy in patients who are not surgical candidates. Octreotide reduces gastric acid secretion, inhibits the release of gastrointestinal hormones and therefore decreases intestinal fluid secretion, slows intestinal motility, decreases bile flow, decreases mucus production, and reduces splanchnic blood flow. Furthermore, it inhibits acetylcholine release, resulting in muscle relaxation and reduction in the colicky pain associated with spastic gut activity. These inhibitory effects on peristalsis and gastrointestinal secretions reduce bowel distention, pain, and vomiting. Octreotide is administered by either subcutaneous bolus or continuous infusion. The recommended starting dose is 0.3 mg/day subcutaneously and may be titrated upward until symptoms are controlled; most patients require 0.6 to 0.9 mg/day. Octreotide is expensive, and the cost-to-benefit ratio must be considered, especially for patients who may require prolonged treatment. The main side effects of octreotide are gastrointestinal (nausea, vomiting, abdominal pain), injection site reactions, and hyperglycemia.


Despite aggressive supportive care, a malignant bowel obstruction does not resolve with medical management in most patients with advanced cancer. Without aggressive symptom management, patients with persistent malignant bowel obstructions can develop feculent emesis, intractable pain, and distress.


Interventional


Surgical exploration is the initial treatment of choice for patients with a single site of obstruction, a reasonable quality of life, good performance status, and well-controlled systemic disease. Additionally, for patients who present with a malignant bowel obstruction leading to the diagnosis of cancer, surgery, with or without a diverting ostomy, is standard care. With successful resection of an obstruction point, bowel function may return for an extended period, thus reducing requirements for supportive medications.


A less invasive alternative to surgery is an endoscopically placed colonic stent. Because urgent surgical intervention is associated with a modest risk of morbidity and mortality—16% to 23% and 5% to 20%, respectively—colonic stents are used in patients who are not operative candidates. In surgical candidates, temporary stents may be used for symptom relief before subsequent surgical intervention. Colonic stents provide immediate relief of the obstruction and rapid symptom improvement. Left-sided colon lesions are technically more amenable to stenting. Complications occur in 10% to 20% of cases and include stent migration, pain, bleeding, occlusion, and bowel perforation.


Venting gastrostomy tubes (percutaneous gastric tubes placed into the stomach) relieve intractable nausea, vomiting, and pain by decompressing the stomach and proximal small bowel. They also enable a patient to eat and drink small amounts without symptoms, thus allowing social interactions at mealtime. Oral medications can be administered by clamping the gastric tube for 30 to 90 minutes, thereby allowing some absorption in the stomach and proximal small intestine, although bioavailability of medications in this setting is unpredictable. All patients with advanced cancer and a malignant bowel obstruction, with or without surgical intervention, have a poor prognosis and a high rate of in-hospital mortality.

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Apr 13, 2019 | Posted by in ANESTHESIA | Comments Off on Hematology/Oncology

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