Cancer of the Liver
Hepatic
tumors may be malignant or benign. Benign liver tumors were uncommon until the
widespread use of oral contraceptives. With the use of oral contraceptives,
benign tumors of the liver occur most frequently in women in their reproductive
years.
Few
cancers originate in the liver. Primary liver tumors usually are associated
with chronic liver disease, hepatitis B and C infections, and cirrhosis.
Hepatocellular carcinoma (HCC) is by far the most common type of primary liver
cancer, but it is rare in the United States (Bacon & Di Bisceglie, 2000).
HCC is usually nonresectable because of rapid growth and metastasis. Other
types of primary liver cancer include cholangiocellular carcinoma and combined
hepatocellular and cholangiocellular carcinoma. If found early, resection may
be possible, but early detection is unlikely. Cir-rhosis, chronic infection
with hepatitis B and C, and exposure to certain chemical toxins (eg, vinyl
chloride, arsenic) have been im-plicated as causes of HCC. Cigarette smoking
has also been iden-tified as a risk factor, especially when combined with alcohol
use. Some evidence suggests that aflatoxin, a metabolite of the fungus Aspergillus flavus, may be a risk factor
for HCC. This is especiallytrue in areas where HCC is endemic (ie, Asia and
Africa). Afla-toxin and other similar toxic molds can contaminate food such as
ground nuts and grains and may act as a co-carcinogen with he-patitis B. The
risk of contamination is greatest when these foods are stored unrefrigerated in
tropical or subtropical climates.
Metastases
from other primary sites are found in the liver in about half of all advanced
cancer cases (Bacon & Di Bisceglie, 2000). Malignant tumors are likely to
reach the liver eventually, by way of the portal system or lymphatic channels,
or by direct extension from an abdominal tumor. Moreover, the liver apparently
is an ideal place for these malignant cells to thrive. Often the first
evi-dence of cancer in an abdominal organ is the appearance of liver
metastases; unless exploratory surgery or an autopsy is performed, the primary tumor
may never be identified.
The
early manifestations of malignancy of the liver include pain, a continuous dull
ache in the right upper quadrant, epigastrium, or back. Weight loss, loss of
strength, anorexia, and anemia may also occur. The liver may be enlarged and
irregular on palpation. Jaundice is present only if the larger bile ducts are
occluded by the pressure of malignant nodules in the hilum of the liver.
As-cites develops if such nodules obstruct the portal veins or if tumor tissue
is seeded in the peritoneal cavity.
The
liver cancer diagnosis is based on clinical signs and symp-toms, the history
and physical examination, and the results of laboratory and x-ray studies.
Increased serum levels of bilirubin, alkaline phosphatase, AST, GGT, and lactic
dehydrogenase may occur. Leukocytosis (increased white blood cells),
erythrocytosis (increased red blood cells), hypercalcemia, hypoglycemia, and
hypocholesterolemia may also be seen on laboratory assessment.
The
serum level of alpha-fetoprotein (AFP), which serves as a tumor marker, is
elevated in 30% to 40% of patients with pri-mary liver cancer. Levels of
carcinoembryonic antigen (CEA), a marker of advanced cancer of the digestive
tract, may be elevated. These two markers together are useful to distinguish
between metastatic liver disease and primary liver cancer.
Many
patients have metastases from the primary liver tumor to other sites by the
time diagnosis is made; metastases occur pri-marily to the lung but may also
occur to regional lymph nodes, adrenals, bone, kidneys, heart, pancreas, and
stomach.
X-rays,
liver scans, CT scans, ultrasound studies, MRI, arterio-graphy, and laparoscopy
may be part of the diagnostic workup and may be performed to determine the
extent of the cancer. Pos-itive emission tomograms (PET scans) are used to
evaluate a wide range of metastatic tumors of the liver.
Confirmation
of a tumor’s histology can be made by biopsy under imaging guidance (CT scan or
ultrasound) or laparoscop-ically. Local or systemic dissemination of the tumor
by needle biopsy or fine-needle biopsy can occur but is rare. Some clini-cians
believe that these procedures should not be performed if the tumor is thought
to be resectable; rather, for primary HCC diagnosis should be confirmed by
frozen section at the time of laparotomy.
Although
surgical resection of the liver tumor is possible in some patients, the
underlying cirrhosis, so prevalent in cancer of the liver, increases the risks
associated with surgery. Radiation ther-apy and chemotherapy have been used in
treating cancer of the liver with varying degrees of success. Although these
therapies may prolong survival and improve quality of life by reducing pain and
discomfort, their major effect is palliative.
The
use of external beam radiation for the treatment of liver tumors has been
limited by the radiosensitivity of normal hepatocytes. Doses over 2,500 to
3,000 cGy may result in radiation hepati-tis (O’Grady et al., 2000). More
effective methods of delivering radiation to tumors of the liver include (1)
intravenous or intra-arterial injection of antibodies that are tagged with
radioactive isotopes and specifically attack tumor-associated antigens and (2)
percutaneous placement of a high-intensity source for in-terstitial radiation
therapy (delivering radiation directly to the tumor cells).
Chemotherapy
has been used to improve quality of life and pro-long survival; it also may be
used as adjuvant therapy after sur-gical resection of hepatic tumors. Systemic
chemotherapy and regional infusion chemotherapy are two methods used to
admin-ister antineoplastic agents to patients with primary and metasta-tic
hepatic tumors (O’Grady et al., 2000).
An
implantable pump has been used to deliver a high concen-tration of chemotherapy
to the liver through the hepatic artery. This method provides a reliable,
controlled, and continuous infusion of medication that can be carried out in
the patient’s home. Re-cent studies have begun to show some effective
palliation and modestly improved survival rates (Bacon & Di Bisceglie,
2000).
Percutaneous
biliary or transhepatic drainage is used to bypass biliary ducts obstructed by
liver, pancreatic, or bile duct tumors in patients with inoperable tumors or in
those considered poor surgical risks. Under fluoroscopy, a catheter is inserted
through the abdominal wall and past the obstruction into the duode-num. Such
procedures are used to reestablish biliary drainage, relieve pressure and pain
from the buildup of bile behind the obstruction, and decrease pruritus and
jaundice. As a result, the patient is made more comfortable and quality of life
and sur-vival are improved.
For
several days after its insertion, the catheter is opened to ex-ternal drainage.
The bile is observed closely for amount, color, and presence of blood and
debris. Complications of percutaneous biliary drainage include sepsis, leakage
of bile, hemorrhage, and reobstruction of the biliary system by debris in the
catheter or from encroaching tumor. Therefore, the patient is observed for
fever and chills, bile drainage around the catheter, changes in vital signs,
and evidence of biliary obstruction, including increased pain or pressure,
pruritus, and recurrence of jaundice.
Laser
hyperthermia has been used to treat hepatic metastases. Heat has been directed
to tumors through several methods to cause necrosis of the tumor cells while
sparing normal tissue. In radio-frequency thermal ablation, a needle electrode
is inserted into the liver tumor under imaging guidance. Radiofrequency energy
passes through to the noninsulated needle tip, causing heat and tumor cell
death from coagulation necrosis.
Immunotherapy
is another treatment modality under investi-gation. In this therapy,
lymphocytes with antitumor reactivity are administered to the patient with
hepatic cancer. Regression of the tumor, the desired outcome, has been
demonstrated in patients with metastatic cancer in whom standard treatment has
failed.
Transcatheter
arterial embolization interrupts the arterial blood flow to small tumors by
injecting small particulate embolic or chemotherapeutic agents into the artery
supplying the tumor. Ischemia and necrosis of the tumor occur as a result.
For
multiple small lesions, ultrasound-guided injection of al-cohol promotes
dehydration of tumor cells and tumor necrosis (Habib, 2000; O’Grady et al.,
2000).
Surgical
resection is the treatment of choice when HCC is con-fined to one lobe of the
liver and the function of the remaining liver is considered adequate for
postoperative recovery. In the case of metastasis, hepatic resection can be
performed when the pri-mary site can be completely excised and the metastasis
is limited. Metastases to the liver, however, are rarely limited or solitary.
Capitalizing on the regenerative capacity of the liver cells, some surgeons
have successfully removed 90% of the liver. However, the presence of cirrhosis
limits the ability of the liver to regener-ate. Staging of liver tumors aids in
predicting the likelihood of surgical cure. A staging system for liver tumors
is summarized in Chart 39-11.
In
preparation for surgery, the patient’s nutritional, fluid, and general physical
status is assessed and efforts are undertaken to ensure the best physical
condition possible. Support, explanation, and encouragement are provided to
help the patient prepare psy-chologically for the surgery.
Extensive
diagnostic studies may be performed. Specific stud-ies may include liver scan,
liver biopsy, cholangiography, selective hepatic angiography, percutaneous
needle biopsy, peritoneoscopy, laparoscopy, ultrasound, CT scans, MRI, and
blood tests, particu-larly determinations of serum alkaline phosphatase, AST,
and GGT and its isoenzymes.
Removal of a lobe of the liver is
the most commonsurgical procedure for excising a liver tumor. If it is
necessary to restrict blood flow from the hepatic artery and portal vein beyond
15 minutes, it is likely that hypothermia will be used. For a right-liver
lobectomy or an extended right lobectomy (including the me-dial left lobe), a
thoracoabdominal incision is used. An extensive abdominal incision is made for
a left lobectomy.
In cryosurgery (cryoablation), tumors are de-stroyed by
liquid nitrogen at −196° C. To destroy the diseased tis-sue, two or three freeze-and-thaw cycles
are administered via probes during open laparotomy. This technique has been
used alone or as an adjunct to hepatic resection in HCC and colorectal
metastases not amenable to radical surgical excision. The efficacy of
cryosurgery is still being evaluated; indications and outcomes require further
investigation.
Removing the
liver and replacing it witha healthy donor organ is another way to treat liver
cancer. Recur-rence of the primary liver malignancy after transplantation,
how-ever, has been reported to occur in 70% to 85% of cases, and the survival
time after recurrence is brief. Metastasis and recurrence may be enhanced by
the immunosuppressive therapy needed to prevent rejection. The patient with
small tumors may have a good prognosis after transplantation, but recurrence is
common with tumors greater than 8 cm in diameter or those that are multi-focal
or have vascular invasion (Bacon & Di Bisceglie, 2000). See the discussion
of liver transplantation that follows.
If the
patient has had surgery to treat liver cancer, potential problems related to
cardiopulmonary involvement include vascu-lar complications and respiratory and
liver dysfunction. Metabolic abnormalities require careful attention. A
constant infusion of 10% glucose may be required in the first 48 hours to
prevent a precipitous fall in the blood glucose level resulting from decreased
gluconeogenesis. Because extensive blood loss may occur as well, the patient
will receive infusions of blood and IV fluids. The patient requires constant,
close monitoring and care for the first 2 or 3 days, similar to postsurgical
abdominal and thoracic nursing care.
The
patient undergoing cryosurgery is monitored closely for hypothermia,
hemorrhage, or bile leak; myoglobinuria can occur as a result of tissue
necrosis and is minimized by hydration, di-uresis, and at times medications
(allopurinol) to bind to and aid in the excretion of toxic products.
If the
patient will receive chemotherapy or radiation therapy in an effort to relieve
symptoms, he or she may be discharged home while still receiving one or both of
these therapies. The patient may also go home with a biliary drainage system in
place. The need for teaching is great because of the need for the patient to
participate in care and the family’s role in care at home.
The nurse
instructs the patient torecognize and report the complications and side effects
of the chemotherapy that may occur and the actions and desired and undesirable
effects of the specific chemotherapy regimen. The nurse also emphasizes the
importance of follow-up visits to assess the patient and the tumor’s response
to chemotherapy and radi-ation therapy.
If the
patient is receiving chemotherapy on an outpatient basis, the nurse explains
the patient’s and family’s role in managing the chemotherapy infusion and in
assessing the infusion/insertion site. The nurse encourages the patient to
resume routine activi-ties as soon as possible, while cautioning him or her to
avoid ac-tivities that may damage the infusion pump or site.
The
family and the patient at home with a biliary drainage system in place
typically fear that the catheter will be dislodged. They need reassurance and
instruction to reduce their fear that the catheter will fall out easily. The
patient and family also re-quire instruction on catheter care. They need to
learn how to keep the catheter site clean and dry and how to assess the
catheter and its insertion site. Irrigation of the catheter with sterile normal
saline solution or water may be prescribed to keep the catheter patent and free
of debris. The patient and caregivers are taught proper technique to avoid
introducing bacteria into the biliary system or catheter during irrigation.
They are instructed not to aspirate or draw back on the syringe during irrigation
to prevent entry of irritating duodenal con-tents into the biliary tree or
catheter. The patient and caregivers are also instructed about the signs of
complications and are en-couraged to notify the nurse or physician if problems
or ques-tions arise.
In many
cases, referral for home care enablesthe patient with liver cancer to be at
home in a familiar environ-ment with family and friends. Because of the poor
prognosis as-sociated with liver cancer, the home care nurse serves a vital
role in assisting the patient and family to cope with the symptoms that may
occur and the prognosis. The home care nurse assesses the patient’s physical and
psychological status, the adequacy of pain relief, nutritional status, and the
presence of symptoms indicat-ing complications of treatment or progression of
disease. During home visits, the nurse assesses the function of the
chemotherapy pump, the infusion site, and the biliary drainage system, if
indi-cated. The nurse collaborates with the other members of the health care
team, the patient, and the family to ensure effective pain man-agement and to
manage other problems that may occur: weak-ness, pruritus, inadequate dietary
intake, jaundice, and symptoms associated with metastasis to other sites. The
home care nurse also assists the patient and family in making decisions about
hospice care and assists with initiation of referrals. The patient is
encour-aged to discuss preferences for end-of-life care with family mem-bers
and health care providers.
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