What are the causes of anemia in patients with cancer?
Anemia in cancer patients is often multifactorial. Anemia may result from blood loss due to bleeding from tumors or from gastritis due to the use of nonsteroidal anti-inflammatory agents (NSAIDs). It may also be caused by hemolysis (secondary to antibodies associated with the tumor), disseminated intravascular coagulation (DIC), sepsis, or a paraneoplastic syndrome. Anemia is frequently caused by bone marrow suppression by chemotherapy or by marrow involvement by the tumor.
Define anemia of chronic disease.
Anemia of chronic disease is common in cancer patients. The diagnosis is made when no other cause of anemia can be found and plasma iron is < 60 mg/dl, total iron-binding capacity is 100-250 mg/dl, and ferritin is > 60 ng/ml. The hematocrit is generally 25-30%. An inadequate erythropoietin response to anemia and a blunted response to treatment with recombinant human erythropoietin have been demonstrated in some patients.
What are the predisposing factors for infection in patients with cancer?
Predisposing factors for infection include defects in cellular and humoral immunity, organ compromise due to tumor-related obstruction, chemotherapy-related granulocytopenia, disruption of mucosal (e.g., respiratory and alimentary tract) and integumental surfaces, iatrogenic procedures or placement of prosthetic devices, central nervous system dysfunction, and hyposplenic or postsplenectomy states.
Discuss the sources of infection in patients with cancer.
The vast majority of infections originate from the patients’ own endogenous flora. Sources of infection in neutropenic patients include the lungs, urinary tract, skin, upper aerodigestive tract (mouth, skin, teeth), central nervous system, rectum, perirectum, biopsy sites, and GI tract (appendicitis, cholecystitis, perforations). In investigating the cause of an infection, cultures should include blood, urine, sputum, and, if appropriate to the patient’s clinical status, stool, pleural fluid, or peritoneal fluid.
Which tumors spread to bone most commonly?
Cancers of the lung, breast, kidney, prostate, and thyroid as well as multiple myeloma and malignant melanoma spread to bone most commonly.
Are metastatic bone lesions osteoblastic or osteolytic?
Renal cell carcinoma and multiple myeloma tend to be purely lytic, prostate carcinoma tends to be mainly blastic, and the others are mixed. Tumors that are lytic are most often associated with hypercalcemia, whereas blastic metastases are not generally associated with this complication.
Characterize the pain associated with bone metastases.
The pain of bone metastases is characterized by a dull, aching discomfort that is worse at night and may improve with physical activity.
Which tumors metastasize to the lungs?
Most types of tumors can metastasize to the lungs. Therefore, the more common the tumor, the more commonly it is found to have spread to the lung (e.g., breast cancers). Although they also can spread to the lungs, GI cancers tend to first metastasize locally and to the liver before pulmonary involvement is seen. Tumors that spread via the bloodstream, such as sarcomas, renal cell carcinoma, and colon cancer, tend to produce nodular lung lesions. Those that spread via lymphatic routes, such as cancers of the breast, pancreas, stomach, and liver, often manifest a pattern of lymphangitic spread.
Discuss the symptoms of intracranial metastases.
Headache occurs in up to 50% of patients with intracranial metastases. It is classically described as occurring early in the morning, disappearing or decreasing after arising, and may be associated with nausea and/or projectile vomiting. Other symptoms include focal signs such as unilateral weakness, numbness, seizures, or cranial nerve abnormalities. Nonfocal complaints such as mental status changes or ataxia may occur.
How are intracranial metastases diagnosed and treated?
The diagnosis is made by contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) of the brain. Treatment consists of decreasing intracranial pressure with steroids, followed by radiotherapy. Surgery is recommended for patients with single intracranial lesions.
What are the signs and symptoms of malignant pericardial effusion?
The presentation of malignant pericardial effusion can resemble heart failure, with dyspnea, peripheral edema, and an enlarged heart on chest x-ray. However, the dyspnea is often out of proportion to the degree of pulmonary congestion seen on the x-ray. Kussmaul’s sign, or jugulovenous distention with inspiration, and pulsus paradoxus of > 10 mmHg with distant heart sounds are clues to the presence of a pericardial effusion.
How is the diagnosis of malignant pericardial effusion confirmed?
Confirmation of the clinical diagnosis is made by echocardiogram or CT scan. Malignant effusions are usually exudates and are often hemorrhagic. Cytology is helpful if positive but does not exclude cancer if negative.
Discuss the treatment of malignant pericardial effusion.
Treatment depends on the patient’s condition but should include drainage of the fluid for diagnostic as well as therapeutic reasons. A nonsurgical approach is preferred, with catheter drainage followed by sclerosis of the pericardium, sometimes with a sclerosing agent such as doxycycline. Other approaches include subxiphoid pericardiectomy, balloon pericardiectomy, pericardial window, and pericardial stripping for patients with prolonged life expectancy.
What are the presenting symptoms and signs of spinal cord compression?
Ninety-five percent of cancer patients with spinal cord compression present with back pain. Other symptoms include lower extremity weakness, bowel or bladder incontinence, or increased deep tendon reflexes in the lower extremities.
How is spinal cord compression diagnosed?
The diagnosis is made by MRI or by myelography with CT, which will demonstrate blockage of the spinal canal.
How is spinal cord compression treated?
Treatment is directed first at relieving spinal cord swelling and pain, using high-dose steroids and adequate pain medication. However, definitive treatment must be carried out emergently to prevent further neurologic deterioration, which may be irreversible. Radiotherapy and/or surgery should be initiated immediately. Preservation of neurologic function is generally better with surgery.
Which tumors most commonly cause spinal cord compression?
The most common tumors causing cord compression are lung cancer, breast cancer, prostate cancer, carcinoma of unknown primary, lymphoma, and multiple myeloma. The most common site of cord compression is the thoracic spine, followed by the lumbosacral spine and the cervical spine.
Which tumors are associated with nonbacterial thrombotic endocarditis?
Also known as marantic endocarditis, this paraneoplastic syndrome is associated with mucinous adenocarcinomas, most commonly of the lung, stomach, or ovary, but has been described in other types of cancers as well.
How does nonbacterial thrombotic endocarditis present?
It is manifested by the appearance of embolic peripheral or cerebral vascular events causing arterial insufficiency, encephalopathy, or focal neurologic defects. Heart murmurs are often not present.
How is nonbacterial thrombotic endocarditis diagnosed and treated?
Echocardiograms may be negative, and the diagnosis is usually made post mortem. Treatment with anticoagulants or antiplatelet drugs has been tried with little success.
What are the tumor-related causes of hypercalcemia?
- Lytic bone metastases, which release calcium into the bloodstream. This is the most common cause in solid tumors with bony metastases.
- Humoral hypercalcemia of malignancy (HHM) occurs in patients without bony metastases. Cancers associated with this syndrome secrete a non-PTH substance with activity similar to parathyroid hormone. HHM is associated most commonly with squamous cell cancers of the lung, esophagus, or head and neck but can also be found in renal cell carcinoma, transitional cell carcinoma of the bladder, and ovarian carcinoma.
- Formerly known as osteoclast-activating factor, osteolytic substances such as interleukin 1 (IL-1), IL-6, and TNF-alpha (lymphotoxin) may cause hypercalcemia in plasma cell dyscrasias.
- Vitamin D metabolites produced by some lymphomas may promote intestinal calcium absorption.
What is tumor lysis syndrome?
When rapidly growing tumors are effectively treated with chemotherapy, breakdown products of tumor lysis are released into the bloodstream in large amounts. This process may cause hyperkalemia, hyperuricemia, hyperphosphatemia, and hypocalcemia. Renal failure can result from the hyperuricemia. This complication is seen within hours to days after treatment of tumors such as acute leukemia, Burkitt’s lymphoma, and other rapidly proliferating lymphomas. It is rarely, if ever, seen with solid tumors, but has been described in small cell carcinoma of the lung.
How is tumor lysis syndrome treated?
Treatment is the same as for renal failure, with vigorous hydration, dialysis if necessary, and appropriate treatment of electrolyte disorders. Prophylactic treatment with aggressive hydration and allopurinol prior to administering chemotherapy in susceptible patients can prevent this serious complication.
Which medications are commonly used for cancer pain?
As elucidated in the World Health Organization guidelines, pain medications are to be administered in a three-step ladder according to the intensity and pathophysiology of symptoms and individual requirements. For mild pain, the recommended baseline drugs are NSAIDs. Patients with moderate-to-severe pain generally require an opioid agent such as codeine or oxycodone; severe pain requires a stronger opioid such as morphine.
- National Cancer Database: http://www.facs.org/cancer/ncdb/index.html
- National Guideline Clearinghouse: http://www.guideline.gov/
- PDQ Cancer Information Summaries: http://www.cancer.gov/
- SEER Cancer Statistics Review, 1975-2000: http://seer.cancer.gov/csr/1975_2000/
- American Joint Committee on Cancer: Cancer Staging Manual, 6th ed. New York, Springer-Verlag, 2002.
- Calabresi P, Schein PS (eds): Basic Principles and Clinical Management of Cancer, 2nd ed. New York, Macmillan, 1993.
- Casciato DA, Lowitz BB (eds): Manual of Clinical Oncology, 5th ed. Boston, Little, Brown, 2000.
- DeVita T Jr, Hellman S, Rosenberg SA (eds): Cancer: Principles and Practice of Oncology, 6th ed. Philadelphia, Lippincott Williams & Wilkins, 2001.
- Haskell CM: Cancer Treatment, 4th ed. Philadelphia, W.B. Saunders, 1995.
- Holland JF, Frei E, et al (eds): Cancer Medicine, 6th ed. New York, BC Decker, 2003.
- Tannock IF, Hill RP (eds): The Basic Science of Oncology, 3rd ed. New York, McGraw-Hill, 1998.