Infection and sepsis (cancer)

Related conditions: Any type of infection is a risk for a cancer patient. Pneumonia is especially common in certain types of blood cancer.

Definition: An infection is the growth of a parasitic organism in the body, and sepsis is a widespread infection resulting from the presence of infectious organisms in the bloodstream. Sepsis overwhelms many parts of the body at once. Cancer patients are at risk for sepsis and various more limited infections as a result of their disease and the treatments they receive. Bacteria cause most infections in cancer patients, but serious fungal and viral infections are also common. Infection and sepsis are common causes of death in cancer patients.

Risk factors: All cancer patients are at risk for infection and sepsis. Their risk may be higher or lower depending on the type of cancer they have and their body’s reaction to treatment. Patients at highest risk are those receiving bone marrow or stem cell transplants and patients with acute leukemias. Cancer patients with certain preexisting conditions are also at higher risk for infection.

Etiology and the disease process: Cancer can make the body more vulnerable to infection in several ways. The destruction of tissues resulting from invading tumors may allow infectious organisms access to places they do not normally enter. An example would be Staphylococcus aureus, a type of bacteria that normally lives on the skin. A break in the skin as the result of a malignancy (such as squamous cell carcinoma) may allow S. aureus to invade the inside of the body, causing a dangerous infection.

Tumors may block ducts or other structures in the body. The blockage may trap infectious organisms that the body might have otherwise cleared out. An example is a tumor that blocks a bile duct. Trapped bacteria in the duct can multiply and reach the bloodstream, the liver, or the abdominal cavity, causing infection.

Immunity depends on the normal production and growth of white blood cells. The bone marrow produces these cells, and they mature and take on specialized immune functions in the bloodstream. Cancers that affect the blood or bone marrow the leukemias, lymphomas, and multiple myeloma severely cripple the immune system. Individuals with these types of cancer are at very high risk of death from infection or sepsis.

Cancer treatments also increase the risk of infection and sepsis. Chemotherapy drugs, especially at high doses, cause a condition known as neutropenia, an abnormally low level of neutrophils. Neutrophils are the most common white blood cells, constituents of the immune system. A low neutrophil count (level) means low immunity.

Catheters implanted in cancer patients for the ease of medication delivery and blood draws are a potential gateway through which infectious organisms can enter the body.

Chemotherapy drugs often cause ulceration of the mucous membranes in the mouth and the digestive tract. These ulcerations are a gateway for infectious organisms that may invade areas not normally accessible to them.

Treatment of certain cancers, such as lymphoma, sometimes requires the removal of the patient’s spleen. The spleen is an extremely important part of the body’s immune system. Patients who have had their spleens removed are vulnerable to severe infections for up to twenty-five years following the surgery.

Common sites of infection in cancer patients include the lungs, the skin, and the digestive tract, beginning with the mouth.

Incidence: Incidence depends on the type of cancer or other condition.

Symptoms: Symptoms of sepsis include fever, chills, skin rash, rapid breathing, rapid heart beat, decreased urination, and confusion, hallucination, or agitation. Many early symptoms of sepsis are similar to symptoms of more limited infections. Additional symptoms of nonseptic infection vary by the location of infection and may include any of the following: red streaks on the skin; diarrhea; abdominal pain; nausea or vomiting; ulcerations (open sores) on the skin or in the mouth; difficulty swallowing; sore throat; discharge from the wounds, nose, or any opening in the body (such as the vagina or penis); swelling and tenderness; headache; stiff neck; cough; and difficulty breathing.

Screening and diagnosis: At times, it may be very hard to determine whether symptoms are the result of an infection or a side effect of cancer treatment. Tests that look for the type and cause of infection vary by the location of the suspected infection. Such tests may include biopsy (obtaining a sample of infected tissue and testing it in the laboratory); X rays; blood counts, especially a neutrophil count; liver function tests; and cultures (attempts to grow an infectious organism) grown from samples from stool, sputum, blood, and any oozing from a sore.

Treatment and therapy: Because the vast majority of cancer patients develop bacterial infections, when symptoms of infection develop, doctors immediately start treatment with a broad-spectrum antibiotic. This type of antibiotic is effective against many different bacteria. There are many broad-spectrum antibiotics available. There is no standard initial antibiotic treatment that shows more benefits than others do. If needed, treatment can be modified when tests determine which bacteria cause the patient’s infection.

If antibiotic treatment fails to make the patient better, antifungal medicine is added to the treatment. The most-often used antifungal medicines are amphotericin B and voriconazole.

In cases where the infection centers around the catheter, it may be necessary to remove the catheter to eliminate the infection.

Viral infections, especially with the human herpesvirus family, are also a major problem in cancer patients. The most common treatment is acyclovir, though newer antiviral medications are available. Patients with a history of herpes simplex infection may get acyclovir as a prophylaxis (preventative).

Viral respiratory infections, especially the flu and respiratory syncytial virus (RSV), also present major risks for people with cancer. Treatments for these infections include oseltamivir and zanamivir against influenza, and ribavirin for RSV and hepatitis viruses.

The American Society of Clinical Oncology now recommends the use of granulocyte colony-stimulating factor (G-CSF, filgrastim) for high-risk patients beginning chemotherapy. G-CSF accelerates the production of white blood cells. Studies that looked at a total of more than three thousand patients showed those receiving G-CSF before complications occurred were almost 50 percent less likely to develop neutropenia and infections.

Prognosis, prevention, and outcomes: The outcome of infections in cancer patients varies. It depends on the type of infection, the patient’s overall condition, and the state of the patient’s immune system.

Doctors sometimes give severely immune-compromised patients a prophylactic broad-spectrum antibiotic. Such patients may also get prophylactic antifungal medicine. This method is not recommended for all patients, because resistant bacteria or fungi can develop and cause worse infections. Doctors use prophylactic antibiotic and antifungal treatment in patients after bone marrow transplants or in those whom the doctors expect to stay immune compromised for lengthy periods.

Cancer patients should receive certain vaccinations:

• Annual influenza (“flu”) vaccine
• Pneumonia vaccine (known as a pneumococcal vaccine or 23-valent pneumococcal vaccine)
• Bacterial meningitis vaccine (known as a meningococcal vaccine or 4-valent meningococcal vaccine)

Doctors may recommend other vaccines depending on the patient’s particular disease, treatment, and overall health. People with cancer should never receive vaccination without consulting with their oncologist (cancer specialist).

It is important to remember that while a person is immune compromised, even a mild cold can become life-threatening. Children who receive vaccination with a live virus (for example, chicken pox or live polio vaccines) may pass the live virus to others. These viruses can cause a serious illness in the immune-compromised patient. People receiving treatments for cancer should avoid contact with those who have recently had a live-virus vaccine.

Patients can prevent some infections through the use of certain precautions. These precautions include the following:

• Frequent hand washing (on the part of patient, visitors, and other household members)
• Avoiding undercooked or raw foods
• Letting someone else clean up after pets, especially cat litter boxes and birdcages
• Practicing good oral hygiene
• Thoroughly cleaning any breaks in the skin
• Keeping surgical and catheter sites clean
• Avoiding people with contagious diseases
• Avoiding sexual practices that can result in skin breaks
• Avoiding contact with those who have recently had a live-virus vaccine

Bibliography

Kelvin, Joanne F., and Leslie Tyson. One Hundred Questions and Answers About Cancer Symptoms and Cancer Treatment Side Effects. Sudbury, Mass.: Jones and Bartlett, 2005.

Ko, A., E. H. Rosenbaum, and M. Dollinger. Everyone’s Guide to Cancer Therapy: How Cancer Is Diagnosed, Treated, and Managed Day to Day. 5th ed. Kansas City, Mo.: Andrews McMeel, 2007.

Thiboldeaux, Kim, and Mitch Golant. The Total Cancer Wellness Guide: Reclaiming Your Life After Diagnosis. Dallas: BenBella Books, 2007.