This section has been reviewed and approved by the PLWC Editorial
An infection occurs when harmful bacteria, viruses, or fungi (such as
yeast) invade the body and the immune system is not able to destroy them
quickly enough. People with cancer are more likely to develop infections
because both cancer and cancer treatments can weaken your immune system.
The immune system
The immune system fights harmful organisms (bacteria, viruses, and fungi)
that try to invade the body. The immune system includes the skin, the
spleen, the lymph nodes, and the bone marrow (a spongy, fatty tissue
found inside larger bones). It also includes leukocytes, the
infection-fighting white blood cells (WBCs)
that are made inside the bone marrow. If not enough WBCs
are present, a condition called leukopenia
results, and the body is less able to fight an infection. Neutrophils are WBCs that
destroy harmful bacteria. A low level of neutrophils,
called neutropenia, can increase the risk
of dangerous bacterial infections.
Cancer and cancer treatment can interfere with the functioning of the immune
system in several ways:
- Because the immune
system is busy fighting the cancer, it is less able to protect
against other infections at the same time.
- Lack of sleep, stress,
poor diet, and other side effects of cancer and cancer treatment weaken
the immune system.
- Some chemotherapy drugs
can cause the bone marrow and other parts of the immune system to
malfunction, lowering the production of WBCs.
- Radiation therapy can
also affect the bone marrow, especially if given to extensive areas
of the body or to bones in the pelvis, legs, chest, or abdomen.
- Cancers that affect the
bone marrow directly (including leukemia or lymphoma) or cancers
that metastasize (spread) to the bone (such breast or lung cancers)
can crowd normal bone marrow cells, lowering WBC production.
Signs and symptoms
People with cancer and neutropenia or a low WBC
count are at risk for having a minor infection become serious. Infections
can start almost anywhere, but common places for infections include the
mouth, skin, lungs, urinary tract, rectum, and reproductive organs (such
as the vagina). Talk to your doctor right away if you experience any of
the following signs of infection:
- A fever (temperature of
100.5°F or higher)
- Chills or sweating
- A sore throat or sores
in the mouth
- Abdominal pain
- Pain or burning when
urinating or frequent urination
- Diarrhea or sores around
- A cough or
- Any redness, swelling,
or pain, particularly around a cut or wound
- Unusual vaginal
discharge or itching
If neutropenia is present or the overall WBC
count is low, the doctor may decide to treat the infection with
medications, such as filgrastim (Neupogen), pegfilgrastim (Neulasta), or sargramostim
(Leukine or Prokine)
to encourage the body to make more neutrophils
or other types of WBCs to reduce the risk of an
If an infection does occur, patients may be treated with antibiotics or
antifungal medications. If neutropenia and a
fever develop (called neutropenic fever),
patients may need to be hospitalized in order to receive intravenous (IV)
antibiotics. Patients at high risk for developing an infection, because
of neutropenia or because of chemotherapy or
radiation therapy, may be treated with prophylactic (preventive)
antibiotics or antifungal medications.
Tips for preventing infections
In addition to receiving treatment from your doctor, the following
suggestions can help prevent infections. Avoiding infections when the neutrophil count is low is especially important.
- Get plenty of rest and
eat a well-balanced diet.
- Try to avoid crowded
places and contact with people who are ill.
- Do not share food, drink
cups, utensils, or other personal items like toothbrushes.
- Wash your hands
frequently, especially after using the bathroom or before eating.
- Shower or bathe daily
and use lotion to prevent your skin from becoming dry and cracked.
- Be careful using sharp
objects, such as scissors or knives, and use an electric shaver to
- Do not eat raw foods,
including meats, shellfish, and eggs, and avoid or carefully wash
raw fruits and vegetables.
- Do not change cat litter
or handle animal waste.
- Use gloves for gardening
and housework, especially while cleaning.
- Clean your teeth and
gums with a soft toothbrush and, if your doctor or dentist. prescribes one, use a mouthwash to prevent