Yeast Infection and the Cancer Connection

Candida Albicans, a yeast-like fungus.

What is Candida?

Candida is a group of yeast-like fungi. When growing at body temperature, Candida grow like yeasts, whereas in the soil and at colder temperatures, they appear as molds. There are at least 200 species of Candida, but six are most commonly associated with human infection, and of these, Candida albicans accounts for a good number of yeast infections.

Candida yeasts normally live on the skin and mucous membranes, where they may be found as harmless organisms.

However, when a person’s natural defense mechanisms are compromised, problems can arise, leading to overgrowth of these organisms and infection, emergence of symptoms and the potential for serious disease.

When Candida yeasts cause an infection, the infection is called candidiasis.

Candidiasis – Types, Definitions and Symptoms

The location of the Candida infection is important in the terminology, but also as relates to the types of symptoms that may arise. Infections may be superficial or more widespread.

“Yeast infection.” Though Candida species grow as yeasts elsewhere in the body, Candidiasis of the vagina is commonly referred to simply as a yeast infection. Superficial infections at other mucous membranes or involving the skin may also occur. Itchiness, redness and burning are common symptoms.

Thrush. Candidiasis that develops in the mouth or throat is called thrush, or oropharyngeal candidiasis.

Thrush may appear as a creamy whitish curd-like plaque or layer on the lining of the mouth and throat. Some people report soreness and pain with thrush, and others do not.

Invasive candidiasis. When Candida species invade the bloodstream to spread throughout the body, this is known as invasive candidiasis.

Invasive candidiasis is an important cause of illness in cancer patients. The most common symptoms of invasive candidiasis are fever and chills that don’t respond to antibiotics. Other symptoms may develop if the infection spreads to other parts of the body.

Candidiasis and the Cancer Connection

Candida species are the most common cause of fungal infections in people with cancer. Infections in cancer patients range from mild -- although quite uncomfortable -- superficial infections to invasive ones that are more severe.

Thrush is the most prevalent opportunistic infection in severely ill people, in general, and it is considered a marker of weakening of the immune system in cancer patients. Thrush may also occur in patients not receiving preventive antifungal medication after damage to the lining of the mouth and throat occurs from life-saving chemotherapy or radiation. People with so-called hematologic malignancies, like leukemia and lymphoma, have a higher risk of oral candidiasis than people with solid tumors -- like breast cancer and lung cancer -- and this is because hematologic malignancies often involve processes that normally protect a person from such infections.

People with head and neck cancers receiving radiation and/or chemotherapy develop oral candidasis very often also.

In addition to oral candidiasis, candida can also infect the mucous membranes or lining of structures such as the esophagus, or in the urinary tract -- especially when there is a urinary catheter in place, or a tube to drain the urine.

Invasive fungal infections are important causes of illness in people with cancer, who may have low levels of neutrophils -- a type of white blood cell. Susceptibility to Candida and other serious infections may result from the cancer itself and/or therapies used to treat the cancer, including cytotoxic chemotherapy such as CHOP. A person is said to be neutropenic if the blood neutrophil count is below 1500 cells/mm3, and the severity of the neutropenia can be classified into grades.

Invasive Candidiasis - Risk Factors

Cancer patients may have multiple risk factors for invasive candidiasis. According to the CDC, the following factors are associated with a high risk for developing invasive candidiasis:

  • Central venous catheter
  • Being in the intensive care unit, or ICU
  • Having a weakened immune system -- for example, from bone marrow transplant or cancer chemotherapy
  • Broad-spectrum antibiotic use
  • A very low count of neutrophils
  • Kidney failure or receiving hemodialysis
  • Having surgery, especially gastrointestinal surgery
  • Diabetes


When a person is at high risk for candidiasis, antifungal medicine may be given in advance of a therapy that is known to weaken the immune system. This preventive measure is referred to as prophylaxis.


For milder infections, antifungal rinses, vaginal tablets, suppositories and creams may be used. For severe candidiasis, intravenous antifungal medication can be given to treat the infection.

Sources and Background on Fungal Infections in Cancer Patients:

Centers for Disease Control and Prevention. Candidiasis.

Pfaller MA, Diekema DJ. Epidemiology of invasive candidiasis: a persistent public health problem. Clin Microbiol Rev. 2007 Jan;20(1):133-63.

Bow, EJ. Neutropenic fever syndromes in patients undergoing cytotoxic therapy for acute leukemia and myelodysplastic syndromes. Semin Hematol 46:259–268.

Sankari SL, Gayathri K, Balachander N, Malathi L. Candida in potentially malignant oral disorders. Journal of Pharmacy & Bioallied Sciences. 2015;7(Suppl 1):S162-S164.

Kalantar E, Marashi SM, Pormazaheri H, et al. First experience of Candida non-albicans isolates with high antibiotic resistance pattern caused oropharyngeal candidiasis among cancer patients. J Can Res Ther. 2015;11:388-90

Pappas PG, Rex JH, Sobel JD, Filler SG, Dismukes WE, Walsh TJ, et al. Guidelines for treatment of candidiasis. Clin Infect Dis 2004;38:161-89

Yildirim M, Sahin I, Kucukbayrak A, Ozdemir D, Tevfik Yavuz M, Oksuz S, et al. Hand carriage of Candida species and risk factors in hospital personnel. Mycoses. 2007 May;50(3):189-92.

Ribaud P. Fungal infections and the cancer patient. European Journal of Cancer 1997;33, Supplement 4:S50-S4.

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