Fungal Infections May Cause Cancer or Speed up Cancer Progression

Cancer patients, especially those on immunosuppressive chemotherapy drugs, are at significantly elevated risk for many life-threatening invasive fungal infections, especially Candida and Aspergillus (Richardson 2008). Among leukemia patients, about 10-20% develop life threating Candida infections and at about 5% will develop life threatening Aspergillus infections (Richardson 2008

M Richardson and C Lass-Florl Changing epidemiology of systemic fungal infections. Clinical Infection and Micronbiology 2008;14 (Suppl 4), 5-24. AND
Marina Mohd Bakri et al. Revisiting the association between candida infection and carcinoma, particularly oral squamous cell carcinoma. Journal of Oral Microbiology 2010;2:5780.
AND
Andoni Ramirez-Garcia et al. Candida albicans & cancer: Can this yeast induced cancer development or progression. Critical Reviews in Microbiology 2014; In Press
AND
Nooshin Sohrabi et al. Invasive aspergillosis promotes tumor growth and severity in a tumor-bearing mouse model. Canadian Journal of Microbiology 2010;56:771-6.

While much evidence suggests that cancer and chemotherapy can predispose patients to severe fungal infections, there is also emerging evidence that the presence of fungal infections may promote development and progression of cancer.

Candida species are yeasts (fungi) which commonly grow in the digestive, urinary, genital, and skin areas of humans. A number of studies have linked Candida overgrowth in the mouth to subsequent development of significantly elevated risk of oral squamous cell carcinoma (Bakri 2010). Cell culture and lab animal studies have reported that Candida albicans can produce sufficient quantities of acetaldehyde and N-nitrosobenzylmethylamine (NBMA) to be mutagenic and carcinogenic (Bakri 2010; Gainza 2013).

Other recent research has suggested that C. albicans can increase risk of carcinogenesis by many mechanisms, including production of carcinogenic byproducts, triggering inflammation, increasing adhesion of metastatic tumor cells, induction of the Th17 response, and molecular mimicry (Ramirez 2014).

Infection or colonization of other fungi such as Aspergillus may also promote cancer growth. A mouse study reported that experimental infection with Aspergillus approximately doubled the rate of growth of mammary tumors (Sohrabi 2010). Much more research is needed to examine relationships between fungal infections and cancer.