Occurrence of oral Candida colonization and its risk factors among patients with malignancies in China

Oral colonization of Candida could lead to later development of oropharyngeal candidiasis or candidemia among the immunocompromised patients. This study aims to describe the occurrence and risk factors of oral Candida colonization in patients with malignancies. From October 2012 to March 2013, 78 patients with pulmonary cancer (group I), 101 patients with gastrointestinal tract tumor (group II), 79 patients with hematopoietic system malignant tumor (group III), and 101 healthy controls were consecutively recruited in a hospital in Beijing, China. The oral rinse samples were taken and Candida species were identified; the enzymes activities were tested. In total, 110 and 27 Candida strains were isolated from 91 patients and 26 controls, respectively. The oral colonization rate with Candida albicans in group III (12.7 %) was significant lower than that in group I (30.8 %), group II (33.7 %), and control group (25.7 %). The oral colonization rates with non-albicans Candida species in group I, group II, and group III were 15.4, 10.9, and 12.7 %, respectively, while only one non-albicans Candida strain was identified in control group. The non-albicans Candida species exhibited a lower virulence than C. albicans. Age was an independent risk factor for Candida colonization in patients with pulmonary cancer and digestive tract malignant tumor, "Teeth brush < 1 time/day" was an independent risk factor for Candida colonization in patients with hematopoietic system tumor. The differences of risk factors for oral Candida colonization in patients with different cancers require different strategies for the prevention and control of Candida infection. Old aged patients with pulmonary cancer and digestive tract malignant tumor are high-risk population for Candida colonization. Increasing frequency of teeth brush might be helpful for preventing Candida colonization.