Abstract
Introduction/Background
Enterococcus is the second leading cause of nosocomial infections in the United States behind Staphylococcus aureus. Lung cancer is the most commonly diagnosed type of cancer worldwide, and in the United States, it is responsible for the most cancer related deaths. Studies comparing lung microbiota and fecal flora in lung and colorectal cancer patients showed they exhibited higher levels of Enterococcus faecalis than control groups. One possible mechanism to explain this involves increased production of extracellular superoxides and reactive oxygen species by Enterococcus leading to DNA damage, increasing the risk of mutations and malignancy. The purpose of this study was to evaluate the correlation between Enterococcus infections and the incidence of bronchopulmonary cancer.
Methods
The data was provided by a Health Insurance Portability and Accountability Act (HIPAA) compliant national database to evaluate the patients infected versus patients not infected with Enterococcus using ICD-10 and ICD-9 codes. The Holy Cross Health in Fort Lauderdale, Florida granted access to the database for the purpose of academic research. Standard statistical methods were used.
Outcomes
Between January 2010 and December 2019, 28,669 patients matched in both the infected and control group. The two groups were matched by Age Range and CCI score (Charlson Comorbidity Index). The incidence of bronchopulmonary cancer was 6.94% (1,992 patients) in the Enterococcus group compared to 3.03% (871 patients) in the control group. The difference was statistically significant (p value=2.2x 10^-16) with an odds ratio 0.4099171 and a range of 0.3821333-0.4397211 with a 95% confidence interval. The study shows a statistically significant correlation between Enterococcus and a reduced incidence of bronchopulmonary cancer.
Discussion
The data in this study suggests that patients with present or history of Enterococcus infections exhibit a reduced incidence of lung cancer. Existing data in the literature indicates that patients with lung cancer have higher levels of Enterococcus in their lung microbiota compared to a control group. Further studies regarding the possible mechanism behind Enterococcus and cancer are needed to establish a stronger correlation between the two. Additionally, it was interesting to see this study reveal that on average, patients in the control group had both higher amount paid and longer stays in the hospital.
