From the Guidelines
Streptococcus mitis bacteremia is not typically caused by colon cancer directly. While colon cancer can potentially lead to bacteremia through mechanisms like tumor invasion into blood vessels or compromised intestinal barriers, S. mitis is not commonly associated with colon cancer-related bloodstream infections. The provided evidence 1 focuses on the management of colon cancer emergencies, such as obstruction and perforation, and the use of antibiotic prophylaxis to prevent surgical site infections. However, it does not specifically address the relationship between colon cancer and S. mitis bacteremia.
S. mitis is a viridans group streptococcus that normally resides in the oral cavity and upper respiratory tract. Bacteremia with this organism is more commonly associated with dental procedures, poor oral hygiene, endocarditis, or immunosuppression. In cancer patients, S. mitis bacteremia is more frequently seen in those with hematologic malignancies or neutropenia, particularly following chemotherapy, rather than solid tumors like colon cancer.
Some key points to consider in the management of colon cancer emergencies include:
- The use of antibiotic prophylaxis to prevent surgical site infections, as recommended by the 2017 WSES guidelines 1
- The importance of considering bacterial translocation in patients with intestinal obstruction, even without systemic signs of infection 1
- The need for early and appropriate empirical antimicrobial therapy in critically ill patients with sepsis 1
If S. mitis bacteremia is detected in a patient with colon cancer, clinicians should consider other sources such as dental infections, endocarditis, or central line infections, rather than assuming the colon cancer is the source. Treatment typically involves appropriate antibiotics such as penicillin, ampicillin, or ceftriaxone, with duration based on the source and severity of infection.
From the Research
Causes of Strep Mitis Bacteremia
- Strep mitis bacteremia can be caused by various factors, but its association with colon cancer is not directly established in the provided studies.
- However, studies have shown that other streptococcal species, such as Streptococcus bovis and Streptococcus gallolyticus, are associated with colon and rectal cancers 2, 3.
- Streptococcus bovis bacteremia/endocarditis has been linked to an increased risk of colon cancer, with reported incidence rates ranging from 6-67% 4.
- Other bacteria, such as Bacteroides fragilis, Fusobacterium nucleatum, and Clostridium septicum, have also been associated with an increased risk of colorectal cancer 3, 5.
Association with Colon Cancer
- The association between streptococcal bacteremia and colon cancer is thought to be related to the disruption of the intestinal microbiota and the translocation of bacteria from the gut to the bloodstream 3.
- Studies have shown that patients with bacteremia from specific intestinal microbes, including Streptococcus gallolyticus and Bacteroides fragilis, have an increased risk of developing colorectal cancer 3, 5.
- The exact pathophysiology of this association is not fully understood, but it is thought to involve the interaction between the intestinal microbiota and the host immune system 4.
Clinical Implications
- Clinicians should be aware of the potential association between streptococcal bacteremia and colon cancer, particularly in patients with Streptococcus bovis or Streptococcus gallolyticus bacteremia 2, 3, 4.
- Patients with bacteremia from these species should undergo rigorous evaluation for colon cancer, including colonoscopy and other diagnostic tests 3, 4.
- Early detection and treatment of colon cancer can improve patient outcomes, highlighting the importance of recognizing the potential association between streptococcal bacteremia and colon cancer 4.