Novel insights at the crossroads of antibiotic use and cancer risk

The continuous use of antibiotics is associated with the spread of antimicrobial resistances and the not yet clear link to cancer development. Many conventional antibiotics have already shown different effects on a variety of cancer types raising questions for their ra- tional use in cancer. However, discrepancy in the ob- served trend for some antibiotics reducing cancer de- velopment and being associated with higher risk of cancer underscores the lack of understanding the complex link between antibiotics and cancer. Here, we briefly summarize the possible antibiotic-mediated effects on cancer and conclude that those effects can be direct via i) specific targeting of tumor/cancer, ii) antimicrobial activity and iii) immunomodulatory activ- ity whereby iv) indirectly caused effects primarily af- fect immune equilibrium between bacteria, cancer and immune cells. Furthermore, we also conclude that there is a great need for bulk profiling, comprehensive screening programs in all countries and in-depth stud- ies to understand the risks and benefits of antibiotic use.

Automated summary

The continuous use of antibiotics is associated with the spread of antimicrobial resistances and the unclear link to cancer development. Conventional antibiotics have different effects on various cancer types, raising questions about their rational use in cancer treatment. The complex link between antibiotics and cancer involves direct effects through specific targeting of tumor/cancer, antimicrobial activity, and immunomodulatory activity, as well as indirect effects primarily affecting the immune equilibrium between bacteria, cancer, and immune cells. Comprehensive screening programs and in-depth studies are needed to understand the risks and benefits of antibiotic use.