New Cancer Treatment: A Common Antibiotic After Radiation Therapy Fights Tumors Away

A majority of all cancer patients undergo radiation therapy at some point during their treatment. Several studies have pointed towards the effectiveness of hypo-fractionated radiotherapy which involves higher doses of radiation over the course of fewer treatments. Such treatment has the ability to impact other cancer cells in the body which had missed the radiation.

A new study conducted by experts at the University of Pennsylvania has found that administering a dose of the common antibiotic 'Vancomycin' not only aided the body’s immune cells to kill the cancer cells that were treated under radiation therapy but also killed cancer cells that were further away. Such an effect is called the ‘abscopal effect’.

'Vancomycin' alters the gut microbiome in such a way that it can help the body’s immune system effectively attacks the tumor cells post radiation therapy. After successfully confirming the abscopal effect in mice models, they are planning to test the approach in a human trial soon.

“Our study shows that vancomycin seems to boost the effectiveness of the hypo-fractionated radiation itself on the targeted tumor site while also aiding the abscopal effect, helping the immune system fight tumors away from the treatment site,” PennMedicine News quoted the study’s senior author Andrea Facciabene, Ph.D., an Associate Professor of Radiation Oncology in Penn’s Perelman School of Medicine as saying.

The authors also conveyed that this finding is only superficial when it comes to understanding the connection between the gut microbiome and its impact on the immune responses induced by radiotherapy. They opine that further research on this topic is essential to understand the implications of specific strains of bacteria. The study highlights the role played by antibiotics in treating cancer patients.

The researchers chose vancomycin specifically because:

• The antibiotic targets gram-positive bacteria and can disrupt the gut microbiome.
• It is a large molecule and thereby it stays inside the gut without circulating to the rest of the body similar to the action of other antibiotics.
• It is not systemic and thereby has a limited impact on the rest of the body’s community of microbes.

They are planning a phase-1 study to implement approach into clinical use.