Microbiome health may influence skin cancer activity, treatment response

Key takeaways:

• Disturbances in the microbial ecosystem affect the immune system and can be oncogenic or tumor suppressive.
• Fecal transplants may help restore the gut microbiome.

CHICAGO — The skin and gut microbiome may be associated with developing or protecting against skin cancer as well as responding to cancer treatment, according to a speaker at the American Society for Dermatologic Surgery Annual Meeting.

“The research into the microbiome and its association with melanoma and other skin cancers — it’s still very, very early,” M. Laurin Council, MD, MBA, FAAD, FACMS, director of dermatologic surgery and of the micrographic surgery and dermatologic oncology fellowship at Washinton University School of Medicine in St. Louis, said during her presentation. “The microbiome may be altered. We don’t know if this is causal or if it’s the effect of having the cancer, but there is some association there and we are starting to understand it in other cancers.”

Like other cancers, there are some compositional changes in the microbiome of patients who have skin cancer compared with those who do not, according to Council.

“We don't know whether skin cancer alters the microbiome or whether this altered microbiome leads to patients developing skin cancer,” Council said.

Disturbances in the microbial ecosystem have been found to affect the immune system and the outcomes can be oncogenic or tumor suppressive. Council explained that fecal analysis studies show an altered microbial ecosystem is associated with a poor response to PD-1 and PD-L1 inhibitor treatments, which are used for many skin cancers.

Therefore, restoring the microbiome may help protect against skin cancers and positively influence treatment responses, according to Council.

One study referenced by Council found that patients treated with antibiotics who received fecal transplants achieved a restored microbiome “very, very quickly” compared with those who did not receive a transplant.

“Restoring the microbiome could be protective or it could also have an effect on the response to treatment,” Council concluded.