Aggressive antibiotic treatments for staphylococcal skin infections in patients with cutaneous T-cell lymphoma (CTCL) also appear to reduce the activity of the cancer itself, according to new findings published online ahead of print in Blood (July 22, 2019).
In a press release the authors, researchers from the LEO Foundation Skin Immunology Research Center at the Faculty of Health and Medical Sciences, the University of Copenhagen, note that cytokines released by the immune system during bacterial infections also accelerate the growth of CTCL. The study showed that treating the bacterial infection can slow this process.
‘When we inhibit the staphylococcal bacteria with antibiotics, we simultaneously remove the activation of the immune cells," said senior author professor Niels Ødum in the release.This means that the immune cells do not produce as many cytokines, and therefore the cancer cells cannot use those cytokines to spur their own growth.
"As a result, the cancer cells are inhibited from growing as fast as they did during the bacterial attack. This finding is ground-breaking as it is the first time ever that we see this connection between bacteria and cancer cells in patients,” he said.
There has historically been a reluctance to treat CTCL patients with infections in the skin using antibiotics due to concerns that the infections would reoccur with antibiotic-resistant staphylococci strains. However, the researchers say they believe that the new results will change this.
“It has previously been seen that antibiotics have had some kind of positive effect on some of these patients, but it has never been studied what it actually does to the cancer itself," said Prof. Ødum.
"Our finding shows that it may actually be a good idea to give patients with staphylococci on the skin this treatment because it inhibits the cancer and at the same time possibly reduces the risk of new infections,” he said.
The investigators plan to follow up on this research to look more closely at the link between bacteria and cancer.
“We do not know if this finding is only valid for lymphoma," Prof. Ødum said.
"We see it particularly in this type of cancer because it is a cancer within the immune system. The cancer cells already ’understand’ the signals that the immune cells send out. When the immune cells are put to work, so are the cancer cells. At any rate, it is very interesting and relevant to take a closer look at the interaction between bacteria and cancer, which we see here."
“The next step will be the development of new treatments that only target the ‘bad’ bacteria, without harming the ‘good’ bacteria, which protects the skin,” he said.