Bacterial infections, common in patients with skin lymphoma, have an active role in cancer growth and progression, and may be drivers of the disease, researchers report in the study titled “Staphylococcus aureus enterotoxin A (SEA) stimulates STAT3 activation and IL-17 expression in cutaneous T-cell lymphoma,” published in Blood.
According to the American Cancer Society, skin lymphomas are rare, accounting for about 5 percent of all non-Hodgkin lymphomas. The most common are T-cell lymphomas, where specific immune system cells, CD4-T-lymphocytes, turn into cancer cells and exhibit parasitic-like behavior to other immune system cells. The skin’s defense mechanisms are also compromised in patients with skin lymphomas, leading to more frequent bacterial infections.
The team observed that toxins produced by certain staphylococcus bacteria enable cancer cells to further obstruct and damage the immune system’s response through chemical signals sent by these cells. The discovery implies that microbes might be active drivers of lymphoma progression. Professor Niels Ødum, from the University of Copenhagen, explained in a press release, “We have gained important insight into the processes that activate cancer cells and make them grow. Patients’ frequent bacteria infections might not be a mere side effect of the disease — on the contrary, toxins in the bacteria actually ‘benefit’ cancer cells. Our next step is examining whether combating infections can slow down the growth of cancer cells and thus stop the disease.”
The team plans to study how bacteria affect the immune system’s defense mechanisms and contribute to disease, in order to better understand how bacteria and their toxins worsen cancer, possibly opening new therapeutic avenues. Researchers also need to determine which lymphoma patients might benefit from antibiotic therapy, as only some bacteria produce toxins.
Skin lymphoma can be rather difficult to diagnosis, as it is often confused with other benign skin conditions, such as eczema. Disease progression is also rather unpredictable, sometimes staying inactive for years and other times becoming an aggressive and potentially life-threatening condition. The mechanisms behind the disparity in disease course, and the cause of the cancer itself, are still largely unknown.