Skin Microbiome and Treatment-Related Skin Toxicities in Patients With Cancer: A Mini-Review

Abstract

The human skin hosts millions of bacteria, fungi, archaea, and viruses. These skin microbes play a crucial role in human immunological and physiological functions, as well as the development of skin diseases, including cancer when the balance between skin commensals and pathogens is interrupted. Due to the linkages between inflammation processes and skin microbes, and viral links to skin cancer, new theories have supported the role a dysbiotic skin microbiome plays in the development of cancer and cancer treatment-related skin toxicities. This review focuses on the skin microbiome and its role in cancer treatment-related skin toxicities, particularly from chemotherapy, radiation therapy, and immunotherapy. The current literature found changes in the diversity and abundance of the skin microbiome during cancer treatments such as radiation therapy, including lower diversity of the skin microbiome, an increased Proteobacteria/Firmicutes ratio, and a higher abundance of pathogenic Staphylococcus aureus. These changes may be associated with the development and severity of treatment-related skin toxicities, such as acute radiation dermatitis, hand-foot syndrome in chemotherapy, and immunotherapy-induced rash. Several clinical guidelines have issued potential interventions (e.g., use of topical corticosteroids, phototherapy, and non-pharmaceutical skin care products) to prevent and treat skin toxicities. The effectiveness of these promising interventions in alleviating treatment-related skin toxicities should be further tested among cancer patients.

Radiation Dermatitis: Radiation-Induced Effects on the Structural and Immunological Barrier Function of the Epidermis

“…Lifestyle factors like obesity, chronic sun exposure and smoking appear to increase the risk of radiation dermatitis [ 22 ]. In addition, the skin microbiome, particularly its colonization by Staphylococcus aureus , may play a role in the development of severe radiation dermatitis [ 24 ]. Patients with genetic disorders affecting their DNA repair capacity are at a higher risk of developing severe radiation dermatitis [ 22 , 25 ].…”

“…This system categorizes radiation dermatitis into four grades: grade 1, characterized by faint erythema with dry desquamation; grade 2, with moderate to brisk erythema and patchy, moist desquamation mostly in the skin folds; grade 3: showing confluent, moist desquamation in areas other than the skin folds; grade 4, presenting with skin ulceration with trauma-associated or spontaneous bleeding [ 30 ]. IR exposure weakens the skin’s natural defenses against microbes, increasing the risk of bacterial infections, commonly caused by S. aureus [ 24 ]. The itching, discomfort and pain associated with skin reactions from radiation dermatitis can significantly impact patients’ quality of life.…”

Plants against cancer: the immune-boosting herbal microbiome: not of the plant, but in the plant. Basic concepts, introduction, and future resource for vaccine adjuvant discovery

“…When the normal flora is overtaken by pathogenic flora, as documented in thousands of studies [indicating changes in the composition of microbial communities in malignant versus healthy non-malignant tissues], it increases the risk of cancer ( 76 , 214 – 216 ). Pathogenic flora that contribute to cancer can spread locally (e.g., from the vagina to the cervix ( 217 ), or from the respiratory system to the lungs ( 218 )) or distally as bacteria originating in the oral cavity (e .g., Porphyromonas gingivalis, Tannerella forsythia, Veillonella parvula, F. nucleatum, Parvimonas Micra , etc.…”

Association of Skin Microbiome Dynamics With Radiodermatitis in Patients With Breast Cancer

“…Radiodermatitis substantially impairs the quality of life of patients undergoing radiation therapy and poses a risk for clinical complications . To date, the interindividual differences regarding the severity of radiodermatitis are not sufficiently understood . This lack of information impedes individualized prophylactic treatment approaches and leads to unsatisfying management of radiodermatitis for many patients.…”

“…1 To date, the interindividual differences regarding the severity of radiodermatitis are not sufficiently understood. 2,3 This lack of information impedes individualized prophylactic treatment approaches and leads to unsatisfying management of radiodermatitis for many patients.…”