In recent years, the understanding of the human microbiome has expanded significantly, shedding light on its impact on various aspects of health and disease. One fascinating area of research is the skin microbiome, a diverse community of microorganisms that inhabit the skin's surface. Emerging evidence suggests that the skin microbiome plays a crucial role in modulating the body's response to cancer treatment, particularly in the context of skin toxicities induced by therapies like chemotherapy and immunotherapy.

Cancer treatments, such as chemotherapy and immunotherapy, often cause a range of skin-related side effects. These may include rash, pruritus (itching), dryness, and more severe conditions like Stevens-Johnson syndrome or toxic epidermal necrolysis. These side effects not only impact the patient's quality of life but may also lead to treatment interruptions or dose reductions, affecting the overall effectiveness of the cancer therapy. 

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.

​Most skin diseases or infections are associated with skin microbiome dysbiosis, a term that describes a disruption or imbalance in microbiota homeostasis. Proactive skincare is recommended by physicians for patients undergoing RT as these products aid in minimising skin reactions by maintaining the epidermal barrier and possibly stabilising microbial homeostasis. 

As our understanding of the intricate relationship between the skin microbiome and cancer treatment-related skin toxicities deepens, researchers are hopeful that microbiome-targeted interventions could become valuable additions to the arsenal of supportive care for cancer patients. By harnessing the power of the microbiome, we may not only alleviate the burden of skin toxicities but also enhance the overall effectiveness of cancer therapies. Continued research in this field holds the promise of improving the quality of life for cancer patients undergoing treatment.