34783 Metagenomic microbial profiling of keratinocyte carcinomas in solid organ transplant recipients

In healthy individuals, a symbiotic relationship exists between the host and its microbiota; however, disruption of this ecosystem may lead to chronic inflammation and skin diseases such as atopic dermatitis, psoriasis, rosacea, and acne. Altered microbiota has also been linked to malignancies such as breast, colorectal, and gastric cancers. Solid organ transplant recipients are at increased risk of malignancy, especially at microbiota-rich sites such as the skin. In contrast, the incidence of common malignancies in more sterile areas (i.e., breast and prostate) are reduced post-transplantation. Medication-induced immunosuppression may play a role in carcinogenesis, in part by decreasing immune-mediated tumor surveillance. However, it does not account for the striking increase in cancer at high microbial density sites. Therefore, it is essential to understand the complex interplay between the skin microbiota, inflammation, and immunity in health and disease. To date, there are no studies that have investigated the cutaneous microbiota in transplant recipients. We hypothesize that metagenomic sequencing will reveal microbial dysbiosis in patients post-transplant, thereby identifying tumour-specific species/strains of bacteria. By understanding the microbiota-host interactions of keratinocyte carcinomas in transplant recipients, we further the development of diagnostic and prognostic tools essential for the management of skin cancer. Identifying specific tumour-associated microbes holds great therapeutic potential, with treatment options including prebiotics, probiotics, antibiotics, and microbial transplants.