Skin cancer reflects the most common cancer worldwide and surgical site infections (SSIs) represent one of the most common and potentially preventable sources of morbidity and healthcare cost escalation associated with its surgical treatment. Surprisingly, there is very little data reporting the organisms cultured from SSIs in skin cancer surgery, with existing guidelines instead extrapolated from common skin pathogens rather than actual cultured organisms. Here we define the microbiology of SSIs specific to skin cancer surgery in Aoteoroa, and test these against existing empiric treatment guidelines.
All consenting patients presenting to the Manchester See & Treat Unit over a 6-month period were included. Patients receiving any form of antibiotics within a week prior to surgery were excluded. In postoperative follow up, wound cultures were assessed from all clinically significant infections as defined according to a validated wound infection score of 4 (range 0-7) and/or wounds which were prescribed postoperative antibiotics within 3 weeks of surgery. Data aggregated and reviewed relative to published empiric treatment guidelines.
One hundred-four clinically significant SSIs were identified from 333 lesions treated, with cultures available in 27%. Cultured organisms included MSSA (79%), MRSA (14%), coagulase-negative Staphylococci (11%), and “skin flora” (14%).
We unexpectedly found an overwhelming preponderance of Staphylococcus and underrepresentation of other skin flora such as strep in real-world SSIs. Empiric guidelines inaccurately predicted effective treatment in 14% of cases, exclusively due to MRSA.
We present the first comprehensive report of SSI microbiology following skin cancer surgery. Noting the overwhelming predominance of Staphylococcus sp. (76%) – and the rate of MRSA approaching prevalence warranting empiric first-line treatment, we can formulate rationalized empiric treatment for SSIs following skin cancer surgery.