Nonmelanoma skin cancer (NMSC), either basal cell carcinoma (BCC) or squamous cell carcinoma (SCC), is the commonest cancer worldwide. The usual treatment is surgical excision, where a cut is made around the malignancy including an area of normal tissue, removing all of the skin cancer cells and curing the patient.
Guidelines published by the British Association of Dermatologists quote a 5% incomplete excision rate, enabling practitioners to advise patients on possible outcomes and providing a benchmark for audit targets.
However, in a new study published in the British Journal of Dermatology, Abhilash Jain, Associate Professor of Plastic and Hand Surgery at NDORMS, University of Oxford reveals that current guidelines underestimate the rates of incomplete excision.
“We found that the proportion of incomplete excisions is actually 11% for basal cell carcinomas, more than double the current guidelines,” said Jain. “That’s important because as practitioners, globally, we need to be able to give our patients information about possible chances of failure. A one in 20 rate is significantly different to a one in ten.”
Incomplete excisions may require further surgery or increased surveillance, which burdens patients and healthcare systems, increasing the costs and morbidity of skin cancer care.
For the study, a trainee group of young plastic surgeons carried out the most comprehensive review to date of primary clinical studies. They analysed 3477 citations in 100 separate studies with a total of 106,832 BCC and 21,569 SCC excisions included. Importantly, Mohs micrographic surgeries were excluded from the analysis as their near 100% success rate obscures the real figures.
Variations in the incomplete excision rate ranged from 4.7% to 20.4%. Differences were found by operating specialty (dermatologists, plastic surgeons, general practitioners, ophthalmology etc.).
Abhilash said: “The variance can be explained by many factors including the degree of surgical training within the specialty and the complexity of the surgery. We would argue that a 5% blanket rate is not correct but that excision by specialists may reduce treatment failure. Our recommendation is that guidelines are refined to take account of the type of tumour, and to the specialism of surgeons performing the procedure. This will give us a better idea of what we tell our patients, and also how we audit our outcomes.
A forthcoming audit of current plastic surgery outcomes in the UK will provide the evidence to support amendments to update current guidelines,” he concluded.