Project Summary:
Cutaneous squamous cell carcinoma (cSCC) is the second most common non-melanoma skin cancer (NMSC), encompassing up to 20% of all cases. While the majority of squamous cell carcinomas have an excellent prognosis, it is estimated that 3% of tumors locally recur, 4% metastasize to lymph nodes, and 1.5% result in death3. Although most are successfully treated with surgery alone, there exists a specific subset of cSCCs which display high-risk features associated with an increased risk of metastasis and death. These features include tumor size, depth of invasion, perineural involvement, and poor histologic differentiation, amongst other factors.
Multiple standards have been developed over the years to stage and stratify cSCCs based on these high-risk factors. The two most widely used current systems are the American Joint Committee on Cancer cSCC staging system for cutaneous epidermal tumors of the head and neck 8th edition (AJCC-8) and the Brigham and Women’s Hospital tumor staging system (BWH). While there is currently no standard definition for high-risk cutaneous SCC (hr-cSCC), Stage T3 or greater tumors per the AJCC-8 staging guidelines and Stage T2b or greater tumors per the BWH staging system have been associated with worse prognosis and negative disease-related outcomes (DROs) defined as local metastasis, nodal metastasis, and death. In a recent study comparing these two staging systems, cSCCs that were T3 and above by AJCC-8 guidelines accounted for only 18% of total cases of cSCC but 70% of negative DROs and those T2b and above by BWH staging accounted for only 9% of total cases of cSCC but 67% of DROs. A recent single-institution study suggests that imaging studies positively affect disease outcomes, but it is still unknown if these results are generalizable or which specific patients may benefit from imaging. It is also unknown what specific imaging studies may be most beneficial. Imaging practices vary widely across institutions within Wisconsin.
This project will allow its researchers to critically evaluate current practices and determine which patients may benefit from pre-operative and surveillance imaging. It will also help them clarify which imaging modality is most beneficial, create evidence-based guidelines, and standardize practice patterns within their multidisciplinary team. This study will also allow the project team to critically assess the role of sentinel lymph node biopsy in the management of hr-cSCC patients and optimize patient outcomes in southeast Wisconsin.