2. Tumor Staging Systems and Prognostic Stratification
Author: MD, MSCE Anokhi Jambusaria-Pahlajani
Publisher: Springer Berlin Heidelberg
Squamous cell carcinoma (SCC) is the 2nd most common cancer diagnosed worldwide. While overall cure rates are excellent, 2–5 % of tumors recur, metastasize, and cause death. Generally accepted risk factors for recurrence and metastasis include size > 2 cm, depth beyond Clark’s Level IV or V, poorly differentiated or undifferentiated histology, location on the lip, location on the ear, perineural invasion (PNI), recurrent tumors, and tumors occurring in an immunosuppressed host. These risk factors have served as the foundation for the development of the American Joint Committee on Cancer (AJCC) and International Union Against Cancer (UICC) staging systems, as well as National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines for cutaneous SCC.
In 2010, the AJCC divided cutaneous SCC staging from other nonmelanoma skin cancer staging and proposed a separate staging system based on review of available literature and expert consensus opinion. Several studies have demonstrated this new stratification system may be suboptimal and have published alternative systems which offer improved prognostic discrimination. This chapter will review the available data on high-risk cutaneous SCC, summarize the current staging and prognostic stratification systems, identify areas of ambiguity in SCC staging and outcomes, and discuss areas of research that may improve future prognostic stratification systems.