Implementation of staging systems in clinical practice for cutaneous squamous cell carcinoma

Staging systems have been poorly implemented in clinical practice in cutaneous squamous cell carcinoma (CSCC) mainly because guidelines have been essentially based on risk factors rather than in T stage itself. However, its extensive use would be desirable in patient’s management. Forty years after the publication of the First edition of the American Joint Committee on Cancer (AJCC) Staging System, the Eight edition (AJCC-8) was recently published with relevant changes in skin cancer (1), including CSCC. The AJCC-8 considers T1 a CSCC <2 cm of horizontal size, T2 a tumor ≥2 cm up to 4 cm and T3 a tumor ≥4 cm. Also, the AJCC-8 considers T3 a tumor with a thickness >6 mm, with perineural invasion (of nerves ≥0.1 mm or of nerves deeper than the dermis) and when slight bone erosion exists. A CSCC is classified as T4 if extensive bone invasion exists or when invasion through the foramen of the skull is developed