The incidence and risk factors of metastasis for cutaneous squamous cell carcinoma--implications on the T-classification system.

Cutaneous squamous cell carcinoma (cSCC) constitutes the most common cancer capable of metastasis. While the latest version of the American Joint Committee on Cancer guidelines represents a significant step forward in accurate staging of cSCC, several proven independent risk factors remain excluded. We review the current literature on the incidence and proven independent risk factors of metastasis for cSCC and proposes their full inclusion in the staging system for primary lesions.