Squamous cell carcinoma of the skin: Emerging need for novel biomarkers

Table 2 Risk factors for recurrence and metastasis of cutaneous squamous cell carcinoma

Variable	Approximate relative risk1
	Recurrence	Metastasis
Rapid tumor growth	-	-
Tumor size > 2 cm	2	2
Tumor location (lip/ear)	2	3
Immunosuppression	-	2
Previous radiotherapy	-	-
Previously treated cSCC	3	4
RDEB -associated cSCC	-	-
Tumor depth > 4 mm	2	5
Poor differentiation	2	3
Acantholytic features	-	-
Spindle-cell features	-	-
Perineural invasion	5	5

Originated from Alam et al[1], with permission.

¹A relative risk of 1 is defined as the likelihood of recurrence or metastasis of a small primary cutaneous squamous cell carcinoma (cSCC). Dashes indicate an association with increased risk, but of which there are insufficient data to estimate the relative risk. RDEB: Recessive dystrophic epidermolysis bullosa.