Table 3. Site-Specific Crude Risk of Metastasis by Site of Primary cSCC .

Site of Primary Tumora	Nonmetastatic cSCCb			Metastatic cSCC			Crude Risk of mcSCC by Primary Sitec
	No. of Patients (n = 92 814)		M:F Ratio	No. of Patients		M:F Ratio
	Male	Female		Male	Female		Male	Female
Lip (cutaneous)	882	740	1.2	23	11	2.1	1.67	2.05
Eyelid, including canthus	643	511	1.3	19	3	6.3	1.89	0.81
Ear	8518	370	23.0	214	10	21.4	1.60	3.73
Face	14 691	9807	1.5	230	71	3.2	1.00	1.00
Scalp or neck	13 193	1805	7.3	205	23	8.9	0.99	1.76
Trunk, including perianal	3393	2317	1.5	62	18	3.4	1.17	1.07
Upper limb, including shoulder	7735	5884	1.3	54	34	1.6	0.45	0.80
Lower limb, including hip	2587	7856	0.3	36	63	0.6	0.89	1.11
Skin NOS	8157	3725	2.2	0	0	NA	0.00	0.00
All sites	59 799	33 015	1.8	843	233	3.6	0.90	0.97

Abbreviations: cSCC, cutaneous squamous cell carcinoma; mcSCC, metastatic cSCC; M:F, male to female; NA, not applicable; NOS, not otherwise specified.

^aIncludes primary cSCC if metastatic or if first cSCC was diagnosed from January 1, 2013, through December 31, 2015. Excludes patients who developed metastases from primary tumors before 2013 (n = 93 890).

^bIncludes primary tumors that had not metastasized during the 2013-2015 follow-up period.

^cRisk by site of primary tumor was compared with that for the face.