Supplemental Digital Content 1. Tumor Staging Criteria AJCC-7 (2010)
T1 Tumor ≤ 2 cm in greatest dimension and with 0-1 high-risk factor
T2 Tumor > 2 cm in greatest dimension or with 2 or more high- risk factors
T3 Invasion of orbit, maxilla, mandible, or temporal bones T4 Invasion of other bones or direct PNI of skull base High-
risk factors
Invasion to fat/muscle, PNI, primary site ear, primary site non- hair bearing lip, poorly differentiated
AJCC-8 (2016) T1 < 2cm
T2 ≥ 2 cm and < 4 cm
T3 ≥ 4 cm or minor bone erosion or PNI (≥0.1mm) or invasion beyond subcutaneous fat (> 6mm)
T4a Gross cortical bone erosion with marrow invasion
T4b Tumors with skull base invasion and/or skull base foramen involvement
BWH (2013) T1 0 high-risk factors
T2a 1 high-risk factor T2b 2-3 high risk factors
T3 ≥ 4 high-risk factors or bone invasion High-
risk factors
Tumor diameter ≥ 20 mm, poorly differentiated, PNI ≥ 0.1 mm, invasion to muscle
AJCC-7 = American Joint Committee on Cancer 7
thedition staging criteria. AJCC-8 = American Joint Committee on Cancer 8
thedition staging criteria. BWH = Brigham and Women’s Hospital staging criteria.
PNI = perineural invasion.
Supplemental Digital Content 2. Comparison of Treatment in Cases and Controls by Stage
Cases Controls Cases Controls
No. % No. % No. % No. %
All Tumors 412 100 291 100 Total BWH T1 333 100 227 100
Primary cSCC Tx Primary cSCC Tx
Mohs 293 71 219 75 Mohs 231 69 167 74
Excision 86 21 58 20 Excision 72 22 46 20
Radiation 11 3 6 2 Radiation 5 2 1 0
ED&C 10 2 5 2 ED&C 7 2 5 2
Topical creams* 6 1 0 0 Topical creams 5 2 0 0
No treatment 4 1 2 1 No treatment 4 1 2 1
Other 1 0 2 1 Other 1 0 2 1
Unknown* 21 5 6 2 Unknown* 20 6 5 2
Total AJCC-8 T1 341 100 230 100 Total BWH T2a 74 100 58 100
Primary cSCC Tx Primary cSCC Tx
Mohs 236 69 170 74 Mohs 59 80 48 83
Excision 74 22 46 20 Excision 12 16 10 17
Radiation 6 2 1 0 Radiation 5 7 3 5
ED&C 7 2 5 2 ED&C 3 4 0 0
Topical creams 5 1 0 0 Topical creams 1 1 0 0
No treatment 4 1 2 1 No treatment 0 0 0 0
Other 1 0 2 1 Other 0 0 0 0
Unknown* 21 6 5 2 Unknown 1 1 1 2
Total AJCC-8 T2 59 100 48 100 Total BWH T2b 4 100 5 100
Primary cSCC Tx Primary cSCC Tx
Mohs 49 83 39 81 Mohs 2 50 3 60
Excision 9 15 9 19 Excision 2 50 2 40
Radiation 3 5 1 2 Radiation 0 0 2 40
ED&C 2 3 0 0 ED&C 0 0 0 0
Topical creams 1 2 0 0 Topical creams 0 0 0 0
No treatment 0 0 0 0 No treatment 0 0 0 0
Other 0 0 0 0 Other 0 0 0 0
Unknown 0 0 1 2 Unknown 0 0 0 0
Total AJCC-8 T3 12 100 13 100 Total BWH T3 1 100 1 100
Primary cSCC Tx Primary cSCC Tx
Mohs 8 67 10 77 Mohs 1 25 1 20
Excision 3 25 3 23 Excision 0 0 0 0
Radiation 2 17 4 31 Radiation 1 25 0 0
ED&C 1 8 0 0 ED&C 0 0 0 0
Topical creams 0 0 0 0 Topical creams 0 0 0 0
No treatment 0 0 0 0 No treatment 0 0 0 0
Other 0 0 0 0 Other 0 0 0 0
Unknown 0 0 0 0 Unknown 0 0 0 0
Cases = Tumors from immunosuppressed patients. Controls = Tumors from immunocompetent patients. Tx = Treatment. AJCC-7 = American Joint Committee on Cancer 7th edition staging criteria. AJCC-8 = American Joint Committee on Cancer 8th edition staging criteria. BWH = Brigham and Women’s Hospital staging criteria. ED&C = electrodessication and curettage. * = Significant difference between cases and controls (p < 0.05).
