Most of the lesions affected the skin of the head and neck.
Parameters:
(1) diameter of the tumor
(2) perineural invasion
(3) depth of invasion
|
Parameter
|
Finding
|
Points
|
|
diameter of the lesion
|
< 4 cm
|
0
|
|
|
>= 4 cm
|
1
|
|
perineural invasion
|
absent
|
0
|
|
|
present
|
1
|
|
depth of invasion
|
not beyond subcutaneous tissue
|
0
|
|
|
deep, extending into adjacent tissues (beyond subcutaneous tissue)
|
1
|
number of high risk factors =
= SUM(points for all 3 parameters)
Interpretation:
• minimum number of high risk factors: 0
• maximum number of high risk factors: 3
• The presence of no risk factors represented the low risk group.
• The presence of one or more risk factors represented the high risk group.
|
Number of Risk Factors
|
Probability of 3 year Survival
|
Probability of 5 Year Survival
|
|
0
|
100%
|
100%
|
|
>= 1
|
70%
|
58%
|
Additional factors associated with a worse survival:
(1) locally recurrent tumor (I assume after a previous adequate excision)
(2) depth of invasion >= 0.7 cm
Limitations:
• A well-differentiated verrucous carcinoma of the skin may grow quite large, often at little risk to the patient. See N Engl J Med. 2005; 352: 488.
