Risk groups for non-melanoma skin cancer

Doctors classify most non-melanoma skin cancers into risk groups that are based on several prognostic factors, including the size of the cancer and where it is located. The risk groups allow the doctor to estimate the chance that the cancer will come back (recur). Doctors also use the risk groups to help plan the best treatment.

The prognosis is usually very good for BCC because it can be found and treated early. BCC is classified as low or high risk based on its risk of coming back.

BCC is put in the low-risk group when:

• It is on the trunk of the body, arms, legs, hands, feet, nails, ankles, cheeks, forehead, scalp or neck.
• It is 2 cm or smaller.
• It is nodular or superficial.
• It is a primary cancer that has not come back after treatment.
• The edge of the cancerous area is clear and smooth.
• The immune system is not weakened.
• There was no previous radiation therapy to the area.
• There is no cancer in or around nerves.

BCC is put in the high-risk group when:

• It is on the trunk of the body, arms, legs, hands, feet, nails, ankles, cheeks, forehead, scalp, neck, eyelids, eyebrows, nose, lips, ears, genitals or skin around the eyes.
• It is larger than 2 cm.
• It is an aggressive subtype, such as infiltrative, morpheaform or micronodular.
• It has come back after treatment.
• The edge of the cancerous area is uneven.
• The immune system is weakened.
• There was previous radiation therapy to the area.
• The cancer has grown into or around nerves.

SCC is classified as low or high risk based on its risk of coming back.

SCC is put in the low-risk group when:

• It is on the trunk of the body, arms, legs, hands, feet, nails, ankles, cheeks, forehead, scalp or neck.
• It is smaller than 2 cm.
• It is less than 2 mm deep or Clark’s classification level I, II or III.
• The edge of the cancerous area is clear and smooth.
• It is low grade.
• It is growing slowly.
• It is caused by ultraviolet radiation.
• It is a primary cancer that has not come back after treatment.
• The immune system is not weakened.
• There was no previous radiation therapy to the area.
• There is no cancer in or around nerves.

SCC is put in the high-risk group when:

• It is on the ears, lips or scalp.
• It is 2 cm or larger.
• It 2 mm or more deep or Clark’s classification level IV or V.
• It is high grade.
• It is growing quickly.
• The edge of the cancerous area is uneven.
• It is a high-risk subtype like desmoplastic SCC or adenosquamous carcinoma of the skin.
• It has come back after treatment.
• The immune system is weakened.
• There was previous radiation therapy to the area.
• It started from a chronic wound or scar.
• The cancer has grown into or around nerves, the lymphatic system or blood system.