Clark level
The Clark level is a staging system that describes the layer of a skin the melanoma has reached. The Clark scale has five levels:
Level 1: Melanoma is confined to the epidermis (the outer layer of the skin).
Level 2: Melanoma has invaded the papillary dermis (the outermost layer of the dermis, the next layer of skin).
Level 3: Melanoma has invaded throughout the papillary dermis and is touching on the next, deeper layer of the dermis.
Level 4: Melanoma has invaded this next deeper layer, the reticular dermis.
Level 5: Melanoma has now invaded the fat under the dermis.
The current staging system adopted by the
American Joint Committee on Cancer (AJCC) no longer considers the Clark level.
This is because the Clark level has been found to be less prognostic and more
subjective than other alternatives. The AJCC system assigns a stage based on
tumour, node, metastasis (TNM). The goal is that melanomas of the same stage will
have similar characteristics, treatment options, and outcomes2.