Melanoma Staging - What is the difference between Level and Stage?

When one is first diagnosed with a Melanoma, it is often associated with anxiety and distress. What does this mean? Many will ask. Melanoma has been depicted by social media, general media and the internet as a deadly disease. This is true, if the Melanoma is advanced. When a Melanoma has been diagnosed early, it can be a curable cancer, with excellent prognosis and long-term outcome. The way we, as doctors determine whether your melanoma is advanced or not, is dependent on its Level and Stage.

What is a Level?

Melanoma levels is the depth of melanoma cell invasion in the skin. This is determined by histopathology study of the biopsy sample under the microscope by specialist pathologists. Obviously, the deeper through the skin a melanoma has invaded, the greater potential it has, of spreading. There are 5 levels (or depth) of melanoma, reflecting how deep the melanoma has progressed through the anatomical layers of skin. This is always reported with Breslow thickness, which measures the physical depth of melanoma invasion in millimeters. The reason both the Level and Breslow Thickness are taken into account when considering the seriousness of the melanoma, is because in certain part of the body, the skin layers are thicker, e.g. the back. Thus even though the report may say that the melanoma is only Level II, but the thickness is 1.2mm. Some studies have shown that it is the Breslow Thickness that seem to have a better correspondence to the likelihood of spread, than the Level itself. 

What is the Stage? 

Melanoma staging is whether the melanoma has advanced beyond the skin. This is often determined by either physical examination of nearby lymph node groups or imaging studies such as CT scans, Ultrasounds, PET/CT or MRI. Stage I and II Melanoma are confined to the skin, with different depth. Stage III Melanoma means it has progressed beyond the original tumour as satellite lesions in the surrounding skin or travelled to a lymph node basin nearby. Stage IV Melanoma means the Melanoma has travelled to a distant site, usually an organ such as the lung, bones, liver or brain.

What does this all mean?

Thus, a Level IV melanoma means a melanoma tha has invaded through a few of the skin layers, but if it is less than 1mm thick, it is only considered to be Stage I disease. But a Stage IV melanoma means the melanoma has spread throughout the body, and usually has very poor prognosis. Do not confuse the Level and Stage, as these have very different meanings: a Level IV melanoma has a very different management and outcome compared to a Stage IV melanoma. 

Speak to your doctor or surgeon if you are unclear. Be direct and ask the hard questions if you are unsure as to what your melanoma means and what your prognosis is in the long term. It often helps to have a relative or friend with you during the consultatiion as it is often quite easy to be overwhelmed with both emotion and information.