13. WHAT ARE THE STAGES OF MELANOMA?

The extent and seriousness of melanoma is measured using a staging system.  The Staging system for melanoma runs from stage 0 through to stage IV.  It is important to accurately stage melanoma as different stages of melanoma require different treatments and have different outlooks. Determining the stage of melanoma requires an examination of the primary tumour and an examination to determine if distant spread has taken place.    

When examining a primary tumour two scales are used, namely the Breslow Measurement System and the Clark Level System.  The Breslow Measurement System describes the thickness of a tumour and grades a melanoma on a scale of I - IV.  While the Clark Level System measures the depth of the tumour on a scale of I to V.  This is achieved by measuring the number of skin layers the tumour inhabits, thus giving an indication of the tumour's invasiveness.  Both measurement systems are used when determining the overall staging of the melanoma and the patient's prognosis.  In the absence of any further spread, a primary tumour will place a patient in stage 0, Stage I or stage II of the overall staging system - dependant on the scores of the Breslow Measurement and Clark Level Systems.  It is considered that that the most accurate system is the Breslow system measuring the total depth of the tumour and eg tumours less than >74 mm in depth have over a 98% survival rate in 10 years12.

When a primary melanoma has metastasized and reached other parts of the body, its staging will depend on the extent of its spread.  A melanoma that has spread to the lymph gland/s or surrounding tissue and not to a distant lymph node or other organ/s will be considered to be in stage III.  On the other hand, a melanoma that has spread to a distant organ/s or distant lymph glands will be considered a stage IV melanoma.     More detailed information on the staging system for melanoma can be obtained from the American Caner Society by following the below link:        

http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_melanoma_staged_50.asp?sitearea