The staging for melanoma will include assessing the local extent of the primary tumour, whether there is further spread to the local skin or lymph node areas and the presence of metastatic disease.
The extent of the primary melanoma in terms of depth of invasion at microscopic assessment has a significant impact on outcome. Patients with stage 1 disease have a 90% ten year survival, stage 2 has a 60% and stage 3 has a 30% ten year survival. Only five per cent of patients with stage 4 disease survive five years.
The assessment of lymph nodes spread can be undertaken by clinical examination and imaging investigations. CT scanning of the body would be offered to patients with a medium to high risk of metastases. Other imaging tests including a Chest x-ray, liver ultrasound may also be used to identify disease. PET scanning may be considered in selected cases. The assessment of urinary melanogen and a serum protein S100 remain poorly validated.
Thus the staging is based on the depth/thickness of invasion for stages 1-2 disease; the overall staging is thus:
Stage 1A. Localised: Less than 0.75mm depth.
Stage 1B.Localised: 0.76-1.5 mm depth.
Stage 2A. Localised: 1.5 - 4mm depth.
Stage 2B. Localised: More than 4mm depth.
Stage 3. Nodal metastases in the regional draining nodes
Stage 4. Metastatic disease to other organs.
