No widely accepted or standardized staging classification based upon prognosis is available. A commonly used staging system is based upon clinical presentation:[1]

• Stage IA: Primary tumor smaller than 2 cm with no evidence of spread to lymph nodes or distant sites.
• Stage IB: Primary tumor 2 cm or larger with no evidence of spread to lymph nodes or distant sites.
• Stage II: Regional node involvement but no evidence of distant metastases.
• Stage III: Presence of systemic metastases beyond the regional lymph nodes.

References

1. Aasi SZ, Leffell DJ: Cancer of the skin. In: DeVita VT Jr, Hellman S, Rosenberg SA, eds.: Cancer: Principles and Practice of Oncology. 7th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2005, pp 1717-44.