Interactive Guide to Melanoma Staging & Prognosis
TNM staging is the internationally recognized system used to describe the extent of melanoma cancer spread. This comprehensive classification helps oncologists determine treatment options, predict outcomes, and communicate effectively about a patient's condition.
The TNM system evaluates three critical components: T (primary tumor characteristics), N (lymph node involvement), and M (distant metastasis). Together, these factors determine the overall stage from 0 to IV, which directly correlates with prognosis and survival rates.
Select the appropriate criteria for each component to determine the overall melanoma stage
Click on each stage to learn about specific criteria and prognosis
The T classification is based on tumor thickness (Breslow depth) and the presence or absence of ulceration, which are the most important prognostic factors for localized melanoma.
The N classification describes regional lymph node involvement, including micrometastases (≤2.0mm), macrometastases (>2.0mm), and in-transit/satellite metastases.
The M classification describes the presence or absence of distant metastases and their anatomic site, with serum LDH levels as an additional prognostic factor.
5-year overall survival rates based on AJCC 8th edition staging (approximate values)
Breslow thickness (tumor depth) is the most important prognostic factor for localized melanoma. It measures how deeply the melanoma has grown into the skin and directly correlates with survival rates. Ulceration presence is the second most important factor, as it indicates more aggressive tumor behavior.
Survival statistics are based on large population studies and represent averages. Individual outcomes can vary significantly based on patient age, overall health, tumor characteristics, treatment response, and access to care. These numbers should be discussed with your oncologist in the context of your specific situation.
Sentinel lymph node biopsy (SLNB) is a procedure to determine if melanoma has spread to nearby lymph nodes. It's typically recommended for melanomas >1mm thick or those with high-risk features. The results directly impact N staging and treatment decisions.
The AJCC staging system is updated approximately every 6-8 years as new research provides better understanding of prognostic factors. The current system is the 8th edition (2017). Staging may also be revised during treatment if new information becomes available through imaging or surgical findings.
Ulceration refers to the loss of the overlying epidermis above a melanoma, visible under microscopic examination. It indicates more aggressive tumor behavior and is associated with worse prognosis. Ulceration automatically places a melanoma in the "b" subcategory (e.g., T2b vs T2a).
The initial pathologic stage (pTNM) is determined at diagnosis and doesn't change. However, clinical staging may be updated if metastases develop during follow-up. Additionally, staging may be refined after sentinel lymph node biopsy or if additional pathological information becomes available.
