Staging Melanoma
Staging melanoma is the process used to describe the extent of the disease. The doctor will take into account the tumor thickness and depth, and whether the melanoma cells have spread, or metastasized, to the lymph nodes or other parts of the body. Staging helps the melanoma treatment team develop an appropriate treatment plan and determine the prognosis, or outlook.
|
Melanoma Stage
|
Description
|
Treatment Option
|
|---|---|---|
| 0 | The tumor is confined to epidermis and has not entered the dermis, a deeper layer of the skin. This stage of melanoma is also called melanoma in situ. | The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary; however, continued skin examination to evaluate for a new melanoma or other skin cancer will continue. |
| IA | The tumor is less than 1 millimeter thick. The outer layer of skin does not look cracker or scraped (ulcerated). It has not spread to any lymph nodes or other organs. | The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary. |
| IB | The tumor is either less than 1 millimeter thick and ulcerated, or 1–2 millimeters thick and not ulcerated. It has not spread to any lymph nodes or other organs. | The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary. |
| IIA | The tumor is either 1–2 millimeters thick and ulcerated, or 2–4 millimeters thick and not ulcerated. It has not spread to any lymph nodes or other organs. | The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary. |
| IIB | The tumor is either 2–4 millimeters thick and ulcerated, or more than 4 millimeters thick and not ulcerated. It has not spread to any lymph nodes or other organs. | The tumor and some surrounding tissue are removed surgically. Additional treatment(s) may be recommended. |
| IIC | The tumor is more than 4 millimeters thick and is ulcerated. These are aggressive tumors that are more likely to spread. | The tumor and some surrounding tissue are removed surgically. Additional treatment(s) may be recommended. |
|
IIIA IIIB IIIC |
The tumor may be of any thickness. It may or may not be ulcerated. The cancer cells have spread either to a few nearby lymph nodes, or to some tissue just outside the tumor but not to the lymph nodes. | The tumor and lymph nodes that have cancer cells are removed surgically. Additional treatment(s) may be recommended. |
| IV | The cancer cells have spread to the lymph nodes, other organs in the body, or areas far from the original site of the tumor. This is called metastatic melanoma. | The tumor and lymph nodes that have cancer cells are removed surgically. Additional treatment(s) may be recommended. |
How is my melanoma stage determined?
Taking effect in January 2010, the American Joint Commission on Cancer (AJCC) published the 7th edition of the AJCC Cancer Staging Manual. This was greatly expanded to include over 60,000 patients from 17 cancer centers and organizations to become a more inclusive diagnosis system. This is the most commonly used system of melanoma staging and contains three key pieces of information:
T – Tumor - Based on the tumor thickness, a number (from 0 to 4) is assigned, and based on the ulceration, a letter (a or b) is assigned. The staging definition of metastatic melanoma when the primary site is unknown is to be categorized as stage III and not stage IV.
N – Nodes (Lymph) – Based on whether or not the melanoma has spread to lymph nodes, a number (from 0 to 3) is assigned. Nodal tumor deposits of any size are to be included in staging nodal disease.
M – Metastasized – Based on whether or not the melanoma has spread to other organs.
The M category is primarily defined by the site or sites of distant metastases:
- M1a - skin/soft tissue/distant nodal
- M1b - lung
- M1c - all visceral metastitic sites; patients with an an increased serum lactic dehydrogenase level are all categorized as M1c regardless of the site or sites of distant disease.
Mitotic Rate: Primary tumor mitotic rate is an important independent adverse predictor of survival and increased mitotic rate was associated with declining survival rates. Mitotic rate is expressed as the number of mitoses/mm2.
It must be noted that additional analyses have provided further insight regarding melanoma patient survival. Despte the nature of the evidence-based TNM staging system, patient age, site of primary tumor, number of sites, etc., combined with the TNM system may more accurately reflect an individual patient's outcome. The AJCC's Individualized Melanoma Patient Outcome Prediction Tools can be found online at www.melanomaprognosis.org.
Melanoma Diagnostics Indicators
To determine the specific stage of a melanoma, there are two common diagnostic indicators:
Clark’s Level
The Clark’s level is commonly misunderstood as the melanoma stage diagnosis. The Clark’s level only refers to how deep the tumor has penetrated into the skin. Research has shown that the Clark’s level diagnosis is not a great predictor of outcome.
Clark's Level I - Confined to epidermis – also called “in situ” melanoma
Clark's Level II - Invasion of the papillary dermis (upper)
Clark's Level III - Filling of the papillary dermis (lower)
Clark's Level IV - Extending into the reticular dermis
Clark's Level V - Invasion of the subcutaneous tissue
Breslow Thickness
The Breslow thickness of the melanoma is a better melanoma stage diagnostic indicator than the Clark’s level; it is a continuous variable and more accurate in its determinations.
The Breslow thickness is a measure (in millimeters) of the vertical depth of the tumor measured from the granular cell (very top) layer downward. An instrument called an Ocular Micrometer is used to measure the thickness of the excised tumor.
Tumor thickness remains the most powerful prognostic indicator that can be determined from evaluation of the primary melanoma itself. Because of the accuracy of determining outcomes, the Breslow thickness is commonly included in a melanoma diagnosis.
Breslow Thickness and Survival Rate:
- <1mm: 5-year survival is 95-100%
- 1-2mm: 5-year survival is 80-96%
- 2.1-4mm: 5-year survival is 60-75%
- >4mm: 5-year survival is 37-50%
(800) 673-1290
