Stages of Melanoma

After a melanoma diagnosis, doctors will try to determine if cancer has spread and matured and, if so, how far it has spread. This process is staging. The cancer stage indicates how much cancer is present in the body. It helps determine the severity of the malignancy and the best treatment options available. Doctors also utilize the cancer stage when discussing the patient’s survival rates. 

The location of cancer also comes under staging. Staging includes the information about the spread of cancer or its application to other body sections. Doctors utilize diagnostic tests to determine cancer’s stage. Therefore, doctors can only do staging after administering all of the tests. Knowing and understanding the stage can assist doctors to choose the best course of treatment and anticipate a patient’s prognosis or the possibility of recovery. Different types of cancer have other stage descriptions.

Stage 0 (melanoma in situ) is the most advanced stage, followed by stages I (1) through IV. However, the researchers have used capital letters for further subdivision. The lower the number, the less cancer has spread, in general. A higher number, such as stage IV, indicates that cancer has progressed further. An earlier letter within a stage denotes a lower stage. Each person’s cancer journey is unique. However, the doctors use similar approaches to treat malignancies at similar stages. This is because similar malignancies have similar treatment outcomes.

How to determine the stage?

One of the most often used melanoma staging approaches is The American Joint Committee on Cancer TNM system. It is based on three critical pieces of information:

The central or the primary tumor’s extent (T): How far has the malignancy penetrated the skin? Do ulcers infect the malignancy?

Tumor thickness: The Breslow measurement is used to determine the thickness of a melanoma. Melanomas less than 1 millimetre thick (about 1/25 of an inch) have an extremely low likelihood of spreading. Melanoma has a higher chance of spreading as it grows wider.

Ulceration: Ulceration occurs when the skin over the melanoma breaks away. Ulcerated melanomas have a poor prognosis.

The spread of the infection to neighbouring lymph nodes (N): Is there any evidence that the malignancy has migrated to neighbouring lymph nodes?

The spread of cancer to distant places (metastasis): Has cancer progressed to other parts of the body, such as lymph nodes or organs? (Melanoma can spread practically anywhere in the body, although the lungs, liver, brain, bones, and skin or lymph nodes are the most common sites of spread.)

Factors used for staging melanoma

To determine the stage of melanoma, the lesion and some surrounding healthy tissue need to be surgically removed and analyzed using a microscope. Medical practitioners use the melanoma’s thickness, measured in millimetres, and the other attributes described in the Diagnosis to help identify the stage of the disease. 

Medical practitioners also use the results from diagnostic tests to confirm these questions about the stage of melanoma:

  • How thick or deep is the melanoma tumor? Commonly known as primary melanoma or primary tumor. 
  • Where is the tumor exactly located?
  • Has the melanoma spread and spread to the lymph nodes? If so, where and how many?
  • Has the melanoma metastasized to different parts of the body? If Yes, where and how much?

The results are all put together to identify the stage of melanoma for each person. The stages of melanoma include stage 0 and stages I through IV. The stage provides a path of describing cancer, so doctors can work together to create the best treatment plan and understand a patient’s prognosis.

The staging system uses the pathologic stage, also known as the surgical stage. By evaluating the removed tissue during an operation, doctors are able to identify this. Surgery might not always be the answer sometimes(or at all). Doctors instead give a clinical stage to cancer. This is identified based on the results of physical exams, biopsies, and imaging tests explained in the melanoma skin cancer trials. The clinical-stage will be used to assist the plan of treatment. Cancer has sometimes developed and spread farther than the clinical stage estimates, so it may not predict a person’s outlook as accurately as a pathologic stage. 

Melanoma stage grouping

Stage 0

Melanoma in situ are the melanoma cells that are only in the epidermis or outer layer of the skin. Melanoma is unlikely to spread to other regions of the body at this stage.

Stage I:

The original melanoma is still limited to the skin and is relatively thin. Depending on the thickness of the melanoma and whether a pathologist finds ulceration under a microscope, Stage I is separated into two subgroups, IA and IB.

Stage II:

Melanoma in stage II is thicker than melanoma in stage I, extending through the epidermis and deeper into the dermis, the skin’s dense inner layer. It has a more significant potential for spreading. Stage II is classified into three subgroups based on the thickness of the melanoma and the presence of ulceration: A, B, or C.

Stage III:

In-transit metastasis, satellite metastasis, or microsatellite disease defines melanoma that has progressed locally or through the lymphatic system to a regional lymph node near where cancer started or to a skin spot on the way to a lymph node. The lymphatic system, which is part of the immune system, drains fluid from bodily tissues via a network of tubes and arteries. Depending on the size and number of lymph nodes associated with melanoma, if the primary tumour contains satellite or in-transit lesions, and whether it appears ulcerated under a microscope, Stage III is categorized into four subgroups: A, B, C, or D.

Stage IV:

Melanoma that has spread to other body regions through the bloodstream, such as distant sites on the skin or soft tissue, remote lymph nodes, or other organs such the lung, liver, brain, bone, or gastrointestinal tract, is classified as this stage. To evaluate Stage IV further, the location of distant metastases taken into consideration:

  • M1a: Cancer has only matured and spread to distant skin and soft-tissue sites.
  • M1b: Cancer has matured and spread to the lungs
  • M1c: Cancer has matured and spread to any other position that does not involve the central nervous system known as the CNS.
  • M1d: Cancer has matured and spread to the central nervous system, including the brain, spinal cord, and cerebrospinal fluid, lining the brain and spinal cord.


Recurrent melanoma occurs when melanomas return or come back after the treatment is complete. If and when the melanoma does return, there will be a couple of tests to understand the extent of the recurrence, and these tests may be similar to those done at the time of the original Diagnosis.