Treatment for Melanoma

Melanoma care with Northwestern Medicine Dermatology


Melanoma is one of the more dangerous types of skin cancer. It is responsible for the greatest number of skin cancer deaths. According to the American Cancer Society, there are over 106,000 new melanomas diagnosed each year, as well as over 7,000 deaths.1 While this can stem from existing moles, more often, it shows up suddenly on healthy skin. Once a melanoma develops, it may spread to other areas of the body. This serious skin cancer is highly curable if caught early. This is why early diagnosis and treatment are critical.

Your clinician uses staging to help decide your treatment. Breslow thickness is the depth of the primary tumor’s vertical invasion into the skin. This is the most important factor your physician uses to determine your prognosis.2

T Category Breslow Thickness (millimeters) Ulceration Status
T1a less than or equal to 0.8 without
T1b 0.8 - 1.0 with or without
T2a greater than 1.0 - 2.0 without
T2b greater than 1.0 - 2.0 with
T3a greater than 2.0 - 4.0 without
T3b greater than 2.0 - 4.0 with
T4a greater than 4.0 without
T4b greater than 4.0 with

*The presence of ulceration (a break in the skin causing both loss of the epidermis and exposure of the underlying dermis) automatically upgrades the sub-category from “a” to “b.”3

TNM Staging System
Melanoma is usually staged using the American Joint Committee on Cancer’s TNM staging system. Staging a tumor helps your physician understand the prognosis or outlook for what the disease course may look like. The TNM stage also helps your physician decide the best course of treatment and follow-up monitoring.

There are three main components of the TNM staging system:

  • T – Primary Tumor. This is calculated based on how deep (in millimeters) the tumor cells reach into the layers of the skin. It is recorded as the Breslow thickness as well as the presence or absence of ulceration.
  • N – Nodal involvement. This component is based on if any tumor cells are detected in lymph nodes next to the main site where the melanoma was found.
  • M – Metastasis. This component measures any spread of the tumor to distant body sites.

Lower numbers in each category correspond to a more favorable prognosis. For instance, a melanoma stage T1aN0M0 has a better prognosis than a melanoma stage T2bN1M1. Together, the combination of the three numbers forms a clinical stage. Your physician uses this to guide how to treat the melanoma and monitor for recurrence or progression of disease.

We also use other staging tools such as the online AJCC calculator and molecular staging tools involving gene expression profiling.


The melanoma stage has a significant role in determining treatment. After a melanoma is confirmed via biopsy, your dermatologist will make treatment suggestions based on the melanoma’s stage, your genetic profile and your overall health.


  1. Survival Rates for Melanoma Skin Cancer. American Cancer Society. Accessed September 15th, 2021.
  2. Balch CM, Soong S-J, Gershenwald JE, et al. Prognostic factors analysis of 17,600 melanoma patients: validation of the American Joint Committee on Cancer melanoma staging system. Journal of clinical oncology. 2001;19(16):3622-3634.
  3. Gershenwald JE, Scolyer RA, Hess KR, et al. Melanoma staging: evidenceā€based changes in the American Joint Committee on Cancer eighth edition cancer staging manual. CA: a cancer journal for clinicians. 2017;67(6):472-492.