Melanoma (staging)

Melanoma cancer staging refers to TNM classification of primary cutaneous melanoma. The system does not apply to the primary non-cutaneous melanomas. The following article reflects the 8^th edition manual published by the American Joint Committee on Cancer (AJCC), which has been used for staging since January 1, 2018 ¹.

Primary tumor (T)

• TX: primary tumor thickness cannot be assessed

• T0: no evidence of primary tumor

• Tis: melanoma in situ, including lentigo maligna and superficial spreading melanoma

• T1: ≤1 mm in maximum thickness recorded to nearest 0.1mm (not nearest 0.01 mm)

  • T1a: <0.8 mm without ulceration (U-)

  • T1b: <0.8 mm with ulceration (U+) or 0.8-1.0 mm with or without ulceration

• T2: >1 mm but ≤2 mm

  • T2a: >1.0-2.0 without ulceration

  • T2b: >1.0-2.0 with ulceration

• T3: >2.0 mm but ≤4.0 mm

  • T3a: >2.0-4.0 without ulceration

  • T3b: >2.0-4.0 with ulceration

• T4: >4.0 mm

  • T4a: >4.0 mm without ulceration

  • T4b: >4.0 mm with ulceration

Regional lymph node (N)

• N0: no evidence of nodal metastasis (by imaging, clinical examination or pathological evaluation)

• N1: one involved node or any in-transit (ITM), satellite, and/or microsatellite metastases with no tumor-involved nodes

  • N1a: one clinically occult node (i.e. detected by sentinel lymph node biopsy SLNB). No ITM/satellite/microsatellites

  • N1b: one clinically detected node. No ITM/satellite/microsatellites

  • N1c: no regional node disease but presence of in-transit (ITM), satellite, and/or microsatellite metastases

• N2: 2 or 3 tumor-involved nodes or in-transit, satellite, and/or microsatellite metastases with 1 tumor-involved node

  • N2a: 2 or 3 clinically occult (i.e. detected by SLNB). No ITM/satellite/microsatellites

  • N2b: 2 or 3, at least 1 of which was clinically detected. No ITM/satellite/microsatellites

  • N2c: 1 clinically occult or clinically detected with presence of in-transit (ITM), satellite, and/or microsatellite metastases

• N3: ≥4 tumor-involved nodes or in-transit, satellite, and/or microsatellite metastases with ≥2 tumor-involved nodes, or any number of matted nodes without or with in-transit, satellite, and/or microsatellite metastases

  • N3a: ≥4 clinically occult (i.e. detected by SLNB). No ITM/satellite/microsatellites

  • N3b: ≥4, at least 1 of which was clinically detected, or presence of any number of matted nodes. No ITM/satellite/microsatellites

  • N3c: ≥2 clinically occult or clinically detected and/or presence of any number of matted nodes with presence of in-transit (ITM), satellite, and/or microsatellite metastases

Distant metastases (M)

• M0: no clinical or radiographic evidence of distant metastases

• M1: evidence of distant metastases with or without elevation of serum lactate dehydrogenase (LDH) level indicated by (1): LDH elevated or (0): not elevated

  • M1a: distant metastasis to skin, soft tissue including muscle, and/or nonregional lymph node

    • M1a(0): LDH not elevated

    • M1a(1): LDH elevated

  • M1b: distant metastasis to lung with or without M1a sites of disease

    • M1b(0): LDH not elevated

    • M1b(1): LDH elevated

  • M1c: distant metastasis to non-CNS visceral sites with or without M1a or M1b sites of disease

    • M1c(0): LDH not elevated

    • M1c(1): LDH elevated

  • M1d: distant metastasis to CNS with or without M1a, M1b, or M1c sites of disease

    • M1c(0): LDH not elevated

    • M1c(1): LDH elevated

Stage groups

AJCC Prognostic Stage Groups

Stage is defined at different time points in the care of the cancer patient and are based on the continuum of assessment – Clinical (cTNM) – Pathological (pTNM) – Post therapy (ycTNM or ypTNM) – Recurrence (rTNM) and Autopsy (aTNM). A summary of the pathological stage (pTNM) is provided below.

• stage 0

  • pTis N0 M0 

• stage IA

  • pT1a N0 M0

  • pT1b N0 M0

• stage IB

  • pT2a N0 M0

• stage IIA

  • pT2b N0 M0

  • pT3a N0 M0

• stage IIB

  • pT3b N0 M0

  • pT4a N0 M0

• stage IIC

  • pT4b N0 M0

• stage IIIA

  • pT1a-T2a; N1a/N2a; M0

• stage IIIB

  • pT0-T3a; N1a-N2b; M0

• stage IIIC

  • pT0-T4b; N2b-N2c; M0

• stage IIID

  • pT4b; N3a-N3c; M0

• stage IV

  • [Any pT], [Any N], M1a-d

Treatment and prognosis:

Estimated five year survival rates ⁴:

• stage I

  • IA ~ 99%

  • IB ~ 97%

• stage II

  • IIA ~ 94%

  • IIB ~ 87%

  • IIC ~ 82%

• stage III

  • IIIA ~ 93%

  • IIIB ~ 83%

  • IIIC ~ 69%

  • IIID ~32%

• stage IV

  • IV < 10%

See also

• primary cutaneous melanoma

• malignant melanoma

• malignant melanoma metastasis

• cancer staging list