Melanoma staging: Evidence‐based changes in the American Joint Committee on Cancer eighth edition cancer staging manual
- Study type
- Clinical guideline
- Study name
- AJCC 8th Edition Melanoma Staging
- Design
- Evidence-based update of the staging system, based on analysis of a large multicentre database, the 7th edition stage IV database and data from contemporary clinical trials
- Sample size
- More than 46,000 patients with stage I, II and III melanoma from 10 centres worldwide
- Source
- CA A Cancer J Clinicians · 2017
In plain words
Staging shows how far a melanoma has spread and helps the doctor decide on the best treatment plan and outlook. In the 8th edition, this system was updated using information from more than 46,000 patients. Features such as the thickness of the tumour, ulceration (a break in the skin over it), spread to the lymph nodes, the LDH blood level and spread to the brain and spinal cord are now taken into account more precisely. Talk to your own doctor about the stage of your disease.
Key points
Key guideline recommendations
Tumour thickness should be recorded to the nearest 0.1 mm, not 0.01 mm.
T1a is defined as less than 0.8 mm without ulceration and T1b as 0.8 to 1.0 mm with or without ulceration, or less than 0.8 mm with ulceration; mitotic rate is no longer a T-category criterion.
Pathological (not clinical) stage IA includes T1b N0 M0 (previously pathological stage IB).
The "microscopic" and "macroscopic" N-category descriptors for regional nodal metastases are changed to "clinically occult" and "clinically apparent".
Prognostic stage III groupings are based on N-category and T-category criteria (primary tumour thickness and ulceration) and increase from 3 to 4 subgroups (IIIA to IIID).
The presence of microsatellite, satellite or in-transit metastases is categorised as N1c, N2c or N3c depending on the number of tumour-involved regional lymph nodes (if any).
An LDH level descriptor is added to each M1 subcategory; elevated LDH no longer upstages to M1c.
A new M1d category is added for central nervous system metastases.
Study population
Patients with stage I, II and III melanoma diagnosed from 1998 onwards (from 10 centres worldwide). In addition, the AJCC 7th edition stage IV database and data from contemporary clinical trials were examined.
Endpoints
The aim was to update the TNM classification and stage grouping criteria for melanoma in the AJCC 8th edition based on analysis of the databases mentioned. Details of the statistical methods and analysis endpoints are given in the full text of the paper.
Safety and side effects
This is not an interventional study and reports no safety or treatment adverse-event data.
Clinical significance and place in guidelines
According to the abstract, this evidence-based revision of the AJCC melanoma staging system guides patient treatment, provides better prognostic estimates and refines the stratification of patients entering clinical trials. The main changes include recording tumour thickness to 0.1 mm, removing mitotic rate from the T criteria, four subgroups for stage III, adding an LDH descriptor to the M1 categories and a new M1d category for central nervous system metastases. The date and status of implementation of this edition in each country or centre, and its concordance with current clinical guidelines, should be checked separately.
Limitations
The abstract does not report the level of evidence or grade of recommendations. The stage I to III data came from 10 centres and from patients diagnosed from 1998 onwards. Details of the methodology, survival results for each stage and limitations are given in the full text of the paper.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.