Melanoma staging: Evidence‐based changes in the American Joint Committee on Cancer eighth edition cancer staging manual

Abstract

To update the melanoma staging system of the American Joint Committee on Cancer (AJCC) a large database was assembled comprising >46,000 patients from 10 centers worldwide with stages I, II, and III melanoma diagnosed since 1998. Based on analyses of this new database, the existing seventh edition AJCC stage IV database, and contemporary clinical trial data, the AJCC Melanoma Expert Panel introduced several important changes to the Tumor, Nodes, Metastasis (TNM) classification and stage grouping criteria. Key changes in the eighth edition AJCC Cancer Staging Manual include: 1) tumor thickness measurements to be recorded to the nearest 0.1 mm, not 0.01 mm; 2) definitions of T1a and T1b are revised (T1a, <0.8 mm without ulceration; T1b, 0.8–1.0 mm with or without ulceration or <0.8 mm with ulceration), with mitotic rate no longer a T category criterion; 3) pathological (but not clinical) stage IA is revised to include T1b N0 M0 (formerly pathologic stage IB); 4) the N category descriptors “microscopic” and “macroscopic” for regional node metastasis are redefined as “clinically occult” and “clinically apparent”; 5) prognostic stage III groupings are based on N category criteria and T category criteria (ie, primary tumor thickness and ulceration) and increased from 3 to 4 subgroups (stages IIIA–IIID); 6) definitions of N subcategories are revised, with the presence of microsatellites, satellites, or in-transit metastases now categorized as N1c, N2c, or N3c based on the number of tumor-involved regional lymph nodes, if any; 7) descriptors are added to each M1 subcategory designation for lactate dehydrogenase (LDH) level (LDH elevation no longer upstages to M1c); and 8) a new M1d designation is added for central nervous system metastases. This evidence-based revision of the AJCC melanoma staging system will guide patient treatment, provide better prognostic estimates, and refine stratification of patients entering clinical trials.

Melanoma Staging: American Joint Committee on Cancer (AJCC) 8th Edition and Beyond

“…[10][11][12][13] With the proposal in place to record tumor thickness measurements to the nearest 0.1 mm, a 0.8 mm cut point was explored for patients with T1 melanoma along with ulceration and mitosis (i.e., \ 1 vs. C 1 mitosis/mm 2 ). In this analysis, the addition of a 0.8-mm tumor thickness stratum was a more powerful prognostic factor than mitotic rate (as a dichotomous variable).…”

“…As emphasized by the AJCC melanoma expert panel, for these reasons, mitotic rate should be collected for all invasive melanomas. 7,13 Comparison of stages I and II substage melanomaspecific survival rates between the AJCC 7th and 8th editions demonstrate more favorable survival in the 8th edition compared with the 7th edition. An important contributing factor was the requirement that to be included in the 8th edition analysis, SLN biopsy had to be performed for patients with T2 and thicker melanomas, and if performed in patients with a T1 melanoma, the status of the SLN was used.…”

Melanoma Surveillance Strategies: Different Approaches to a Shared Goal

“…With longer follow-up, these patients continue to experience appreciable rates of local, regional, and distant recurrences, and 10-year melanoma-specific survival rates are reported as 75-98%. 3 The optimal intervals for surveillance are undoubtedly influenced by the relative lag in time to recurrence as patients and providers weigh the benefits of ongoing reassurance with the risks of anxiety associated with resource-intensive clinic visits over a long period of time. Also reporting from the Australian experience, a retrospective study of early-stage melanoma patients followed at 3-to 6-month intervals showed that for every 1000 patients, more than 8000 clinic visits were conducted.…”

ECCO essential requirements for quality cancer care for melanoma: Defining how to organise care

“…Sentinel lymph node biopsy (SLNB) is recommended as a diagnostic and staging procedure for patients with melanomas thicker than 1 mm or with additional risk factors and is the strongest prognostic marker. Staging follows the recommendations of the American Joint Committee on Cancer (Gershenwald et al, 2017). …”

“…• Pathologists must establish a correct diagnosis according to the specific tumour entities listed in the WHO classification and must supply a pathology report with a list of items for pathological staging and refinement of prognostic models according to current guidelines (synoptic check-lists or structured reports are preferred) (Gershenwald et al, 2017;Scolyer et al, 2013). …”