Table 3.
Differences Between the 6th Edition (2002) and the Recommended 7th Edition (2009) of the Melanoma Staging System
| Factor | 6th Edition Criteria | Recommended 7th Edition Criteria | Comments |
|---|---|---|---|
| Thickness | Primary determinant of T staging | Same | Thresholds of 1.0, 2.0, and 4.0 mm |
| Level of invasion | Used only for defining T1 melanomas | Same | Used as a default criterion only if mitotic rate cannot be determined |
| Ulceration | Included as a secondary determinant of T and N staging | Same | Signifies a locally advanced lesion; dominant prognostic factor for grouping stages I, II, and III |
| Mitotic rate per mm2 | Not used | Used for categorizing T1 melanoma | Mitosis ≥ 1/mm2 used as a primary criterion for defining T1b melanoma |
| Satellite metastases | In N category | Same | Merged with in transit lesions |
| Immunochemical detection of nodal metastases | Not included | Included | Must include at least one melanoma-associated marker (eg, HMB-45, Melan-A, MART-1) unless diagnostic cellular morphology is present |
| 0.2 mm threshold of defined N+ | Implied | No lower threshold of staging N+ disease | Isolated tumor cells or tumor deposits < 0.1 mm meeting the criteria for histologic or immunohistochemical detection of melanoma should be scored as N+ |
| Number of nodal metastases | Primary determinant of N staging | Same | Thresholds of 1 v 2-3 v 4+ nodes |
| Metastatic volume | Included as a second determinant of N staging | Same | Clinically occult (microscopic) nodes are diagnosed at sentinel node biopsy v clinically apparent (macroscopic) nodes diagnosed by palpation or imaging studies, or by the finding of gross (not microscopic) extracapsular extension in a clinically occult node |
| Lung metastases | Separate category as M1b | Same | Has a somewhat better prognosis than other visceral metastases |
| Elevated serum LDH | Included as a second determinant of M staging | Same | Recommend a second confirmatory LDH level if elevated |
| Clinical v pathologic staging | Sentinel node results incorporated into definition of pathologic staging | Large variability in outcome between clinical and pathologic staging; sentinel node staging encouraged for standard patient care, should be required prior to entry into clinical trials |
Abbreviation: LDH, lactate dehydrogenase.