American Joint Committee on Cancer (2000, 2001)

 
The most recent effort at staging melanoma was that undertaken preliminarily by the AJCC in 200016 and officially by it in 2001.17 This is how the latest endeavor of the AJCC reads:
 
Stage IA. Thickness < 1.0 mm without ulceration and level II/III
Stage IB. Thickness < 1.0 mm with ulceration or level IV/V
Or Thickness 1.01 to 2.0 mm without ulceration
Stage IIA. Thickness 1.01 to 2.0 mm with ulceration
Or Thickness 2.01 to 4.0 mm without ulceration
Stage IIB. Thickness 2.01 to 4.0 mm with ulceration
Or Thickness >4.0 mm without ulceration
Stage IIC. Thickness >4.0 mm with ulceration
Stage IIIA. Findings from Stages IA-IIB and micrometastases in 1 to 3 lymph nodes
Stage IIIB. Findings from Stage IIC and micrometastases in 1 to 3 lymph nodes
Or Findings from Stages IA-IIB and macrometastasis to 1 to 3 lymph nodes
Or Findings from Stages IA-IIC and in-transit metastasis without positive nodes
Stage IIIC. Findings from Stages IA-IIC and macrometastasis to 1–3 lymph nodes
Or 4 or more metastatic nodes / matted nodes
Or in-transit metastasis with positive lymph nodes
Stage IV. Distant skin, subcutaneous, or nodal metastasis
Or visceral metastasis
Or any distant metastasis with elevated serum lactate dehydrogenase (LDH)
 
How ironic it is that one of the five criteria considered paramount by the AJCC in regard to its system of staging was that it be "easy" to use! The system set forth by the AJCC in 2001 is the most complicated system to date, rendering it virtually unworkable. For practical purposes, the latest system of the AJCC does away with all the criteria that heretofore the committee itself had held dear, chief among those being Clark's levels. In addition, thresholds for measuring melanoma were changed dramatically from those proposed by Breslow, that is, < 0.75 mm, 0.76 to 1.5 mm, > 1.5 mm, to < 1.0 mm, 1.01 to 2.0 mm, 2.01 to 4.0 mm and > 4.0 mm. This change in numbers complicates further the ability to perform comparisons between statistics generated in regard to melanomas staged with this system and those staged differently in the past.
 
New criteria given importance by the AJCC are ulceration, macrometastasis versus micrometastasis, and elevation of the enzyme LDH. The addition of ulceration is particularly enigmatic when one considers that ulceration may be a mere consequence of external trauma. The AJCC distinguishes between macrometastases, namely, those evident clinically, and micrometastases, to wit, those visualizable only by microscopy, and assigns different clinical significance to them. That distinction also seems to be contrived; a metastasis is a metastasis, irrespective of its size.
 
By invoking macro- and micrometastases, the AJCC reverted to the days of Ackerman and Del Regato in 1947 when lymph node dissection was deemed to be obligatory rather than elective, and cancers were staged according to whether lymph nodes affected were apparent clinically and/or histopathologically or seemingly not at all. This is what those co-authors wrote then: "When a tumor is located in an area from which lymphatic drainage is predictable, a radical dissection of the anticipated metastatic node areas is mandatory."