KAUAI, HAWAII – Melanoma , resulting in an evidence-based improved prognosis for many of them, Laura Korb Ferris, MD, PhD, said at the Hawaii Dermatology Seminar provided by Skin Disease Education Foundation/Global Academy for Medical Education.
, of the department of dermatology, University of Pittsburgh, highlighted some of the key changes in the eighth edition of the , which is now in effect. She also described the clinical implications of important updates introduced in the 2018 National Comprehensive Cancer Network (NCCN) guidelines for the diagnosis and management of melanoma.
The AJCC eighth edition
The eighth edition is built upon an AJCC database of more than 46,000 patients with stage I-III melanoma diagnosed since 1998 at 10 academic medical centers. The AJCC panel made no changes in stage IV melanoma guidance because the newer targeted therapies have rapidly changed treatment outcomes in that setting and longer follow-up is needed to assess the full impact.
The current edition of the AJCC melanoma staging manual creates a new subcategory within pathologic stage III. In the melanoma staging world, that’s exciting news, especially because this change has important implications for prognosis.
This fourth subcategory, stage IIID, is for melanomas, which in the Tumor, Nodes, Metastasis (TNM) classification scheme, are primary tumor stage T4b, meaning greater than 4.0 mm in thickness and with ulceration; regional lymph node N3a, b, or c, based upon the number of metastatic nodes involved and whether they were clinically occult nodal metastases detected by sentinel lymph node biopsy (SLNB) or clinically detected; and M0, meaning no distant metastatic disease. In the 8th edition, the AJCC staging system can be applied in patients with T2 through T4 primary melanoma only if they have undergone SLNB.
This new approach to stage III disease makes for more homogeneous patient subgroups, which in turn provides much better stratification of prognosis than was possible in the seventh edition of the AJCC staging manual, which dates back to 2010. Most strikingly, the 5-year melanoma-specific survival rate for patients with stage IIIA disease was 78% in the seventh edition of AJCC, but it climbs to 93% in the eighth edition. For patients with stage IIIB melanoma, 5-year melanoma-specific survival improved from 59% in the seventh edition to 83% in the current iteration, while in stage IIIC, the jump is from 40% to 69%. All this is made possible because the eighth edition separates out patients with the new stage IIID, whose 5-year melanoma-specific survival is only 32%, Dr. Ferris explained.