Need to restage Korean melanoma patients following publication of the 8th edition of the American Joint Committee on Cancer staging manual

Background: The tumor, nodes and metastasis (TNM) classification and stage grouping have been updated in the 8th edition of the American Joint Committee on Cancer (AJCC) melanoma staging manual. However, restaging all the previous cases are not recommended. Aims: The aims of the study were to investigate the necessity of restaging Korean melanoma patients staged by the previous edition of the AJCC manual. Methods: Differences in the staging criteria of the 7th and 8th editions of the AJCC manual were identified. The staging of 276 primary melanomas from January 2011 to December 2018 was classified by both 7th and 8th editions of the manual and their differences were compared. Results: Staging by 7th and 8th edition of the AJCC manual differed in 64 cases (23.2%). The pathological prognostic staging changed in 35 (12.7%), and 29 (10.5%) had changes in only TNM classification but not the pathological staging. None of the patients needed additional sentinel lymph node biopsy or systemic treatment as a result of restaging. Additional counseling was needed for the patients, because melanoma-specific survival was increased in the 8th edition. Limitations: This is a retrospective study with relatively small number of patients at a single tertiary center in Korea. Conclusion: Assessment of the need for additional sentinel lymph node biopsy or systemic treatment is recommended because of the latest changes in the AJCC melanoma staging manual. Although the restaging of previously staged melanomas is not significantly needed in our patients, still the differences in TNM classification and/or pathological prognostic staging suggest the need to separately recognize the patients previously staged by 7th edition and recently staged by 8th edition. Careful counseling about melanoma-specific survival is needed for Asian patients.