Comparison of seventh and eighth edition of AJCC staging system in melanomas at locoregional stage

BackgroundThe eighth edition of the American Joint Committee on Cancer (AJCC) staging system has been effective since January 2018. It has introduced some major changes in the localized/locoregional melanoma classification. However, it has not been demonstrated how this classification was validated on external, clinical data.Patients and methodsIn this retrospective study, we have included 2474 patients diagnosed with cutaneous melanoma in localized or locoregional stage. They were treated surgically in our Center between years 1998 and 2014. Melanoma-specific and overall survival were calculated for each stage according to TNM7 and TNM8 using Kaplan-Meier estimator.ResultsThe melanoma-specific survival rates in our patients were similar to those reported from original cohort used to build TNM8 classification except for stage IIIC (5-year melanoma-specific survival 44.6% vs 51.8%, respectively for TNM7 vs TNM8).ConclusionOur study validated the eighth edition of TNM melanoma staging system as a viable tool in prognosis of the long-term survival of patients with localized or locoregionally advanced melanoma on an independent cohort. The new TNM 8 system has brought important improvements in prognostic assessment for melanoma patients. Deeper understanding of the significance of satellite/in-transit lesions may be required.