Prognosis of Patients With Primary Melanoma Stage I and II According to American Joint Committee on Cancer Version 8 Validated in Two Independent Cohorts: Implications for Adjuvant Treatment

Abstract

Purpose: The first randomized trial of adjuvant treatment with checkpoint inhibitor in stage II melanoma reported a significant reduction in risk of tumor recurrence. This study evaluates two independent data sets to further document survival probabilities for patients with primary stage I and II melanoma.

Patients and methods: The Central Malignant Melanoma Registry (CMMR) in Germany evaluated 17,544 patients with a primary diagnosis of stage I and II melanoma from 2000 to 2015. The exploratory cohort consisted of 6,725 patients from the Center for Dermato-Oncology at the University of Tübingen, and the confirmatory cohort consisted of 10,819 patients from 11 other German centers. Survival outcomes were compared with published American Joint Committee on Cancer version 8 (AJCCv8) stage I and II survival data.

Results: For the two CMMR cohorts in stage IA compared with the AJCCv8 cohort, melanoma-specific survival rates at 10 years were 95.1%-95.6% versus 98%; 89.7%-90.9% versus 94% in stage IB; 80.7%-83.1% versus 88% in stage IIA; 72.0%-79.9% versus 82% in stage IIB; and 57.6%-64.7% versus 75% in stage IIC, respectively. Recurrence rates were approximately twice as high as melanoma-specific mortality rates in stages IA-IIA.

Conclusion: The melanoma-specific survival rates in the two CMMR cohorts across stages I and II are less favorable than published in AJCCv8. This has important implications for the consideration of adjuvant treatment in this population.

FIG 1.

Survival rates and patient number at risk for stage I and II melanoma, according to American Joint Committee on Cancer version 8: (A) MSS, CMMR exploratory cohort; (B) MSS, CMMR confirmatory cohort; (C) OS, exploratory cohort; (D) OS, confirmatory cohort; (E) RFS, exploratory cohort; and (F) RFS, confirmatory cohort. CMMR, Central Malignant Melanoma Registry; MSS, melanoma-specific survival; OS, overall survival; RFS, recurrence-free survival.

FIG 2.

The MSS of patients with primary melanoma staged according to the AJCC classification version 8 was substantially lower in the CMMR in Germany compared with the IMDDP published with the AJCC classification version 8. Patients with stage IB and above are sentinel lymph node biopsy staged. Curves were generated using an interactive digitizing software program (DigitizeIt) on the basis of the originals. (A) Patients in the exploratory cohort of the CMMR with first diagnosis in 2000-2015 (n = 6,725). (B) Patients in the IMDDP diagnosed since 1998 (n = 15,691). AJCC, American Joint Committee on Cancer; CMMR, Central Malignant Melanoma Registry; IMDDP, International Melanoma Database and Discovery Platform; MSS, melanoma-specific survival.

FIG A1.

Hazard rates for stage I and II melanoma, according to AJCCv8 for total collective (N = 17,544): (A) death due to melanoma and (B) death due to other causes. AJCCv8, American Joint Committee on Cancer version 8.