External validation of a prognostic model to predict survival of patients with sentinel node-negative melanoma

Abstract

Background Identifying patients with sentinel node‐negative melanoma at high risk of recurrence or death is important. The European Organisation for Research and Treatment of Cancer (EORTC) recently developed a prognostic model including Breslow thickness, ulceration and site of the primary tumour. The aims of the present study were to validate this prognostic model externally and to assess whether it could be improved by adding other prognostic factors. Methods Patients with sentinel node‐negative cutaneous melanoma were included in this retrospective single‐institution study. The β values of the EORTC prognostic model were used to predict recurrence‐free survival and melanoma‐specific survival. The predictive performance was assessed by discrimination (c‐index) and calibration. Seeking to improve the performance of the model, additional variables were added to a Cox proportional hazards model. Results Some 4235 patients with sentinel node‐negative cutaneous melanoma were included. The median follow‐up time was 50 (i.q.r. 18·5–81·5) months. Recurrences and deaths from melanoma numbered 793 (18·7 per cent) and 456 (10·8 per cent) respectively. Validation of the EORTC model showed good calibration for both outcomes, and a c‐index of 0·69. The c‐index was only marginally improved to 0·71 when other significant prognostic factors (sex, age, tumour type, mitotic rate) were added. Conclusion This study validated the EORTC prognostic model for recurrence‐free and melanoma‐specific survival of patients with negative sentinel nodes. The addition of other prognostic factors only improved the model marginally. The validated EORTC model could be used for personalizing follow‐up and selecting high‐risk patients for trials of adjuvant systemic therapy.

Proposed quality performance indicators of sentinel lymph node biopsy for cutaneous melanoma

“…The performance benchmark of SLNB should be set by world-leading tertiary institutions and we have compared our results against the outcomes of the Sentinel Lymph Node Working Group, Melbourne Melanoma Project and Melanoma Institute Australia who recently published FNR results of 10.3%, 10.1% and 15.9%, respectively; with notable contributors to these studies being the California Pacific Medical Center, Mayo Clinic, The Alfred Hospital, Royal Prince Alfred Hospital and University of Sydney. [37][38][39] Given our findings and current evidence, we recommend an FNR of less than 15% be used as a QPI. The 13.7% complication rate in our study is comparable to other papers with rates ranging from 9.5% to 25%; Moody et al conducted a systematic review in 2016 identifying an average complication rate of 11.3% across 21 studies.…”

“…The author always has these cases independently reviewed to exclude melanoma micrometastases. The performance benchmark of SLNB should be set by world‐leading tertiary institutions and we have compared our results against the outcomes of the Sentinel Lymph Node Working Group, Melbourne Melanoma Project and Melanoma Institute Australia who recently published FNR results of 10.3%, 10.1% and 15.9%, respectively; with notable contributors to these studies being the California Pacific Medical Center, Mayo Clinic, The Alfred Hospital, Royal Prince Alfred Hospital and University of Sydney 37–39 . Given our findings and current evidence, we recommend an FNR of less than 15% be used as a QPI.…”

Clinical Relevance of Serum Kyn/Trp Ratio and Basal and IFNγ-Upregulated IDO1 Expression in Peripheral Monocytes in Early Stage Melanoma

“…However, this approach allowed us to analyse all samples in the same run (eliminating batch-to-batch variation) and to connect the experimental data with long-term clinical outcome. The necessity of long-term follow-up was evidenced in a large cohort of melanoma patients, in which progression occurred after 5 years or more in 18.2% of progressing patients ( 71 ). Biomarkers that allow earlier identification of patients who have higher risk to progress pave the way to personalized management.…”

Author response to: Comment on: External validation of a prognostic model to predict survival of patients with sentinel node-negative melanoma

“…The authors initially developed and published the European Organisation for Research and Treatment of Cancer (EORTC) calculator for predicting risk of recurrence and melanoma‐specific mortality for sentinel node‐negative melanoma patients. This calculator is now validated through a geographical external study that ensures the transportability of the predictive performance of the model to the Australian population. The AJCC has recognized the importance of accurate individualized prediction models.…”