Validation of a prognostic calculator to predict recurrence and mortality in melanoma patients undergoing sentinel lymph node biopsy

Abstract

Background

The American Joint Committee on Cancer staging system (AJCC) is currently the gold standard for determining melanoma prognosis. However, it may not accurately reflect survival in certain substages, nor recurrence risk, prompting development of other predictive models. A validated predictive tool has been shown to perform well in two academic centers. We sought to investigate the performance of this nomogram in a regional cancer referral center, with the goal of future use for adjuvant treatment decisions.

Methods

A retrospective review of patients with T1b or greater melanomas, undergoing sentinel lymph node biopsy at a tertiary referral center between January 1, 2005, and June 30, 2022, was performed. Those with microsatellites or in-transit metastasis were excluded. Demographic, pathologic and treatment-related factors were linked to recurrence and survival data. The nomogram was assessed for the ability to discriminate recurrence and survival utilizing 6 prognostic factors (Breslow thickness, ulceration, age, tumour location, sentinel lymph node status and maximal lymph node metastasis diameter).

Results

486 patients were eligible for inclusion. The median age was 64 years (IQR: 54–73), with a Breslow thickness of 1.8 mm (IQR: 1.2–3.0). 95 patients (19.5 %) had pathologically positive sentinel lymph nodes, with 138 patients (28.4 %) developing recurrent disease. When applying this model to our population, the AUC for recurrence-free survival was 0.75 (95 % CI: 0.66–0.84), while melanoma-specific survival was 0.85 (95 % CI: 0.76–0.94).

Conclusion

The melanoma predictive tool performed well at predicting recurrence and survival in our population. The online calculator may assist clinicians advising patients on the merits of adjuvant treatments.