The extensive global use of Melanoma Institute Australia’s online tool for estimating the risk of nodal metastasis in newly diagnosed melanoma patients has prompted an international study to validate its accuracy and improve its precision across diverse populations worldwide.

The MIA Sentinel Node Metastasis Risk calculator was the first tool launched on the growing www.melanomarisk.org.au platform, which now features six tools designed to inform patient care.

The calculator was developed using data from 3,477 Australian patients in MIA’s database. It uses six input parameters – age, Breslow thickness, melanoma subtype, tumour mitotic rate, presence of ulceration and lymphovascular invasion – to determine the risk a newly diagnosed melanoma patient’s disease has spread to their lymph nodes at a level only microscopically detectable.

A surgically invasive sentinel node biopsy (SNB) is the only way to determine if lymph node spread has occurred for most melanomas when they are first diagnosed. Traditionally, the guidelines for selection of patients for SNB has largely been based on the Breslow thickness of the primary melanoma alone. However, this study has shown that using the six parameter MIA tool is much better than traditional methods for patient selection.

Since its release in August 2020, the Sentinel Node Metastasis Risk online calculator has been used over 130,000 times per year for new cases.

Associate Professors Alexander Varey and Serigne Lo, who led the Melanoma Institute Australia melanoma risk platform, developed the international cohort study protocol and invited international colleagues to contribute data.

A pooled analysis of 15,731 patients from six countries demonstrated that the MIA calculator is robust and valid across diverse populations, with results released today in JAMA Dermatology.

‘An estimated 350,000 new melanoma cases are diagnosed globally each year, meaning this risk tool is being used for over one third of all melanoma cases across the world,’ A/Prof Lo said.

‘These findings reinforce the tool’s reliability in predicting the risk a melanoma has spread to the lymph nodes in diverse patient groups, providing clinicians worldwide with greater confidence in its use for everyday practice,’ A/Prof Varey added.

The JAMA Dermatology paper “Global Applicability of a Risk Prediction Tool for Sentinel Node Positivity in Patients With Primary Cutaneous Melanoma” can be accessed here.