56: International Validation Study of the Melanoma Institute Australia Sentinel Node Metastasis Risk Nomogram

Friday, March 24, 2023

10:14 AM – 10:24 AM

Location: Veterans Memorial Auditorium

First Author(s)

SL

Serigne Lo, MSc, PhD

A/prof
Melanoma Institute Australia; The University of Sydney, United States

Disclosure(s): No financial relationships to disclose

Author(s)

Caroline Gjorup, MD, PhD, FEBOPRAS

Fellow
Melanoma Institute Australia; The University of Sydney, New South Wales, Australia

Disclosure(s): No financial relationships to disclose
AH

Annette Hougaard Chakera, MD, PhD

Consultant plastic surgeon
Department of Plastic Surgery, Herlev University Hospital, Denmark, United States

Disclosure information not submitted.
LR

Lisbet Rosenkrantz Hölmich, MD, dr.med.

Professor
Department of Plastic Surgery, Herlev University Hospital, University of Copenhagen, United States

Disclosure information not submitted.
Marc D. Moncrieff, MD FRCS(Plast.)

Professor of Plastic and Reconstructive Surgery
Norfolk & Norwich University Hospital
Norwich, United Kingdom

Disclosure(s): No financial relationships to disclose
AR

Alistair Ross, MD, FRCS

Consultant plastic surgeon
Department of Plastic Surgery Guy's and St Thomas' NHS Foundation Trust London, United Kingdom, United States

Disclosure information not submitted.
OC

Oliver Cassell, MB ChB, FRCS (Ed), FRCS (Plast), MS

Consultant plastic surgeon
Oxford University Hospitals NHS Foundation Trust, UK, United States

Disclosure information not submitted.
JM

Jiawen Ma, MD

Dr
Melanoma Institute Australia, United States

Disclosure information not submitted.
RO

Roger Olofsson Bagge, MD, PhD

A/prof
Department of Surgery, Sahlgrenska University Hospital, Sweden, United States

Disclosure information not submitted.
EB

Eduardo Bertolli, MD, PhD

Surgical Oncologist
Hospital A. C. Camargo Cancer Center, São Paulo, Brazil, United States

Disclosure information not submitted.
CS

Cimarron Sharon, MD

Dr.
Hospital of the University of Pennsylvania, US, United States

Disclosure information not submitted.
Giorgos Karakousis, MD

Professor of Surgery
Hospital of the University of Pennsylvania
Philadelphia, Pennsylvania, United States

Disclosure information not submitted.
MK

Mohammed Kashani-Sabet, MD

Dr.
California Pacific Medical Center, San Francisco, CA, United States

Disclosure information not submitted.
GA

George Adigbli, MRCS, DPhil

Academic Clinical Fellow & Specialty Registrar in Plastic Surgery
Nuffield Dept. of Surgical Sciences, University of Oxford
Oxford, England, United Kingdom

Disclosure information not submitted.
RS

Richard Scolyer, BMedSci, MBBS, MD, FRCPA, FRCPath, FAHMS

Professor
Melanoma Institute Australia and Faculty of Medicine and Health, The University of Sydney, Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital and NSW Health Pathology, Sydney,, United States

Disclosure information not submitted.
John Thompson, MD

Emeritus Professor Melanoma and Surgical Oncology
Melanoma Institute Australia, The University of Sydney
North Sydney, New South Wales, Australia

Disclosure information not submitted.

Abstract Presenter(s)

Alexander H. Varey, MBChB MRCS(Eng) FRACS FRCS(Plast) PhD (he/him/his)

A/Prof
Melanoma Institute Australia; Department of Plastic Surgery, Westmead Hospital; Faculty of Medicine and Health, The University of Sydney
North Sydney, New South Wales, Australia

Disclosure(s): Novartis Pharmaceuticals Australia Pty Ltd: Speaker (Terminated, May 1, 2022)

Disclosure(s):

Serigne Lo, MSc, PhD: No financial relationships to disclose

Caroline Gjorup, MD, PhD, FEBOPRAS: No financial relationships to disclose

Marc D. Moncrieff, MD FRCS(Plast.): No financial relationships to disclose

Alexander H. Varey, MBChB MRCS(Eng) FRACS FRCS(Plast) PhD: Novartis Pharmaceuticals Australia Pty Ltd: Speaker (Terminated, May 1, 2022)

Introduction: Calculating an accurate prognosis for newly diagnosed melanoma patients is achieved by performing sentinel lymph node biopsy (SNB) at the time of wide local excision of the primary tumour. The Melanoma Institute Australia Nomogram was developed in 2020 using 3477 patients from the Melanoma Institute Australia (MIA) institutional database and validated using 3496 patients from the MD Anderson Cancer Center melanoma database. To ensure applicability of the MIA nomogram worldwide, however, the MIA nomogram’s predictive performance should be assessed using melanoma patient data from around the world.

Methods: This retrospective validation study collected data from the national Danish Melanoma Database, and from seven cancer centres (Sweden, UK, USA, and Brazil). Demographic and primary tumor parameters relevant to the nomogram (age, Breslow tumour thickness, melanoma subtype, presence of ulceration, mitotic rate, and lymphovascular invasion) as well as SN status were collected. The discrimination index (AUC) and calibration plot analysis were performed on the pooled cohort. Subgroup analysis was conducted by country.

Results: The pooled cohorts consisted of 15,282 patients (Table 1) including 2819 with all 6 required parameters available. Patients with missing 1, 2 or 3 optional parameters were 8715, 3646, 102, respectively. The AUC was 71.1% (95% CI 70.0 – 72.2%) for the whole cohort. This increased to 73.3% (95% CI 70.8 - 75.8%) in the subset with all 6 parameters available. When 1, 2 or 3 optional parameters were missing, the AUCs were 70.9% (95% CI 68.3 - 71.7), 72.7% (95% CI 70.9 - 74.5) and 71.9% (95% CI 60.0 - 83.7), respectively. The AUC by country varied from 69.7% to 73.4%. The calibration was excellent with an intercept and calibration slope of 0.03 and 0.98, respectively.

Conclusions: The results demonstrated the generalisability of the MIA nomogram to a wider melanoma population. Furthermore, the nomogram retained good predictive performance even when up to three of the optional parameters were missing. Therefore, use of the nomogram can spare low-risk patients the inconvenience, cost and potential risks of SN biopsy while ensuring that high-risk patients are offered the SN procedure.

Learning Objectives:

Upon completion, participant will be able to list the countries in which the MIA sentinel node metastasis risk calculator has been validated.
Upon completion, participant will be able to describe the C-statistics for the MIA sentinel node metastasis risk calculator in the validation cohorts.
Upon completion, participant will be able to determine the validity of using the MIA sentinel node metastasis risk calculator in their own institution.