Sentinel node for malignant melanoma: An observational study of a consecutive single centre experience

Identification of high-risk patients with a seven-biomarker prognostic signature for adjuvant treatment trial recruitment in American Joint Committee on Cancer v8 stage I-IIA cutaneous melanoma

PURPOSE

Many patients with resected American Joint Committee on Cancer (AJCC) early-stage cutaneous melanoma nonetheless die of melanoma; additional risk stratification approaches are needed.

PATIENTS AND METHODS

Using prospectively-collected whole-tissue sections, we assessed in consecutive stage I-IIA patients (N = 439), a previously-validated, immunohistochemistry-based, 7-biomarker signature to prognosticate disease-free survival (DFS), melanoma-specific survival (MSS; primary end-point) and overall survival (OS), independent of AJCC classification.

RESULTS

Seven-marker signature testing designated 25.1% of patients (110/439) as high-risk (stage IA, 13.3% [43/323], IB, 53.2% [42/79], and IIA, 67.6% [25/37]). A Kaplan-Meier analysis demonstrated high-risk patients to have significantly worse DFS, MSS and OS versus low-risk counterparts (P < 0.001). In multivariable Cox regression modelling also including key clinicopathological/demographic factors, 7-marker signature data independently prognosticated the studied end-points. Models with the 7-marker signature risk category plus clinicopathological/demographic covariates substantially outperformed models with clinicopathological/demographic variables alone in predicting all studied outcomes (areas under the receiver operator characteristic curve 74.1% versus 68.4% for DFS, 81.5% versus 71.2% for MSS, 80.9% versus 73.0% for OS; absolute differences 5.7%, 10.3% and 7.9%, respectively, favouring 7-marker signature risk category-containing models).

CONCLUSION

In patients with AJCC early-stage disease, the 7-marker signature reliably prognosticates melanoma-related outcomes, independent of AJCC classification, and provides a valuable complement to clinicopathological/demographic factors.

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

BACKGROUND

Melanoma is a leading cause of morbidity and mortality in Australia and New Zealand. New Zealand has the highest melanoma incidence in the world alongside Australia at 54 per 100 000 persons. The aim of this study is to conduct a retrospective quality audit of sentinel lymph nodal biopsy (SLNB) practices from 2007 to 2019 of a high-volume melanoma surgeon. Primary outcome was false negative rate (FNR). Secondary outcomes were sentinel node (SN) identification and removal rate, and complication rates.

METHODS

A database was maintained, containing n = 553 consecutive SLNB's for cutaneous melanoma from 31 August 2007 to 31 August 2019. Patient characteristics and details of the primary lesion, sentinel lymph node biopsy, recurrence and complications were recorded.

RESULTS

SN's were successfully identified in 444 (99.6%) out of 446 patients with an FNR of 9.1%. Positive SN's were identified in 70 (12.7%) SLNB's. Complications occurred in 76 out of 553 (13.7%) SLNB's. A review of internationally published literature reveals an SN identification rate of 94.4-99.5% with an FNR of 4.0-37.5%. SLNB is the best staging tool for melanoma and gives potential access to adjuvant systemic treatment if >1 mm deposits are found. It is a day-stay procedure with a low-complication rate.

CONCLUSION

SLNB is a safe and reliable procedure utilized for cutaneous melanoma. We propose our data should be used alongside international SN series to establish Quality Performance Indicators to improve melanoma management.