Level of Evidence Review for a Gene Expression Profile Test for Cutaneous Melanoma

Temporal Recurrence of Cutaneous Melanoma: Analysis of a Case Series

Introduction

The recurrence of cutaneous melanoma is one of the main reasons for surveillance after primary tumor treatment, and there is still little data on melanoma recurrence related to the Brazilian population.

Objective

We sought to evaluate the profile of patients with cutaneous melanoma recurrence within five years of (early) and five years after (late) initial diagnosis.

Methods

Patients diagnosed between 2006 and 2014 in a private reference service in Belo Horizonte, Brazil, were included. Demographic, clinical, histopathological, and disease evolution variables were collected and analyzed using the R version 4.0.0 program. A p-value less than 0.05 was considered significant.

Results

The sample was composed of 331 patients with melanoma, and the 43 patients with recurrence presented with higher mean age (p=0.049), male predominance (p=0.030), a lower proportion of Breslow thickness under 0.8mm (p<0.001), and a more significant presence of mitosis (p=0.007). The 29 patients (8.8%) with early recurrence presented with tumors with ulceration (p<0.018). Late recurrence occurred in 14 patients (4.2%). Five patients relapsed after 10 years; most of them had tumors up to 1mm thick, without ulceration, regression, or satellitosis, but with the presence of mitosis.

Conclusion

The possibility of cutaneous melanoma recurrence after five, and even 10, years, although rare, might indicate the need for longer medical follow-up. Multicenter studies may better characterize Brazilian patient profiles of those with early and late recurrence of melanoma.

Using Gene Expression Profiling to Personalize Skin Cancer Management

Risk-stratification of cancer, traditionally performed through staging, directs optimal disease management decisions with the result of improved patient outcomes. Many forms of cutaneous cancer have overall excellent survival rates, but conventional staging methods are imperfect in identifying high-risk patients. Gene expression profiling (GEP) is a clinically available, objective metric that can be used in conjunction with traditional clinicopathological staging to help clinicians stratify risk in patients with skin cancer, even in those who lack traditional risk markers. For patients with melanoma, the 31-GEP test provides personalized prognostic information that can guide risk-appropriate clinical management and surveillance decisions. The i31-GEP integrates 31-GEP results with clinicopathological features to provide a risk of recurrence (i31-GEP for ROR) and likelihood of having a positive sentinel lymph node biopsy (SLNB) (i31-GEP for SLNB) for patients with melanoma. For patients with cutaneous squamous cell carcinoma who have at least one risk factor, the 40-GEP test allows for better risk stratification by identifying the high-risk patients who are most likely to develop metastasis. These tests can be easily integrated into clinical practice to help guide treatment choices.

Cross-Platform Omics Prediction procedure: a statistical machine learning framework for wider implementation of precision medicine

In this modern era of precision medicine, molecular signatures identified from advanced omics technologies hold great promise to better guide clinical decisions. However, current approaches are often location-specific due to the inherent differences between platforms and across multiple centres, thus limiting the transferability of molecular signatures. We present Cross-Platform Omics Prediction (CPOP), a penalised regression model that can use omics data to predict patient outcomes in a platform-independent manner and across time and experiments. CPOP improves on the traditional prediction framework of using gene-based features by selecting ratio-based features with similar estimated effect sizes. These components gave CPOP the ability to have a stable performance across datasets of similar biology, minimising the effect of technical noise often generated by omics platforms. We present a comprehensive evaluation using melanoma transcriptomics data to demonstrate its potential to be used as a critical part of a clinical screening framework for precision medicine. Additional assessment of generalisation was demonstrated with ovarian cancer and inflammatory bowel disease studies.

Picomets: Assessing single and few cell metastases in melanoma sentinel lymph node biopsies

BACKGROUND

Lymph node involvement is a significant prognostic factor for melanoma. Both number of positive nodes and disease burden within a lymph node affects survival. However, the significance of few tumor cells within a single node and subsequent optimal management remains without consensus. We investigated the implications of minimal nodal disease on clinical outcomes.

METHODS

We reviewed 752 patients who underwent lymph node sampling at time of primary melanoma resection at our institution over 15 years. We deemed patients who had 1 node with 1 to 4 atypical cells staining positive for either Melan-A or Sox-10 as having "picomets." We examined the initial clinicopathological features, subsequent management, and outcomes.

RESULTS

Thirty-three patients (4%) met criteria for having picomets. The most common number of positively staining atypical cells was 1 (n = 13). Nodal staging at initial pathology review varied, and overall stage ranged from IA to IIIC. Four patients underwent further therapy, none of whom had recurrent disease. Of the 29 patients undergoing observation/surveillance only, 5 had disease recurrence (17%).

CONCLUSION

Although patients with picomets had better outcomes than historical stage matched cohorts, a small subset had recurrent disease. Staging patients with picomets as "N0" may not reflect the true negative prognostic significance of picomets. A larger population of patients meeting picomets criteria is needed to draw further conclusions.

Exosomes: Emerging Diagnostic and Therapeutic Targets in Cutaneous Diseases

Skin is the largest human organ and is continuously exposed to various exogenous and endogenous trigger factors affecting body homeostasis. A number of mechanisms, including genetic, inflammatory and autoimmune ones, have been implicated in the pathogenesis of cutaneous diseases. Recently, there has been considerable interest in the role that extracellular vesicles, particularly exosomes, play in human diseases, through their modulation of multiple signaling pathways. Exosomes are nano-sized vesicles secreted by all cell types. They function as cargo carriers shuttling proteins, nucleic acids, lipids etc., thus impacting the cell-cell communications and transfer of vital information/moieties critical for skin homeostasis and disease pathogenesis. This review summarizes the available knowledge on how exosomes affect pathogenesis of cutaneous diseases, and highlights their potential as future targets for the therapy of various skin diseases.

A Dermatologist's Guide to Implementation of Gene Expression Profiling in the Management of Melanoma

BACKGROUND. With the advent of effective therapeutics, melanoma mortality rates have decreased, yet incidence rates are continuing to rise, making accurate prognostication for risk of recurrence increasingly important. Gene expression profiling (GEP) is a clinically available, objective metric that can be used in conjunction with traditional clinicopathological staging to help physicians stratify risk in melanoma patients. There is a gap in guidance from the American Joint Committee on Cancer (AJCC) and the National Comprehensive Cancer Network (NCCN) regarding how to utilize GEP in melanoma care. OBJECTIVE. An expert panel of 31-GEP test users sought to provide clarification of use options and a rational clinical workflow to guide appropriate application of the 31- GEP test in everyday practice. METHODS. The authors participated in an in-depth review of the literature and panel discussion regarding current limitations of melanoma risk assessment and opportunities for improvement with GEP. The panel reviewed 1) validation and clinical impact data supporting the use of sentinel lymph node biopsy (SLNB), 2) existing primary data and meta-analyses for 31-GEP testing in melanoma risk assessment, 3) AJCC, NCCN, and Melanoma Prevention Working Group (MPWG) data and guidelines for GEP use in melanoma risk assessment, and 4) experiences, rationales, and scenarios in which 31-GEP testing may be helpful for risk assessment. RESULTS. The 31-GEP test is useful and actionable for patient care when applied in accordance with current NCCN guidelines. Stratification of patients into low (Class 1a), intermediate (Class 1b or 2a), or high (Class 2b) risk categories can inform multidisciplinary conference discussion and can assist with determining the intensity of imaging, surveillance, and follow-up care. Patient-specific features of the disease and individual circumstances should be considered in the decision to use 31-GEP testing. CONCLUSION. The authors suggest a clinical workflow that integrates 31-GEP testing under the umbrella of current national guidelines. Application of the test in appropriate patient populations can improve risk assessment and inform clinical decision-making.