Using a 31-Gene Expression Profile Test to Stratify Patients with Stage I-II Cutaneous Melanoma According to Recurrence Risk: Update to a Prospective, Multicenter Study

Long-term outcomes and patterns of recurrence in patients with thin melanoma and a negative sentinel lymph node biopsy: a single-center experience

The majority of patients diagnosed with melanoma have thin melanomas (≤1 mm). Data on the rate and pattern of recurrence after a negative sentinel lymph node biopsy (SLNB) are sparse. We retrospectively searched our institutional database and retrieved the records of patients with thin melanomas who underwent an SLNB with negative results. We analyzed patterns of recurrence, time to recurrence, and mode of diagnosis. Thirteen of the 198 patients with thin melanomas and negative SLNB results had tumor recurrence (6.5%): two local in transit (15.4%), three regional (21.3%), and eight distant (61.5%). Distant recurrences tended to occur later than local or regional ones [median disease-free survival = 50 months (95% confidence interval: 36.1-63.9) vs. 34 and 15 months (95% confidence interval: 5.4-24.6), P  = 0.005, respectively]. The percentage of patients with tumor thickness ≥0.8 mm was higher among those who sustained recurrence (84.6 vs. 64.9% for no recurrence, P  = 0.04). The majority of patients with recurrence were not being followed up when diagnosed (69%), and they are presented because of clinical symptoms. Patients with recurrence had lower survival compared with those without recurrence (median: 118 months vs. ongoing survival, P  < 0.001, respectively). Melanoma recurrence in patients with thin melanomas and negative SLNBs is rare, tends to be distant, and negatively affects prognosis. Recurrence tends to occur in patients with melanoma thickness ≥0.8 mm. Further studies are needed to identify patients with high recurrence risk and determine optimal follow-up protocols.

Clinical, dermatoscopic, histological and molecular predictive factors of distant melanoma metastasis: A systematic review and meta-analysis

BACKGROUND

Melanoma metastasis to distant sites is associated with diminished survival rates and poor prognosis. Except of Breslow thickness and ulceration that are currently used in melanoma staging, the investigation of additional clinicopathological, dermatoscopic and molecular factors that could predict tumors with aggressive biologic behavior is of paramount importance.

METHODS

A literature search was conducted in PubMed, Scopus, Cochrane databases and gray literature until November 2023. Observational studies (including cohorts and case-control studies) were included and clinical and histopathological factors of primary cutaneous melanomas, along with dermatoscopic and molecular predictors of distant metastasis (DM) and distant metastasis-free survival (DMFS) were assessed. Random - effect models were preferred, the results were presented as Hazard Ratios (HRs) with 95 %Confidence Intervals (CIs) and the I2 index quantified heterogeneity. Subgroup analysis according to AJCC stage and sensitivity analysis were also conducted.

RESULTS

One hundred forty-three and 101 studies were included in the qualitive and quantitative synthesis, respectively. Regarding clinical factors, males, compared to females, and head and neck location, compared to trunk, demonstrated higher risk for DM [n=36, HR 1.49, 95%CI 1.36 - 1.63, I2 33% and n=21, HR 1.24, 95 %CI 1.01 - 1.52, I2 62 %]. Both factors had similar effects on DMFS. Breslow thickness and ulceration were significant predictors or DM. Additional factors that posed an increased risk for DM were nodular (n=15, HR 2.51, 95 %CI 1.83 - 3.43, I2 56 %) and lentigo maligna subtypes (n=12, HR 1.87, 95 %CI 1.27 - 2.75, I2 0 %), compared to superficial spreading subtype, lymphovascular invasion (n=9, HR 2.05, 95 %CI 1.18 - 3.58, I2 78 %), SLN positivity and BRAF+ mutational status. In contrast, regression was a negative predictor of DM (n=15, HR 0.59, 95 %CI 0.44 - 0.79, I2 68 %). Two studies focused on dermatoscopic factors and found that low pigmentation and the presence of blue-white veil might predict DM development. The results of subgroup analysis for stage I-II patients were essentially similar and sensitivity analysis did not reveal significant alterations, despite the moderate or high heterogeneity in some categories.

CONCLUSIONS

Clinical and histological characteristics of the tumor along with dermatoscopic features and molecular parameters hold significant prognostic information and could be incorporated into models to predict melanomas with high metastatic potential.

Management of melanoma: can we use gene expression profiling to help guide treatment and surveillance?

Although the incidence of cutaneous melanoma (CM) has been increasing annually, the mortality rate has been decreasing, likely due to better prevention, earlier detection, improved surveillance, and the development of new therapies. Current clinical management guidelines by the National Comprehensive Cancer Network (NCCN) are based on patient risk assignment using staging criteria established by the American Joint Committee on Cancer (AJCC). However, some patients with localized disease (stage I-II), generally considered to have a good prognosis, will develop metastatic disease and die, whereas some patients with later stage disease (stage III-IV) will be cured by surgery, adjuvant therapy, and/or systemic therapy. These results emphasize the importance of identifying patients whose risk may be over or underestimated with standard staging. Gene expression profile (GEP) tests are noninvasive molecular tests that assess the expression levels of a panel of validated genes, providing information about tumor prognosis, including the risk of recurrence, metastasis, and cancer-specific death. GEP tests can provide prognostic information beyond standard staging that may aid clinicians and patients in treatment and surveillance management decisions. This review describes how combining clinicopathologic staging with a robust assessment of tumor biology may provide information that will allow more refined intervention and long-term management.

Sentinel lymph node risk prognostication in primary cutaneous melanoma through tissue-based profiling, potentially redefining the need for sentinel lymph node biopsy

PURPOSE OF REVIEW

The role of Sentinel Lymph Node Biopsy (SLNB) is pivotal in the contemporary staging of cutaneous melanoma. In this review, we examine advanced molecular testing platforms like gene expression profiling (GEP) and immunohistochemistry (IHC) as tools for predicting the prognosis of sentinel lymph nodes. We compare these innovative approaches with traditional staging assessments. Additionally, we delve into the shared genetic and protein markers between GEP and IHC tests and their relevance to melanoma biology, exploring their prognostic and predictive characteristics. Finally, we assess alternative methods to potentially obviate the need for SLNB altogether.

RECENT FINDINGS

Progress in adjuvant melanoma therapy has diminished the necessity of Sentinel Lymph Node Biopsy (SLNB) while underscoring the importance of accurately identifying high-risk stage I and II melanoma patients who may benefit from additional anti-tumor interventions. The clinical application of testing through gene expression profiling (GEP) or immunohistochemistry (IHC) is gaining traction, with platforms such as DecisionDx, Merlin Assay (CP-GEP), MelaGenix GEP, and Immunoprint coming into play. Currently, extensive validation studies are in progress to incorporate routine molecular testing into clinical practice. However, due to significant methodological limitations, widespread clinical adoption of tissue-based molecular testing remains elusive at present.

SUMMARY

While various tissue-based molecular testing platforms have the potential to stratify the risk of sentinel lymph node positivity (SLNP), most suffer from significant methodological deficiencies, including limited sample size, lack of prospective validation, and limited correlation with established clinicopathological variables. Furthermore, the genes and proteins identified by individual gene expression profiling (GEP) or immunohistochemistry (IHC) tests exhibit minimal overlap, even when considering the most well-established melanoma mutations. However, there is hope that the ongoing prospective trial for the Merlin Assay may safely reduce the necessity for SLNB procedures if successful. Additionally, the MelaGenix GEP and Immunoprint tests could prove valuable in identifying high-risk stage I-II melanoma patients and potentially guiding their selection for adjuvant therapy, thus potentially reducing the need for SLNB. Due to the diverse study designs employed, effective comparisons between GEP or IHC tests are challenging, and to date, there is no study directly comparing the clinical utility of these respective GEP or IHC tests.

Sentinel lymph node assessment in melanoma: current state and future directions

Assessment of sentinel lymph node status is an important step in the evaluation of patients with melanoma for both prognosis and therapeutic management. Pathologists have an important role in this evaluation. The methodologies have varied over time, from the evaluation of dimensions of metastatic burden to determination of the location of the tumour deposits within the lymph node to precise cell counting. However, no single method of sentinel lymph node tumour burden measurement can currently be used as a sole independent predictor of prognosis. The management approach to sentinel lymph node-positive patients has also evolved over time, with a more conservative approach recently recognised for selected cases. This review gives an overview of past and current status in the field with a glimpse into future directions based on prior experiences and clinical trials.