Current controversies in early-stage melanoma: Questions on management and surveillance

Exploring Small-Diameter Melanomas: A Retrospective Study on Clinical and Dermoscopic Features

BACKGROUND

Early melanoma detection allows for timely intervention and treatment, significantly improving the chances of favorable outcomes for patients. Small-diameter melanoma (SDM) typically represents an initial growth phase of cutaneous melanoma. One of the challenges in detecting melanoma in their early stage lies in the fact that dermoscopy criteria have been primarily designed for fully developed lesions. Early-stage melanomas may be difficult to detect and possibly even be overlooked or misinterpreted during examinations.

METHODS

The primary aim of this study was to identify valuable clinical and dermoscopic clues to enhance the detection of SDMs. To achieve this objective, we conducted a comprehensive retrospective analysis, including forty SDMs with a diameter of 5 mm or less. These cases were diagnosed over an 8-year period and were collected from five referral centers across Brazil. Seven experienced dermatologists independently assessed the dermoscopic features of each lesion. Additionally, this study includes demographic and histological information.

RESULTS

The study encompassed a total of 28 patients, of which 16 were females, accounting for 58% of the participants, with an average age of 43.6 years. Among the small-diameter melanomas (SDMs) under investigation, the majority, constituting 27 cases (69.2%), were identified as "de novo" lesions, i.e., not associated with a nevus. Additionally, eight SDMs (20%) exhibited invasive characteristics, with Breslow index measurements ranging between 0.2 to 0.4 mm, suggesting an early stage of malignancy. During dermoscopic examinations, the most prevalent features observed were irregular dots and globules, present in 95% and 87.5% of cases, respectively. Moreover, brown structureless areas were identified in 70% of lesions, followed by atypical network (67.5%), pseudopods (55%), dotted vessels (47.5%), flat structureless blue-gray areas (42.5%), and irregular blotches (40%). Notably, all SDM were diagnosed in patients under surveillance through total body skin photography (TBSP) and Digital Dermoscopy (DD).

CONCLUSIONS

Dermoscopy significantly enhances the diagnostic accuracy of melanoma, even in its early stages. Particularly for high-risk patients with numerous nevi, the identification of a new lesion or subtle changes on dermoscopy during follow-up may serve as the sole clue for an early diagnosis. This emphasizes the critical role of dermoscopy in SDM detection and reinforces the importance of surveillance in high-risk patients for timely and effective management.

Not Your Mother's Melanoma: Causes and Effects of Early Melanoma Diagnosis

The year 2022 will herald approximately 100,000 new cases of cutaneous melanoma (CM), and over 7000 deaths from CM. Over the past 40 years, CM incidence has increased nearly six-fold; however, annual mortality has remained relatively constant. These trends encapsulate the phenomenon of overdiagnosis. Increased recognition of indolent lesions that appear histologically malignant may be leading to a melanoma epidemic. Enhanced melanoma awareness, screening efforts, physician uncertainty, medical-legal pressures, and diagnostic scrutiny using tools like immunohistochemical staining, mole mapping, dermoscopy, confocal microscopy, and molecular diagnostics contribute to increased CM diagnosis. As a result, current melanoma staging and treatment guidelines are being challenged. Existing standards fail to accurately identify histologically benign lesions that are lethal or, conversely, histologically malignant lesions that are innocuous. Healthcare systems and, more importantly, patients suffer from this diagnostic ambiguity that leads to the over-treatment of innocuous melanomas and under-treatment of aggressive melanomas. As dermatology continues to experience a shift towards earlier diagnosis of melanoma, management strategies must adapt. Herein, we review factors that may contribute to the increased incidence of melanoma, emphasize deficiencies in current staging systems, and provide insights into the future of melanoma management via precision medicine.

Follow-up of primary melanoma patients with high risk of recurrence: recommendations based on evidence and consensus

In spite of the good prognosis of patients with early-stage melanoma, there is a substantial proportion of them that develop local or distant relapses. With the introduction of targeted and immune therapies for advanced melanoma, including at the adjuvant setting, early detection of recurrent melanoma and/or second primary lesions is crucial to improve clinical outcomes. However, there is a lack of universal guidelines regarding both frequency of surveillance visits and diagnostic imaging and/or laboratory evaluations. In this article, a multidisciplinary expert panel recommends, after careful review of relevant data in the field, a consensus- and experience-based follow-up strategy for melanoma patients, taking into account prognostic factors and biomarkers and the high-risk periods and patterns of recurrence in each (sub) stage of the disease. Apart from the surveillance intensity, healthcare professionals should focus on patients' education to perform regular self-examinations of the skin and palpation of lymph nodes.

Management of Transected Invasive Melanoma: A Single Institution Retrospective Review

BACKGROUND

Deep transection of invasive melanoma precludes accurate measurement of Breslow depth, which may affect tumor staging.

OBJECTIVE

To determine the frequency of upstaging of transected invasive melanomas after excision, characterize the impact on National Comprehensive Cancer Network (NCNN)-recommended treatment, and determine predictors of subsequent upstaging.

MATERIALS AND METHODS

A retrospective review of invasive melanomas between January 2017 and December 2019 at a single institution. Deeply transected biopsy reports were compared with subsequent excisions to calculate the frequency of upstaging.

RESULTS

Three hundred sixty (49.6%) of 726 invasive melanomas identified were transected. Forty-nine (13.6%) transected tumors had upstaging that would have altered NCCN-recommended management. "Broadly" transected tumors had upstaging that would have resulted in a change in the management in 5/23 cases (21.7%) versus 2/41 cases (4.9%) for "focally" transected tumors (p = .038). Breslow depth increased by 0.59 mm on average for "broad" transection versus 0.06 mm for "focal" transection (p =< .01). Of the 89 transected pT1a melanomas, specimens with gross residual tumor or pigment after biopsy were upstaged in 8/17 (47.1%) of cases versus 5/72 (6.9%) of specimens without (p =< .01).

CONCLUSION

Upstaging of deeply transected invasive melanomas that would alter NCCN-recommended management occurred in 13.6% of cases. Broad transection and gross residual tumor or pigment after biopsy predicted higher likelihood of upstaging.

Need to restage Korean melanoma patients following publication of the 8th edition of the American Joint Committee on Cancer staging manual

BACKGROUND

The tumor, nodes and metastasis (TNM) classification and stage grouping have been updated in the 8th edition of the American Joint Committee on Cancer (AJCC) melanoma staging manual. However, restaging all the previous cases are not recommended.

AIMS

The aims of the study were to investigate the necessity of restaging Korean melanoma patients staged by the previous edition of the AJCC manual.

METHODS

Differences in the staging criteria of the 7th and 8th editions of the AJCC manual were identified. The staging of 276 primary melanomas from January 2011 to December 2018 was classified by both 7th and 8th editions of the manual and their differences were compared.

RESULTS

Staging by 7th and 8th edition of the AJCC manual differed in 64 cases (23.2%). The pathological prognostic staging changed in 35 (12.7%), and 29 (10.5%) had changes in only TNM classification but not the pathological staging. None of the patients needed additional sentinel lymph node biopsy or systemic treatment as a result of restaging. Additional counseling was needed for the patients, because melanoma-specific survival was increased in the 8th edition.

LIMITATIONS

This is a retrospective study with relatively small number of patients at a single tertiary center in Korea.

CONCLUSION

Assessment of the need for additional sentinel lymph node biopsy or systemic treatment is recommended because of the latest changes in the AJCC melanoma staging manual. Although the restaging of previously staged melanomas is not significantly needed in our patients, still the differences in TNM classification and/or pathological prognostic staging suggest the need to separately recognize the patients previously staged by 7th edition and recently staged by 8th edition. Careful counseling about melanoma-specific survival is needed for Asian patients.

Evaluation of a Gene Expression Profiling Assay in Primary Cutaneous Melanoma

BACKGROUND

A significant proportion of deaths from cutaneous melanoma occur among patients with an initial diagnosis of stage 1 or 2 disease. The Decision-Dx Melanoma (DDM) 31-gene assay attempts to stratify these patients by risk of recurrence. This study aimed to evaluate this assay in a large single-institution series.

METHODS

A retrospective chart review of all patients who underwent surgery for melanoma at a large academic cancer center with DDM results was performed. Patient demographics, tumor pathologic characteristics, sentinel node status, gene expression profile (GEP) class, and recurrence-free survival (RFS) were reviewed. The primary outcomes were recurrence of melanoma and distant metastatic recurrence.

RESULTS

Data from 361 patients were analyzed. The median follow-up period was 15 months. Sentinel node biopsy was performed for 75.9% (n = 274) of the patients, 53 (19.4%) of whom tested positive. Overall, 13.6% (n = 49) of the patients had recurrence, and 8% (n = 29) had distant metastatic recurrence. The 3- and 5-year RFS rates were respectively 85% and 75% for the class 1A group, 74% and 47% for the class 1B/class 2A group, and 54% and 45% for the class 2B group. Increased Breslow thickness, ulceration, mitoses, sentinel node biopsy positivity, and GEP class 2B status were significantly associated with RFS and distant metastasis-free survival (DMFS) in the univariate analysis (all p < 0.05). In the multivariate analysis, only Breslow thickness and ulceration were associated with RFS (p < 0.003), and only Breslow thickness was associated with DMFS (p < 0.001).

CONCLUSION

Genetic profiling of cutaneous melanoma can assist in predicting recurrence and help determine the need for close surveillance. However, traditional pathologic factors remain the strongest independent predictors of recurrence risk.

Analyzing Controversies in Management and Surveillance of Early-Stage Melanoma

The incidence of cutaneous melanoma continues to rise dramatically worldwide, presenting a significant burden to the healthcare system. Despite this, there is still controversy in the guidelines regarding follow-up surveillance for patients with thin melanoma. Since there are no randomized clinical trials to support evidence-based guidelines for follow-up surveillance, dermatologic and oncologic organizations have developed their own recommendations based on expert opinion. However, these recommendations differ widely and are often vague, resulting in considerable variability in the management of early-stage melanoma among clinicians. The benefits of frequent follow-up visits are early detection of recurrent lesions, lower cost of early-stage melanoma compared to that of late-stage melanoma, decreased need for sentinel lymph node biopsy and adjuvant therapies, and the opportunity to educate patients on self-examination and sun protection. However, the high cost of screening and potential increased rates of biopsy, as well as over-imaging and overtreating, pose serious concerns about this approach. While more rigorous research is needed to resolve this controversy, currently clinicians should follow a relatively universal recommendation to tailor the follow-up regimen based on the patient's relative risk of recurrence and comfort.

Correlation of tumor-infiltrating immune cells of melanoma with overall survival by immunogenomic analysis

AIMS

Different types of tumor-infiltrating immune cells not only augment but also dampen antitumor immunity in the microenvironment of melanoma. Therefore, it is critical to provide an overview of tumor-infiltrating immune cells in melanoma and explore a novel strategy for immunotherapies.

METHODS

We analyzed the immune states of different stages in melanoma patients by the immune, stromal, and estimation of stromal and immune cells in malignant tumor tissues using expression data (ESTIMATE) scores. Immune cell types were identified by the estimating relative subsets of RNA transcripts (CIBERSORTx) algorithm in 471 melanoma and 324 healthy tissues. Moreover, we performed a gene set variation analysis (GSVA) to determine the differentially regulated pathways in the tumor microenvironment.

RESULTS

In melanoma cohorts, we found that ESTIMATE and immune scores were involved in survival or tumor clinical stage. Among the 22 immune cells, CD8⁺ T cells, M2 macrophages, and regulatory T cells (Tregs) showed significant differences using the CIBERSORTx algorithm. Furthermore, GSVA identified the immune cell-related pathways; the primary immunodeficiency pathway, intestinal immune network for IgA, and TGF-β pathways were identified as participants of the crosstalk in CD8⁺ T cells, Tregs, and M2 macrophages in the melanoma microenvironment.

CONCLUSION

These results reveal the cellular and molecular characteristics of immune cells in melanoma, providing a method for selecting targets of immunotherapies and promoting the efficacy of therapies for the treatment of melanoma.

Germline mutations predisposing to melanoma

Nearly 15% of melanomas occur in patients with a family history and a subset of these patients have a germline mutation in a melanoma predisposing gene. CDKN2A mutations are responsible for the majority of hereditary melanoma, but many other susceptibility genes have been discovered in recent years, including CDK4, TERT, ACD, TERF2IP, POT1, MITF, MC1R, and BAP1. Additionally, melanoma risk is increased in mixed cancer syndromes caused by mutations in PTEN, BRCA2, BRCA1, RB1, and TP53. While early onset, multiple tumors, and family cancer history remain the most valuable clinical clues for hereditary melanoma, characteristic epithelioid cytology of melanocytic tumors may suggest an underlying BAP1 mutation. Herein, we review the clinical and histopathologic characteristics of melanocytic tumors associated with these germline mutations and discuss the role of genetic counseling.

Prognostic gene expression profiling in melanoma: necessary steps to incorporate into clinical practice

Prognostic gene expression profiling (GEP) tests for cutaneous melanoma (CM) are not recommended in current guidelines outside of a clinical trial. However, their use is becoming more prevalent and some practitioners are using GEP tests to guide patient management. Thus, there is an urgent need to bridge this gap between test usage and clinical guideline recommendations by obtaining high-quality evidence to guide us toward best practice use of GEP testing in CM patients. We focus here on the opportunities and uncertainties associated with prognostic GEP testing in CM, review how GEP testing was incorporated into clinical care guidelines for uveal melanoma and breast cancer and discuss the role of clinical trials to determine best use in patients with CM.