Sentinel lymph node biopsy in melanoma: controversies and current guidelines

Management of Non-Melanoma Skin Cancer: Radiologists Challenging and Risk Assessment

Basal cell carcinoma, squamous cell carcinoma, and Merkel cell carcinoma are the three main types of nonmelanoma skin cancers and their rates of occurrence and mortality have been steadily rising over the past few decades. For radiologists, it is still difficult to treat patients with advanced nonmelanoma skin cancer. Nonmelanoma skin cancer patients would benefit greatly from an improved diagnostic imaging-based risk stratification and staging method that takes into account patient characteristics. The risk is especially elevated among those who previously received systemic treatment or phototherapy. Systemic treatments, including biologic therapies and methotrexate (MTX), are effective in managing immune-mediated diseases; however, they may increase susceptibility to NMSC due to immunosuppression or other factors. Risk stratification and staging tools are crucial in treatment planning and prognostic evaluation. PET/CT appears more sensitive and superior to CT and MRI for nodal and distant metastasis as well as in surveillance after surgery. The patient treatment response improved with advent and utilization of immunotherapy and different immune-specific criteria are established to standardized evaluation criteria of clinical trials but none of them have been utilized routinely with immunotherapy. The advent of immunotherapy has also arisen new critical issues for radiologists, such as atypical response pattern, pseudo-progression, as well as immune-related adverse events that require early identification to optimize and improve patient prognosis and management. It is important for radiologists to have knowledge of the radiologic features site of the tumor, clinical stage, histological subtype, and any high-risk features to assess immunotherapy treatment response and immune-related adverse events.

Progressing Vulvar Melanoma Caused by Instability in cKIT Juxtamembrane Domain: A Case Report and Review of Literature

In order to identify the molecular pathways governing melanoma and track its progression, the next-generation sequencing (NGS) approach and targeted sequencing of cancer genes were employed. The primary tumor, as well as metastatic tissue, of an 84-year-old patient diagnosed with vulvar melanoma (VM), were investigated. The primary tumor specimen showed multiple somatic mutations in TP53 gene, suggesting its major contribution to melanoma origin. The metastatic sample showed additional alterations, including other melanoma-related genes. Clinical relevancy is postulated to juxtamembrane region instability of KIT gene (c-KIT). We did not identify BRAF or NRAS alterations, which are typical for the most common melanoma pathway–MAPK cascade. However, it should be noted that this is the first report evidencing PDGFRA in melanoma, although its role in triggering VM needs to be further elucidated.

Application of an indocyanine green surgical fluorescence imaging system in sentinel lymph node biopsy of acral malignant melanoma

Background

Regional lymph node status is an independent influencing factor for the prognosis of acral malignant melanoma, and the accuracy of sentinel lymph node biopsy (SLNB) is directly related to the judgment of regional lymph node status. This study aimed to explore the application value of indocyanine green (ICG) surgical fluorescence imaging system in the SLNB of acral malignant melanoma.

Methods

A total of 34 patients with acral malignant melanoma were admitted to the Department of Burn and Plastic Surgery in Jiangsu Provincial People’s Hospital from January 2020 to March 2020. Among these patients, 22 required SLNB. ICG and methylene blue (MB) were combined to intraoperatively trace the sentinel lymph nodes (SLNs). The total number of SLNs detected during the operation was counted. We compared the number, detection rate, as well as the detection rate and false negative rate of positive SLNs of SLNs detected by ICG, MB, and ICG combined with MB.

Results

A total of 56 SLNs were detected in the 22 patients, among which 55 were detected by ICG (98%), 41 were detected by MB (71%), and 56 (100%) were detected by ICG combined with MB, and the average number of SLNs were 2.5, 1.64, and 2.55, respectively. A total of nine SLNs were detected, of which nine were detected by ICG (100%), seven by MB (78%), and nine by ICG combined with MB (100%). Patients with negative SLNs had no recurrence at the 6-month follow-up.

Conclusions

Compared with MB, the ICG fluorescent imaging system can improve the detection rate of SLNs in patients with acral malignant melanoma. Also, ICG combined with MB was superior to ICG alone.

The natural history of thin melanoma and the utility of sentinel lymph node biopsy

BACKGROUND AND OBJECTIVES

Current literature may overestimate the risk of nodal metastasis from thin melanoma due to reporting of data only from lesions treated with SLNB. Our objective was to define the natural history of thin melanoma, assessing the likelihood of nodal disease, in order to guide selection for SLNB.

METHODS

Retrospective review. The primary outcome was the rate of nodal disease. Clinicopathologic factors were evaluated to find associations with nodal disease.

RESULTS

Five hundred and twelve lesions, follow up available for 488 (median: 48 months). Lesions treated with WLE/SLNB compared to WLE alone were more likely to have high-risk features. The rate of nodal disease was higher in the WLE/SLNB group (24 positive SLNB, five false-negative SLNB with nodal recurrence: 10.2%) compared to WLE alone (four nodal recurrences: 2.0%). Univariate analysis showed age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm² , and ulceration were associated with nodal disease. Multivariate analysis confirmed the association of age ≤45 and ulceration.

CONCLUSIONS

SLNB for melanoma 0.75-0.99 mm should be considered in patients age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm² , and/or with ulceration. Thin melanoma <0.85 mm without high-risk features may be treated with WLE alone.

Clinical and biological determinants of melanoma progression: Should all be considered for clinical management?

Cutaneous melanoma is a heterogeneous disease affecting the regulation of multiple genes and proteins that contribute to melanoma progression. Survival for patients with locally invasive disease varies greatly, even within tumour stages based on current prognostic criteria. This has prompted investigations into the value of additional clinical or biological parameters predicting survival. In particular, the improved knowledge of tumour biology has fed the hope that the outcome may be predicted at the molecular level. The prognostic value of numerous potential biomarkers has therefore been evaluated in protein and gene expression studies, and genomic associations with melanoma prognosis are beginning to emerge. These potential biomarkers interrogate key tumour and host processes important for tumour development and progression, such as proliferation, invasion and migration through epithelial mesenchymal transition or the host immune or vascular responses. This research may allow more individualised information on prognosis if the challenges regarding the quality and validation of studies are overcome.

Molecular markers to complement sentinel node status in predicting survival in patients with high-risk locally invasive melanoma

Sentinel lymph node status is a major prognostic marker in locally invasive cutaneous melanoma. However, this procedure is not always feasible, requires advanced logistics and carries rare but significant morbidity. Previous studies have linked markers of tumour biology to patient survival. In this study, we aimed to combine the predictive value of established biomarkers in addition to clinical parameters as indicators of survival in addition to or instead of sentinel node biopsy in a cohort of high-risk melanoma patients. Patients with locally invasive melanomas undergoing sentinel lymph node biopsy were ascertained and prospectively followed. Information on mortality was validated through the National Death Index. Immunohistochemistry was used to analyse proteins previously reported to be associated with melanoma survival, namely Ki67, p16 and CD163. Evaluation and multivariate analyses according to REMARK criteria were used to generate models to predict disease-free and melanoma-specific survival. A total of 189 patients with available archival material of their primary tumour were analysed. Our study sample was representative of the entire cohort (N = 559). Average Breslow thickness was 2.5 mm. Thirty-two (17%) patients in the study sample died from melanoma during the follow-up period. A prognostic score was developed and was strongly predictive of survival, independent of sentinel node status. The score allowed classification of risk of melanoma death in sentinel node-negative patients. Combining clinicopathological factors and established biomarkers allows prediction of outcome in locally invasive melanoma and might be implemented in addition to or in cases when sentinel node biopsy cannot be performed.

Basal cell carcinoma: a comprehensive review for the radiologist

OBJECTIVE. Basal cell carcinoma (BCC) is the most common malignancy in the United States. The purpose of this article is to provide a comprehensive description of the clinicopathologic features, diagnostic workup, staging, treatment, and follow-up of BCC. CONCLUSION. Radiology plays an important role in the evaluation and staging of locally advanced and metastatic BCC. MRI is the modality of choice for assessing perineural disease and is equivalent or superior to CT for evaluating bony involvement. CT and PET/CT are used to evaluate metastatic disease.

Sentinel lymph node biopsy in oral and oropharyngeal squamous cell carcinoma: current status and unresolved challenges

Because imaging with ultrasound, computed tomography, magnetic resonance imaging or positron emission tomography is unreliable for preoperative lymph node staging of early-stage oral and oropharyngeal squamous cell carcinoma (OSCC), elective neck dissection has been typically performed. The targeted sampling of sentinel lymph nodes (SLN) identified by lymphoscintigraphy and detected by gamma probe has become an effective alternative for the selection of patients for regional nodal resection. With careful consideration to technique, high SLN detection rates have been reported. Advanced techniques including intraoperative handheld gamma camera imaging and freehand single photon emission computed tomography (SPECT) are expected to increase surgical confidence in these procedures. This review gives an update on SLN biopsy in patients with OSCC including clinical standards and controversial aspects.

Sentinel lymph node biopsy in melanoma: final results of MSLT-I

EVALUATION OF: 

Morton DL, Thompson JF, Cochran AJ et al. Final trial report of sentinel-node biopsy versus nodal observation in melanoma. N. Engl. J. Med. 370(7), 599–609 (2014). In 1994 an international randomized controlled clinical trial, MSLT-I, opened to study the utility of sentinel lymph node biopsy (SLNB) for patients with clinically localized melanoma. This trial compared outcomes of patients treated with wide local excision (WLE) and SLNB (followed by immediate completion lymph node dissection [CLND] for those with a positive sentinel node [SN]) with outcomes of patients treated with WLE alone and CLND upon the development of clinically apparent disease. In February 2014 the final analysis of long-term outcomes data was published. Importantly, these data showed that the rates of nodal positivity were the same between the two arms of the trial. Although no difference in 10-year melanoma-specific survival was noted between the two arms, this was not entirely surprising as the overall rate of nodal disease within the trial was 20.8%, meaning that 79.2% of patients could not derive a benefit from SLNB. Subset analysis was performed to determine the impact of early intervention for those patients most likely to have a benefit from early detection. This analysis showed that for patients with nodal disease and intermediate-thickness melanoma (defined as 1.2–3.5-mm Breslow depth), early treatment following positive SLNB was associated with improved 10-year distant disease-free survival and improved 10-year melanoma-specific survival.