Melanoma Biopsies Research Articles

Enhanced Risk Stratification for Sentinel Lymph Node Biopsy in Head and Neck Melanoma Using the Merlin Assay (CP-GEP).

Sentinel lymph node biopsy (SLNB) for head and neck melanomas involves complex challenges due to intricate lymphatic networks and delicate anatomic structures. The Merlin Assay (CP-GEP), merging clinicopathologic data with gene expression profiling, offers a non-invasive method to identify patients who have a low risk for nodal metastasis, potentially sparing these low-risk patients from surgical procedures. This study evaluated 250 clinically node-negative patients with stage I, II, or III melanoma from the Mayo Clinic and University Hospitals Cleveland Medical Center who had tumors in the head and neck region diagnosed between 2004 and 2021. All the patients underwent SLNB. The Merlin Assay, using the CP-GEP model, combines patient age at diagnosis, Breslow thickness, and gene expression of eight specific genes from the primary tumor to predict the risk of nodal metastasis. The SLNB positivity rate was 14% overall, and CP-GEP predicted a possible 40.8% reduction in SLNB procedures with a negative predictive value (NPV) of 98%. For 215 SLNB-negative patients (5-year recurrence-free survival [RFS] of 76.9%, distant metastasis-free survival [DMFS] of 84.3%, and melanoma-specific survival [MSS] of 90.6%), CP-GEP improved risk stratification by identifying 100 patients as low risk with 5-year RFS of 86.1%, DMFS of 92.7%, and MSS of 95.3%. Among 167 T1-T2 patients, the SLNB positivity rate was 8.4%, and CP-GEP achieved an SLNB reduction rate of 56.3% with an NPV of 98.9%. The Merlin Assay effectively categorizes head and neck melanoma patients by risk, enabling more accurate clinical decision-making regarding SLNB and follow-up evaluation, especially for early-stage melanoma patients.

ICG-guided sentinel lymph node biopsy in melanoma is as effective as blue dye: A retrospective analysis

IntroductionSentinel lymph node biopsy (SLNB) is a key procedure in the staging and management of melanoma. Traditionally, it is performed using a dual-mapping technique combining a radioactive isotope (RI) and blue dye (BD). Fluorescence-guided surgery with indocyanine green (ICG) has emerged as an alternative tracer, offering potential advantages in real-time visualization and operative efficiency. This study compares the efficacy of RI + ICG with RI + BD in SLNB for melanoma. MethodsWe conducted a retrospective cohort study at a single center, including 311 patients who underwent SLNB for melanoma. Patients were divided into two groups: RI + BD (n = 227, January 2010–August 2022) and RI + ICG (n = 84, August 2022–February 2024). SLN detection rates, positive SLN rates, operative times, and postoperative complications were compared between the two groups. ResultsBoth groups were clinically and pathologically comparable. SLN detection rates were 100 % in the RI + BD group and 98.8 % in the RI + ICG group (p = 0.1). The median number of lymph nodes resected was lower in the RI + ICG group as compared to the RI + BD group (p = 0.047). While positive SLN rates were higher in the RI + ICG group (9.5 % vs. 6.2 %), this difference was not statistically significant (p = 0.3). ICG alone could not identify all the positive SLN. Postoperative complications, including seroma, did not differ significantly between groups. ConclusionsICG-guided SLNB is comparable to BD-guided SLNB in terms of detection rate and SLN positivity, although it can not be used alone to identify all positive SLNBs. ICG-based fluorescence imaging is a promising technique that may enhance surgical efficiency in melanoma management.

Desmosome mutations impact the tumor microenvironment to promote melanoma proliferation.

Desmosomes are transmembrane protein complexes that contribute to cell-cell adhesion in epithelia and other tissues. Here, we report the discovery of frequent genetic alterations in the desmosome in human cancers, with the strongest signal seen in cutaneous melanoma where desmosomes are mutated in >70% of cases. In primary but not metastatic melanoma biopsies, the burden of coding mutations in desmosome genes associates with a strong reduction in desmosome gene expression. Analysis by spatial transcriptomics and protein immunofluorescence suggests that these expression decreases occur in keratinocytes in the microenvironment rather than in primary melanoma cells. In further support of a microenvironmental origin, we find that desmosome gene knockdown in keratinocytes yields markedly increased proliferation of adjacent melanoma cells in keratinocyte/melanoma co-cultures. Similar increases in melanoma proliferation are observed in media preconditioned by desmosome-deficient keratinocytes. Thus, gradual accumulation of desmosome mutations in neighboring cells may prime melanoma cells for neoplastic transformation.

Impact of skin biopsy practices: A comprehensive nationwide study on skin cancer and melanoma biopsies.

Due to a multitude of factors, skin cancer incidence is increasing and challenges medical professionals in biopsy decision-making. While skin cancer may have a profound impact on the patient and be costly for society, there is little knowledge about the number and cost of benign skin lesions biopsied as collateral damage. This study evaluates the number and costs of skin biopsies in Denmark over 15 years, focusing on benign and malignant skin lesions and melanomas across medical settings. It aims to determine the benign to malignant ratio (BMR) and number needed to biopsy (NNB) and estimate the direct cost of benign skin lesion biopsies in the Cancer Pathway from the perspective of a public healthcare system. The study included 4,481,207 biopsy specimens from January 2007 to June 2022 from the Danish Pathology Data Bank, of which 151,988 from the Cancer Pathway were included in the primary analysis of BMR. The national reimbursement rates for biopsies were used, alongside histopathological examination costs extracted from several pathology departments, for a Monte-Carlo simulation of a simple cost and sensitivity analysis. The number of biopsies increased by 39.1% from 2007 to 2021. Overall BMR for malignancy was 4.1:1, and NNB for melanoma was 31.8, but biopsies performed on clinical suspicion of malignancy or melanoma had a BMR and NNB of 1.5:1 and 2.8, respectively. The cost of benign skin biopsies performed on suspicion of cancer or melanoma in 2021 was €6.6M, predominantly in hospitals. A healthcare system that employs filtering functions before biopsy of skin lesions can achieve some of the lowest BMR reported in the world, but with most benign skin lesion excisions due to suspicion of malignancy performed in the expensive hospital setting. Including clinical reason for biopsy in diagnostic accuracy studies using NNB is crucial.

Are Positive Biopsy Margins in Melanoma Significant?: A Cohort Study of Micro- Versus Macroscopic Margin Status and Their Impact on Residual Disease and Survival.

Presence of positive biopsy margins in melanoma can provoke anxiety over potential disease progression from delays to surgical excision, but their impact on outcomes is unknown. We aimed to compare the presence of residual melanoma in the surgical excision specimen and survival between patients with negative, microscopically positive, and macroscopically positive biopsy margins. Patients with cutaneous melanoma who underwent surgical excision over a 13-year period were included. Biopsy characteristics, residual disease in the surgical specimen, and overall and recurrence-free survival were compared between patients with negative, microscopically positive (only scar visible), and macroscopically positive (visible remaining melanoma) biopsy margins. Of 901 patients, 42.4%, 33.3%, and 24.3% had negative, microscopically positive, and macroscopically positive margins, respectively. The incidence of residual invasive melanoma in the surgical specimen varied (P < 0.001), occurring in 5.5%, 17.0%, and 74.9% of patients, respectively. Both microscopically and macroscopically positive margins were associated with residual disease (P < 0.001) but only the latter predicted worse overall (P = 0.013) and recurrence-free survival (P = 0.009). Kaplan-Meier estimated survival was comparable between those with negative and microscopically positive margins, but overall (P = 0.006) and recurrence-free survival (P = 0.004) were significantly worse in the macroscopically positive margin group. These patients had worse prognosis melanoma, with 33.8% being stage III disease, and 23.2% having positive sentinel lymph nodes. Patients and physicians may be reassured in the presence of microscopically positive biopsy margins which arenot associated with worse survival, However, patients with macroscopically positive margins have poorer prognosis and should be treated within an acceptable time frame.

Dual PD-L1/SOX10 Immunohistochemistry Combined With Digital Imaging Enhances Stratification Accuracy of Patients With Metastatic Melanoma.

Immune checkpoint inhibitor therapy has demonstrated an overall survival benefit in patients with advanced melanoma. Though the significance of programmed death-ligand 1 (PD-L1) expression on melanoma cells as a predictive biomarker of response remains inconclusive, some reports indicate that a PD-L1 expression of <1% of tumor cells may be associated with better outcomes with dual immunotherapy. Adequate patient selection for combination therapy is critical given the higher frequency of adverse effects compared with monotherapy. Immunohistochemical (IHC) PD-L1 interpretation in tumor cells is challenging when inflammatory cells are present and cutoffs are low. We studied 36 metastatic melanoma biopsies from Immune checkpoint inhibitor-naive patients, previously stained and scored for PD-L1 IHC using the tumor proportion score (TPS). Cases were classified into 3 groups: <1%, 1% to 5%, and >5%. After de-coverslipping, SRY-related HMG-box-10 (SOX10) IHC was performed on PD-L1 IHC slides with a red chromogen, and subsequently scanned and scored by ≥2 dermatopathologists. This assessment determined that 25% of cases (9/36) had a TPS ≥ 1%, in contrast to the single IHC assay (63.8%). The majority of the 1-5% group (11/13, 84.6%) underwent a change of category to <1% TPS. In the >5% group, 60% of cases (6/10) were downgraded to <1% and 1% to 5% (4 and 2 cases, respectively). Our study suggests that PD-L1 IHC evaluation could benefit from dual PD-L1/SOX10 IHC. Dual IHC is expected to decrease the interference caused by PD-L1 expression on inflammatory cells, and digital imaging proves useful for the preservation and analysis of stains. Refining PD-L1 evaluation in metastatic melanoma may improve clinical decisions between single and combination immunotherapy, with potentially profound consequences in response and quality of life.

Clinicopathologic features and surgical management in vulvovaginal melanoma – A retrospective single-center study

Background and AimsVulvovaginal melanoma is a rare malignancy characterized with poor prognosis. The aim of this study was to review vulvovaginal melanoma patients treated in Helsinki University Hospital. Objective was to evaluate the clinicopathologic features, treatment and factors affecting outcome. MethodsSingle-center retrospective review on patients treated between 2001 and 2021 was conducted. Data were collected from medical records. Clinicopathologic features, treatment, survival, and prognostic factors were analyzed. ResultsA total of 21 patients were included in the analysis. Localization was vulvar in 86% (n=18) and vaginal in 14% (n=3). Median age at diagnosis was 80 years. Initial treatment included surgery in 18 patients (86%); wide local excision in 19%, radical excision in 62%, and pelvic exenteration in 4.8%. Negative margins were achieved in 83% (n=15). Eleven (52%) patients underwent inguinal treatment: sentinel lymph node biopsy in 33%, direct lymphadenectomy in 14%, and both in 4.8%. Nine patients experienced melanoma recurrence. Recurrences were locoregional (n=1), distant (n=4), and both locoregional and distant (n=4). Median disease-free survival was 18.9M and median overall survival (OS) was 36.5M. 5-year relative OS was 20%. Melanoma was cause of death for seven patients (33%). Vaginal localization tended to worsen prognosis. Nodal status was the only melanoma characteristic significantly associated with survival. Surgical radicality did not affect survival. ConclusionsVulvovaginal melanoma is associated with an extremely poor survival and high rates of recurrence, primarily involving distant metastasis. In local control, wide local excision seems to be viable alternative to more radical surgery. Nodal status is a key prognostic factor emphasizing the importance of further research into the applicability of sentinel lymph node biopsy for vulvovaginal melanoma.

Next day sentinel node biopsy for melanoma after lymphoscintigraphy using 99mTc-labelled nanocolloid does not adversely affect long-term outcomes.

Sentinel Lymph Node Biopsy (SLNB) is an important management tool for early-stage melanoma. Different radiopharmaceuticals are used internationally to localise the sentinel node using lymphoscintigraphy (LSG) before surgery. Recent reports have suggested that a delayed interval between LSG and SLNB using 99mTc-labelled nanocolloid tracer has an adverse survival impact, but not with 99mTc-labelled antimony sulphide colloid. This study aims to analyse survival outcome in a prospective cohort of melanoma patients undergoing same day or next day SLNB after LSG using 99mTc-labelled nanocolloid. Outcome data were reviewed for patients undergoing SLNB, stratified by time interval between LSG and SLNB at a single UK academic centre. Kaplan-Meier survival analysis was used to assess overall survival (OS), melanoma-specific survival (MSS) and progression-free survival (PFS). Cox multivariable regression analysis identified independent risk factors. 925 patients had LSG using the 99mTc-nanocolloid tracer between 2009 and 2019, with a median follow-up of 6.36years. No difference was seen on univariate analysis in OS, MSS, PFS, or nodal recurrence between patients undergoing same day or next day SLNB (Log-rank P = 0.437, 0.293, 0.587, 0.342 respectively). In addition, nodal recurrence as first site or anytime site of recurrence in SLNB negative patients was similar between the groups (Log-rank P = 0.093 and 0.457 respectively). Stratified analysis of time did not demonstrate an outcome difference (MSS Log-rank P = 0.938). Cox multivariable regression did not show time interval to independently influence OS, MSS or PFS. We do not find a significant effect on long-term outcomes when SLNB is performed the day after LSG with 99mTc-labelled nanocolloid tracer. We infer that tracer migration is not clinically significant within 24h of injection based on long term clinical outcome data.

Transcutaneous sentinel lymph node detection in skin melanoma with near-infrared fluorescence imaging using indocyanine green.

The aim of the study is to assess whether indocyanine green (ICG) fluorescence can replace technetium in the preoperative detection of sentinel lymph nodes (SLN) from cutaneous melanoma. The current golden standard for SLN detection is the radioisotope technetium. A promising alternative is fluorescence imaging (FLI) using ICG. In this study, we enrolled patients undergoing sentinel lymph node biopsy (SLNB) for skin melanoma at the Erasmus Medical Center between November 2022 and July 2023. The SLNB procedure was performed as a standard of care. After general anesthesia, ICG was injected intradermally around the primary tumor site. Both the patient and the surgeon were not blinded for the location of the SLN. FLI was performed before incision, in vivo after incision, and ex vivo. Fluorescent SLNs were confirmed using the gamma probe in all cases. Thirty-two patients were included in this study, and a total of 39 SLNs were harvested. The transcutaneous detection rate of ICG was 21.9%. The combined ex vivo ICG fluorescence and technetium uptake was 94.9%. One SLN contained only ICG (2.6%) and one SLN contained only technetium-uptake (2.6%). FLI using ICG resulted in a relatively low transcutaneous detection, which means that exclusive use of this technique in its present form is not feasible. However, we did find a high accumulation of ICG in the SLN, indicating the potential of ICG in combination with other imaging techniques.

Sentinel lymph node positivity in melanoma: Which risk prediction tool is most accurate?

BackgroundSentinel lymph node biopsy for melanoma determines treatment and prognostic factors and improves disease-specific survival. To risk-stratify patients for sentinel lymph node biopsy consideration, Memorial Sloan Kettering Cancer Center and Melanoma Institute Australia developed nomograms to predict sentinel lymph node positivity. We aimed to compare the accuracy of these 2 nomograms. MethodsA multi-institutional study of patients with melanoma receiving sentinel lymph node biopsy between September 2018 and December 2022 was performed. The accuracy of the 2 risk prediction tools in determining a positive sentinel lymph node biopsy was analyzed using receiver operating characteristic curves and area under the curve. ResultsIn total, 532 patients underwent sentinel lymph node biopsy for melanoma; 98 (18.4%) had positive sentinel lymph node. Increasing age was inversely related to sentinel lymph node positivity (P < .01); 35.7% of patients ≤30 years had positive sentinel lymph node compared with 9.7% of patients ≥75 years. When we analyzed the entire study population, accuracy of the 2 risk prediction tools was equal (area under the curveMemorial Sloan Kettering Cancer Center: 0.693; area under the curveMIA: 0.699). However, Memorial Sloan Kettering Cancer Center tool was a better predictor in patients aged ≥75 years (area under the curveMemorial Sloan Kettering Cancer Center: 0.801; area under the curveMelanoma Institute Australia: 0.712, P < .01) but Melanoma Institute Australia tool performed better in patients with a higher mitotic index (mitoses/mm2 ≥2; area under the curveMemorial Sloan Kettering Cancer Center: 0.659; area under the curveMelanoma Institute Australia: 0.717, P = .027). Both models were poor predictors of sentinel lymph node positivity in young patients (age ≤30 years; area under the curveMemorial Sloan Kettering Cancer Center: 0.456; area under the curveMelanoma Institute Australia: 0.589, P = .283). ConclusionThe current study suggests that the 2 risk stratification tools differ in their abilities to predict sentinel lymph node positivity in specific populations: Memorial Sloan Kettering Cancer Center tool is a better predictor for older patients, whereas Melanoma Institute Australia tool is more accurate in patients with a higher mitotic index. Both nomograms performed poorly in predicting sentinel lymph node positivity in young patients.

High-frequency ultrasound accuracy in preoperative cutaneous melanoma assessment: A meta-analysis.

High-frequency ultrasound (HFUS) can safely and efficiently visualize cutaneous tumour characteristics including depth. We aimed to evaluate its accuracy in measuring melanoma depth against the gold standard, histopathology, for treatment planning. A review of publications was conducted in March 2023 through five electronic databases. Thirty-six included articles studied patients who received HFUS (≥10 MHz) measurements, melanoma biopsy or excision, and reported a tumour depth correlation coefficient between HFUS and histopathology. We analysed correlation coefficients between HFUS and histopathology, measured tumour depths and shed light on reasons for mismeasurements. Additionally, we identified the reporting of critical metrics including, lesion characteristics, melanoma subtype, type of correlation coefficient, 95% confidence intervals for Pearson coefficients and sample size. The most common tumour imaged was superficial spreading melanoma on the trunk and extremities, followed by head/face. Maximum ultrasound frequencies ranged from 13 MHz to 100 MHz with participants ranging from 5 to 264. Histopathology and HFUS correlation coefficients ranged from 0.417 to 0.997 (median: 0.94, mean: 0.89 and SD: 0.13). Lower frequency probes (10-20 MHz) were less accurate in assessing melanoma thickness, with a cumulative mean correlation coefficient of 0.87 compared to 0.94 (20-25 MHz) and 0.98 (≥70 MHz). Studies demonstrated higher sonographic accuracy in melanomas >0.75 mm. Additionally, ultrasound may report increased melanoma depth compared to histopathology for reasons including lymphocytic infiltration, presence of a nevus and shrinkage during specimen processing. Furthermore, we found a gap in the reporting of details such as fundamental characteristics of lesion populations. Specifically, 86% (31 out of 36) of the studies failed to report one or more critical metrics, such as mean, median or range of lesion depths. HFUS may serve as a supplementary tool for preoperative melanoma assessment, with increased accuracy in thicker tumours. Frequencies <20 MHz are less reliable in assessing depth. Frequencies ≥70 MHz demonstrate stronger correlations to histopathology. Higher ultrasound accuracy was seen for melanomas with Breslow depth >0.75 mm.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma: Results of a Single-Center Analysis

Sentinel lymph node biopsy (SLNB) in cutaneous melanoma is a staging step in cases of unaffected regional lymph nodes. This method is included in routine practice in many medical facilities of the Russian Federation.Aim. To analyze the results of SLNB in cutaneous melanoma performed using gamma scintigraphy technique with the 99mTc-containing technefit radiopharmaceutical agent.Materials and methods. The prospective study included 97 patients (39.2 % (38/97) men and 60.8 % (59/97) women) with primary cutaneous melanoma who received surgical treatment at the Republican Clinical Oncological Dispensary (Ufa) between February of 2021 and January of 2023. Mean patient age was 57.2 ± 13.2 years (95 % confidence interval (CI) 53.8–61.3 years), mean Breslow thickness per biopsy and histological examination after wide tumor resection was 2.89 ± 2.7 mm (95 % CI 2.2–3.76 mm), median follow-up period was 14 months (interquartile range 8–18 months). 99mTc-containing technefit radiopharmaceutical agent was administered intradermally around melanoma/scar. Accumulation of the radiopharmaceutical in the regional lymph nodes was evaluated using single-photon emission computed tomography/computed tomography (SPECT/CT). Intraoperatively the sentinel lymph node (SLN) was identified using a portable gamma probe. Morphological evaluation was performed in accordance with the protocol approved at the Republican Clinical Oncological Dispensary and based on the updated protocol of the European Organisation for Research and Treatment of Cancer (EORTС) (2019).Results. The percentage of successfully mapped SLNs after radiopharmaceutical administration was 93.8 % (91/97). Mean number of visualized SLNs per SPECT/CT data was 1.7 ± 1.1 SLN (95 % CI 1.5–1.9). SLN biopsy was performed in 91.8 % (89/97) patients. Mean number of identified SLNs during SLNB was 1.9 ± 1.2 (95 % CI 1.6–2.3). Histological and immunohistochemical examinations showed SLN metastases in 22.5 % (20/89) patients; in 77.5 % (69/89) patients, no lymph node metastases were found. SLN biopsy allowed to perform disease staging. During follow-up in 3 patients with negative SLNs metastases in the regional lymph nodes were found, as well as in 2 patients with positive SLNs. The frequency of false negative SLNB results was 13 % (3/23), negative post-test probability was 2.8 % (2/69). V600E mutation in the BRAF gene was found in 42.3 % (22/52) patients.Conclusion. SLN biopsy using the technefit radiopharmaceutical showed satisfactory results: SLNs were identified in 93.8 % of cases. Morphological examination showed SLN metastases in 22.5 % (20/89) of patients.

Use of Real-World FHIR Data Combined with Context-Sensitive Decision Modeling to Guide Sentinel Biopsy in Melanoma.

Background: To support clinical decision-making at the point of care, the "best next step" based on Standard Operating Procedures (SOPs) and actual accurate patient data must be provided. To do this, textual SOPs have to be transformed into operable clinical algorithms and linked to the data of the patient being treated. For this linkage, we need to know exactly which data are needed by clinicians at a certain decision point and whether these data are available. These data might be identical to the data used within the SOP or might integrate a broader view. To address these concerns, we examined if the data used by the SOP is also complete from the point of view of physicians for contextual decision-making. Methods: We selected a cohort of 67 patients with stage III melanoma who had undergone adjuvant treatment and mainly had an indication for a sentinel biopsy. First, we performed a step-by-step simulation of the patient treatment along our clinical algorithm, which is based on a hospital-specific SOP, to validate the algorithm with the given Fast Healthcare Interoperability Resources (FHIR)-based data of our cohort. Second, we presented three different decision situations within our algorithm to 10 dermatooncologists, focusing on the concrete patient data used at this decision point. The results were conducted, analyzed, and compared with those of the pure algorithmic simulation. Results: The treatment paths of patients with melanoma could be retrospectively simulated along the clinical algorithm using data from the patients' electronic health records. The subsequent evaluation by dermatooncologists showed that the data used at the three decision points had a completeness between 84.6% and 100.0% compared with the data used by the SOP. At one decision point, data on "patient age (at primary diagnosis)" and "date of first diagnosis" were missing. Conclusions: The data needed for our decision points are available in the FHIR-based dataset. Furthermore, the data used at decision points by the SOP and hence the clinical algorithm are nearly complete compared with the data required by physicians in clinical practice. This is an important precondition for further research focusing on presenting decision points within a treatment process integrated with the patient data needed.

Enhancing the utility of chromosome 6 and 8 testing in uveal melanoma biopsies.

The aim of this study was to evaluate the significance of testing the gain of chromosome 8 and the gain of chromosome 6 as prognostic markers in histopathological samples of enucleated eyes in with uveal melanoma. This is a retrospective study of 54 enucleated eyes. The status of chromosomes 3, 8 and 6 was tested by CISH, and FISH was used in a few samples. A follow-up for the detection of metastases was conducted in all patients. The statistical significance of chromosomal abnormalities as a prognostic factor for the development of metastases was determined. The study group consists of 54 patients (average age 63 years), 28 men (51.9%) Monosomy 3 together with gain of chromosome 8 was found in 10 samples (18.5%). Both chromosomal abnormalities were detected in 6 (11%) patients. No chromosomal abnormality in 3 or 8 was detected in 21 (38.9%) patients. Abnormalities of chromosome 6 were present in 6 (11%) patients. Progression free survival after 5 years was 33.3% (95% CI 0.0; 83.3) in these patients. Our findings indicate a correlation between progression-free survival and the presence of changes in chromosome 3 and e 8 in uveal melanomas. The results underline the necessity of testing for both chromosomal aberrations.

The number needed to biopsy for cutaneous melanoma in academic dermatology clinics.

A standard metric for melanoma detection is the number needed to biopsy (NNB). This metric has been used to evaluate practicing dermatologists, dermatology advanced practice professionals, and primary care providers. This metric, however, has rarely been applied to residency clinics. We aimed to determine the NNB at the University of Colorado residency clinics. Moreover, we sought to determine the impact of the coronavirus disease 2019 (COVID-19) pandemic on NNB. This study is a retrospective analysis of biopsies performed from 2016 to 2022 at the Denver Health Medical Center and the Rocky Mountain Regional Veteran Affairs dermatology clinics. Differential diagnosis at the time of biopsy was searched for keywords including melanoma, melanoma in situ, and lentigo maligna. Skin biopsies that included re-excisions were excluded. The NNB was subsequently generated by dividing the number of biopsied lesions with suspected melanoma by the number of histologically confirmed melanomas. The data was further separated by pre-COVID-19 (2016-February 2020), COVID-19 shutdown period (March 2020-July 2020), and post-COVID-19 (March 2020-present). Demographic data, including age, sex, race, and Fitzpatrick type, were collected. There were 2230 biopsies with suspected melanoma in the differential diagnosis at both clinic sites from 2016 to 2022. Of these, 362 were histologically confirmed melanoma. Total NNB was 6.16. The pre-COVID-19 NNB was 5.86, and the post-COVID-19 NNB was 6.91. Residency clinics have NNB similar to published values of practicing dermatologists. Furthermore, within these clinics, the impact of the COVID-19 pandemic was appreciated by a relative, although statistically insignificant, increase in NNB.

Abstract 4306: Label-free melanoma phenotype classification using AI-based morphological profiling

Abstract Melanoma plasticity and heterogeneity contribute to therapeutic resistance and mortality, and the ability of melanoma cells to switch from melanocytic to mesenchymal phenotypes results in increased invasion and metastasis. Investigating the role of these phenotypic states has been challenging due to limited marker availability for each cell state. High-parameter molecular methods such as RNAseq have produced more descriptive gene signatures of phenotypic states, but these methods are cell-destructive, labor-intensive, expensive, and can take days to weeks to obtain a readout. Different morphologies have been observed for melanocytic and mesenchymal phenotypic states in culture, thus we hypothesized that morphology could provide an orthogonal method to define and study phenotypes. We utilized the Deepcell platform to develop a classifier to predict the phenotype of melanoma cells as melanocytic or mesenchymal based on morphology alone. This method is free of labels and utilizes viable cells, overcoming the technical and practical limitations of traditional, marker-based methods. We used 20 patient-derived cell lines with known melanocytic or mesenchymal transcription scores to develop the ‘Melanoma Phenotype Classifier’ to phenotype melanoma cells based on morphology alone. A classifier accuracy of &amp;gt;88% was achieved, and morphological analysis of the images revealed distinct morphotypes for each phenotype, highlighting distinct morphological differences. To further link phenotypic state with multi-dimensional morphological profiles, we performed genetic and chemical perturbations known to shift the phenotypic state. The Melanoma Phenotype Classifier successfully predicted shifts in phenotypes driven by these perturbations. These results further demonstrate how phenotype is linked to distinct morphological changes that are detectable by artificial intelligence. Lastly, we applied the Melanoma Phenotype Classifier to dissociated melanoma biopsies, which revealed phenotypic heterogeneity that was confirmed by single cell RNASeq. This work establishes a link between cellular morphology and melanoma phenotype and lays the groundwork for the use of morphology as a label-free method of phenotyping viable melanoma cells. Citation Format: Evelyn Lattmann, Andreja Jovic, Julie Kim, Aizhan Tastanova, Tiffine Pham, Christian Corona, Kiran Saini, Zhouyang Lian, Senzeyu Zhang, Ryan Carelli, Kevin B. Jacobs, Manisha Ray, Vivian Lu, Stephane C. Boutet, Mahyar Salek, Maddison Masaeli, Mitchell P. Levesque. Label-free melanoma phenotype classification using AI-based morphological profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4306.

Utility of Indocyanine Green for Sentinel Lymph Node Biopsy in Pediatric Sarcoma and Melanoma

BackgroundIndocyanine green (ICG) is a fluorescent dye with increasing use for adult sentinel lymph node biopsy (SLNB). The utility of ICG in pediatric oncology remains understudied. We aim to describe our experience using ICG for SLNB in pediatrics versus standard blue dye. MethodsA retrospective review of pediatric patients with melanoma or sarcoma who underwent SLNB with technetium plus ICG or blue dye from 2014 to 2023 at a large academic children's hospital was conducted. ResultsTwenty-four patients were included; 58.3% were male with median age 13 years (range 4–21 years). The majority had a melanocytic tumor (91.7%) and 8.3% had sarcoma. All patients received technetium with concomitant blue dye (62.5%) or ICG (37.5%). ICG more reliably identified radioactive SLNs, compared to blue dye (mean 100% vs 78.3 ± 8.3%, p = 0.03). There was no significant difference in median operative time (ICG 82 min [68–203] vs blue dye 93 min [78–105], p = 0.84). Seven patients had positive SLNs (29.2%), with recurrence in 2 patients (8.3%) and 1 death (4.2%). There were no adverse events. ConclusionICG-directed SLNB in children is a safe and effective alternative to blue dye. Use of ICG did not add to operative time, and more often identified sentinel nodes versus blue dye. Type of StudyOriginal Research Article, Retrospective Comparative Study. Level of EvidenceIII.

Regional lymph node evaluation in pediatric conventional melanoma subtype: a single-center 10-year review

PurposeTo assess the prognostic and therapeutic significance of sentinel lymph node biopsy (SLNB) and completion lymph node dissection (CLND) in pediatric conventional melanoma (CM), while evaluating potential predictive factors for outcomes.MethodsWe conducted a retrospective analysis of medical records spanning 2009–2020, focusing on patients aged 18 or younger with localized cutaneous conventional melanoma.ResultsAmong the 33 patients, SLNB detected metastasis in 57.6% of cases, with 52.6% undergoing CLND. Positive SLN patients had higher relapse risk (HR 5.92; 95% CI 1.27–27.7; P = 0.024) but similar overall survival (HR 3.19; 95% CI 0.31–33.1, P = 0.33).No significant differences in disease-free survival (DFS) and OS were found between patients who underwent CLND and those who did not (HR 1.91; 95% CI 0.49–7.43, P = 0.35, and HR 0.52; 95% CI 0.03–8.32, P = 0.64, respectively). Univariate analysis showed age at diagnosis (P = 0.02) correlated with higher recurrence risk, with a 21% hazard increase per additional year of age.ConclusionsPositive SLN status and age at diagnosis were associated with worse DFS in CM patients. Our study did not find any prognostic or therapeutic value in CLND for pediatric melanoma. Further multicenter trials are needed to confirm our single-institution experience.Level of evidenceLevel IV.

Sentinel lymph node biopsy for melanoma in the older population: A prospective analysis of outcomes.

The use of sentinel lymph node biopsy (SLNB) in the older population, defined as those over 70 years old, has been debated since the adoption of SLNBinto routine practice. Interestingly, there remains a paucity of evidence, especially regarding the rates of SLNB positivity, complications, and subsequent adjuvant therapy in those with node positivity. Data on patient's comorbidities, positivity rates, complication rates, and subsequent adjuvant treatments were collected prospectively from 998 patients (644 patients < 70 and 354 patients ≥ 70 years old) between 2016 and 2022. Patients aged ≥ 70 were found to have a higher prevalence of comorbidities, including hypertension, diabetes and hyperlipidaemia. The mean Breslow thickness was 2.2 and 2.5 in the under and over 70 groups respectively (p = 0.03). The mean mitotic rate was found to be 3.3 in the under 70 s and 4.1 in the over 70 s (p = 0.02). Despite these results, no significant differences were observed in the positivity rates of sentinel lymph node biopsies or in the treatment options selected for positive results. The under 70 s were more likely to experience loss of sensation (p < 0.01), but no difference was found in the total number of complications between the two groups. Although patients aged 70 and above had a greater incidence of comorbidities, the study revealed that they had lower complications rates and there was no significant variation in the SLNB positivity rate or chosen treatment options between the two age groups. This study supports the move to physiological rather than chronological age assessments in SLNB of the elderly.

Investigation of prognostic factors for non-sentinel lymph node metastasis in patients undergoing sentinel lymph node biopsy for cutaneous malignant melanoma: Experience from a reference centre in Turkey

BackgroundIn the light of the results of recent randomised controlled trials regarding the role of nodal observation and completion lymph node dissection (CLND), studies from different populations are needed. The aim of our study was to present our experience with sentinel lymph node biopsy (SLNB) and CLND and the clinical and histopathological factors associated with a positive non-sentinel node. MethodsIn this single-centre, retrospective study, we reviewed histopathological reports of patients with primary cutaneous melanoma who underwent SLNB and CLND over a period of 7 years. The primary outcomes were the positivity rates of SLNBs and CLNDs. Secondary outcomes were metastatic tumour burden in positive sentinel nodes and presence of perinodal invasion. ResultsAmong the 110 participants who underwent SLNB (53 females, 57 males), the mean Breslow thickness of the primary tumour was 4.1 (0.3–41) mm. Ulceration appeared in 62.7% of lesions. The SLNBs were positive in 38 patients (34.5%), with 35 (92.1%) undergoing CLND, among which 9 (25.7%) showed metaNBstasis. Positive SLNB was linked to a higher Breslow thickness (p = 0.022), whereas CLND results lacked such an association (p = 0.76). Perinodal invasion (p = 0.006) and sentinel lymph node metastasis exceeding 1 mm (p = 0.017) was associated with a higher probability of non-sentinel node metastasis. ConclusionTo adapt the results of the new cohort study on SLNB and melanoma to different populations, studies with different patient groups highlighting the problems and suggested solutions are needed.