The natural course of cutaneous melanoma

When does a melanoma metastasize? Implications for management

Selecting which patients with clinically-localized melanoma require treatment other than wide excision of the primary tumor is based on the risk or presence of metastatic disease. This in turn is linked to survival. Knowing if and when a melanoma is likely to metastasize is therefore of great importance. Several studies employing a range of different methodologies have suggested that many melanomas metastasize long before the primary lesion is diagnosed. Therefore, waiting for dissemination of metastatic disease to become evident before making systemic therapy available to these patients may be less effective than giving them post-operative adjuvant therapy initially if the metastatic risk is high. The identification of these high-risk patients will assist in selecting those to whom adjuvant systemic therapy can most appropriately be offered. Further studies are required to better identify high-risk patients whose primary melanoma is likely to have already metastasized.

Positron Emission Tomography/Computed Tomography Transformation of Oncology: Melanoma and Skin Malignancies

Skin cancers are the most common cancers, with melanoma resulting in the highest cause of death in this category. Accurate clinical, histologic, and imaging staging with fludeoxyglucose positron emission tomography (FDG PET) is most important to guide patient management. Whilst surgical excision with clear margins is the gold-standard treatment for primary cutaneous melanoma, targeted therapies have generated remarkable and rapid clinical responses in melanoma, for which FDG PET also plays an important role in assessment of treatment response and post-therapy surveillance. Non-FDG PET tracers, advanced PET technology, and PET radiomics may potentially change the landscape of the utilization of PET in the imaging of patients with cutaneous malignancies.

Inflammatory breast cancer biomarkers and biology

Inflammatory breast cancer (IBC) is a unique breast cancer with a highly virulent course and low 5- and 10-year survival rates. Even though it only accounts for 1-5% of breast cancers it is estimated to account for 10% of breast cancer deaths annually in the United States. The accuracy of diagnosis and classification of this unique cancer is a major concern within the medical community. Early molecular and biological studies incidentally included IBC samples with other conventional breast cancers and were not informative as to the unique nature of the disease. Subsequent molecular studies that focused specifically on IBC demonstrated that IBC has a unique biology different from other forms of breast cancer. Additionally, a handful of unique signature genes that are hallmarks of IBC have also been suggested. Further understanding of IBC biology can help with diagnosis and treatment of the disease. The current article reviews the history and highlights of IBC studies.

Tumoral inflammatory infiltrate does not predict metastases in thin primary cutaneous melanomas

BACKGROUND

In cutaneous melanomas in general, tumor inflammatory infiltrate (TII) can protect against distant metastases, but there is no consensus when only thin primary cutaneous melanomas (TPCM) are considered.

OBJECTIVE

To investigate the presence of TII in TPCM and the relationship between TII and the occurrence of metastases.

METHODS

Case-control study including 50 patients with TPCM, 22 metastatic (MC group) and 28 non-metastatic (NMC group). The presence of TII was evaluated and, if present, qualified as mild, moderate or marked.

RESULTS

The mean age was 50.7 years in the MC and 56.2 years in the NMC group (p = 0.234), and the male sex predominated in the MC group (63.6%). The average Breslow thickness was higher in the MC when compared to that observed in the NMC (respectively 0.8 vs. 0.6 mm, p = 0.012). The presence of ulceration occurred in 22.7% of the MC and 17.9% of the NMC (p = 0.732). TII was present in all 50 TPCM, being marked or moderate in 67.9% of the NMC and 54.5% in the MC group (p = 0.503). In the multivariate analysis, the presence of moderate and marked TII had an Odds Ratio (OR) of 0.57 (95% Confidence Interval [CI]: 0.18‒1.8) and adjusted OR of 0.68 (95% CI 0.13‒3.99).

STUDY LIMITATIONS

Small sample size.

CONCLUSIONS

TII was present in all TPCM (with and without metastases), and it was not possible to demonstrate a protective effect of TII against the appearance of metastases.

Patterns of Recurrence of Cutaneous Melanoma: A Literature Review

The incidence of melanoma has been dramatically increasing over the last decades. Melanoma is considered to have a high metastatic potential and it can progress via lymphatic vessels or through hematogenous metastasis. Different patterns of recurrence have been described, namely, local, satellite, and in transit metastasis (LCIT), lymphatic metastasis, and systemic metastasis. With a more advanced melanoma stage at diagnosis, there is a higher risk for systemic metastasis in comparison to LCIT; in contrast, early-stage melanoma tends to recur more frequently as LCIT and less commonly as systematic metastasis. The aim of this review was to summarize the patterns of recurrence of cuta-neous melanoma, giving the clinician a practical summary for diagnosis, prognosis, and surveillance. There is a knowledge gap of the common patterns of recurrence that needs to be addressed to better identify patients at high risk of disease recurrence and personalize surveillance strategies as well as patient counseling.

The Diagnosis and Management of Cutaneous Metastases from Melanoma

Melanoma is one of the deadliest skin tumors, accounting for almost 90% of skin cancer mortality. Although immune therapy and targeted therapy have dramatically changed the prognosis of metastatic melanoma, many patients experience disease progression despite the currently available new treatments. Skin metastases from melanoma represent a relatively common event as first sign of advanced disease or a sign of recurrence. Skin metastases are usually asymptomatic, although in advanced stages, they can present with ulceration, bleeding, and superinfection; furthermore, they can cause symptoms related to compression on nearby tissues. Treatments vary from simple surgery resections to topical or intralesional local injections, or a combination of these techniques with the most recent systemic immune or target therapies. New research and studies should focus on the pathogenesis and molecular mechanisms of the cutaneous metastases of melanoma in order to shed light on the mechanisms underlying the different behavior and prognoses of different patients.

Darovasertib, a novel treatment for metastatic uveal melanoma

The FDA granted orphan drug designation to darovasertib, a first-in-class oral, small molecular inhibitor of protein kinase C (PKC), for the treatment of uveal melanoma, on 2 May 2022. Primary uveal melanoma has a high risk of progressing to metastatic uveal melanoma, with a poor prognosis. The activation of the PKC and mitogen-activated protein kinase pathways play an essential role in the pathogenesis of uveal melanoma, and mutations in the G protein subunit alpha q (GNAQ), and G protein subunit alpha11 (GNA11) genes are considered early events in the development of uveal melanoma. Compared to other PKC inhibitors, such as sotrastaurin and enzastaurin, darovasertib is significantly more potent in inhibiting conventional (α, β) and novel (δ, ϵ, η, θ) PKC proteins and has a better tolerability and safety profile. Current Phase I/II clinical trials indicated that darovasertib, combined with the Mitogen-activated protein kinase/Extracellular (MEK) inhibitors, binimetinib or crizotinib, produced a synergistic effect of uveal melanoma. In this article, we summarize the development of drugs for treating uveal melanomas and discuss problems associated with current treatments. We also discuss the mechanism of action, pharmacokinetic profile, adverse effects, and clinical trial for darovasertib, and future research directions for treating uveal melanoma.

Targeting the cMET pathway to enhance immunotherapeutic approaches for mUM patients

The liver is the most preferential initial site of metastasis for uveal melanoma (mUM), and this preference is associated with rapid mortality in mUM patients. Despite the significant clinical benefits of Immune checkpoint inhibitors (ICIs) in metastatic cutaneous melanoma patients, ICIs have shown little to no benefit in mUM patients. A potential reason for this inefficiency of ICI could be partly devoted to the involvement of the liver itself, thanks to its rich source of growth factors and immunosuppressive microenvironment. Uveal melanoma cells show increased expression of a transmembrane protein called cMET, which is known as the sole receptor for the Hepatocyte growth factor (HGF). Hyperactivation of cMET by HGF contributes to mUM development, and the liver, being the major source of HGF, may partially explain the metastasis of uveal melanoma cells to the liver. In addition, cMET/HGF signaling has also been shown to mediate resistance to ICI treatment, directly and indirectly, involving tumor and immune cell populations. Therefore, targeting the cMET/HGF interaction may enhance the efficacy of immunotherapeutic regimes for mUM patients. Hence in this minireview, we will discuss the rationale for combining cMET inhibitors/antibodies with leading immune checkpoint inhibitors for treating mUM. We will also briefly highlight the challenges and opportunities in targeting cMET in mUM.

Timing and necessity of staging imaging in clinical stage II cutaneous melanoma: Cost-effectiveness and clinical decision analysis

BACKGROUND

Preoperative imaging in clinical stage II melanoma is not indicated per National Comprehensive Cancer Network (NCCN) guidelines but remains common in clinical practice.

METHODS

Patients presenting with cutaneous clinical stage II melanoma from 2007 to 2019 were retrospectively reviewed. A clinical decision analysis with cost data was designed to understand ideal practice patterns in managing stage II melanoma, with pre-versus selective post-operative imaging as the initial decision node.

RESULTS

There were 277 subjects included, and 143 underwent preoperative imaging (49.5%). This changed management (i.e. no surgery) in one patient (0.4%). Overall, 16 patients had additional findings on imaging (5.8%). Upfront surgery with selective postoperative imaging was a more cost-effective strategy than routine performance of preoperative imaging, with savings of $1677 per patient.

CONCLUSION

Preoperative imaging is a low yield, costly approach for patients with clinical stage II melanoma with minimal impact on the decision to proceed with surgical management.

Clinicopathological Characteristics Predicting Further Recurrence and Survival Following Resection of In-Transit Melanoma Metastases

BACKGROUND

In-transit metastases (ITMs) affect approximately 4% of patients with cutaneous melanoma. This study sought to identify clinical and pathological characteristics that predict further recurrence and survival following resection of ITMs.

PATIENTS AND METHODS

Patients (n = 573) who underwent surgical resection of their first presentation of ITM following previous surgical treatment of an American Joint Committee on Cancer (AJCC) stage I-II melanoma between 1969 and 2017 were identified from an institutional database. Clinicopathological predictors of patterns of recurrence and survival following ITM resection were sought.

RESULTS

The median time of ITM development was 2.4 years after primary melanoma resection. ITMs were most frequently located on the lower limb (51.0%). The most common melanoma subtype associated with ITM development was nodular melanoma (44.1%). After surgical resection of a first ITM, 65.4% of patients experienced recurrent disease. Most recurrences were locoregional (44.7%), with distant metastasis occurring in 23.9% of patients. Lower limb ITMs were more frequently associated with subsequent ITMs [odds ratio (OR) 2.41, p = 0.0002], and the lowest risk of distant metastasis (p < 0.0001) compared with other primary sites. Primary melanomas and ITM on head and neck, as well as the presence of ulceration, were associated with worse survival.

CONCLUSIONS

Recurrence after surgical resection of a first ITM was common. Patterns of recurrence differed according to anatomical site; further ITM recurrences were more likely for lower limb ITMs, which were also associated with longer distant recurrence-free survival. Distant metastasis was more common for ITM on the head and neck, with worse survival.

Sex Differences in Cutaneous Melanoma: Incidence, Clinicopathological Profile, Survival, and Costs

Background: This study aims to provide a comprehensive overview of sex-related characteristics of cutaneous malignant melanoma (CMM), with special reference to its incidence, clinicopathological profile, overall survival, and treatment-related costs. Methods: This retrospective cohort study included all 1,279 CMM patients who were registered in 2015 in the Veneto Cancer Registry (a population-based registry including all 4,900,000 regional residents). The by-sex comparisons included tumor stage and site, histological subtype, and other clinical-pathological variables. A Cox regression analysis was used to test the association between sex and survival, adjusting for the main covariates. Treatment costs were calculated by linking patients with several administrative regional databases. Results: Age-specific incidence rates were significantly higher for men among people >50 years old. For men, the trunk was the most common primary site (59.3%), whereas for women the lower limbs (32.1%) were the most common primary site, followed by the trunk (31.8%), which was lower than for men (p < 0.001). At presentation, the frequency of early stage CMM was higher among women, who also featured a significantly lower risk of death (p = 0.016), after adjusting for covariates. Men also incurred higher costs for melanoma treatment in the first year after their diagnosis. Conclusions: Among younger adults, CMM was more common in women, whereas among older adults, it was more common in men. Sex also influences patients' histopathological characteristics at diagnosis. Women had better overall survival after adjusting for demographic, pathological, and clinical profiles. The costs of treatment were also lower for women with CMM.

Cardiac Metastases from Choroidal Melanoma

In patients with uveal melanoma, cardiac metastases can present without any symptoms. It is becoming more common than previously thought and highlights the importance of routine surveillance after definitive treatment.

Outcomes After Curative Metastasectomy for Patients with Malignant Melanoma: A Systematic Review and Meta-analysis

BACKGROUND

Evidence on the role of curative metastasectomy (CM) for malignant melanoma (MM) patients is limited, especially in the current era of effective systemic therapy. A systematic review and meta-analysis were performed to ascertain the role of CM compared with incomplete or nonsurgical treatment for patients with MM.

METHODS

Medline, Embase, and Scopus databases were searched for studies investigating CM for MM until 30 September 2021. The review included studies that compared CM with no-CM and reported a hazard ratio (HR) after multivariate analysis for overall survival. A random-effects model with inverse variance was used to calculate pooled HR. The Newcastle-Ottawa Scale was used to assess the risk of bias.

RESULTS

For the final analysis, 40 studies including 31,282 patients (CM, 9958; no-CM, 21,324) were considered. Compared with no-CM, CM was associated with a significantly lower risk of death (HR, 0.42; 95% confidence interval [CI], 0.38-0.47; p < 0.00001). Subgroup analysis showed that the outcome was independent of the effective systemic therapy and anatomic location of metastasis. An unfavorable prognosis was associated with advancing age, elevated lactate dehydrogenase (LDH), male gender, prior stage 3 disease, multiple metastases and organ sites, and shorter disease-free interval.

CONCLUSION

Curative metastasectomy for MM is associated with a lower risk of death than non-curative treatment methods. Selection bias and underlying weakness of studies reduced the strength of evidence in this review. However, CM should be a part of the multimodality treatment of MM whenever technically feasible.

Genome-Wide Association Study Suggests the Variant rs7551288*A within the DHCR24 Gene Is Associated with Poor Overall Survival in Melanoma Patients

Simple Summary

The aim of this work was to investigate prognostic genetic factors in melanoma patients. Phenotypic and disease data as well as biomaterial were collected after informed consent from patients followed up in a Skin Cancer Center of a University clinic. Genome-wide analysis (GWAS) was performed with survival data of 556 melanoma patients and genetic data including more than 300,000 common polymorphisms. The SNP rs7551288 reached suggestive genome-wide significance (p = 2 × 10⁻⁶). This intronic variant of the DHCR24 gene is involved in the cholesterol synthesis pathway. Further analyses and a literature review suggest an important role of this locus for the clinical course of disease in melanoma patients.

Abstract

Melanoma incidence rates are high among individuals with fair skin and multiple naevi. Established prognostic factors are tumour specific, and less is known about prognostic host factors. A total of 556 stage I to stage IV melanoma patients from Germany with phenotypic and disease-specific data were analysed; 64 of these patients died of melanoma after a median follow-up time of 8 years. Germline DNA was assessed by the HumanCoreExome BeadChip and data of 356,384 common polymorphisms distributed over all 23 chromosomes were used for a genome-wide analysis. A suggestive genome-wide significant association of the intronic allele rs7551288*A with diminished melanoma-specific survival was detected (p = 2 × 10⁻⁶). The frequency of rs7551288*A was 0.43 and was not associated with melanoma risk, hair and eye colour, tanning and total naevus count. Cox regression multivariate analyses revealed a 5.31-fold increased risk of melanoma-specific death for patients with the rs7551288 A/A genotype, independent of tumour thickness, ulceration and stage of disease at diagnoses. The variant rs7551288 belongs to the DHCR24 gene, which encodes Seladin-1, an enzyme involved in the biosynthesis of cholesterol. Further investigations are needed to confirm this genetic variant as a novel prognostic biomarker and to explore whether specific treatment strategies for melanoma patients might be derived from it.

The Impact of Surveillance Imaging Frequency on the Detection of Distant Disease for Patients with Resected Stage III Melanoma

BACKGROUND

It is not known whether there is a survival benefit associated with more frequent surveillance imaging in patients with resected American Joint Committee on Cancer stage III melanoma.

OBJECTIVE

The aim of this study was to investigate distant disease-free survival (DDFS), melanoma-specific survival (MSS), post distant recurrence MSS (dMSS), and overall survival for patients with resected stage III melanoma undergoing regular computed tomography (CT) or positron emission tomography (PET)/CT surveillance imaging at different intervals.

PATIENTS AND METHODS

A closely followed longitudinal cohort of patients with resected stage IIIA-D disease treated at a tertiary referral center underwent 3- to 4-monthly, 6-monthly, or 12-monthly surveillance imaging between 2000 and 2017. Survival outcomes were estimated using the Kaplan-Meier method, and log-rank tests assessed the significance of survival differences between imaging frequency groups.

RESULTS

Of 473 patients (IIIA, 19%; IIIB, 31%; IIIC, 49%; IIID, 1%) 30% underwent 3- to 4-monthly imaging, 10% underwent 6-monthly imaging, and 60% underwent 12-monthly imaging. After a median follow-up of 6.2 years, distant recurrence was recorded in 252 patients (53%), with 40% detected by surveillance CT or PET/CT, 43% detected clinically, and 17% with another imaging modality. Median DDFS was 5.1 years (95% confidence interval 3.9-6.6). Among 139 IIIC patients who developed distant disease, the median dMSS was 4.4 months shorter in those who underwent 3- to 4-monthly imaging than those who underwent 12-monthly imaging.

CONCLUSION

Selecting patients at higher risk of distant recurrence for more frequent surveillance imaging yields a higher proportion of imaging-detected distant recurrences but is not associated with improved survival. A randomized comparison of low versus high frequency imaging is needed.

A 41-Year-Old Woman with a Late Cerebral Metastasis 16 Years After an Initial Diagnosis of Cutaneous Melanoma

Patient: Female, 41-year-old

Final Diagnosis: Melanoma brain metastasis

Symptoms: Intrercranial hemorraghe

Medication:—

Clinical Procedure: —

Specialty: Neurosurgery

Sinusoidal Growth Pattern of Hepatic Melanoma Metastasis: Implications for Histopathologic Diagnosis

Metastatic tumors interface with liver in multiple patterns, of which, the rare "sinusoidal" growth pattern can be subtle and easily overlooked on biopsy. We sought to characterize the metastasis-to-liver interface patterns of melanoma compared with other tumor types and assess the incidence of metastatic melanoma in histologically normal-appearing targeted liver lesion biopsies. Liver lesion samples from 54 melanoma patients were assessed. Nearly normal-appearing cases, defined as no obvious malignancy on routine hematoxylin and eosin stain (n=24), were stained with SOX10 and confirmed with MelanA. Tumor-to-liver interface patterns were determined in biopsies overtly positive for metastatic melanoma (n=30) versus other hepatic metastases as controls (colon, n=28; breast, n=20; pancreaticobiliary, n=20; and neuroendocrine, n=28). Of the 24 nearly normal-appearing liver biopsies from melanoma patients, 3 had subtle melanoma cells detected in sinusoids, confirmed with immunohistochemistry. Of 30 livers overtly positive for melanoma, 8 showed the sinusoidal pattern, compared with none in other metastases. In total, 11/33 (33%) cases of metastatic melanoma liver biopsies demonstrated the sinusoidal pattern. We describe 11 metastatic melanoma cases in liver with the rare sinusoidal pattern, 3 of which were subtle and easy to miss on routine hematoxylin and eosin stain. Given that sinusoidal metastasis does not elicit a tissue reaction, it is prudent for the pathologists to be aware of this pattern of metastases and have a low threshold to order immunostains for accurate diagnosis and optimal patient care.

Use of Nanoparticles in Delivery of Nucleic Acids for Melanoma Treatment

Melanoma accounts for 4% of all skin cancer malignancies, with only 14% of diagnosed patients surviving for more than 5 years after diagnosis. Until now, there is no clear understanding of the detailed molecular contributors of melanoma pathogenesis. Accordingly, more research is needed to understand melanoma development and prognosis.All the treatment approaches that are currently applied have several significant limitations that prevent effective use in melanoma. One major limitation in the treatment of cancer is the acquisition of multidrug resistance (MDR). The MDR results in significant treatment failure and poor clinical outcomes in several cancers, including skin cancer. Treatment of melanoma is especially retarded by MDR. Despite the current advances in targeted and immune-mediated therapy, treatment arms of melanoma are severely limited and stand as a significant clinical challenge. Further, the poor pharmacokinetic profile of currently used chemotherapeutic agents is another reason for treatment failure. Therefore, more research is needed to develop novel drugs and carrier tools for more effective and targeted treatment.Nucleic acid therapy is based on nucleic acids or chemical compounds that are closely related, such as antisense oligonucleotides, aptamers, and small-interfering RNAs that are usually used in situations when a specific gene implicated in a disorder is deemed a therapeutically beneficial target for inhibition. However, the proper application for nucleic acid therapies is hampered by the development of an effective delivery system that can maintain their stability in the systemic circulation and enhance their uptake by the target cells. In this chapter, the prognosis of the different types of melanoma along with the currently used medications is highlighted, and the different types of nucleic acids along with the currently available nanoparticle systems for delivering these nucleic acids into melanoma cells are discussed. We also discuss recently conducted research on the use of different types of nanoparticles for nucleic acid delivery into melanoma cells and highlight the most significant outcomes.

A Radiolabeled Self-assembled Nanoparticle Probe for Diagnosis of Lung-Metastatic Melanoma

Melanoma is a highly malignant skin cancer that frequently metastasizes to the lung, bone, and brain at an early phase. Therefore, noninvasive detection of metastasized melanoma could be beneficial to determine suitable therapeutic strategies. We previously reported a biocompatible ternary anionic complex composed of plasmid DNA (pDNA), polyethyleneimine (PEI), and γ-polyglutamic acid (γ-PGA) based on an electrostatic interaction, which was highly taken up by melanoma cells (B16-F10), even if it was negatively charged. Here, we developed a radiolabeled γ-PGA complex by using indium-111 (111In)-labeled polyamidoamine dendrimer (4th generation; G4) instead of pDNA and iodine-125 (125I)-labeled PEI instead of native PEI, and evaluated its effectiveness as a melanoma-targeted imaging probe. This ternary complex was synthesized at a theoretical charge ratio; carboxyl groups of 111In-diethylenetriaminepentaacetic acid (DTPA)-G4 : amino groups of 125I-PEI : carboxyl groups of γ-PGA was 1 : 8 : 16, and the size and zeta potential were approximately 29 nm and -33 mV, respectively. This complex was taken up by B16-F10 cells with time. Furthermore, a biodistribution study, using normal mice, demonstrated its accumulation in the liver, spleen, and lung, where macrophage cells are abundant. Almost the same level of radioactivity derived from both 111In and 125I was observed in these organs at an early phase after probe injection. Compared with the normal mice, significantly higher lung-to-blood ratios of radioactivity were observed in the B16-F10-lung metastatic cancer model. In conclusion, the radiolabeled γ-PGA complex would hold potentialities for nuclear medical imaging of lung metastatic melanoma.

Circulating Tumor DNA Testing Opens New Perspectives in Melanoma Management

Malignant melanoma accounts for about 1% of all skin cancers, but it causes most of the skin cancer-related deaths. Circulating tumor DNA (ctDNA) testing is emerging as a relevant tool for the diagnosis and monitoring of cancer. The availability of highly sensitive techniques, including next generation sequencing (NGS)-based panels, has increased the fields of application of ctDNA testing. While ctDNA-based tests for the early detection of melanoma are not available yet, perioperative ctDNA analysis in patients with surgically resectable melanoma offers relevant prognostic information: i) the detection of ctDNA before surgery correlates with the extent and the aggressiveness of the disease; ii) ctDNA testing after surgery/adjuvant therapy identifies minimal residual disease; iii) testing ctDNA during the follow-up can detect a tumor recurrence, anticipating clinical/radiological progression. In patients with advanced melanoma, several studies have demonstrated that the analysis of ctDNA can better depict tumor heterogeneity and provides relevant prognostic information. In addition, ctDNA testing during treatment allows assessing the response to systemic therapy and identifying resistance mechanisms. Although validation in prospective clinical trials is needed for most of these approaches, ctDNA testing opens up new scenarios in the management of melanoma patients that could lead to improvements in the diagnosis and therapy of this disease.

Features associated with melanoma metastasis in Latvia

Cutaneous melanoma (CM) is the most aggressive form of skin cancer, exhibits an increasing incidence worldwide and has a high potential to develop metastasis. The current study aimed to identify a set of parameters that may aid in predicting the probability and timing of the onset of CM metastasis. A retrospective analysis was performed using the archive data of 2,026 patients with CM that were treated at the Riga East University Hospital Latvian Oncology Centre, which is the largest oncological hospital in the country, between 1998 and 2015. A case-control study design was employed, where patients with metastasis (n=278) were used as the cases and patients without metastasis were used as the controls. The present study examined the associations between metastasis and potential risk factors and constructed multivariate models of features that predicted metastasis using stepwise regression. Time until metastasis was analyzed using negative binomial regression models. The results of the present study indicated an increase in the number of melanomas that developed metastases during 1998–2015. Tumor Breslow thickness was demonstrated to be significantly larger in patients with metastasis compared with those without (P=0.012). The presence of ulceration significantly increased the risk of metastases [odds ratio (OR), 1.66; 95% CI, 1.07-2.59; P=0.033]. The absence of pigment in melanoma tissues was indicated to lead to a greater likelihood of metastasis (OR, 2.14; 95% CI, 1.10-4.19; P=0.035). Shorter times from diagnosis until the onset of metastases were observed in older patients (incident rate ratio (IRR), 6.85; 95% CI, 2.43-19.30; P=2.78×10⁻⁴), and a borderline significant association was observed in those with ulcerated tumors (IRR, 1.33; 95% CI, 0.98-1.80; P=0.064). Therefore, the main features associated with the development of melanoma metastasis in Latvia were indicated to be tumor ulceration, absence of pigment and Breslow thickness.

Melanoma: Prognostic Factors and Factors Predictive of Response to Therapy

BACKGROUND

A better understanding of prognostic factors and biomarkers that predict response to treatment is required in order to further improve survival rates in patients with melanoma. Prognostic Factors: The most important histopathological factors prognostic of worse outcomes in melanoma are sentinel lymph node involvement, increased tumor thickness, ulceration and higher mitotic rate. Poorer survival may also be related to several clinical factors, including male gender, older age, axial location of the melanoma, elevated serum levels of lactate dehydrogenase and S100B. Predictive Biomarkers: Several biomarkers have been investigated as being predictive of response to melanoma therapies. For anti-Programmed Death-1(PD-1)/Programmed Death-Ligand 1 (PD-L1) checkpoint inhibitors, PD-L1 tumor expression was initially proposed to have a predictive role in response to anti-PD-1/PD-L1 treatment. However, patients without PD-L1 expression also have a survival benefit with anti-PD-1/PD-L1 therapy, meaning it cannot be used alone to select patients for treatment, in order to affirm that it could be considered a correlative, but not a predictive marker. A range of other factors have shown an association with treatment outcomes and offer potential as predictive biomarkers for immunotherapy, including immune infiltration, chemokine signatures, and tumor mutational load. However, none of these have been clinically validated as a factor for patient selection. For combined targeted therapy (BRAF and MEK inhibition), lactate dehydrogenase level and tumor burden seem to have a role in patient outcomes.

CONCLUSION

With increasing knowledge, the understanding of melanoma stage-specific prognostic features should further improve. Moreover, ongoing trials should provide increasing evidence on the best use of biomarkers to help select the most appropriate patients for tailored treatment with immunotherapies and targeted therapies.

Epithelioid angiomyolipoma mimicking metastatic melanoma in a liver tumor

It is well known to pathologists that melanoma is "the great mimicker," looking like almost any other tumor, and able to metastasize anywhere in the body. We report a case of a 48-year-old female with a history of metastatic melanoma 4 years before, who presented with a hepatic mass. Microscopic examination of the liver mass revealed sheets of pleomorphic, epithelioid cells, which expressed a pan-melanocytic cocktail (MART1, HMB45, and tyrosinase). These findings were initially interpreted as metastatic melanoma and the case was transferred for dermatopathology consultation. We compared the morphology of this tumor to the primary melanoma and noticed that the primary melanoma showed nevoid cytology, morphologically distinct from the liver lesion. Consequently, we performed additional immunohistochemical studies, which determined that the liver mass was negative for S100 and SOX10, and established a final diagnosis of epithelioid angiomyolipoma. The key for reaching the correct diagnosis was the morphologic comparison with the original lesion and the evaluation of a wider immunohistochemical profile. For appropriate management in patients with new lesions, even in the context of a patient with known metastatic disease, it is essential to consider other neoplasms in the differential diagnosis.

Statins may reduce disease recurrence in patients with ulcerated primary melanoma

BACKGROUND

Statins may restrict the cellular functions required for melanoma growth and metastasis.

OBJECTIVES

To determine whether long-term statin use commenced before diagnosis of a primary melanoma is associated with reduced risk of melanoma recurrence.

METHODS

We prospectively followed a cohort of patients newly diagnosed between 2010 and 2014 with localized tumour-stage T1b to T4b melanoma in Queensland, Australia. We used Cox regression analyses to examine associations between long-term statin use and melanoma recurrence for the entire cohort, and then separately by sex and by presence of ulceration, due to evidence of effect modification.

RESULTS

Among 700 patients diagnosed with stage T1b to T4b primary melanoma (mean age 62 years, 59% male, 28% with ulcerated tumours), 94 patients (13%) developed melanoma recurrence within 2 years. Long-term statin users (n = 204, 29%) had a significantly lower risk of disease recurrence than nonusers [adjusted hazard ratio (HR_adj ) 0·55, 95% confidence Interval (CI) 0·32-0·97] regardless of statin subtype or potency. Compared with nonusers of statins, risk of recurrence was significantly decreased in male statin users (HR_adj 0·39, 95% CI 0·19-0·79) but not in female statin users (HR_adj 0·82, 95% CI 0·29-2·27) and in statin users with ulcerated (HR_adj 0·17, 95% CI 0·05-0·52) but not nonulcerated (HR_adj 0·91, 95% CI 0·46-1·81) primary melanoma.

CONCLUSIONS

Statins commenced before melanoma diagnosis may reduce the risk of melanoma recurrence, especially in men and in those with ulcerated tumours. Clinical trial evaluation of the potential role of statins in improving the prognosis of high-risk melanoma is warranted.

Influence of 18F-FDG PET/CT on clinical management and outcome in patients with advanced melanoma not primarily selected for surgery based on a linked evidence approach

PURPOSE

To evaluate the clinical benefit of positron emission tomography (PET)/computed tomography (CT) in patients with advanced melanoma, primarily not selected for surgery based on management changes and survival data using the linked evidence approach (LEA).

METHODS

A total of 201 ¹⁸F-FDG PET/CT examinations (n = 33, stage III and n = 168, stage IV) in 119 melanoma patients, primarily not scheduled for surgery, were analysed regarding their impact on clinical management. Patients were selected from a prospective oncological PET/CT registry. The three PET/CT indication groups included unclear lesions in conventional imaging (n = 8), routine follow-up after multiple surgeries (n = 115) and therapy response evaluation of systemic therapy (n = 78). PET/CT-induced management changes were categorized either as major (change from follow-up to surgical or systemic treatment or vice versa, change from surgery to systemic therapy or vice versa) or minor (modifications in systemic therapy). The expected benefit of changes was determined via the linked evidence approach (LEA) connecting registry data, outcome data including overall survival and evidence of diagnostic accuracy of PET/CT based on existing literature.

RESULTS

Related to the total study cohort, a change of management after PET/CT was observed in 48% of scans, including 10% minor and 38% major changes. Major changes involved a shift either from follow-up (33/201) or therapy pause (7/201) to systemic therapy, to surgical or other local therapy (26/201) and BSC (2/201). Nine out of 201 cases resulted in treatment pause of systemic therapy. We could confirm the prognostic value of PET/CT-based management by observing a 5-year survival rate more than roughly doubled in patients followed up after tumour exclusion or under local therapy compared with patients under systemic therapy. We could argue for a patient benefit from PET/CT-based management changes using results on accuracy and therapeutic effects from the literature.

CONCLUSION

The use of PET/CT in advanced melanoma patients, primarily not considered for surgery, resulted in frequent changes of management associated with a relevant expected clinical benefit especially in patients classified by PET/CT as tumour-free or eligible for radical surgery.

Risk of Melanoma Recurrence After Diagnosis of a High-Risk Primary Tumor

Importance

With emerging new systemic treatments for metastatic melanoma, early detection of disease recurrence is increasingly important.

Objective

To investigate the risk of melanoma recurrence in patients with a localized melanoma at a high risk of metastasis.

Design, Setting, and Participants

A total of 1254 patients with newly diagnosed, histologically confirmed tumor category T1b to T4b melanoma in Queensland, Australia, were recruited prospectively between October 1, 2010, and October 1, 2014, for participation in a cohort study. Data analysis was conducted from February 8, 2018, to February 20, 2019. We used Cox proportional hazards regression analysis to examine associations between patient and tumor factors and melanoma recurrence.

Exposures

Disease-free survival (DFS) by melanoma tumor category defined by the 7th vs 8th editions of the AJCC Cancer Staging Manual (AJCC 7 vs AJCC 8).

Main Outcomes and Measures

Melanoma recurrences were self-reported through follow-up questionnaires administered every 6 months and confirmed by histologic or imaging findings.

Results

Of 1254 patients recruited, 825 individuals (65.8%) agreed to participate. Thirty-six were found to be ineligible after providing consent and a further 89 patients were excluded after reclassifying tumors using AJCC 8, leaving 700 participants with high-risk primary melanoma (mean [SD] age, 62.2 [13.5] years; 410 [58.6%] men). Independent predictors of recurrence were head or neck site of primary tumor, ulceration, thickness, and mitotic rate greater than 3/mm2 (hazard ratio, 2.36; 95% CI, 1.19-4.71). Ninety-four patients (13.4%) developed a recurrence within 2 years of diagnosis: 66 tumors (70.2%) were locoregional, and 28 tumors (29.8%) developed at distant sites. After surgery for locoregional disease, 37 of 64 patients (57.8%) remained disease free at 2 years, 7 patients (10.9%) developed new locoregional recurrence, and 20 patients (31.3%), developed distant disease. Two-year DFS was similar when comparing AJCC 7 and AJCC 8, for T1b (AJCC 7, 253 [93.3% DFS]; AJCC 8, 242 [93.0% DFS]) and T4b (AJCC 7 and AJCC 8, 50 [68.0% DFS] category tumors in both editions. Patients with T2a to T4a tumors who did not have a sentinel lymph node biopsy (SLNB) at diagnosis had lower DFS than patients with the same tumor category and a negative SLNB (T2a: 136 [91.1%; 95% CI, 86.4-95.9] vs 96 [96.9%; 95 % CI, 93.4-100.0]; T4a: 33 [78.8%; 95% CI, 64.8-92.7] vs 6 [83.3; 95% CI, 53.5-100.0]).

Conclusions and Relevance

These findings suggest that 13.4% of patients with a high-risk primary melanoma will experience disease recurrence within 2 years. Head or neck location of initial tumor, SLNB positivity, and signs of rapid tumor growth may be associated with primary melanoma recurrence.

Mediastinal metastatic melanoma: an unusual case presentation of recurrent melanoma

Mediastinal malignant melanoma is rare as both primary and metastatic lesions. We present the case of a 50-year-old man with diagnosis of recurrent melanoma of the mediastinum. Our patient was previously treated for cutaneous melanoma in 2001 with surgical excision. He presented with symptoms of exertional dyspnoea, dull chest pain and non-productive cough for 12 weeks. CT revealed a large heterogeneously enhancing mass, measuring 10.7×7.6 cm, centred within the aortopulmonary window which abutted the adjacent pericardium. Open biopsy of the epicardial mass was performed via left anterior thoracotomy. Immunohistochemical stains performed on the mass were positive for CD99, focally positive for CD56, SOX10, S100 and WT-1. A diagnosis of metastatic melanoma was established. The patient was started on pembrolizumab with pending BRAF testing. V600E and V600K mutations in exon 15 of the BRAF gene were codetected, and the patient was treated with dabrafenib and trametinib.

Malignant Cutaneous Melanoma: Updates in PET Imaging

BACKGROUND

Cutaneous malignant melanoma is a neoplasm whose incidence and mortality are dramatically increasing. 18F-FDG PET/CT gained clinical acceptance over the past 2 decades in the evaluation of several glucose-avid neoplasms, including malignant melanoma, particularly for the assessment for distant metastases, recurrence and response to therapy.

OBJECTIVE

To describe the advancements of nuclear medicine for imaging melanoma with particular attention to 18F-FDG-PET and its current state-of-the-art technical innovations.

METHODS

A comprehensive search strategy was used based on SCOPUS and PubMed databases. From all studies published in English, we selected the articles that evaluated the technological insights of 18FFDG- PET in the assessment of melanoma.

RESULTS

State-of-the-art silicon photomultipliers based detectors ("digital") PET/CT scanners are nowadays more common, showing technical innovations that may have beneficial implications for patients with melanoma. Steady improvements in detectors design and architecture, as well as the implementation of both software and hardware technology (i.e., TOF, point spread function, etc.), resulted in significant improvements in PET image quality while reducing radiotracer dose and scanning time.

CONCLUSION

Recently introduced digital PET detector technology in PET/CT and PET/MRI yields higher intrinsic system sensitivity compared with the latest generation analog technology, enabling the detection of very small lesions with potential impact on disease outcome.

Late recurrence of melanoma after 10 years - Is the course of the disease different from early recurrences?

BACKGROUND

It is known that melanoma can metastasize and recur many years after the first diagnosis. Although predictive and prognostic factors for melanoma are well defined, there is still insufficient information about the factors affecting the recurrence period and the effect of the recurrence time to survival.

OBJECTIVES

This study investigates the course of melanoma to show prognostic factors comparing early and late recurrence patients. The main objective is to uncover the effect of the recurrence time on the progression of the disease.

METHODS

In this retrospective study, late recurrence (LR) was defined as melanoma recurrence 10 years after the first diagnosis and early recurrence (ER) was defined as recurrence within 10 years. Gender, age, localization of primary tumour, time to first metastasis, survival rates, histological subtype, stage, tumour thickness, invasion level, ulceration and regression of the primary melanoma were documented. Survival curves were evaluated using the Kaplan-Meier and compared with the log-rank test. Multivariate Cox proportional hazard models were used to identify significant independent prognostic factors for melanoma-specific survival (MSS).

RESULTS

A total of 1537 melanoma patients were analysed. Early metastasis was developed in 1438 patients (93.6%), and 99 patients (6.4%) developed late metastasis. Late recurrence patients were younger (P < 0.001) and had fewer ulcerated (P = 0.005), fewer head/neck localized (P = 0.009) and thinner (P < 0.001) melanomas than ER patients. The MSS time (mean ± SD) was nearly identical for LR (31 ± 4.4 months 95% CI [22.3-39.7]) and ER (32 ± 1.9 months [28.3-35.7]). Multivariate regression analysis revealed male gender (hazard ratio [HR = 1.4, P < 0.001), truncal tumour localization (HR = 1.7, P < 0.001), tumour thickness (HR = 1.4, P < 0.045) and ulceration (HR = 1.3, P < 0.008) as significant independent prognostic factors for MSS.

CONCLUSION

Although ER and LR patients are found to have different clinicopathologic features, the time of the first recurrence after diagnosis do not seem to have an effect on the survival.

Lipoblast-Like Morphology in a Uveal Melanoma with Delayed Metastasis to the Liver

Uveal melanomas are typically described as having epithelial or spindled cell morphology; however, as is the nature of melanomas, the morphology of the malignant melanocytes can be varied. We describe a unique case of metastatic uveal melanoma with lipoblast-like morphology, identified in the liver during an autopsy of a 75-year-old woman. Apart from a remote history of uveal melanoma in the right eye, there was no other history of cancer, and there were no concerning skin lesions present. The liver exhibited hepatomegaly with diffuse and extensive involvement of malignant tumor cells. Histopathological evaluation of liver sections showed malignant epithelioid and spindle cell proliferation. A distinct, spiculated, tan-white area revealed sheets of malignant cells with small and large vacuoles within the cytoplasm and scalloped nuclei, mimicking lipoblasts and adipocytes. Immunohistochemical stains confirmed these cells to be malignant melanoma cells. Being aware of this morphology in uveal melanomas is important especially when there is metastasis to the liver, so that it is not mistaken for more benign processes such as steatosis.

Uveal Versus Cutaneous Melanoma; Same Origin, Very Distinct Tumor Types

Here, we critically evaluated the knowledge on cutaneous melanoma (CM) and uveal melanoma (UM). Both cancer types derive from melanocytes that share the same embryonic origin and display the same cellular function. Despite their common origin, both CM and UM display extreme differences in their genetic alterations and biological behavior. We discuss the differences in genetic alterations, metastatic routes, tumor biology, and tumor-host interactions in the context of their clinical responses to targeted- and immunotherapy.

Local treatment of oligometastatic disease: current role

The presence of distant metastases has long been a predictor of poor outcome in solid cancer. However, in an oncologic situation called oligometastatic disease (OMD), multiple studies have revealed a survival benefit with aggressive treatment of these metastases. Besides surgery and radiation therapy, local thermal therapies have developed into a treatment option for OMD. Most studies concerning local therapy of OMD are available for colorectal cancer, which is therefore the focus of this article. Furthermore, this review gives a basic overview of the most popular ablation techniques for treatment of OMD.

Postsurgical treatment landscape and economic burden of locoregional and distant recurrence in patients with operable nonmetastatic melanoma

Supplemental Digital Content is available in the text.

Surgery is the mainstay treatment for operable nonmetastatic melanoma, but recurrences are common and limit patients’ survival. This study aimed to describe real-world patterns of treatment and recurrence in patients with melanoma and to quantify healthcare resource utilization (HRU) and costs associated with episodes of locoregional/distant recurrences. Adults with nonmetastatic melanoma who underwent melanoma lymph node surgery were identified from the Truven Health MarketScan database (1 January 2008 to 31 July 2017). Locoregional and distant recurrence(s) were identified on the basis of postsurgery recurrence indicators (i.e. initiation of new melanoma pharmacotherapy, new radiotherapy, or new surgery; secondary malignancy diagnoses). Of 6400 eligible patients, 219 (3.4%) initiated adjuvant therapy within 3 months of surgery, mostly with interferon α-2b (n=206/219, 94.1%). A total of 1191/6400 (18.6%) patients developed recurrence(s) over a median follow-up of 23.1 months (102/6400, 1.6% distant recurrences). Among the 219 patients initiated on adjuvant therapy, 73 (33.3%) experienced recurrences (distant recurrences: 13/219, 5.9%). The mean total all-cause healthcare cost was $2645 per patient per month (PPPM) during locoregional recurrence episodes and $12 940 PPPM during distant recurrence episodes. In the year after recurrence, HRU was particularly higher in patients with distant recurrence versus recurrence-free matched controls: by 9.2 inpatient admissions, 54.4 inpatient days, 8.8 emergency department admissions, and 185.9 outpatient visits (per 100 person-months), whereas all-cause healthcare costs were higher by $14 953 PPPM. It remains to be determined whether the new generation of adjuvant therapies, such as immune checkpoint inhibitors and targeted agents, will increase the use of adjuvant therapies, and reduce the risk of recurrences and associated HRU/cost.

Exploring Differential Connexin Expression across Melanocytic Tumor Progression Involving the Tumor Microenvironment

The incidence of malignant melanoma, one of the deadliest cancers, continues to increase. Here we tested connexin (Cx) expression in primary melanocytes, melanoma cell lines and in a common nevus, dysplastic nevus, and thin, thick, and metastatic melanoma tumor progression series involving the tumor microenvironment by utilizing in silico analysis, qRT-PCR, immunocyto-/histochemistry and dye transfer tests. Primary melanocytes expressed GJA1/Cx43, GJA3/Cx46 and low levels of GJB2/Cx26 and GJC3/Cx30.2 transcripts. In silico data revealed downregulation of GJA1/Cx43 and GJB2/Cx26 mRNA, in addition to upregulated GJB1/Cx32, during melanoma progression. In three melanoma cell lines, we also showed the loss of GJA1/Cx43 and the differential expression of GJB1/Cx32, GJB2/Cx26, GJA3/Cx46 and GJC3/Cx30.2. The dominantly paranuclear localization of connexin proteins explained the ~10–90 times less melanoma cell coupling compared to melanocytes. In melanocytic tumor tissues, we confirmed the loss of Cx43 protein, fall of cell membrane and elevated paranuclear Cx32 with moderately increased cytoplasmic Cx26 and paranuclear Cx30.2 positivity during tumor progression. Furthermore, we found Cx43, Cx26 and Cx30 proteins upregulated in the melanoma adjacent epidermis, and Cx43 in the tumor flanking vessels. Therefore, differential connexin expression is involved in melanocytic tumor progression where varying connexin isotypes and levels reflect tumor heterogeneity-related bidirectional adaptive interactions with the microenvironment.

Inhibition of mTORC2/RICTOR Impairs Melanoma Hepatic Metastasis

Mammalian target of rapamycin complex 2 (mTORC2) with its pivotal component rapamycin-insensitive companion of mTOR (RICTOR) is the major regulator of AKT phosphorylation and is increasingly implicated in tumor growth and progression. In cutaneous melanoma, an extremely aggressive and highly metastatic disease, RICTOR overexpression is involved in tumor development and invasiveness. Therefore, we investigated the impact of RICTOR inhibition in melanoma cells in vitro and in vivo with special emphasis on hepatic metastasis. Moreover, our study focused on the interaction of tumor cells and hepatic stellate cells (HSC) which play a crucial role in the hepatic microenvironment. In silico analysis revealed increased RICTOR expression in melanoma cells and tissues and indicated higher expression in advanced melanoma stages and metastases. In vitro, transient RICTOR knock-down via siRNA caused a significant reduction of tumor cell motility. Using a syngeneic murine splenic injection model, a significant decrease in liver metastasis burden was detected in vivo. Moreover, stimulation of melanoma cells with conditioned medium (CM) from activated HSC or hepatocyte growth factor (HGF) led to a significant induction of AKT phosphorylation and tumor cell motility. Blocking of RICTOR expression in cancer cells diminished constitutive and HGF-induced AKT phosphorylation as well as cell motility. Interestingly, RICTOR blockade also led to an abrogation of CM-induced effects on AKT phosphorylation and motility in melanoma cells. In conclusion, these results provide first evidence for a critical role of mTORC2/RICTOR in melanoma liver metastasis via cancer cell/HSC interactions.

Hepatic Progression-free and Overall Survival After Regional Therapy to the Liver for Metastatic Melanoma

OBJECTIVES

Regional therapy for metastatic melanoma to the liver represents an alternative to systemic therapy. Hepatic progression-free survival (HPFS), progression-free survival (PFS), and overall survival (OS) were evaluated.

MATERIALS AND METHODS

A retrospective review of patients with liver metastases from cutaneous or uveal melanoma treated with yttrium-90 (Y90), chemoembolization (CE), or percutaneous hepatic perfusion (PHP) was conducted.

RESULTS

Thirty patients (6 Y90, 10 PHP, 12 CE, 1 PHP then Y90, 1 CE then PHP) were included. Multivariate analysis showed improved HPFS for PHP versus Y90 (P=0.004), PHP versus CE (P=0.02) but not for CE versus Y90. PFS was also significantly different: Y90 (54 d), CE (52 d), PHP (245 d), P=0.03. PHP treatment and lower tumor burden were significant predictors of prolonged PFS on multivariate analysis. Median OS from time of treatment was longest, but not significant, for PHP at 608 days versus Y90 (295 d) and CE (265 d), P=0.24. Only PHP treatment versus Y90 and lower tumor burden had improved OS on multivariate analysis (P=0.03, 0.03, respectively).

CONCLUSIONS

HPFS and PFS were significantly prolonged in patients treated with PHP versus CE or Y90. Median OS in PHP patients was over double that seen in Y90 or CE patients but was significant only between PHP and Y90.

Thermal liquid biopsy for monitoring melanoma patients under surveillance during treatment: A pilot study

BACKGROUND

Differential Scanning Calorimetry (DSC) is a technique traditionally used to study thermally induced macromolecular transitions, and it has recently been proposed as a novel approach for diagnosis and monitoring of several diseases. We report a pilot study applying Thermal Liquid Biopsy (TLB, DSC thermograms of plasma samples) as a new clinical approach for diagnostic assessment of melanoma patients.

METHODS

Multiparametric analysis of DSC thermograms of patient plasma samples collected during treatment and surveillance (63 samples from 10 patients) were compared with clinical and diagnostic imaging assessment to determine the utility of thermograms for diagnostic assessment in melanoma. Nine of the ten patients were stage 2 or 3 melanoma subjects receiving adjuvant therapy after surgical resection of their melanomas. The other patient had unresectable stage 4 melanoma and was treated with immunotherapy. Two reference groups were used: (A) 36 healthy subjects and (B) 13 samples from 8 melanoma patients who had completed successful surgical management of their disease and were determined by continued clinical assessment to have no evidence of disease.

RESULTS

Plasma thermogram analysis applied to melanoma patients generally agrees with clinical evaluation determined by physical assessment or diagnostic imaging (~80% agreement). No false negatives were obtained from DSC thermograms. Importantly, this methodology was able to detect changes in disease status before it was identified clinically.

CONCLUSIONS

Thermal Liquid Biopsy could be used in combination with current clinical assessment for the earlier detection of melanoma recurrence and metastasis.

GENERAL SIGNIFICANCE

TLB offers advantages over current diagnostic techniques (PET/CT imaging), limited in frequency by radiation burden and expense, in providing a minimally-invasive, low-risk, low-cost clinical test for more frequent personalized patient monitoring to assess recurrence and facilitate clinical decision-making.

Patterns of genomic evolution in advanced melanoma

Genomic alterations occurring during melanoma progression and the resulting genomic heterogeneity between metastatic deposits remain incompletely understood. Analyzing 86 metastatic melanoma deposits from 53 patients with whole-exome sequencing (WES), we show a low branch to trunk mutation ratio and little intermetastatic heterogeneity, with driver mutations almost completely shared between lesions. Branch mutations consistent with UV damage indicate that metastases may arise from different subclones in the primary tumor. Selective gain of mutated BRAF alleles occurs as an early event, contrasting whole-genome duplication (WGD) occurring as a late truncal event in about 40% of cases. One patient revealed elevated mutational diversity, probably related to previous chemotherapy and DNA repair defects. In another patient having received radiotherapy toward a lymph node metastasis, we detected a radiotherapy-related mutational signature in two subsequent distant relapses, consistent with secondary metastatic seeding. Our findings add to the understanding of genomic evolution in metastatic melanomas.

As melanoma progresses, it evolves. Here, in advanced melanoma the authors study genomic evolution, highlighting trunk mutations dominated by the ultraviolet damage signature, common late truncal whole-genome duplication events, as well as selective copy number gain of mutant BRAF.

Functional interplay between secreted ligands and receptors in melanoma

Melanoma, the most aggressive form of skin cancer, results from the malignant transformation of melanocytes located in the basement membrane separating the epidermal and dermal skin compartments. Cutaneous melanoma is often initiated by solar ultraviolet radiation (UVR)-induced mutations. Melanocytes intimately interact with keratinocytes, which provide growth factors and melanocortin peptides acting as paracrine regulators of proliferation and differentiation. Keratinocyte-derived melanocortins activate melanocortin-1 receptor (MC1R) to protect melanocytes from the carcinogenic effect of UVR. Accordingly, MC1R is a major determinant of susceptibility to melanoma. Despite extensive phenotypic heterogeneity and high mutation loads, the molecular basis of melanomagenesis and the molecules mediating the crosstalk between melanoma and stromal cells are relatively well understood. Mutations of intracellular effectors of receptor tyrosine kinase (RTK) signalling, notably NRAS and BRAF, are major driver events more frequent than mutations in RTKs. Nevertheless, melanomas often display aberrant signalling from RTKs such as KIT, ERRB1-4, FGFR, MET and PDGFR, which contribute to disease progression and resistance to targeted therapies. Progress has also been made to unravel the role of the tumour secretome in preparing the metastatic niche. However, key aspects of the melanoma-stroma interplay, such as the molecular determinants of dormancy, remain poorly understood.

Association between the use of surveillance PET/CT and the detection of potentially salvageable occult recurrences among patients with resected high-risk melanoma

The optimal surveillance for patients with resected high-risk melanoma is controversial. Select locoregional or oligometastatic recurrences can be cured with salvage resection. Data on the ability of PET/CT to detect such recurrences are sparse. We evaluated whether surveillance PET/CT in patients with resected stage III-IV melanoma led to detection of clinically occult recurrences amenable to curative-intent salvage treatment. We retrospectively identified 1429 melanoma patients who underwent PET/CT between January 2008 and October 2012 at Mayo Clinic (Rochester, Minnesota). A total of 1130 were excluded because of stage I-II, ocular or mucosal melanoma, incomplete resection, PET/CT not performed for surveillance or performed at a different institution, and records not available. A total of 299 patients were eligible. Overall, 162 (52%) patients developed recurrence [locoregional: 77 (48%), distant: 85 (52%)]. The first recurrence was clinically occult in 98 (60%) and clinically evident in 64 (40%). Clinically evident recurrences were more often superficial (skin, subcutaneous, or nodal) or in the brain, whereas clinically occult recurrences more often visceral. Overall, 90% of all recurrences were detected by 2.8 years. In all, 70% of patients with recurrence underwent curative-intent salvage treatment (locoregional: 94%, distant: 48%), with similar rates for clinically occult versus clinically evident recurrences (66 vs. 75%, P=0.240). Overall survival was superior among those who underwent curative-intent salvage treatment [5.9 vs. 1.2 years; hazard ratio=4.27, 95% confidence interval (CI)=2.68-6.80; P<0.001], despite 79% developing recurrence again. PET/CT had high sensitivity (88%, 95% CI=79.94-93.31%), specificity (90%, 95% CI=88.56-91.56%), and negative predictive value (99%, 95% CI=98.46-99.52%). However, the positive predictive value was only 37% (95% CI=31.32-43.68%). In patients with resected stage III-IV melanoma, surveillance PET/CT detected a large proportion of clinically occult recurrences amenable to curative-intent salvage treatment. Despite a high rate of second relapse, curative-intent salvage treatment was associated with superior overall survival. Even though PET/CT had high sensitivity, specificity, and negative predictive value, positive predictive value was poor, highlighting the need for histologic confirmation of PET/CT-detected abnormalities.

Cutaneous Melanoma with Tonsillar Metastasis

Metastases to the tonsillar fossa due to hematogenous dissemination is an extremely rare phenomenon associated with advanced-stage disease and poor prognosis. In the present report we describe a case of cutaneous melanoma with a metastasis to the tonsil approximately 4 years after the initial diagnosis of the primary disease treated with palliative radiation therapy.

miR‑367 enhances the proliferation and invasion of cutaneous malignant melanoma by regulating phosphatase and tensin homolog expression

Melanoma presents a serious threat to human health but the underlying mechanisms have not been fully identified. Increasing evidence indicates that microRNAs exert a significant influence on the tumorigenesis and metastasis of different types of cancer. The present study aimed to identify the role of microRNA (miR)‑367 in the initiation and progression of melanoma and investigate its potential target. A total of 50 melanoma samples and 25 benign nevi tissues were used in the present study. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis were performed to determine the expression of mRNA and protein, respectively. Cell proliferation and invasion were assessed by CCK‑8, wound healing and Transwell assays. A proposed target mRNA of miR‑367 was determined using a luciferase reporter assay and an in vivo xenograft model was used to evaluate the function of miR‑367 in the progression of melanoma. It was revealed that miR‑367 was overexpressed in melanoma tissues and cell lines. The miR‑367 level in tumor tissues was positively correlated with tumor thickness, tumor stage, lymph node involvement, distant metastasis and the patient survival rate. A high miR‑367 level was observed to enhance the growth, migration and invasion of melanoma cells. Conversely, low miR‑367 levels suppressed the proliferation and invasion of melanoma cells. Furthermore, miR‑367 was revealed to bind directly to phosphatase and tensin homolog (PTEN) mRNA and regulate the expression of the PTEN protein. miR‑367 markedly increased the growth and invasion of melanoma cells, whereas the cotransfection of PTEN vectors limited the promoting function of miR‑367 in the proliferation and invasion of A375 cells. The upregulation of miR‑367 promoted tumor growth in vivo. In conclusion, the results revealed that miR‑367 serves a positive role in the development of melanoma and may be an important target for the treatment of cutaneous melanoma.

Evaluation of 18F-FDG PET/CT Parameters for Detection of Lymph Node Metastasis in Cutaneous Melanoma

PURPOSE

The purpose of this study was to investigate the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) parameters in the detection of regional lymph node (LN) metastasis in patients with cutaneous melanoma.

METHODS

We evaluated patients with cutaneous melanoma who underwent FDG PET/CT for initial staging or recurrence evaluation. A total of 103 patients were enrolled, and 165 LNs were evaluated. LNs that were confirmed pathologically or by follow-up imaging were included in this study. PET parameters, including maximum standardized uptake value (SUVmax), total lesion glycolysis and tumour-to-liver ratio, were used to determine the presence of metastases, and the results were compared with CT-determined LN metastasis. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off values of the FDG PET parameters.

RESULTS

A total of 93 LNs were malignant, and 84 LNs were smaller than 10 mm. In all 165 LNs, an SUVmax of >2.51 showed a sensitivity of 73.1%, a specificity of 88.9%, and an accuracy of 80.0% in detecting metastatic LNs. CT showed a higher specificity (87.3%) and lower accuracy (65.5%). For non-enlarged regional LNs (<10 mm), an SUVmax cut-off value of 1.4 showed the highest negative predictive value (81.3%). For enlarged LNs (≥10 mm), an SUVmax cut-off value of 2.4 showed the highest sensitivity (90.7%) and accuracy (88.9%) in detecting metastatic LNs.

CONCLUSIONS

In patients with cutaneous melanoma, an SUVmax of >2.4 showed a high sensitivity (91%) and accuracy (89%) in detecting metastasis in LNs ≥1 cm, and LNs <1 cm with an SUVmax <1.4 were likely to be benign.