BRAFV600E mutation status of involuting and stable nevi in dabrafenib therapy with or without trametinib

Erbium: YAG laser treatment efficacy and association with histologic features for giant congenital melanocytic nevi management

BACKGROUND

Limited research exists on laser treatment of giant congenital melanocytic nevus (GCMN).

OBJECTIVE

We sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response.

METHODS AND MATERIALS

Between 2019 and 2022, we enrolled 30 medium-to-giant CMN patients who underwent Er: YAG laser treatment. All patients received biopsies before and after laser treatments. Clinical efficacy outcomes were evaluated by the investigator's global assessment (IGA), 5-point scale of depigmentation, and Vancouver Scar Scale (VSS) scores at least 6 months after treatment.

RESULTS

Of the 30 cases, 18 (60.0%) showed improvement (IGA score ≥3). Eight (26.7%) patients showed repigmentation. Eight (26.7%) patients developed hypertrophic scars. The average IGA, depigmentation, and VSS scores were 2.93, 3.57, and 3.20. The IGA score was higher (3.24 ± 1.18 vs. 2.22 ± 0.97, p = 0.031) and a lower repigmentation rate (14.3% vs. 55.6%, p = 0.032) was observed in the cases with Grenz zone. The IGA score was higher (3.33 ± 1.24 vs. 2.13 ± 0.89, p = 0.023) and the repigmentation rate was lower (11.1% vs. 50.0%, p = 0.034) also in the cases with the melanocytes nests with aggregation of melanin. Lesions with superficial ablation resulted in less hypertrophic scar formation than those with deep ablation (5.9% vs. 53.8%, p < 0.05).

CONCLUSION

The Er: YAG laser demonstrated effective clinical results for GCMNs. The grenz zone and the melanocytes nests with aggregation of melanin are promising predictors of laser efficacy.

In-Depth Characterisation of Real-World Advanced Melanoma Patients Receiving Immunotherapies and/or Targeted Therapies: A Case Series

Immunotherapies and targeted therapies have shown significant benefits for melanoma survival in the clinical trial setting. Much less is known about the characteristics and associated outcomes of those receiving such therapies in real-world settings. This study describes the characteristics of patients with advanced melanoma receiving immuno- and/or targeted therapies in a real-world setting. This prospective cohort study enrolled participants aged >18 years, diagnosed with advanced melanoma and currently undergoing immuno- and/or targeted therapies outside a clinical trial for follow-up with three-dimensional (3D) total-body imaging. Participants (n = 41) had a mean age of 62 years (range 29−86), 26 (63%) were male and the majority (n = 26, 63%) had ≥2 comorbidities. After a median of 39 months (range 1−52) follow-up, 59% (n = 24/41) of participants were alive. Despite multiple co-morbidities, the survival of participants with advanced melanoma treated using immuno- and/or targeted therapies was similar or better in our real-world setting compared to those treated in clinical trials using similar therapies. Larger studies powered to evaluate phenotypic and socio-economic characteristics, as well as specific comorbidities associated with survival in a real-world setting, are required to help determine those who will most benefit from immuno- and/or targeted therapies.

Can Combination MEK and Akt Inhibition Slay the Giant Congenital Nevus?

The clinical management of large and giant congenital melanocytic nevi (lgCMN) relies heavily upon iterative surgical procedures. In this issue Rouille et al. (2019) use lgCMN explants and a newly developed patient-derived xenograft model to show that the local administration of MEK and Akt inhibitors limits the lgCMN proliferative potential. These findings, along with emerging reports, support continued investigation of targeted therapies in lgCMN.

The paradox of cancer genes in non-malignant conditions: implications for precision medicine

Next-generation sequencing has enabled patient selection for targeted drugs, some of which have shown remarkable efficacy in cancers that have the cognate molecular signatures. Intriguingly, rapidly emerging data indicate that altered genes representing oncogenic drivers can also be found in sporadic non-malignant conditions, some of which have negligible and/or low potential for transformation to cancer. For instance, activating KRAS mutations are discerned in endometriosis and in brain arteriovenous malformations, inactivating TP53 tumor suppressor mutations in rheumatoid arthritis synovium, and AKT, MAPK, and AMPK pathway gene alterations in the brains of Alzheimer's disease patients. Furthermore, these types of alterations may also characterize hereditary conditions that result in diverse disabilities and that are associated with a range of lifetime susceptibility to the development of cancer, varying from near universal to no elevated risk. Very recently, the repurposing of targeted cancer drugs for non-malignant conditions that are associated with these genomic alterations has yielded therapeutic successes. For instance, the phenotypic manifestations of CLOVES syndrome, which is characterized by tissue overgrowth and complex vascular anomalies that result from the activation of PIK3CA mutations, can be ameliorated by the PIK3CA inhibitor alpelisib, which was developed and approved for breast cancer. In this review, we discuss the profound implications of finding molecular alterations in non-malignant conditions that are indistinguishable from those driving cancers, with respect to our understanding of the genomic basis of medicine, the potential confounding effects in early cancer detection that relies on sensitive blood tests for oncogenic mutations, and the possibility of reverse repurposing drugs that are used in oncology in order to ameliorate non-malignant illnesses and/or to prevent the emergence of cancer.

Personalized and targeted mutational analysis of multiple second primary melanomas under kinase inhibitors

BACKGROUND

Second primary melanomas (SPMs) are new developed primary melanomas occurring in a subset of patients affected by BRAF-mutated metastatic melanoma during treatment with BRAF-inhibitors. A drug-induced paradoxical activation of mitogen-activated protein kinase (MAPK) signaling pathway in BRAF-wild type/RAS-mutated cells have been proposed as a possible molecular mechanism but data on the mutational status of SPMs are lacking. In order to better understand genetic alterations affecting the biological mechanism of SPMs, we performed a personalized and targeted next-generation sequencing analysis of a patient affected by metastatic melanoma who developed multiple SPMs during treatment with encorafenib (LGX818).

METHODS

Using a cancer panel of 50 genes for solid tumors enriched with a custom panel of 10 genes specifically involved in melanoma pathogenesis, we analyzed the primary melanoma, two SPMs, one benign compound nevus and the normal DNA extracted from blood lymphocytes of the patient.

RESULTS

We identified HRAS Q61 somatic mutation in one SPM developed in a pre-existing nevus. In the primary melanoma, besides the BRAF mutation, we identified the clinically actionable IDH1 R132C somatic mutation. Both SPMs were BRAF wild type. The patient harbors the recently recognized pathogenetic germline variant KDR Q472. We observed that mutations detected in tumor samples involving genes related to melanoma pathogenesis (TP53, PIK3CA, FGFR3, ATF1, KIT, HRAS and MAP2K2) were present in heterozygosis in the germline status of the patient.

CONCLUSIONS

Our results support the paradoxical mechanism of MAPK pathway for SPMs under BRAF inhibitors. Moreover, they suggest that targeted mutational assessment based on matching somatic and germline analysis represent a promising approach to detect the neoplastic landscape of the tumor and to identify most accurate treatment in metastatic melanoma patient.

Complete regression of primary melanoma associated with nevi involution under BRAF inhibitors: A case report and review of the literature

Melanoma is one of the most immunogenic tumors among human neoplasms, with numerous clinical observations of partial or completely regressed tumors. It is an aggressive tumor, with the greatest reported number of somatic mutations, BRAF mutation being the most common one. BRAF mutation is also present in a higher percentage in benign nevi. Complete regression of primary tumor and involution of nevi are, however, rare phenomenon in melanoma that can appear in relation with UV exposure, surgical trauma, target therapy in melanoma, pregnancy or host immune response to an evolving melanoma tumor. We present the case of a 58-year-old man with a completely regressed metastatic melanoma who developed a second melanoma with concomitant involution of papillomatous nevi under BRAF inhibitors treatment. In reviewed literature we have found 53 cases of completely regressed primary melanomas, neither of them reporting nevi involution. Complete regression of primary tumor can occur as an immune response to tumor progression. Nevi can involute under BRAF inhibitor therapy, but development of new malignant lesions under BRAF inhibitors is linked to BRAF wild-type. Documentation of primary tumor and dynamic changes in nevi highlight the need of a good clinical skin examination and increase the utility of baseline and sequential dermoscopy in melanoma.

Sequential digital dermatoscopic imaging of patients with multiple atypical nevi

Patients with multiple atypical nevi are at higher risk of developing melanoma. Among different techniques, sequential digital dermatoscopic imaging (SDDI) is a state-of-the art method to enhance diagnostic accuracy in evaluating pigmented skin lesions. It relies on analyzing digital dermatoscopic images of a lesion over time to find specific dynamic criteria inferring biologic behavior. SDDI can reduce the number of necessary excisions and finds melanomas in an early—and potentially curable—stage, but precautions in selecting patients and lesions have to be met to reach those goals.

Dermoscopic assessment of skin toxicities in patients with melanoma during treatment with vemurafenib

Introduction

The use of vemurafenib in melanoma has improved the survival of patients; however, it is associated with skin toxicities.

Aim

To assess skin toxicities by dermoscopy in patients treated with vemurafenib.

Material and methods

Eight patients with BRAF V600 mutation positive metastatic melanoma were examined dermoscopically during vemurafenib treatment. All skin lesions occurring during therapy were assessed clinically and dermoscopically using a hand-held dermoscope with polarised and non-polarised light. Skin lesions suspected for malignancy appearing during therapy were totally surgically excised with consecutive histopathological examination.

Results

All 8 examined patients developed skin toxicity. The majority of patients (7/8) presented G1 skin toxicity according to CTCAE version 4.3. Only 1 of them had G2 skin toxicity. The most common dermoscopy findings in our study were hyperkeratotic verrucas in 5 patients (5/8) with structureless pattern. In some of them we also observed central dots, exophytic proliferation, hairpin vessels and homogeneous haemorrhage. Other findings were hyperkeratosis of the nipples (5/8) with brownish to yellowish, angular clods with a tendency to be more confluent in dermoscopy. Palmar plantar erythrodysaesthesia (3/8) showed dermoscopically a yellowish, homogeneous pattern. Four melanocytic skin lesions in 2 patients were surgically excised due to suspected malignant transformation. In most of them we observed an atypical pigmented network (abrupt cut-off, big holes), atypical globules and a homogeneous blue pattern; however, histopathological diagnosis excluded any malignancy.

Conclusions

Dermoscopy seems to be an easily performed and valuable method for assessment of skin toxicities during oncological therapy, at any time of the treatment.

Melanoma: Genetic Abnormalities, Tumor Progression, Clonal Evolution and Tumor Initiating Cells

Melanoma is an aggressive neoplasia issued from the malignant transformation of melanocytes, the pigment-generating cells of the skin. It is responsible for about 75% of deaths due to skin cancers. Melanoma is a phenotypically and molecularly heterogeneous disease: cutaneous, uveal, acral, and mucosal melanomas have different clinical courses, are associated with different mutational profiles, and possess distinct risk factors. The discovery of the molecular abnormalities underlying melanomas has led to the promising improvement of therapy, and further progress is expected in the near future. The study of melanoma precursor lesions has led to the suggestion that the pathway of tumor evolution implies the progression from benign naevi, to dysplastic naevi, to melanoma in situ and then to invasive and metastatic melanoma. The gene alterations characterizing melanomas tend to accumulate in these precursor lesions in a sequential order. Studies carried out in recent years have, in part, elucidated the great tumorigenic potential of melanoma tumor cells. These findings have led to speculation that the cancer stem cell model cannot be applied to melanoma because, in this malignancy, tumor cells possess an intrinsic plasticity, conferring the capacity to initiate and maintain the neoplastic process to phenotypically different tumor cells.

Melanocytic lesion evolution patterns with targeted therapies and immunotherapies for advanced metastatic melanoma: An observational study

BACKGROUND/OBJECTIVES

Various cutaneous side-effects have been reported with anti-melanoma systemic therapies. This study investigated the changes in melanocytic lesion pigmentation in patients on four different therapies.

METHODS

We analysed the serial dermatoscopic photographs of atypical melanocytic lesions taken from patients with advanced metastatic melanoma on four different systemic therapies (selective BRAF-inhibitor monotherapy, dabrafenib combined with trametinib [D&T], anti-programmed cell death protein 1 [anti-PD1] therapies, and anti-PD1 combined with ipilimumab) seen from February 2013 to May 2016. We compared these changes with the melanocytic lesions of 10 control patients.

RESULTS

In the control group, 19% of naevi lightened, 64% did not change and 17% darkened. Only the BRAF inhibitor group showed more darkened lesions than controls (37%, P < 0.001). Meanwhile, there were more lightened naevi in the D&T therapy group (86%, P < 0.001) as well as the anti-PD1 and ipilimumab groups (59%, P < 0.001) than controls. Patients on anti-PD1 monotherapy had more lightened (49%) and fewer darkened naevi (9%) than controls, but differences were not significant.

CONCLUSIONS

Our study showed that different anti-melanoma systemic therapies have different effects on the pigmentation of melanocytic lesions. BRAF inhibitor may have the propensity to cause darkening while D&T therapy and anti-PD1 caused lightening compared with controls. The findings emphasise the importance of regular dermatological monitoring in specialised clinics for patients on anti-melanoma systemic therapy. Clinicians should expect changes in the global pigmentation of melanocytic lesions but be suspicious of lesions with structural changes.

Melanocytic nevi and melanoma: unraveling a complex relationship

Approximately 33% of melanomas are derived directly from benign, melanocytic nevi. Despite this, the vast majority of melanocytic nevi, which typically form as a result of BRAF^V600E-activating mutations, will never progress to melanoma. Herein, we synthesize basic scientific insights and data from mouse models with common observations from clinical practice to comprehensively review melanocytic nevus biology. In particular, we focus on the mechanisms by which growth arrest is established after BRAF^V600E mutation. Means by which growth arrest can be overcome and how melanocytic nevi relate to melanoma are also considered. Finally, we present a new conceptual paradigm for understanding the growth arrest of melanocytic nevi in vivo termed stable clonal expansion. This review builds upon the canonical hypothesis of oncogene-induced senescence in growth arrest and tumor suppression in melanocytic nevi and melanoma.

Testing of viable human skin cell dilution cultures as an approach to validating microsampling

Skin biopsies are a valuable technique in the diagnosis of cutaneous inflammatory and neoplastic conditions. We were interested to test the minimal size or equivalent volume by dilution of proteolytically disassociated skin tissue required to allow the isolation and propagation of cutaneous cells, for freezing, storage and biochemical analysis. It was possible to propagate with 100% efficiency fibroblast and melanocytic cells from a 0.1 to 0.5 mm³ equivalent neonatal foreskin sample using a combination of DispaseII and CollagenaseIV. The smallest tissue dilution that allowed melanocytic cell culture was 0.01 mm³, which equated to approximately 16 cells based on the average skin density of melanocytes. However, passaging of cells to create frozen stocks was achieved routinely only from 1 mm³ skin, equating to 1560 cells. Tissue-specific antigen expression of these cultures was tested by western blot of total protein extracts. There was no pigmentation antigen expression in fibroblast cultures; however, smooth muscle actin protein expression was high in fibroblast but absent from melanocytic cell strains. Melanocytic cells expressed pigmentation antigens and E-cadherin, but these were not detected in fibroblasts. Moreover, maturation of these melanocytic cells resulted in a decrease of Dopachrome Tautomerase antigen expression and induction of Tyrosinase protein consistent with the differentiation potential seen in cell cultures derived routinely from large sections of skin tissue.

RAMAN spectroscopy imaging improves the diagnosis of papillary thyroid carcinoma

Recent investigations strongly suggest that Raman spectroscopy (RS) can be used as a clinical tool in cancer diagnosis to improve diagnostic accuracy. In this study, we evaluated the efficiency of Raman imaging microscopy to discriminate between healthy and neoplastic thyroid tissue, by analyzing main variants of Papillary Thyroid Carcinoma (PTC), the most common type of thyroid cancer. We performed Raman imaging of large tissue areas (from 100 × 100 μm² up to 1 × 1 mm²), collecting 38 maps containing about 9000 Raman spectra. Multivariate statistical methods, including Linear Discriminant Analysis (LDA), were applied to translate Raman spectra differences between healthy and PTC tissues into diagnostically useful information for a reliable tissue classification. Our study is the first demonstration of specific biochemical features of the PTC profile, characterized by significant presence of carotenoids with respect to the healthy tissue. Moreover, this is the first evidence of Raman spectra differentiation between classical and follicular variant of PTC, discriminated by LDA with high efficiency. The combined histological and Raman microscopy analyses allow clear-cut integration of morphological and biochemical observations, with dramatic improvement of efficiency and reliability in the differential diagnosis of neoplastic thyroid nodules, paving the way to integrative findings for tumorigenesis and novel therapeutic strategies.

Genetics of melanocytic nevi

Melanocytic nevi are a benign clonal proliferation of cells expressing the melanocytic phenotype, with heterogeneous clinical and molecular characteristics. In this review, we discuss the genetics of nevi by salient nevi subtypes: congenital melanocytic nevi, acquired melanocytic nevi, blue nevi, and Spitz nevi. While the molecular etiology of nevi has been less thoroughly studied than melanoma, it is clear that nevi and melanoma share common driver mutations. Acquired melanocytic nevi harbor oncogenic mutations in BRAF, which is the predominant oncogene associated with melanoma. Congenital melanocytic nevi and blue nevi frequently harbor NRAS mutations and GNAQ mutations, respectively, while Spitz and atypical Spitz tumors often exhibit HRAS and kinase rearrangements. These initial 'driver' mutations are thought to trigger the establishment of benign nevi. After this initial phase of the cell proliferation, a senescence program is executed, causing termination of nevi growth. Only upon the emergence of additional tumorigenic alterations, which may provide an escape from oncogene-induced senescence, can malignant progression occur. Here, we review the current literature on the pathobiology and genetics of nevi in the hope that additional studies of nevi promise to inform our understanding of the transition from benign neoplasm to malignancy.

Cutaneous adverse events in patients treated with BRAF inhibitor-based therapies for metastatic melanoma for longer than 52 weeks

BACKGROUND

BRAF inhibitor-based therapies have been shown to induce cutaneous toxicities, with onset generally in the first 8-26 weeks of therapy.

OBJECTIVES

To determine whether cutaneous toxicities persist in patients who have remained on BRAF inhibitor-based therapies for longer than 52 weeks, and therefore whether ongoing dermatology assessment is required.

METHODS

All patients treated with the BRAF inhibitors vemurafenib or dabrafenib or combination BRAF inhibitor and mitogen-activated protein kinase kinase (MEK) inhibitor therapy at Westmead Hospital, Sydney, Australia underwent regular dermatological assessments for the duration of therapy. All patients enrolled in a clinical trial, and 18% of patients in the compassionate access scheme underwent a baseline assessment prior to commencement of therapy and every 4-8 weeks thereafter. Patients' adverse events were recorded in a specific database.

RESULTS

Patients continued to develop cutaneous adverse events after 52 weeks of continuous therapy. Patients on single-agent BRAF inhibitor therapy suffered from Grover disease (45%), plantar hyperkeratosis (45%), verrucal keratosis (18%) and even cutaneous squamous cell carcinoma (16%). The most frequent adverse event seen in patients in the combination BRAF and MEK inhibitor group was an acneiform eruption (40%).

CONCLUSIONS

Patients on BRAF inhibitor-based therapies need to continue to have regular dermatological follow-up independent of the duration of their therapy.

Melanocytic naevi with globular and reticular dermoscopic patterns display distinct BRAF V600E expression profiles and histopathological patterns

BACKGROUND

BRAF (v-raf murine sarcoma viral oncogene homologue B) V600E mutations have been detected with high frequency in melanocytic naevi. Few studies have stratified analyses by naevus dermoscopic pattern.

OBJECTIVES

To determine the frequency of BRAF V600E expression and histopathological pattern in acquired melanocytic naevi distinguished by a globular vs. reticular dermoscopic pattern.

METHODS

We retrospectively identified histologically proven melanocytic naevi with banal reticular or globular dermoscopic patterns and evaluated BRAF V600E expression using immunohistochemistry.

RESULTS

BRAF V600E expression was detected in 11 of 12 globular naevi vs. four of 13 reticular naevi (91·7% vs. 30·1%, P = 0·004). A predominantly dermal growth pattern (P < 0·001) and the presence of large junctional nests (P = 0·017) were each associated with a globular dermoscopic pattern. The presence of either a predominantly dermal growth pattern or large junctional nests was found in 13 of 15 naevi positive for BRAF V600E and in two of 10 naevi negative for BRAF V600E (86·7% vs. 20%, P = 0·002).

CONCLUSIONS

The frequency of BRAF V600E mutations differs in naevi distinguished by unique dermoscopic structures and microanatomical growth patterns. Globular naevi, which most often histologically correspond to a predominantly dermal growth pattern and/or the presence of large junctional nests, are significantly more likely to express BRAF V600E than reticular naevi. These preliminary results require validation, but may directly inform future studies of naevogenesis and melanoma genesis.