Second primary melanomas treated with BRAF blockers: study by reflectance confocal microscopy

Melanoma types by in vivo reflectance confocal microscopy correlated with protein and molecular genetic alterations: A pilot study

Cutaneous melanoma (CM) is one of the most prevalent skin cancers, which lacks both a prognostic marker and a specific and lasting treatment, due to the complexity of the disease and heterogeneity of patients. Reflectance confocal microscopy (RCM) in vivo analysis is a versatile approach offering immediate morphological information, enabling the identification of four primary cutaneous RCM CM types. Whether RCM CM types are associated with a specific protein and molecular genetic profiles at the tissue level remains unclear. The current pilot study was designed to identify potential correlations between RCM CM types and specific biological characteristics, combining immunohistochemistry (IHC) and molecular analyses. Eighty primary CMs evaluated at patient bedside with RCM (type 1 [19, 24%], type 2 [12, 15%], type 3 [7, 9%] and type 4 [42, 52%]) were retrospectively evaluated by IHC stains (CD271, CD20, CD31, cyclin D1), fluorescence in situ hybridization FISH for MYC gain and CDKN2A loss and molecular analysis for somatic mutations (BRAF, NRAS and KIT). RCM CM types correlated with markers of stemness property, density of intra-tumoral lymphocytic B infiltrate and cyclin D1 expression, while no significant association was found with blood vessel density nor molecular findings. RCM CM types show a different marker profile expression, suggestive of a progression and an increase in aggressiveness, according to RCM morphologies.

NRAS Q61R and BRAF G466A mutations in atypical melanocytic lesions newly arising in advanced melanoma patients treated with vemurafenib

BACKGROUND

BRAF inhibition has improved overall survival in patients with BRAF mutant melanoma, but this is associated with a range of known and predictable cutaneous side effects, including squamous cell carcinomas associated with RAS mutations.

METHODS

We identified three severely dysplastic nevi, one atypical intraepidermal melanocytic proliferation, and four melanoma in situ lesions, newly arising in four patients undergoing treatment with vemurafenib. To characterize mutations in these atypical melanocytic lesions, we used a custom iPlex panel detecting 74 mutations in 13 genes known to play a role in melanoma pathogenesis.

RESULTS

We identified an NRAS mutation at codon 61 (Q61R) and a rare BRAF exon 11 mutation (G466A) in atypical melanocytic lesions that arose in patients treated with vemurafenib.

CONCLUSION

There appears to be development or accelerated growth of atypical melanocytic lesions in the setting of BRAF inhibition. Our results underscore the need for careful surveillance for melanocytic lesions in patients on BRAF inhibitor therapy and shed light on potential mechanisms for melanoma pathogenesis in the context of BRAF pathway blockade. Further studies are warranted to show a causal relationship.

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.

Discriminating Nevi from Melanomas: Clues and Pitfalls

Reflectance confocal microscopy (RCM) together with dermoscopy enables improved differentiation of melanomas from most nevi. The resulting high sensitivity for detecting melanoma with RCM is complemented by a concomitant increased specificity, which results in the reduction of unnecessary biopsies of nevi. Although RCM can achieve high diagnostic accuracy for early melanoma detection, false-negative and false-positive cases of melanoma are occasionally encountered. This article reviews the essential clues and pitfalls for the diagnosis of melanoma via RCM and highlights the importance of evaluating RCM findings in light of the clinical scenario and dermoscopic features.

Confocal microscopy characterization of BRAFV600E mutated melanomas

Thanks to modern techniques, molecular signatures for melanoma are now identifiable and have opened new horizons in the treatment of metastatic disease with molecular-targeted therapies. We distinguish different melanoma subtypes on the basis of genetic mutations such as BRAFV600E and we can therefore hypothesize the existence of corresponding morphological patterns that might be detected in vivo by noninvasive diagnostic tools such as dermoscopy and confocal microscopy. Eight BRAFV600E mutated melanomas (six primary and two metastases) were collected, matched in terms of age, sex, and thickness wild-type controls, and analyzed. In this preliminary study, regression, corresponding to fibrosis and melanophages in the dermis, was the predominant pattern and was also observed confocally when dermoscopy showed no peppering. In particular, confocal microscopy could not only detect regression but also provided a semiquantitative analysis of its grade through the count of melanophages. Confocal microscopy can be proposed as a useful tool in the preliminary screening and characterization of BRAFV600E mutated melanomas, providing new insights for patients' screening and follow-up.

Methods of Melanoma Detection

Detection and removal of melanoma, before it has metastasized, dramatically improves prognosis and survival. The purpose of this chapter is to (1) summarize current methods of melanoma detection and (2) review state-of-the-art detection methods and technologies that have the potential to reduce melanoma mortality. Current strategies for the detection of melanoma range from population-based educational campaigns and screening to the use of algorithm-driven imaging technologies and performance of assays that identify markers of transformation. This chapter will begin by describing state-of-the-art methods for educating and increasing awareness of at-risk individuals and for performing comprehensive screening examinations. Standard and advanced photographic methods designed to improve reliability and reproducibility of the clinical examination will also be reviewed. Devices that magnify and/or enhance malignant features of individual melanocytic lesions (and algorithms that are available to interpret the results obtained from these devices) will be compared and contrasted. In vivo confocal microscopy and other cellular-level in vivo technologies will be compared to traditional tissue biopsy, and the role of a noninvasive "optical biopsy" in the clinical setting will be discussed. Finally, cellular and molecular methods that have been applied to the diagnosis of melanoma, such as comparative genomic hybridization (CGH), fluorescent in situ hybridization (FISH), and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), will be discussed.

Cutaneous adverse effects of targeted therapies: Part II: Inhibitors of intracellular molecular signaling pathways

The last decade has spawned an exciting new era of oncotherapy in dermatology, including the development of targeted therapies for metastatic melanoma and basal cell carcinoma. Along with skin cancer, deregulation of the PI3K-AKT-mTOR and RAS-RAF-MEK-ERK intracellular signaling pathways contributes to tumorigenesis of a multitude of other cancers, and inhibitors of these pathways are being actively studied. Similar to other classes of targeted therapies, cutaneous adverse effects are among the most frequent toxicities observed with mitogen-activated protein kinase pathway inhibitors, PI3K-AKT-mTOR inhibitors, hedgehog signaling pathway inhibitors, and immunotherapies. Given the rapid expansion of these families of targeted treatments, dermatologists will be essential in offering dermatologic supportive care measures to cancer patients being treated with these agents. Part II of this continuing medical education article reviews skin-related adverse sequelae, including the frequency of occurrence and the implications associated with on- and off-target cutaneous toxicities of inhibitors of the RAS-RAF-MEK-ERK pathway, PI3K-AKT-mTOR pathway, hedgehog signaling pathway, and immunotherapies.

Melanoma patients under vemurafenib: prospective follow-up of melanocytic lesions by digital dermoscopy

Second primary melanomas (SPMs) induced by vemurafenib have been recently described. The aim of this study was to define the dermoscopical signs of melanoma in this context. Patients underwent a total body examination before receiving vemurafenib. Each single melanocytic lesion was registered before therapy by digital dermoscopy (DD), and then repeated monthly until therapy disruption. Forty-two patients were included, the mean duration of follow-up was 6.7 months, and a mean number of 51 lesions per patients were captured and followed. A total number of 2,155 lesions were recorded, of which 56.1% presented at least one change during the study. More common changes concerned the color of the lesions (up to 15%) and appearance or disappearance of globules (14.6%). Thirty-six of the melanocytic lesions were surgically excised, 21 were classified as a nevus, 1 was a lentigo, and 14 as a second new primary melanoma (occurring in 21% of our patients). DD allowed us to excise only 36/2,155 (1.6%) of the lesions and permitted us to detect 14 SPM in the 42 patients with a highly efficient malignant/benign ratio of 63.6%. Although vemurafenib is now tested in an adjuvant setting DD should be systematically used in order to accurately detect SPM and reduce the number of unnecessary excisions.