The Impact of Next-generation Sequencing on Interobserver Agreement and Diagnostic Accuracy of Desmoplastic Melanocytic Neoplasms

Next-generation sequencing (NGS) is increasingly being utilized as an ancillary tool for diagnostically challenging melanocytic neoplasms. It is incumbent upon the pathology community to perform studies assessing the benefits and limitations of these tools in specific diagnostic scenarios. One of the most challenging diagnostic scenarios faced by skin pathologists involves accurate diagnosis of desmoplastic melanocytic neoplasms (DMNs). In this study, 20 expert melanoma pathologists rendered a diagnosis on 47 DMNs based on hematoxylin and eosin sections with demographic information. After submitting their diagnosis, the experts were given the same cases, but this time with comprehensive genomic sequencing results, and asked to render a diagnosis again. Identification of desmoplastic melanoma (DM) improved by 7%, and this difference was statistically significant (P<0.05). In addition, among the 15 melanoma cases, in the pregenomic assessment, only 12 were favored to be DM by the experts, while after genomics, this improved to 14 of the cases being favored to be DM. In fact, some cases resulting in metastatic disease had a substantial increase in the number of experts recognizing them as DM after genomics. The impact of the genomic findings was less dramatic among benign and intermediate-grade desmoplastic tumors (BIDTs). Interobserver agreement also improved, with the Fleiss multirater Kappa being 0.36 before genomics to 0.4 after genomics. NGS has the potential to improve diagnostic accuracy in the assessment of desmoplastic melanocytic tumors. The degree of improvement will be most substantial among pathologists with some background and experience in bioinformatics and melanoma genetics.

CAP-ACP Workload Model for Advanced Diagnostics in Precision Medicine

OBJECTIVES

In precision medicine, where oncologic management is tailored to the individual's clinical and genetic profiles, advanced diagnostic testing provides prognostic information and guides management in a growing number of malignancies. There is a need to capture the work pathologists perform to meet this demand by providing medically relevant, timely, and accurate testing results. This work includes not only direct patient consults (interpretation of results and issuing reports) but the administrative and medical oversight as well as the research needed to provide the necessary quality assurance, quality control, direction, and framework for the laboratory.

METHODS

An expert panel of Canadian pathologists involved in advanced diagnostics was convened to establish and beta test a model for workload assessment in advanced diagnostics.

RESULTS

All aspects of the advanced diagnostics workload were detailed and applied to models based on members' experience, including medical oversight, administration, and the introduction of new testing and platforms. Models for biomarker testing were developed for simple and complex or multiplexed assays, and a detailed model was developed to assess the workload for next-generation sequencing-based assays.

CONCLUSIONS

This paper provides the first detailed proposal for capturing an advanced diagnostic workload to enable appropriate pathologist allotment for performing all the steps required to run an advanced diagnostic service.

Defining the Criteria for Reflex Testing for BRAF Mutations in Cutaneous Melanoma Patients

Targeted therapy has been developed through an in-depth understanding of molecular pathways involved in the pathogenesis of melanoma. Approximately ~50% of patients with melanoma have tumors that harbor a mutation of the BRAF oncogene. Certain clinical features have been identified in BRAF-mutated melanomas (primary lesions located on the trunk, diagnosed in patients <50, visibly pigmented tumors and, at times, with ulceration or specific dermatoscopic features). While BRAF mutation testing is recommended for stage III-IV melanoma, guidelines differ in recommending mutation testing in stage II melanoma patients. To fully benefit from these treatment options and avoid delays in therapy initiation, advanced melanoma patients harboring a BRAF mutation must be identified accurately and quickly. To achieve this, clear definition and implementation of BRAF reflex testing criteria/methods in melanoma should be established so that patients with advanced melanoma can arrive to their first medical oncology appointment with a known biomarker status. Reflex testing has proven effective for a variety of cancers in selecting therapies and driving other medical decisions. We overview the pathophysiology, clinical presentation of BRAF-mutated melanoma, current guidelines, and present recommendations on BRAF mutation testing. We propose that reflex BRAF testing should be performed for every melanoma patient with stages ≥IIB.

Narrowband ultraviolet B therapy for refractory immune-related lichenoid dermatitis on PD-1 therapy: a case report

Treatment with programmed cell death 1 inhibitors is associated with a wide range of cutaneous immune-related adverse events, with lichenoid eruptions representing one of the major cutaneous toxicities. We describe the case of an 81-year-old man with metastatic melanoma treated with pembrolizumab who subsequently developed a delayed-onset generalized lichenoid dermatitis. After failing multiple lines of systemic immunosuppression, narrowband ultraviolet B (NBUVB) phototherapy three times per week for 17 sessions resulted in a significant clinical response in his cutaneous eruption and was well tolerated. NBUVB is a safe, lower-cost modality that induces local, skin-specific immunosuppression without the toxicities of traditional systemic immunosuppressive agents. To date, this is the first report of use of NBUVB in immune-related lichenoid dermatitis resistant to multiple standard therapies.

Liquid chromatography coupled to multiple reaction monitoring (LC-MRM) for quantification of PD-L1 and PD1-signaling proteins in non-small cell lung carcinoma (NSCLC)

e21040

Background: Improving the predictive biomarkers arena of checkpoint inhibitors (CPIs) beyond PD-L1 immunohistochemistry (IHC) is one of the most important unmet need in NSCLC. Up to 50% of patients that show positive PD-L1 expression by IHC do not respond to anti-PD-L1 treatments, and patients with low/undetectable PD-L1 have significantly improved survival with CPI. Moreover, PD-L1 IHC is heterogeneous, can be affected by tissue fixation time and post-translational modifications like glycosylation. Also, multiple studies indicated that PD-L1 expression alone does not reliably reflect the immune status of the tumor, thus requiring the measurement of other members of the PD1 signalling pathway. Methods: To address these issues, we developed a multiplexed targeted mass spectrometry-based (MS) assay for the quantitation of protein members of the PD-1/PD-L1 axis in formalin fixed paraffin-embedded (FFPE) tissue.The effect of fixation time on protein recovery was determined using differentially fixed H1915 cells. Liquid chromatography (LC) coupled to MRM was used to develop a targeted assay for PD-L1, PD-1, PD-L2, NT5E, LCK and ZAP70. Results: After 30 minutes fixation 33.6 µg of protein were extracted per mg of FFPE H1915 cells, while protein recovery after 7 days was 55.8 µg/mg, with greater variability (18% and 28% CV, p-value = ns). The optimized LC-MRM method allows the quantitation of PD-L1 and PD-1 down to 23 amol on-column. We evaluated the utility of our MRM assays using the H1915 FFPE cells (PD-L1 3+ by IHC) and determined an endogenous concentration of PD-L1 and NT5E as being 33.2±0.1 amol/µg of total protein and 4.8±0.5 fmol/µg respectively. Noteworthy, a known glycosylation site of PD-L1 was quantified at 10.9±0.3 amol/µg of total protein (30% of total). As increases sensitivity was required, anti-peptide antibodies were generated against the 15 best peptides. We then evaluated this LC-MRM method using MDA-MB-436 cells with lower levels of PD-L1 protein assessed by IHC. Determination of endogenous PD-L1 concentration (3.0 amol/µg of total protein) was achieved using anti-peptide immuno-enrichment followed by MRM. Conclusions: We developed a fixation time independent extraction technique for FFPE and optimized a highly sensitive LC-MRM method that allows the absolute quantification of our targets. This proteomic workflow allows absolute quantification of the PD-1/PD-L1 axis from FFPE tissue using immuno-enrichment and a multiplexed LC-MRM method.

BORIS/CTCFL promotes a switch from a proliferative towards an invasive phenotype in melanoma cells

Melanoma is among the most aggressive cancers due to its tendency to metastasize early. Phenotype switching between a proliferative and an invasive state has been suggested as a critical process for metastasis, though the mechanisms that regulate state transitions are complex and remain poorly understood. Brother of Regulator of Imprinted Sites (BORIS), also known as CCCTC binding factor-Like (CTCFL), is a transcriptional modulator that becomes aberrantly expressed in melanoma. Yet, the role of BORIS in melanoma remains elusive. Here, we show that BORIS is involved in melanoma phenotype switching. Genetic modification of BORIS expression in melanoma cells combined with whole-transcriptome analysis indicated that BORIS expression contributes to an invasion-associated transcriptome. In line with these findings, inducible BORIS overexpression in melanoma cells reduced proliferation and increased migration and invasion, demonstrating that the transcriptional switch is accompanied by a phenotypic switch. Mechanistically, we reveal that BORIS binds near the promoter of transforming growth factor-beta 1 (TFGB1), a well-recognized factor involved in the transition towards an invasive state, which coincided with increased expression of TGFB1. Overall, our study indicates a pro-invasive role for BORIS in melanoma via transcriptional reprogramming.

The metastatic site does not influence PD-L1 expression in advanced non-small cell lung carcinoma

INTRODUCTION

PD-L1 expression by immunohistochemistry (IHC) testing with Tumor Proportion Score (TPS) ≥50% and ≥1% is required to be eligible for first- and second-line Pembrolizumab treatment for metastatic non-small cell lung cancer (NSCLC) respectively. Stage IV NSCLC often presents with metastasis to multiple distant sites which are easily accessible for biopsy. Knowing whether PD-L1 IHC TPS can be indifferently measured from different metastatic site is therefore an important clinical question. In this study, we evaluated PD-L1 expression in NSCLC from varied distant metastatic sites.

METHODS

A total of 580 NSCLC specimens of distant metastases were retrieved for study, including 35 paired samples from two different metastatic sites. The metastatic sites included brain, bone, remote lymph nodes, serous membranes (pleura, pericardium and peritoneum), extra-thoracic solid organs and skin/soft tissues. The samples were cytology cell blocks, small biopsies or surgical resections. IHC was performed using Dako PD-L1 IHC 22C3 pharmDx. A total of 100 viable tumor cells was required for adequacy. TPS ≥ 50% and 1-49% were defined as high and low PD-L1 expression respectively.

RESULTS

PD-L1 TPS scores were not significantly different across a range of distant metastatic sites nor between metastases in paired samples.

CONCLUSION

Our results suggest that the PD-L1 TPS scoring is similar across different metastatic sites and any site biopsied will yield necessary information for guiding clinical management.

Idiopathic Atrophoderma of Pasini and Pierini: Case report and literature review

Idiopathic Atrophoderma of Pasini and Pierini should be considered on the differential in a patient presenting with an asymptomatic atrophic plaque on the skin. Differentiation from Linear Atrophoderma of Moulin and morphea remains a challenge; however, features of the presentation and tissue biopsy can help establish the diagnosis.

The protein phosphatase 2A regulatory subunit PR70 is a gonosomal melanoma tumor suppressor gene

Male gender is independently and significantly associated with poor prognosis in melanoma of all clinical stages. The biological underpinnings of this sex difference remain largely unknown, but we hypothesized that gene expression from gonosomes (sex chromosomes) might play an important role. We demonstrate that loss of the inactivated X chromosome in melanomas arising in females is strongly associated with poor distant metastasis-free survival, suggesting a dosage benefit from two X chromosomes. The gonosomal protein phosphatase 2 regulatory subunit B, beta (PPP2R3B) gene is located on the pseudoautosomal region (PAR) of the X chromosome in females and the Y chromosome in males. We observed that, despite its location on the PAR that predicts equal dosage across genders, PPP2R3B expression was lower in males than in females and was independently correlated with poor clinical outcome. PPP2R3B codes for the PR70 protein, a regulatory substrate-recognizing subunit of protein phosphatase 2A. PR70 decreased melanoma growth by negatively interfering with DNA replication and cell cycle progression through its role in stabilizing the cell division cycle 6 (CDC6)-chromatin licensing and DNA replication factor 1 (CDT1) interaction, which delays the firing of origins of DNA replication. Hence, PR70 functionally behaves as an X-linked tumor suppressor gene.

Abstract 5528: The protein phosphatase 2A regulatory subunit PR70 is a gonosomal melanoma tumor suppressor gene

Male gender is independently and significantly associated with poor prognosis in melanoma of all clinical stages. The biological underpinnings of this sex difference remain largely unknown, but we hypothesize that gene expression from gonosomes may play an important role. The current study demonstrates that loss of the inactivated X chromosome in melanomas arising in females is strongly associated with poor distant metastasis-free survival, suggesting a dosage benefit of two X-chromosomes. The gonosomal PPP2R3B gene is located on the pseudo-autosomal region (PAR) of the X-chromosome in females and on the Y-chromosome in males. We observed that despite its location on the PAR that predicts equal dosage across genders, PPP2R3B expression is lower in males than in females, and is independently correlated with poor clinical outcome. PPP2R3B codes for the PR70 protein, a regulatory substrate recognizing subunit of PP2A, that decreases melanoma growth by negatively interfering with DNA replication and cell cycle progression through its role in stabilizing CDC6/CDT1 interaction that delays the firing of origins of DNA replication. As such, PR70 behaves functionally as an X-linked tumor suppressor gene.

Citation Format: Léon C.L. Van Kempen, Margaret Redpath, Mounib Elchebly, Kathleen Oros Klein, Andreas Papadakis, James Willmott, Richard Scolyer, Per-Henrik Edqvist, Fredrik Ponten, Dirk Schadendorf, Anke van Rjk, Stefan Michiels, Anne Dumay, Anne Helbling-Leclerc, Philippe Dessen, Jasper Wouters, Marguerite Stass, Celia Greenwood, G. Elias Ghanem, Joost van den Oord, Jean Feunteun, Alan Spatz. The protein phosphatase 2A regulatory subunit PR70 is a gonosomal melanoma tumor suppressor gene [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5528. doi:10.1158/1538-7445.AM2017-5528

Molecular pathology of cutaneous melanoma

Cutaneous melanoma is associated with strong prognostic phenotypic features, such as gender, Breslow's thickness and ulceration, although the biological significance of these variables is largely unknown. It is likely that these features are surrogates of important biological events rather than directly promoting cutaneous melanoma progression. In this article, we address the molecular mechanisms that drive these phenotypic changes. Furthermore, we present a comprehensive overview of recurrent genetic abnormalities, both germline and somatic, in relation to cutaneous melanoma subtypes, ultraviolet exposure and anatomical localization, as well as pre-existing and targeted therapy-induced mutations that may contribute to resistance. The increasing knowledge of critically important oncogenes and tumor-suppressor genes is promoting a transition in melanoma diagnosis, in which single-gene testing will be replaced by multiplex and multidimensional analyses that combine classical histopathological characteristics with the molecular profile for the prognostication and selection of melanoma therapy.

Copeptin and arginine vasopressin at high altitude: relationship to plasma osmolality and perceived exertion

PURPOSE

A diuresis is a key part of acclimatisation to high altitude (HA). Arginine vasopressin (AVP) is a hormone involved in salt and water balance and may potentially have a role in the development of altitude illness. ProAVP (copeptin) is more stable than AVP and is assayed by a straightforward, automated method. We investigated the relationship of AVP to copeptin and the copeptin response to exercise and altitude illness in a large cohort during a field study at HA.

METHODS

48 subjects took part in a 10-day trek at HA. Venous blood samples were taken at 3,833, 4,450 and 5,129 m post-trek (exercise) and the following day at rest. Daily recordings of symptoms of altitude illness, oxygen saturations and perceived exertion were carried out.

RESULTS

AVP and copeptin levels increased with exercise and correlated closely (ρ 0.621 p < 0.001), this was strongest in the stressed state when AVP secretion was highest, at 5,129 m post-exercise (ρ 0.834 p < 0.001). On two-way ANOVA, both altitude (F = 3.5; p = 0.015) and exercise (F = 10.2; p = 0.002) influenced copeptin levels (interaction F = 2.2; p = 0.08). AVP levels were influenced by exercise (F = 14.4; p = 0.0002) but not altitude (F = 2.0; p = 0.12) with no overall group interactions (F = 1.92.6; p = 0.06). There was no association between copeptin or arginine vasopressin and altitude illness. Copeptin correlated with the Borg RPE score and was significantly higher in the group with a Borg score ≥15 (7.9 vs. 3.7 p < 0.001).

CONCLUSION

We have shown that arginine vasopressin and copeptin levels correlate and are suppressed below 5,129 m. Furthermore, we have demonstrated that exertion, rather than altitude illness or increasing osmolality, is the stimulus for increases in copeptin.

Mechanism of death in hanging: a historical review of the evolution of pathophysiological hypotheses

In cases of hanging, the exact mechanism leading to death has yet to be elucidated. Most of our contemporary knowledge is still based on writings from the end of the 19th and the beginning of the 20th century. This article reviews the historic experiments that shaped our current theories. Medico-legal textbooks written in English and French from 1870 to 1930 were reviewed. Various animals, such as rabbits, mice, and dogs, have been used to develop animal models of hanging. Limited human studies on cadavers and judicial hangings have provided some additional insight into the pathophysiology of death by hanging. The main pathophysiological theories described were respiratory asphyxia, interruption to cerebral blood flow because of occlusion of vessels in the neck, and cardiac inhibition secondary to nerve stimulation. The relative contributions of each of these theories to death in cases of hanging is still debated today.

The dual role of the X-linked FoxP3 gene in human cancers

The FoxP3 (forkhead box P3) gene is an X-linked gene that is submitted to inactivation. It is an essential transcription factor in CD4(+)CD25(+)FoxP3 regulatory T cells, which are therapeutic targets in disseminated cutaneous melanoma. Moreover, FoxP3 is an important tumor suppressor gene in carcinomas and has putative cancer suppressor gene function in cutaneous melanoma as well. Therefore understanding the structure and function of the FoxP3 gene is crucial to gaining insight into the biology of melanoma to better develop immunotherapeutics and future therapeutic strategies.

Respiratory, circulatory, and neurological responses to hanging: a review of animal models

The pathophysiology of hanging is still poorly understood. This article presents a review of eight animal models: four models of isolated occlusion of the vessels of the neck (group 1), one model of combined tracheal and vessel occlusion (group 2), and three models of true animal hanging (group 3). Occlusion of the airway passages in group 2 did not accelerate respiratory arrest compared to group 1. Cessation of cerebral blood flow, rather than airway obstruction, seems to be the main cause of respiratory decline. In general, muscular movements ceased after 1-3.5 min and early generalized tonic-clonic convulsions were described. Complete circulatory collapse seems to occur between 4 and 8.5 min. These observations from animal models of hanging are compared with the data collected from filmed human hangings. Avenues to improve animal models are discussed.

Ibuprofen and hydrogel-released ibuprofen in the reduction of inflammation-induced migration in melanoma cells

BACKGROUND

There is growing evidence that inflammation may exacerbate cancer metastasis and several clinical studies show that taking nonsteroidal anti-inflammatory drugs appears to reduce metastases.

OBJECTIVES

The aims of this study were: (i) to examine the effects of ibuprofen on the major proinflammatory cytokine tumour necrosis factor (TNF)-alpha induction of migration of C8161 and HBL human melanoma cells; (ii) to develop ibuprofen-releasing hydrogels (Pluronics F127) for future topical use in reducing metastatic spread of primary melanoma; and (iii) to examine whether the actions of ibuprofen might be explained by induction of apoptosis.

METHODS

Melanoma cells were exposed to 300 U mL(-1) TNF-alpha for a 24-h period prior to making a scratch wound to which ibuprofen or ibuprofen-loaded hydrogels were then added. The effects of relevant concentrations of ibuprofen on cell viability and apoptosis were examined.

RESULTS

Ibuprofen at 10(-3) mol L(-1) significantly reduced TNF-alpha-stimulated migration of both cell types to that of nonstimulated cells (P < 0.001). TNF-alpha-unstimulated cell migration was not significantly affected. Cells responded similarly to SS and SR forms of ibuprofen. Cells treated with ibuprofen sodium salt-loaded hydrogels showed a significant reduction in migration when compared with unloaded hydrogels. Ibuprofen induced apoptosis in HBL cells but had no effect on C8161 melanoma cells apoptosis at concentrations that reduced migration.

CONCLUSIONS

These results demonstrate that TNF-alpha upregulated malignant melanoma migration in vitro and that this could be reduced by ibuprofen both in solution and delivered from a hydrogel. These effects of ibuprofen cannot be attributed simply to induction of apoptosis.

Clinical pharmacokinetics of 1-[((S)-2-hydroxy-2-oxo-1,4,2-dioxaphosphorinan-5-yl)methyl]cytosine in human immunodeficiency virus-infected patients

The pharmacokinetics and bioavailability of 1-[((S)-2-hydroxy-2-oxo-1,4,2-dioxaphosphorinan-5-yl)methyl]cytosi ne (cyclic HPMPC) were examined at four doses in 22 patients with human immunodeficiency virus infection. Two groups of six patients received a single dose of cyclic HPMPC at 1.5 or 3.0 mg/kg of body weight by each of the oral and intravenous routes in a random order with a 2-week washout period between administrations. Additional patients received single intravenous doses of cyclic HPMPC at 5.0 mg/kg (n = 6) or 7.5 mg/kg (n = 4). Serial serum and urine samples were collected at intervals over 24 h after dosing. The concentrations of cyclic HPMPC and cidofovir in serum and urine samples were determined by validated reverse-phase ion-pairing high-performance liquid chromatography methods with derivatization and fluorescence detection. After intravenous administration of cyclic HPMPC, concentrations of cyclic HPMPC declined in a biexponential manner, with a mean +/- standard deviation half-life of 1.09 +/- 0.12 h (n = 22). The pharmacokinetics of cyclic HPMPC were independent of dose over the dose range of 1.5 to 7.5 mg/kg. The total clearance of cyclic HPMPC from serum and the volume of distribution of intravenous cyclic HPMPC were 198 +/- 39.6 ml/h/kg and 338 +/- 65.1 ml/kg, respectively (n = 22). The renal clearance of cyclic HPMPC (132 +/- 27.3 ml/h/kg; n = 22) exceeded the creatinine clearance (86.2 +/- 16.3 ml/h/kg), indicating active tubular secretion. The cyclic HPMPC excreted in urine in 24 h accounted for 71.3% +/- 16.0% of the administered dose. Cidofovir was formed from cyclic HPMPC in vivo with a time to the maximum concentration in serum of 1.64 +/- 0.23 h (n = 22). Cidofovir levels declined in an apparent monoexponential manner, with a mean terminal half-life of 3.98 +/- 1.26 h (n = 22). The cidofovir excreted in urine in 24 h accounted for 9.40% +/- 2.33% of the administered cyclic HPMPC dose. Exposure to cidofovir after intravenous administration of cyclic HPMPC was dose proportional and was 14.9% of that from an equivalent dose of cidofovir. The present study suggests that intravenous cyclic HPMPC also has a lower potential for nephrotoxicity in humans compared to that of intravenous cidofovir. The oral bioavailabilities of cyclic HPMPC were 1.76% +/- 1.48% and 3.10% +/- 1.16% with the administration of doses of 1.5 and 3.0 mg/kg, respectively (n = 6 per dose). The maximum concentrations of cyclic HPMPC in serum were 0.036 +/- 0.021 and 0.082 +/- 0.038 microgram/ml after the oral administration of doses of 1.5 and 3.0 mg/kg, respectively. Cidofovir reached quantifiable levels in the serum of only one patient for each of the 1.5- and 3.0-mg/kg oral cyclic HPMPC doses.