FLT3L governs the development of partially overlapping hematopoietic lineages in humans and mice

FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.

Mycoplasma genitalium screening in a specialized French unit: A retrospective study

OBJECTIVE

Mycoplasma genitalium (MG) infection accounts for 10-35% of non-gonococcal non-chlamydial (NGNC) urethritis. However, given that most people infected with MG do not develop symptoms and that antimicrobial resistance is increasing worldwide, there is no evidence of any benefits of screening asymptomatic individuals. We conducted this study to describe MG screening practices and outcomes at a French Sexually Transmitted Infections (STI) center in which MG testing was performed selectively and multiplex assays were not carried out [i.e., simultaneous screening for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and MG].

METHODS

A retrospective, observational, single-center study was conducted at the STI unit of Saint-Louis Hospital in Paris. The records of all patients undergoing MG testing from January 1st, 2017, to December 31st, 2018, were reviewed. The primary aim of the study was to describe and evaluate the proportion of MG-positive (MG+) patients among those tested. Secondary objectives were determination of the prevalence of MG+ status among symptomatic patients, risk factors associated with MG infection, and therapeutic modalities and efficacy.

RESULTS

Two hundred and forty-nine patients underwent MG testing, 28 (11%) of whom were positive (MG+). The prevalence of MG+ status among symptomatic NGNC patients was 12%. HIV-positive (HIV+) status was significantly associated with MG+ status in univariate and multivariate analyses (Odds Ratio=7.3, 95% Confidence Interval 1.3-41.7; P=0.02). Twenty-three patients (85%) received antibiotics. Eighteen (67%) received azithromycin for 5 days, but 7 had clinical resistance. No quinolone resistance was reported.

CONCLUSION

Despite unavailability of multiplex testing at our facility, which led to targeted-only screening for MG, its relatively high local prevalence is in keeping with what is generally observed at similar facilities across the world, where use of multiplex tests enables systematic screening for MG alongside NG and CT. This reinforces the current recommendations in Europe, France and the US against systematic MG testing or treatment in asymptomatic patients.

Sonidegib in the Treatment of Locally Advanced Basal Cell Carcinoma: a Retrospective Study

Sonidegib, a hedgehog pathway inhibitor, is indicated for treatment of locally advanced basal cell carcinoma, based on the results of the BOLT study. However, to date, no real-world study of sonidegib has been reported. An observational, retrospective, single-centre study (PaSoS study) was conducted. The primary objective was to evaluate the efficacy of sonidegib for treatment of locally advanced basal cell carcinoma in a real-world setting. Secondary objectives included modalities of use, tolerability, tumour evolution, and management after discontinuation. A total of 21 patients treated with sonidegib were included from March 2018 to January 2021. The median follow-up was 18.7 months and median exposure 7.0 months. Objective response (OR) rate was 81.0% (n = 17) including 6 (29%) patients with a complete response (CR). Disease control rate was 100%. First tumour response was rapid, with a median time of 2.3 months. Nine (43%) patients underwent surgery after sonidegib discontinuation, and no relapse was observed. All the patients experienced at least 1 adverse event (AE). Muscle spasms were the most frequent AE (n = 14; 67%), followed by dysgeusia (n = 8; 38%) and alopecia (n = 12; 57%). The efficacy and safety profile of sonidegib in this first-to-date real-life trial are consistent with prior results. Overall, real-world evidence corroborated sonidegib efficacy and tolerability as a first-line treatment for locally advanced basal cell carcinoma.

The Pathogenesis of Giant Condyloma Acuminatum (Buschke-Lowenstein Tumor): An Overview

Giant condyloma acuminatum, also known as Buschke-Lowenstein tumor (BLT), is a rare disease of the anogenital region. BLT is considered a locally aggressive tumor of benign histological appearance, but with the potential for destructive growth and high recurrence rates. BLT development is strongly associated with infection with low-risk human papillomaviruses (HPVs), mostly HPV-6 and -11. Immunity to HPVs plays a crucial role in the natural control of various HPV-induced lesions. Large condyloma acuminata are frequently reported in patients with primary (e.g., DOCK8 or SPINK5 deficiencies) and secondary (e.g., AIDS, solid organ transplantation) immune defects. Individuals with extensive anogenital warts, including BLT in particular, should therefore be tested for inherited or acquired immunodeficiency. Research into the genetic basis of unexplained cases is warranted. An understanding of the etiology of BLT would lead to improvements in its management. This review focuses on the role of underlying HPV infections, and human genetic and immunological determinants of BLT.

Frequency and Genomic Aspects of Intrinsic Resistance to Vismodegib in Locally Advanced Basal Cell Carcinoma

PURPOSE

Vismodegib is approved for the treatment of locally advanced basal cell carcinoma (laBCC), but some cases demonstrate intrinsic resistance (IR) to the drug. We sought to assess the frequency of IR to vismodegib in laBCC and its underlying genomic mechanisms.

EXPERIMENTAL DESIGN

Response to vismodegib was evaluated in a cohort of 148 laBCC patients. Comprehensive genomic and transcriptomic profiling was performed in a subset of five intrinsically resistant BCC (IR-BCC).

RESULTS

We identified that IR-BCC represents 6.1% of laBCC in the studied cohort. Prior treatment with chemotherapy was associated with IR. Genetic events that were previously associated with acquired resistance (AR) in BCC or medulloblastoma were observed in three out of five IR-BCC. However, IR-BCCs were distinct by highly rearranged polyploid genomes. Functional analyses identified hyperactivation of the HIPPO-YAP and WNT pathways at RNA and protein levels in IR-BCC. In vitro assay on the BCC cell line further confirmed that YAP1 overexpression increases the cell proliferation rate.

CONCLUSIONS

IR to vismodegib is a rare event in laBCC. IR-BCCs frequently harbor resistance mutations in the Hh pathway, but also are characterized by hyperactivation of the HIPPO-YAP and WNT pathways.

Immune checkpoint inhibitors increase T cell immunity during SARS-CoV-2 infection

The COVID-19 pandemic has spread worldwide, yet the role of antiviral T cell immunity during infection and the contribution of immune checkpoints remain unclear. By prospectively following a cohort of 292 patients with melanoma, half of which treated with immune checkpoint inhibitors (ICIs), we identified 15 patients with acute or convalescent COVID-19 and investigated their transcriptomic, proteomic, and cellular profiles. We found that ICI treatment was not associated with severe COVID-19 and did not alter the induction of inflammatory and type I interferon responses. In-depth phenotyping demonstrated expansion of CD8 effector memory T cells, enhanced T cell activation, and impaired plasmablast induction in ICI-treated COVID-19 patients. The evaluation of specific adaptive immunity in convalescent patients showed higher spike (S), nucleoprotein (N), and membrane (M) antigen-specific T cell responses and similar induction of spike-specific antibody responses. Our findings provide evidence that ICI during COVID-19 enhanced T cell immunity without exacerbating inflammation.

Emerging drugs for the treatment of basal cell carcinoma

Introduction: Basal cell carcinoma (BCC) is the most frequent skin malignancy, with incidence increasing worldwide. Most BCC can be cured with local treatments (surgery or topical therapies), but advanced or recurrent forms require specific therapies. Significant developments targeting the sonic hedgehog signalization pathway have been made in the past years, paving the way for new therapies.Areas covered: This review details emerging drugs for BCC treatment, focusing on topical, intra-tumoral, and systemic therapies, such as new targeted therapies and immune checkpoint inhibitors. A literature search was conducted to identify ongoing studies using PudMed database and clinicaltrials.gov website.Expert opinion: Although surgery is and will probably remain the gold-standard therapy for BCC, treatment of recurrent, advanced, and metastatic tumors is evolving. Emergence of tumors resistant to targeted therapies lead the way to new approaches. Topical and intra-tumoral treatments represent alternatives to surgical morbidity, and many studies are ongoing. The first results of immune checkpoint inhibitors are encouraging in advanced and metastatic forms of the disease. New targeted therapies are needed to overcome or prevent the resistance to standard hedgehog pathway inhibitors.

Penoscrotal Paget's disease

Paget's disease (PD) denotes an initially intra-epidermal adenocarcinoma that can later invade the dermis and metastasise. Among the extramammary forms of PD (EMPD), penoscrotal presentations are rarer than the vulvar and perianal forms. Once diagnosis has been confirmed by histopathological examination, a search for associated neoplasia must be conducted, although penoscrotal EMPD is less frequently associated with underlying neoplasia than mammary PD (MPD). The associated cancer most often involves a neighbouring organ, with prostate cancer being the most common, or in some cases consists of underlying cutaneous adnexal tumours. First-line therapy consists of surgical excision. Alternatives to surgery (imiquimod, CO₂ laser vaporisation, dynamic phototherapy) may be considered in certain cases.

Actinic cheilitis: a systematic review of treatment options

Actinic cheilitis is a premalignant condition that can progress to squamous cell carcinoma with a higher propensity for metastasis than cutaneous squamous cell carcinoma. Optimal treatment for actinic cheilitis has not been established, and evidence-based estimates of clinical cure in the dermatology literature are limited. Here, we review and synthesize outcome data published for patients with actinic cheilitis after treatment with various modalities. A systematic review was conducted in MEDLINE, Embase and the Cochrane library for English, French and German-language studies and references of included articles from inception to 20 January 2020. Studies were included if they reported on at least six patients with biopsy-proven actinic cheilitis. After quality appraisal, results of studies with the strongest methodology criteria were synthesized. 18 studies of 411 patients (published 1985 to 2016) were included. The majority of the studies were case series. Carbon dioxide laser ablation and vermilionectomy were associated with the most favourable outcomes with fewest recurrences. Chemical peel and photodynamic therapy were associated with higher recurrence. Adverse effects generally resolved in the weeks following treatment and cosmetic outcomes were favourable overall. In conclusion, there is a lack of high-quality comparative studies evaluating different treatment options for actinic cheilitis. The included publications used various outcome measures; however, the majority reported on the recently defined core outcome sets. These results suggest that both carbon dioxide laser ablation and vermilionectomy are effective treatments for actinic cheilitis. Prospective head-to-head studies are needed to compare these treatment modalities and to assess patient preferences.

Follow-Up of Patients With Complete Remission of Locally Advanced Basal Cell Carcinoma After Vismodegib Discontinuation: A Multicenter French Study of 116 Patients

PURPOSE

Vismodegib is a hedgehog pathway inhibitor indicated for the treatment of locally advanced basal cell carcinoma (laBCC), with an objective response rate of 65%, including a 32% complete response (CR). However, adverse effects often lead to drug discontinuation. The objective of our study was to evaluate long-term responses, predictive factors, and management of relapse after vismodegib discontinuation.

METHODS

An observational retrospective study was conducted in nine French oncodermatology units. We included patients with laBCC with CR on vismodegib who discontinued treatment between March 2012 and January 2016; we reviewed charts up to June 2016. The primary objective was to evaluate median relapse-free survival (RFS). Secondary objectives were risk factors associated with RFS, relapse, and death and treatment modalities after relapse and their efficacy.

RESULTS

One hundred sixteen patients with laBCC were included. The median RFS was 18.4 months (95% CI, 13.5 to 24.8 months). The RFS rate at 36 months was 35.4% (95% CI, 22.5% to 47.9%) for the total population and 40.0% (95% CI, 25.7% to 53.7%) for patients without Gorlin syndrome. LaBCC to the limbs and trunk was the only variable independently associated with a higher risk of relapse (hazard ratio, 2.77; 95% CI, 1.23 to 6.22; P = .019). Twenty-seven patients (50%) who experienced relapse during follow-up were retreated with vismodegib, with an objective response in 23 (objective response rate, 85%; CR rate, 37%; partial response rate, 48%) and eligibility for surgery in 24 (42%).

CONCLUSION

Long-term response after vismodegib discontinuation is frequent. Most patients who experience a relapse still respond to vismodegib rechallenge.

Baseline Genomic Features in BRAFV600-Mutated Metastatic Melanoma Patients Treated with BRAF Inhibitor + MEK Inhibitor in Routine Care

In BRAFV600mut metastatic melanoma, the combination of BRAF and MEK inhibitors (BRAFi, MEKi) has undergone multiple resistance mechanisms, limiting its clinical benefit and resulting in the need for response predicting biomarkers. Based on phase III clinical trial data, several studies have previously explored baseline genomic features associated with response to BRAFi + MEKi. Using a targeted approach that combines the examination of mRNA expression and DNA alterations in a subset of genes, we performed an analysis of baseline genomic alterations involved in MAPK inhibitors' resistance in a real-life cohort of BRAFV600mut metastatic melanoma patients. Twenty-seven patients were included in this retrospective study, and tumor samples were analyzed when the BRAFi + MEKi therapy was initiated. The clinical characteristics of our cohort were consistent with previously published studies. The BRAFi + MEKi treatment was initiated in seven patients as a following-line treatment, and had a specific transcriptomic profile exhibiting 14 genes with lower mRNA expression. However, DNA alterations in CCND1, RB1, and MET were only observed in patients who received BRAFi + MEKi as the first-line treatment. Furthermore, KIT mRNA expression was significantly higher in patients showing clinical benefit from the combined therapy, emphasizing the tumor-suppressor role of KIT already described within the context of BRAF-mutant melanoma.

Prise en charge thérapeutique des kératoses actiniques

Dermatologists have many therapeutic options for the management of actinic keratoses (AK), in order to treat individual lesions or wider areas. Field cancerization is an area of sun-damaged skin, where visible and subclinical lesions co-exist, and is prone to the development of further AK lesions and sun-related skin cancers (SC). Treatments available are instrumental or medical. Resistance to treatment or atypical symptoms must lead to a biopsy for histological exam. Cryotherapy is the most frequently used method to destroy small or isolated AK, whereas photodynamic therapy (PDT), 5-fluoro-uracil (5-FU), imiquimod, ingenol mebutate and diclofenac are required for large, multiple lesions, and for the treatment of field cancerization. Side-effects of these therapies are essentially local, including pain, irritation, erythema, edema and scars. There is no randomized comparative study reviewing all these treatments, therefore physicians must also consider clinical characteristics, patient's compliance, side-effects and cost when treating AK. Medicoeconomic data of these treatments have been analyzed in several countries, and annual costs are estimated between 250 € and 2 000 €, with an uncertain cost-effective relation. Finally, beyond treatment of AK lesions, patients with AK are at high risk of developing SC, and must therefore have regular full-body examination, in order to be detected and treated precociously. © 2019 Elsevier Masson SAS. All rights reserved. Cet article fait partie du numéro supplément Kératoses actiniques : comprendre et traiter réalisé avec le soutien institutionnel de Galderma International.

Follow-up of patients with complete remission of locally advanced basal cell carcinoma treated with vismodegib after treatment discontinuation: A retrospective multicentric French study

9535

Background: Vismodegib is a Hedgehog Pathway inhibitor (HPI) indicated for treatment of inoperable locally advanced basal-cell carcinoma (laBCC). Previous studies showed an objective response (OR) rate of 67%, including 34% of complete response (CR). Discontinuation of vismodegib is very frequent, mostly due to intolerable side-effects. Long-term response and predictive factors of relapse after suspension of vismodegib have not yet been evaluated, but should play a crucial role in the management of laBCC patients. Methods: We conducted an observational retrospective study in 9 onco-dermatological French units. Medical charts of laBCC patients treated with vismodegib from March 2012 until June 2016 were reviewed and patients with CR who stopped treatment were selected. Relapse was diagnosed clinically and/or histologically. A survival analysis was conducted, and predictive factors, characterization and management of relapse were studied. Results: 119 laBCC patients achieved CR and stopped treatment. 21 were lost to follow-up and 6 died before relapse. Event-free survival median was 18.4 months (12.1 – 24.1) and cumulative incidence of relapse at 36 months was 59.04% (48.05 - 70.04), implying that more than 40% of patients do not relapse. Multiple BCC and BCC not localized on the head and neck were associated with a higher risk of relapse, independently of the existence of Gorlin syndrome (HR = 3.3 (IC95 = 1.6 - 6.7) and 2.01 (IC95 = 1.05 - 3.87) respectively). Total duration of treatment was not associated with relapse. 50% (n = 27) of patients who relapsed during follow-up were retreated with vismodegib, with an OR of 85.2% (n = 23). 42% (n = 24) were eligible to surgery only and other patients received local treatments. Conclusions: Long term responders after vismodegib treatment discontinuation are frequent independently of the time exposure to the drug before and after CR. Most patients who relapse are still responder to vismodegib rechallenge. Patients with multiple or laBCC not localized on the head and neck are more at risk of relapse after discontinuation. This study emphasizes the interest of treatment of laBCC with HPI.

Neutrophilic eccrine hidradenitis in two patients treated with BRAF inhibitors: a new cutaneous adverse event

Neutrophilic eccrine hidradenitis (NEH) is a rare neutrophilic dermatosis, first described in patients undergoing chemotherapy for a malignant haemopathy. It has polymorphous clinical features and the association of both clinical and histological features is necessary to make a diagnosis. We report the first two cases of NEH in patients treated with a BRAF inhibitor (BRAFi), either dabrafenib or vemurafenib, for a stage IV metastatic melanoma. Disseminated erythematous plaques associated with fever and polyarthralgia occurred early after the initiation of treatment and were badly tolerated. Histological analyses confirmed the diagnosis of NEH. Symptoms disappeared a few days after the cessation of treatment and introduction of topical steroids. The replacement of one BRAFi with another is a therapeutic alternative as it is not necessarily associated with a relapse of NEH. NEH can be added to the spectrum of neutrophilic dermatoses induced by BRAFis. It occurs earlier (3-4 days) than previously described drug-induced NEH (9-12 days) and may be an earlier stage of eccrine squamous syringometaplasia, which has already been reported in the context of BRAFi-treated patients.