Skin cancers are the most frequent cancers in fair-skinned populations, but we can prevent them

Cancers of the skin are the most commonly occurring cancers in humans. In fair-skinned populations, up to 95% of keratinocyte skin cancers and 70-95% of cutaneous melanomas are caused by ultraviolet radiation and are thus theoretically preventable. Currently, however, there is no comprehensive global advice on practical steps to be taken to reduce the toll of skin cancer. To address this gap, an expert working group comprising clinicians and researchers from Africa, America, Asia, Australia, and Europe, together with learned societies (European Association of Dermato-Oncology, Euromelanoma, Euroskin, European Union of Medical Specialists, and the Melanoma World Society) reviewed the extant evidence and issued the following evidence-based recommendations for photoprotection as a strategy to prevent skin cancer. Fair skinned people, especially children, should minimise their exposure to ultraviolet radiation, and are advised to use protective measures when the UV index is forecast to reach 3 or higher. Protective measures include a combination of seeking shade, physical protection (e.g. clothing, hat, sunglasses), and applying broad-spectrum, SPF 30 + sunscreens to uncovered skin. Intentional exposure to solar ultraviolet radiation for the purpose of sunbathing and tanning is considered an unhealthy behaviour and should be avoided. Similarly, use of solaria and other artificial sources of ultraviolet radiation to encourage tanning should be strongly discouraged, through regulation if necessary. Primary prevention of skin cancer has a positive return on investment. We encourage policymakers to communicate these messages to the general public and promote their wider implementation.

Distinct induction pathways of heat shock protein 27 in human keratinocytes: Heat stimulation or capsaicin through phosphorylation of heat shock factor 1 at serine 326 and/or suppression of ΔNp63

Epidermal keratinocytes, forming the outermost layer of the human body, serve as a crucial barrier against diverse external stressors such as ultraviolet radiation. Proper keratinocyte differentiation and effective responses to external stimuli are pivotal for maintaining barrier integrity. Heat is one such stimulus that triggers the synthesis of heat shock proteins (HSPs) when cells are exposed to temperatures above 42 °C. Additionally, activation of the transient receptor potential cation channel subfamily V member 1 (TRPV1) occurs at 42 °C. Here, we explore the interplay between TRPV1 signaling and HSP induction in human keratinocytes. Both heat and capsaicin, a TRPV1 agonist, induce expression of HSP27, HSP70, and HSP90 in keratinocytes. Interestingly, pharmacological inhibition of TRPV1 attenuates heat-induced HSP27 expression, but not that of HSP70 or HSP90. Furthermore, both heat and capsaicin stimulation result in distinct phosphorylation patterns of heat shock factor 1 (HSF1), with phosphorylation at serine 326 being a common feature. Notably, genetic manipulation to mimic dephosphorylation of HSF1 at serine 326 reduces HSP27 levels. Additionally, ΔNp63, a key regulator of epidermal differentiation, negatively modulates HSP27 expression independently of HSF1 phosphorylation status. While heat stimulation has no effect on ΔNp63 expression, capsaicin reduces its levels. The precise role of TRPV1 signaling in keratinocytes warrants further investigation for a comprehensive understanding of its impact on barrier function.

Long-term follow-up results from KEYNOTE-041: Phase 1b study of pembrolizumab in Japanese patients with advanced melanoma

Pembrolizumab demonstrated an acceptable safety profile and promising antitumor activity in Japanese patients with advanced melanoma in the phase 1b KEYNOTE-041 (Study of Pembrolizumab [MK-3475] in Participants With Advanced Melanoma) trial. To evaluate the long-term efficacy and safety of pembrolizumab in Japanese patients with advanced melanoma in KEYNOTE-041. The current analysis reports results of additional follow-up of approximately 12 months since the initial analysis. Eligible patients had locally advanced (unresectable stage III) or metastatic (stage IV) melanoma not amenable to local therapy and had received two or fewer prior systemic therapies. Pembrolizumab 2 mg/kg was given every 3 weeks for up to 2 years or until confirmed progression or unacceptable toxicity. Primary end points included safety, tolerability, and overall response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 by independent central review. The data cutoff for this analysis was August 30, 2017. Forty-two patients were followed up for a median of 22.3 months (range, 2.63-30.82 months). The ORR was 24.3% (nine of 37 evaluable patients [95% confidence interval (CI), 11.8%-41.2%]). Two patients with partial response at the time of the initial analysis achieved complete response. The median overall survival (OS) was 25.1 months (95% CI, 13.1-not reached] and the 30-month OS rate was 46.3% (95% CI, 29.8%-61.3%). The median duration of response was not reached. Treatment-related adverse events (TRAEs) were reported in 78.6% of patients; the incidence of grade 3 to 5 TRAEs was 23.8%. No additional treatment-related deaths occurred since the initial analysis. Pembrolizumab provided durable antitumor activity and an acceptable safety profile in Japanese patients with advanced melanoma.

Safety and effectiveness of avelumab in patients with Merkel cell carcinoma in general clinical practice in Japan: Post-marketing surveillance

Avelumab, a programmed cell death ligand 1 blocking antibody, was approved for its first indication in Japan in September 2017 to treat unresectable Merkel cell carcinoma (MCC). Given that the pivotal JAVELIN Merkel 200 study only included a few Japanese patients, this post-marketing surveillance (PMS) evaluated the safety and effectiveness outcomes of patients with MCC who received avelumab in general clinical practice in Japan. This prospective, non-comparative, multicenter PMS included data from all patients with unresectable MCC who received avelumab between November 22, 2017 (avelumab launch date) and October 31, 2019. The primary objective was to evaluate avelumab safety (i.e., adverse events [AEs], adverse drug reactions [ADRs], and ADRs of safety specifications). The secondary objective was to evaluate avelumab effectiveness (i.e., objective response rate and overall survival [OS] rate). Seventy-five evaluable patients were included, of whom 81.3% experienced AEs of any grade (57.3% experienced AEs of grade ≥ 3; 41.3% experienced AEs of grade 5) and 61.3% experienced ADRs (14.7% experienced ADRs of grade ≥ 3; no grade 5 ADRs were observed). The most common ADRs were pyrexia (18.7%), infusion related reaction (10.7%), and chills (6.7%). The most common ADRs of safety specifications were infusion reactions (any grade: n = 21 [28.0%]; grade 3 or 4: n = 3 [4.0%]), thyroid dysfunction (n = 7 [9.3%]), and hepatic function disorders (n = 4 [5.3%]). The median observation period was 51 weeks. An objective response was achieved by 34/75 patients (45.3%; complete response, 24.0%; partial response, 21.3%) and 6- and 12-month OS rates were 77.7% and 59.6%, respectively. This PMS confirmed the clinical tolerability and effectiveness of avelumab in patients with MCC, with no new safety concerns. The risk-benefit profile of avelumab was comparable with that observed in clinical trials and remains favorable for use in general clinical practice in Japan.

Effects of temozolomide on tumor mutation burden and microsatellite instability in melanoma cells

The efficacy of combination therapy with an immune checkpoint inhibitor (ICI) and cytotoxic chemotherapeutic agents has been investigated in cancer, including melanoma. Before ICIs were introduced, dacarbazine or temozolomide (TMZ) were used to treat melanoma. Several studies using glioma or colorectal cancer cells showed that TMZ can increase the tumor mutation burden (TMB) and induce mismatch repair (MMR) deficiency associated with microsatellite instability (MSI). These could increase immunoreactivity to an ICI, but this has not been evaluated in melanoma cells. We investigated the effects of TMZ on MSI status and TMB in melanoma cells. To evaluate the TMB, we performed whole-exome sequencing using genomic DNA from the human melanoma cell lines Mel18, A375, WM266-4, G361, and TXM18 before and after TMZ treatment. Polymerase chain reaction amplification of five mononucleotide repeat markers, BAT25, BAT26, NR21, NR24, and MONO27, was performed, and we analyzed changes in the MSI status. In all cell lines, the TMB was increased after TMZ treatment (the change amount of TMB with ≤ 5% variant allele frequency [VAF] was 18.0-38.3 mutations per megabase) even in the condition without obvious cytological damage. MSI after TMZ treatment was not observed in any cells. TMZ increased TMB but did not change MSI status in melanoma cells.

Significant and Various Effects of ML329-Induced MITF Suppression in the Melanoma Cell Line

To study the inhibitory effects on microphthalmia-associated transcription factor (MITF)-related biological aspects in malignant melanomas (MMs) in the presence or absence of the low-molecular MITF specific inhibitor ML329, cell viability, cellular metabolic functions, and three-dimensional (3D) spheroid formation efficacy were compared among MM cell lines including SK-mel-24, A375, dabrafenib- and trametinib-resistant A375 (A375DT), and WM266-4. Upon exposure to 2 or 10 μM of ML329, cell viability was significantly decreased in WM266-4, SK-mel-24, and A375DT cells, but not A375 cells, in a dose-dependent manner, and these toxic effects of ML329 were most evident in WM266-4 cells. Extracellular flux assays conducted using a Seahorse bioanalyzer revealed that treatment with ML329 increased basal respiration, ATP-linked respiration, proton leakage, and non-mitochondrial respiration in WM266-4 cells and decreased glycolytic function in SK-mel-24 cells, whereas there were no marked effects of ML329 on A375 and A375DT cells. A glycolytic stress assay under conditions of high glucose concentrations also demonstrated that the inhibitory effect of ML329 on the glycolytic function of WM266-4 cells was dose-dependent. In addition, ML329 significantly decreased 3D-spheroid-forming ability, though the effects of ML329 were variable among the MM cell lines. Furthermore, the mRNA expression levels of selected genes, including STAT3 as a possible regulator of 3D spheroid formation, KRAS and SOX2 as oncogenic-signaling-related factors, PCG1a as the main regulator of mitochondrial biogenesis, and HIF1a as a major hypoxia transcriptional regulator, fluctuated among the MM cell lines, possibly supporting the diverse ML329 effects mentioned above. The findings of diverse ML329 effects on various MM cell lines suggest that MITF-associated biological activities are different among various types of MM.

Pemphigus vulgaris as an immune-related adverse event in recurrent metastatic esophageal squamous cell carcinoma treated with ipilimumab plus nivolumab: a case report and literature review

Ipilimumab plus nivolumab therapy is approved for patients with unresectable advanced esophageal squamous cell carcinoma (ESCC). Although a combination of immune checkpoint inhibitors (ICIs), compared to conventional chemotherapy, can improve overall survival in patients with advanced ESCC, this increases the incidence of immune-related adverse events (irAEs). Here, we describe an ESCC case that developed pemphigus vulgaris (PV), an extremely rare cutaneous irAE, during ipilimumab plus nivolumab treatment. The patient achieved a partial response to treatment. The PV was successfully managed after the cessation of ipilimumab and the use of a topical steroid. We should thus re-treat ESCC with nivolumab monotherapy. In the era of ICIs as standard cancer therapeutics, diagnostic criteria for blistering diseases need to be established to properly manage patients with cutaneous irAEs.

Systemic therapy for Asian patients with advanced BRAF V600-mutant melanoma in a real-world setting: A multi-center retrospective study in Japan (B-CHECK-RWD study)

BACKGROUND

Anti-PD-1-based immunotherapy is considered a preferred first-line treatment for advanced BRAF V600-mutant melanoma. However, a recent international multi-center study suggested that the efficacy of immunotherapy is poorer in Asian patients in the non-acral cutaneous subtype. We hypothesized that the optimal first-line treatment for Asian patients may be different.

METHODS

We retrospectively collected data of Asian patients with advanced BRAF V600-mutant melanoma treated with first-line BRAF/MEK inhibitors (BRAF/MEKi), anti-PD-1 monotherapy (Anti-PD-1), and nivolumab plus ipilimumab (PD-1/CTLA-4) between 2016 and 2021 from 28 institutions in Japan.

RESULTS

We identified 336 patients treated with BRAF/MEKi (n = 236), Anti-PD-1 (n = 64) and PD-1/CTLA-4 (n = 36). The median follow-up duration was 19.9 months for all patients and 28.6 months for the 184 pa tients who were alive at their last follow-up. For patients treated with BRAF/MEKi, anti-PD-1, PD-1/CTLA-4, the median ages at baseline were 62, 62, and 53 years (p = 0.03); objective response rates were 69%, 27%, and 28% (p < 0.001); median progression-free survival (PFS) was 14.7, 5.4, and 5.8 months (p = 0.003), and median overall survival (OS) was 34.6, 37.0 months, and not reached, respectively (p = 0.535). In multivariable analysis, hazard ratios (HRs) for PFS of Anti-PD-1 and PD-1/CTLA-4 compared with BRAF/MEKi were 2.30 (p < 0.001) and 1.38 (p = 0.147), and for OS, HRs were 1.37 (p = 0.111) and 0.56 (p = 0.075), respectively. In propensity-score matching, BRAF/MEKi showed a tendency for longer PFS and equivalent OS with PD-1/CTLA-4 (HRs for PD-1/CTLA-4 were 1.78 [p = 0.149]) and 1.03 [p = 0.953], respectively). For patients who received second-line treatment, BRAF/MEKi followed by PD-1/CTLA-4 showed poor survival outcomes.

CONCLUSIONS

The superiority of PD-1/CTLA-4 over BRAF/MEKi appears modest in Asian patients. First-line BRAF/MEKi remains feasible, but it is difficult to salvage at progression. Ethnicity should be considered when selecting systemic therapies until personalized biomarkers are available in daily practice. Further studies are needed to establish the optimal treatment sequence for Asian patients.

Postmarketing surveillance of nivolumab plus ipilimumab combination therapy in Japanese patients with unresectable malignant melanoma

Although malignant melanoma is relatively rare in Japan, it is often diagnosed at a later stage than in Western countries. Nivolumab and ipilimumab are immune checkpoint inhibitors targeting programmed death 1 and cytotoxic T-lymphocyte-associated protein 4, respectively. Owing to their complementary anticancer effects, nivolumab and ipilimumab combination therapy (N + I) has been studied and approved for treating malignant melanoma in various countries including Japan. Real-world postmarketing surveillance was implemented to record treatment-related adverse events (TRAEs) in patients treated with N + I following its approval in Japan. Patients were eligible for registration if they had unresectable malignant melanoma and started N + I between September 2018 and August 2019. The observation period was 13 weeks from starting N + I. Only safety information was collected and evaluated. The final case report form lock was March 2021. Overall, 173 patients (median age, 66.0 years; performance status 0-1, 88.4%; skin: 53.2%; mucosal: 32.4%) were eligible for the analyses. Overall, 34.1% of patients completed 4 doses of N + I. N + I was discontinued by 63.0% (due to adverse events in 67.9% and disease progression/death in 22.9%). Any grade and grade ≥3 TRAEs were reported in 73.41% and 52.02%, respectively. TRAEs in ≥10 patients were hepatic function abnormal (any grade/grade ≥3: 23.12%/13.29%), pyrexia (10.40%/0.58%), diarrhea (9.25%/2.89%), rash (8.67%/0.58%), hypophysitis (5.78%/5.20%), interstitial lung disease (5.78%/2.89%), and liver disorder (5.78%/4.62%). TRAEs were classified as recovered (36.99% of patients), recovering (44.51%), unrecovered (13.29%), recovered with sequelae (2.31%), and death (1.73%). Overall, 24 of 34 patients (70.59%) with gastrointestinal-related and 53 of 65 (81.54%) liver-related TRAEs received treatment, such as a steroid with/without an immunosuppressant; most patients recovered within 1 to 2 months. In conclusion, this postmarketing surveillance of N + I in patients with unresectable malignant melanoma revealed no new safety concerns compared with results of prior studies. Immune-related TRAEs were generally manageable by appropriate treatment including a steroid.

Fusion with type 2 macrophages induces melanoma cell heterogeneity that potentiates immunological escape from cytotoxic T lymphocytes

Evasion from immunity is a major obstacle to the achievement of successful cancer immunotherapy. Hybrids derived from cell-cell fusion are theoretically associated with tumor heterogeneity and progression by conferring novel properties on tumor cells, including drug resistance and metastatic capacity; however, their impact on immune evasion remains unknown. Here, we investigated the potency of tumor-macrophage hybrids in immune evasion. Hybrids were established by co-culture of a melanoma cell line (A375 cells) and type 2 macrophages. The hybrids showed greater migration ability and greater tumorigenicity than the parental melanoma cells. The hybrids showed heterogeneous sensitivity to New York esophageal squamous cell carcinoma-1 (NY-ESO-1)-specific T-cell receptor-transduced T (TCR-T) cells and two out of four hybrid clones showed less sensitivity to TCR-T compared with the parental cells. An in vitro tumor heterogeneity model revealed that the TCR-T cells preferentially killed the parental cells compared with the hybrids and the survival rate of the hybrids was higher than that of the parental cells, indicating that the hybrids evade killing by TCR-T cells efficiently. Analysis of a single-cell RNA sequencing dataset of patients with melanoma revealed that a few macrophages expressed RNA encoding melanoma differentiation antigens including melan A, tyrosinase, and premelanosome protein, which indicated the presence of hybrids in primary melanoma. In addition, the number of potential hybrids was correlated with a poorer response to immune checkpoint blockade. These results provide evidence that melanoma-macrophage fusion has a role in tumor heterogeneity and immune evasion. © 2023 The Pathological Society of Great Britain and Ireland.

SOX10 Inhibits T Cell Recognition by Inducing Expression of the Immune Checkpoint Molecule PD-L1 in A375 Melanoma Cells

BACKGROUND/AIM

Malignant melanoma is a fatal skin cancer and is among the most immunogenic malignancies expressing melanoma-differentiation antigens and neoantigens. SRY-related HMG-box 10 (SOX10) is a transcription factor and a neural-crest differentiation marker that is used as a diagnostic marker for melanoma whilst playing a role in melanoma initiation through activation of the SOX10-MITF axis. SOX10 was shown to play a role in melanoma initiation by inducing expression of immune checkpoint molecules (e.g., HVEM and CEACAM1). In this study, we aimed to investigate the relationship between SOX10 and the expression an immune checkpoint molecule, programmed death-1 ligand 1 (PD-L1).

MATERIALS AND METHODS

SOX10 overexpression and knockdown was performed using SOX10 gene transfection and SOX10 siRNA transfection into A375 melanoma cells. PD-L1 expression was assessed by flow cytometry and western blotting. T cell response was evaluated using NY-ESO-1 specific TCR-transduced T (TCR-T) cells by IFNγ ELISPOT assay.

RESULTS

SOX10 overexpression increased the expression of PD-L1, whereas SOX10 knockdown, using siRNA, decreased its expression. IFNγ ELISPOT assay revealed that overexpression of SOX10 decreased the susceptibility of cells to NY-ESO-1-specific TCR-T cells.

CONCLUSION

SOX10 has a role in the intrinsic immune suppressive mechanisms of melanoma through expression of PD-L1.

Novel STAT1 Variants in Japanese Patients with Isolated Mendelian Susceptibility to Mycobacterial Diseases

PURPOSE

Heterozygous dominant-negative (DN) STAT1 variants are responsible for autosomal dominant (AD) Mendelian susceptibility to mycobacterial disease (MSMD). In this paper, we describe eight MSMD cases from four kindreds in Japan.

METHODS

An inborn error of immunity-related gene panel sequencing was performed using genomic DNA extracted from whole blood samples. The identified variants were validated using Sanger sequencing. Functional analysis was evaluated with a luciferase reporter assay and co-transfection assay in STAT1-deficient cells.

RESULTS

Patient 1.1 was a 20-month-old boy with multifocal osteomyelitis and paravertebral abscesses caused by Mycobacterium bovis bacillus Calmette-Guérin (BCG). Although the paravertebral abscess was refractory to antimycobacterial drugs, the addition of IFN-γ and drainage of the abscess were effective. Intriguingly, his mother (patient 1.2) showed an uneventful clinical course except for treatment-responsive tuberculous spondylitis during adulthood. Patient 2.1 was an 8-month-old boy with lymphadenopathy and lung nodules caused by BCG. He responded well to antimycobacterial drugs. His mother (patient 2.2) was healthy. Patient 3.1 was a 11-year-old girl with suspected skin tuberculosis. Her brother (patient 3.2) had BCG-osis, but their mother (patient 3.3) was healthy. Patient 4 was an 8-month-old girl with left axillary and supraclavicular lymphadenopathy associated with BCG vaccination. Kindreds 1, 2, and 3 were shown to have novel heterozygous variants (V642F, R588C, and R649G) in STAT1, respectively. Kindred 4 had previously reported heterozygous variants (Q463H). A luciferase reporter assay in STAT1-deficient cells followed by IFN-γ stimulation confirmed that these variants are loss-of-function. In addition, with co-transfection assay, we confirmed all of these variants had DN effect on WT STAT1.

CONCLUSION

Four kindred MSMD subjects with 3 novel variants and 1 known variant in STAT1 were identified in this study. AD STAT1 deficiency might be prevalent in Japanese patients with BCG-associated MSMD.

Bacillus Calmette-Guérin-induced lupus vulgaris in a patient with Mendelian susceptibility to mycobacterial disease caused by a novel STAT1 variation

We reported a case of BCG vaccination-induced lupus vulgaris in an 11-year-old girl with Mendelian susceptibility to mycobacterial disease (MSMD) due to a novel STAT1 gene variation. The dermatologists should suspect MSMD in patients with cutaneous tuberculosis after BCG vaccination. It prevents both the patients and the family members with inborn errors of immunity from receiving inadequate vaccines.

Functional Interplay between IL-9 and Peptide YY Contributes to Chronic Skin Inflammation

Complex interactions between keratinocytes and various cell types, such as inflammatory cells and stromal cells, contribute to the pathogenesis of chronic inflammatory skin lesions. In proinflammatory cytokine‒mediated disease settings, IL-9 plays a pathological role in inflammatory dermatitis. However, IL-9‒related mechanisms remain incompletely understood. In this study, we established tamoxifen-induced keratinocyte-specific IL-9RA-deficient mice (K14^CRE/ERTIl9ra^Δ/Δ mice) to examine the role of IL-9 in multicellular interactions under chronic skin inflammatory conditions. Studies using an imiquimod-induced psoriasis-like model showed that K14^CRE/ERTIl9ra^Δ/Δ mice exhibited a significantly reduced severity of dermatitis and mast cell infiltration compared with control K14^WTIl9ra^fl/fl mice. Transcriptome analyses of psoriasis-like lesions showed that the level of peptide Y-Y (Pyy), a member of the neuropeptide Y family, was markedly downregulated in K14^CRE/ERTIl9ra^Δ/Δ epidermis. Pyy blockade suppressed epidermal thickening and mast cell numbers in imiquimod-treated wild-type mice. Together with in vitro studies indicating that Pyy induced IL-9 production and chemotactic activity in bone marrow‒derived mast cells, these findings suggest that Pyy-mediated interplay between keratinocytes and mast cells contributes to psoriasiform inflammation. Further investigation focusing on the IL-9‒Pyy axis may provide valuable information for the development of new treatment modalities for inflammatory dermatitis.

A rare case of pyoderma gangrenosum occurring at the site of laparoscopic port following laparoscopic radical nephrectomy

Introduction

Pyoderma gangrenosum is a rare dermatological disease associated with underlying inflammatory conditions.

Case presentation

A 59‐year‐old man was diagnosed with right renal cancer cT1aN0M0 and laparoscopic right radical nephrectomy was performed. Five days after surgery, he had a high‐grade fever, surgical site flare, and severe pain. At first, we diagnosed surgical site infection and wound dehiscence. Despite treatment for infection, his general condition and dermatological symptoms did not improve. Thereafter, a dermatologist advised us to perform a skin biopsy and blood culture examinations. Finally, the man was diagnosed with pyoderma gangrenosum according to the pathology of the skin biopsy and negative blood culture. After both intravenous administration of predonisolone and a topical corticosteroid, the high‐grade fever and dermatological symptoms improved greatly.

Conclusion

Although pyoderma gangrenosum is a rare disease, we should bear in mind the disease since the treatment strategy is completely different from that for surgical site infection.

Safety and effectiveness of nivolumab in Japanese patients with malignant melanoma: Final analysis of a post-marketing surveillance

Nivolumab, a monoclonal antibody against human programmed death 1, was approved for the treatment of melanoma in July 2014 in Japan. Because the Japanese phase II studies (ONO-4538-02, ONO-4538-08) enrolled small numbers of melanoma patients, post-marketing surveillance (PMS; JapicCTI-163 272) was conducted to collect safety data in a larger patient population. We report data for melanoma patients who received nivolumab between July 4, 2014 and February 28, 2017. Data collected included baseline characteristics, laboratory tests, treatment-related adverse events (TRAE), and overall survival (OS). Of 2069 enrolled patients, 2008 patients were included in the safety analysis population. There were 1030 (51.3%) males, the median age was 69 years, and 269 patients (13.4%) had a performance status of ≥2. The primary tumor sites were cutaneous (34.4%), mucosal (34.2%), acral lentiginous (18.6%), others (6.8%), and unknown (6.3%). TRAE occurred in 62.1% of patients, the most common being hypothyroidism (14.0%), increased aspartate aminotransferase (8.5%), and increased alanine aminotransferase (6.9%). TRAE of special interest in ≥5% of patients were thyroid dysfunction (24.9%), hepatic dysfunction (20.6%), infusion reactions (11.4%), colitis/severe diarrhea (6.3%), and interstitial lung disease (ILD; 5.0%). Several types of TRAE of special interest, which included myasthenia gravis/myocarditis/myositis/rhabdomyolysis (0.9%), venous thromboembolism (0.2%), immune thrombocytopenic purpura (0.1%), and encephalitis (0.0%), were observed in this PMS. Although these TRAE were not reported in previous studies (ONO-4538-02, ONO-4538-08, CheckMate 066, and CheckMate 037), they have been listed in the current Risk Management Plan. History of ILD and male sex were risk factors for ILD in a multivariable analysis. Age <75 years was a risk factor for hepatic dysfunction. At 12 months, median OS was not reached. In conclusion, these results suggested that there was no concern requiring additional precautions for the safety of nivolumab in Japanese patients with melanoma other than the safety information in the Risk Management Plan.

Clinical history analysis of Japanese melanoma cases and characteristics of melanoma with childhood onset

It remains debatable whether melanoma with a clinical history of early childhood onset truly arises from a nevus. To clarify the clinical and genetic characteristics of melanoma detected at birth or several years afterwards, 249 melanoma cases seen at Shinshu University Hospital between 2006 and 2015 were retrospectively analyzed. Ten (4.0%) cases (median age 39.5 years, range 19-70 years; male/female 2/8; lesion site, 6 extremities, 2 trunk, 1 head, 1 face; cumulative sun damage [CSD] skin, 9 low-CSD, 1 high-CSD; detection at birth 3) had recorded early childhood onset. Median Breslow's tumor thickness in those cases was 6.0 mm (range: 0.4-17.5 mm). The frequency of lesions detected at <20 years of age was significantly higher for low-CSD melanoma (17.5%) than for high-CSD (3.3%) and acral (0.8%) melanoma. Although melanoma with a history of early childhood onset is rare, the characteristics of such cases should be established since most have progressed to an advanced stage at the initial visit.

Difference in immunohistochemical findings among anti-PD-L1 antibodies and their relationships with CD4+ and CD8+ T cells in Japanese melanoma patients

BACKGROUND

The immunohistochemical evaluation of programmed death ligand 1 (PD-L1) is important for selecting treatments. Several antibodies are available for such evaluations, but data regarding the differences in the antibodies' positivity are limited in melanoma, particularly the acral and mucosal types. We investigated the differences in melanoma tissues' PD-L1 expression among the commonly used PD-L1 antibodies and then evaluated the relationship between PD-L1+ tumor cells and tumor-infiltrating lymphocytes (TILs).

PATIENTS AND METHODS

We examined 56 primary lesions and 8 metastatic lymph node samples from 56 Japanese patients with melanoma (28 acral melanoma, 8 mucosal melanoma, 18 cutaneous melanoma, 2 unknown). Immunohistochemical staining was performed using three primary antibodies against PD-L1 (E1L3N, SP142, and 28-8). PD-L1-positive staining in tumor cells was defined as ≥ 1% expression.

RESULTS

The positive rates were 25.0% for 28-8, 34.0% for E1L3N, and 34.0% for SP142 in 64 samples. The positive rates of acral melanoma were 10.7% for 28-8, 21.4% for E1L3N, and 21.4% for SP142. The positive rate of mucosal melanoma for which all three antibodies reacted was 12.5%. The positive rates of cutaneous melanoma were 55.6% for 28-8, 66.7% for E1L3N, and 66.7% for SP142. Significant relationships were observed among the PD-L1+ tumor cells, CD4+ TILs, and CD8+ TILs (p < 0.001).

CONCLUSION

The staining results by E1L3N, SP142, and 28-8 antibodies were within the allowable range, although the positive rates by E1L3N and P142 were slightly higher than that of 28-8. CD4+ TILs and CD8+ TILs were quantitatively correlated with PD-L1-positive tumor cells.

Safety and effectiveness of avelumab in patients with curatively unresectable merkel cell carcinoma (MCC) in a real-world setting: A post-marketing surveillance in Japan

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Background: Avelumab is an anti–PD-L1 monoclonal antibody that was approved in Japan for the treatment of patients with curatively unresectable MCC in Sept 2017. Because the number of Japanese patients with MCC participating in the global Phase II JAVELIN Merkel 200 study was limited (3 patients), Japan was mandated to conduct an all-case surveillance as a post-marketing surveillance (PMS) study. In the all-case surveillance, safety and efficacy information is accumulated with respect to a defined period of time or a defined number of post-approval prescription cases and is provided as real-world data. This report summarizes the results of the final analysis of this MCC PMS. Methods: This PMS is a multicenter, non-comparative, prospective, observational study. Since Nov 2017 (following approval in Japan), all patients with MCC who received at least one dose of avelumab in Japan were enrolled, and case report forms (CRF) were collected for all patients who started treatment through Oct 2019. Results: As of Sept 22, 2021, 152 patients from 86 sites were enrolled, and CRFs were collected from 77 patients. Of the 75 patients (53 sites) who met the analysis adequacy criteria, 48% were female, and the median age at the start of avelumab treatment was 77.0 years (42-95 years). Of the treatment lines in which avelumab was administered, 93.3% (70/75) were prescribed as first-line therapy. The incidence of adverse reactions was 61.3% (46/75), and 9.3% (7/75) discontinued treatment due to adverse reactions. Grade 3 and 4 adverse reactions occurred in 12.0% (9/75) and 4.0% (3/75), respectively; no grade 5 adverse reactions were reported. Infusion reactions were reported in 28.0% (21/75). The objective response rate (proportion of patients whose best response was assessed by the investigator as a complete or partial response) up to 1 year after the start of avelumab treatment was 45.3% (95% CI: 33.8, 57.3). The 1-year overall survival rate was 59.6% (95% CI: 47.0, 70.1). Conclusions: This study report is the first real-world evidence collected and analyzed from actual clinical use of avelumab in patients with curatively unresectable MCC in the East Asia region. Despite the different baseline patient characteristics, avelumab therapy in clinical practice had a manageable safety profile with no new safety concerns and has shown similar efficacy to that observed in the JAVELIN Merkel 200 trial.

Real-world outcomes of Asian patients with advanced BRAF-mutant melanoma treated with first-line BRAF/MEK inhibitors, anti-PD-1 monotherapy, or combination of nivolumab plus ipilimumab: A multicenter retrospective study in Japan (B-CHECK-RWD study)

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Background: The systemic treatment for advanced BRAF-mutant melanoma includes BRAF/MEK inhibitors (BRAF/MEKi), anti-PD-1 monotherapy (aPD1), and the combination of nivolumab plus ipilimumab (NIVO/IPI). Several studies have demonstrated favorable survival benefits for those treated with immunotherapy upfront. Most of these studies, however, were conducted among Caucasian-dominant cohorts; evidence for Asian patients is limited. Therefore, our objective was to assess the efficacy of first-line therapies for Asian patients in a real-world setting. Methods: We retrospectively collected the clinical data of Asian patients with advanced BRAF-mutant melanoma treated with first-line BRAF/MEKi, aPD1, or NIVO/IPI from 26 institutions in Japan. Clinical outcomes were determined by assessing the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) by first-line therapies. Kaplan‐Meier curves and log‐rank tests, as well as multivariable Cox proportional hazard models were used to estimate survival probabilities. Results: We identified 316 Asian patients treated with first-line BRAF/MEKi (n = 224), aPD1 (n = 59), or NIVO/IPI (n = 33) between 2016 and 2021. At baseline, the median age of the patients in each treatment arm was 63, 62, and 54, respectively (p = 0.053). The ORR in the first-line therapy was 69%, 29%, and 27%, respectively (p < 0.001). With a median follow-up of 18.9 months, the median PFS was 16.2, 5.6, and 6.4 months (p = 0.001); and the median OS was 36.9, 37.9 months, and not reached (p = 0.386), respectively. In a multivariable analysis, the predictive factors of short PFS were first-line therapy with aPD1 (HR, 2.44; 95%CI, 1.70-3.50, p < 0.001) or NIVO/IPI (1.73; 1.06–2.83, p = 0.029), BRAF V600K (p = 0.031), ECOG PS ≥2 (p = 0.011), elevated lactate dehydrogenase (LDH) levels (p = 0.001), and M1a/M1c/M1d stages (p = 0.036/ < 0.001/ < 0.001, respectively). Predictive factors of short OS were BRAF V600K (p = 0.042), ECOG PS ≥2 (p = 0.001), elevated LDH levels (p < 0.001), and M1c/M1d stages (both p < 0.001). The OS did not differ significantly by first-line therapies between BRAF/MEKi, aPD1 (1.52; 0.98–2.34, p = 0.061), and NIVO/IPI (0.63; 0.31–1.27, p = 0.194). Conclusions: Although upfront NIVO/IPI showed the longest OS numerically, its superiority over BRAF/MEKi in Asian patients seems to be modest compared with Caucasian patients. Because upfront BRAF/MEKi showed an OS that was comparable with that of aPD1, BRAF/MEKi remains an active first-line therapy option, especially for those who are not amenable to take the high risk of immune-related toxicities.

Concordance in judgment of clinical borders of basal cell carcinomas in Japanese patients: A preliminary study of JCOG2005 (J-BASE-MARGIN)

Basal cell carcinoma is the most common type of skin cancer, and surgical excision with clear margins is the standard of care. Surgical margins are determined based on risk factors (high or low risk) for recurrence according to the National Comprehensive Cancer Network and Japanese basal cell carcinoma guidelines. The clarity of the clinical tumor border (well-defined or poorly defined) is considered a risk factor, and significant discrepancies in the judgment of clinical tumor borders among dermato-oncologists may occur. Therefore, we analyzed the dermato-oncologists' concordance in judging the clinical tumor border of basal cell carcinoma. Forty-seven dermato-oncologists (experts: 37; young trainees: 10) participated in this study. The datasets of clinical and dermoscopic photographs of 79 Japanese cases of head and neck basal cell carcinoma were used to determine the concordance in the judgment of clinical tumor border. The probability of the border that was selected more often was used to calculate the rater agreement rate for each dataset. Correct judgment was defined as a more frequently selected border, and the concordance rate of clarity of clinical tumor border for each dermato-oncologist was calculated based on the definition of the correct judgment. A median concordance rate of 85% or higher for all dermato-oncologists was predefined as an acceptable rate for clinical use. Of the 79 datasets, rater agreement rates were 80-100%, 60-79%, and 51-59% for 55, 19, and five datasets, respectively. The median concordance rate for all dermato-oncologists was 86% (interquartile range: 82-89%). There was no significant difference in the concordance rate between the experts and the trainees (median, 87% vs. 85.5%; p = 0.58). The concordance rates of dermato-oncologists for all datasets were relatively high and acceptable for clinical use.

Stem cell spreading dynamics intrinsically differentiate acral melanomas from nevi

Early differential diagnosis between malignant and benign tumors and their underlying intrinsic differences are the most critical issues for life-threatening cancers. To study whether human acral melanomas, deadly cancers that occur on non-hair-bearing skin, have distinct origins that underlie their invasive capability, we develop fate-tracing technologies of melanocyte stem cells in sweat glands (glandular McSCs) and in melanoma models in mice and compare the cellular dynamics with human melanoma. Herein, we report that glandular McSCs self-renew to expand their migratory progeny in response to genotoxic stress and trauma to generate invasive melanomas in mice that mimic human acral melanomas. The analysis of melanocytic lesions in human volar skin reveals that genetically unstable McSCs expand in sweat glands and in the surrounding epidermis in melanomas but not in nevi. The detection of such cell spreading dynamics provides an innovative method for an early differential diagnosis of acral melanomas from nevi.

Cigarette Smoke Underlies the Pathogenesis of Palmoplantar Pustulosis via an IL-17A-Induced Production of IL-36γ in Tonsillar Epithelial Cells

Palmoplantar pustulosis (PPP) is characterized by sterile pustules on the palms and soles. A strong association between PPP and tobacco smoking has been reported, and it has been speculated that the IL-17A pathway may play an important role in PPP. Recent studies have suggested that IL-36 plays a pivotal role in the pathogenesis of psoriasis and its subtypes. The relationships among IL-36, smoking, and PPP have not been examined. Here, we investigated the relationships among the smoking index, severity of the clinical condition of PPP, and in vitro dynamics of IL-36 in human tonsillar epithelial cells under the condition of exposure to a cigarette smoke extract. The results demonstrated that the Palmoplantar Pustulosis Area and Severity Index was strongly and positively correlated with the smoking index in female patients. Immunohistochemical examinations showed that IL-36γ was highly expressed in tonsillar epithelial cells from patients with PPP but not in those from patients with recurrent tonsillitis without PPP. The in vitro study revealed that IL-17A synergistically induced a release of IL-36γ under cigarette smoke extract exposure. These results suggest that local production of IL-36γ by epithelial cells induced by cigarette smoke exposure plays an important role in the pathogenesis of PPP.

Genetic analyses of a secondary poroma and trichoblastoma in a HRAS-mutated sebaceous nevus

A sebaceous nevus is a congenital skin hamartoma caused by postzygotic HRAS or KRAS mosaic mutations. With age, affected individuals may develop secondary tumors within a sebaceous nevus. RAS mutations are harbored from the onset of sebaceous nevus, and further mutations can be expected to be required in order to explain the initiation of secondary tumors. However, genetic analyses of the secondary tumors have not been conducted. Herein, we describe the rare coexistence of a poroma and a trichoblastoma arising in a sebaceous nevus. This is the first report of an investigation of multiple genes in a secondary tumor in an SN. First, HRAS c.37G>C, which is the common mutation in sebaceous nevus, was detected in all three lesions (sebaceous nevus, poroma, and trichoblastoma). Next, to elucidate the potential second-hit mutations in the secondary poroma and trichoblastoma, we applied a panel sequencing for skin cancers that was newly developed in our institution. Our comparison of the mutational profile of 95 skin cancer-related genes in each of the three lesions newly revealed TP53 p.R158P in the poroma and NOTCH2 p.G329S in the trichoblastoma. TP53 p.R158P has been determined as a pathogenic mutation in other tumors, and NOTCH2 p.G329S was a novel mutation. We identified two novel mutations that may have contributed to the pathogenesis of the secondary tumor's development. The roles of the mutations remain unclear.

IL-13 modulates ∆Np63 levels causing altered expression of barrier- and inflammation-related molecules in human keratinocytes: A possible explanation for chronicity of atopic dermatitis

BACKGROUND

Barrier disruption and an excessive immune response in keratinocytes are now considered to have important roles in the pathophysiology of atopic dermatitis (AD). Furthermore, disturbed keratinocyte differentiation is considered to underlie AD. ΔNp63, a p53-like transcription factor, is a major regulator of keratinocyte differentiation. However, the functional significance of ΔNp63 in AD has not been clarified.

OBJECTIVE

In this study, we aimed to investigate the influence of the type 2 inflammatory environment on ΔNp63 expression and AD-associated molecules regulated by ΔNp63 in keratinocytes.

METHODS

The immunohistochemical expression profiles of ΔNp63 and AD-related molecules were evaluated in human skin tissue. The function of ΔNp63 in the regulation of AD-related molecules and the influence of the type 2 inflammatory environment on ΔNp63 expression were investigated using human primary keratinocytes. Expression of ΔNp63 was manipulated using the RNA interfering method.

RESULTS

In healthy skin tissue, we observed an inverse expression pattern between ∆Np63 and some barrier-related proteins including filaggrin, caspase-14, claudin-1, and claudin-4. ΔNp63 regulated expression of these genes and proteins. In addition, production of IL-1β and IL-33, pro-inflammatory cytokines, was modulated by ΔNp63. Furthermore, prolonged IL-13 exposure increased the thickness of the three-dimensional culture of keratinocytes. IL-13 interfered with ΔNp63 downregulation during calcium-induced keratinocyte differentiation. IL-13 modulated some barrier-related and inflammation-related molecules, which were regulated by ΔNp63.

CONCLUSIONS

We have shown that ΔNp63 modulated AD-related barrier and inflammatory molecules. In addition, ΔNp63 expression was affected by IL-4/IL-13. IL-13-ΔNp63 axis would integrate two major factors of AD pathogenesis: dysregulated barrier and inflammation.

Five-year survival with nivolumab in previously untreated Japanese patients with advanced or recurrent malignant melanoma

We report the 5‐year follow‐up results from a single‐arm, open‐label, multicenter phase II study (ONO‐4538‐08) conducted in Japan. Twenty‐four patients with treatment‐naïve, recurrent, or unresectable stage III/IV malignant melanoma received 3 mg/kg nivolumab every 2 weeks until progressive disease or unacceptable toxicity occurred. The 5‐year overall survival (OS) rate was 26.1%. Five years after the start of nivolumab treatment, there were six survivors. The 5‐year OS rate was 66.7% for patients with a superficial spreading type, 14.3% for acral lentiginous type, and 16.7% for mucosal type. The 5‐year progression‐free survival rate was 17.2%. No new cases of partial response or complete response were observed after 3 years, and overall response and disease control rates were similar to those reported at 3 years. The treatment‐related adverse events reported between the 3‐ and 5‐year follow‐up periods were anemia (grade 2), white blood cell count decrease (grade 2), and psoriasiform dermatitis (grade 2) in one patient each. No new grade 3 or higher treatment‐related adverse events occurred in this period. In conclusion, first‐line treatment with nivolumab in Japanese patients with unresectable or metastatic melanoma resulted in confirmed long‐term survival. No new safety signals were reported in the studied population.

Immunotherapy for advanced melanoma: current situation in Japan

Treatment with immune checkpoint inhibitors provides long-term survival for patients with advanced melanoma. Improvements in the overall survival of advanced melanoma patients have been achieved with anti-PD-1 monotherapy and anti-PD-1+ CTLA4 combination therapy, but there are still many issues to resolve. Acral, mucosal and uveal melanoma have been less responsive to immune checkpoint inhibitors than cutaneous melanoma. For patients who have achieved a good response, it is still not known how long the anti-PD-1 therapy should be administered. Moreover, there is limited treatment for patients who relapse during or after adjuvant anti-PD-1 therapy. Here, we review the current evidence regarding the clinical effects of immunotherapy for advanced melanoma. Moreover, we review previous studies of acral, mucosal and uveal melanoma, and we discuss the recent findings regarding durable response after the cessation of anti-PD-1 therapy, and treatment options for recurrence after adjuvant therapy.