Genomic landscape of circulating tumour DNA in metastatic extramammary Paget's disease.

Although cancer personalized profiling by deep sequencing (CAPP-Seq) of cell-free DNA (cfDNA) has gained attention, the clinical utility of circulating tumour DNA (ctDNA) in extramammary Paget's disease (EMPD) has not been investigated. In this study, genomic alterations in the cfDNA and tumour tissue DNA were investigated in seven patients with metastatic EMPD. CAPP-Seq revealed mutations in 18 genes, 11 of which have not yet been reported in EMPD. The variant allele frequency of some of the mutated genes reflected the disease course in patients with EMPD. In one patient, the mutation was detected even though imaging findings revealed no metastasis. In another patient with triple EMPD (genital area and both axilla), cfDNA sequencing detected the mutation in a rib metastatic lesion, which was also detected in both axilla lesions but not the genital region. Investigations of the ctDNA may be useful towards the elucidation of clonal evolution in EMPD.

Overexpression of Janus kinase 2 protein in extramammary Paget's disease.

Extramammary Paget's disease is a rare malignant tumor of the skin that occurs primarily in the genitocrural region. Although the prognosis of extramammary Paget's disease with distant metastasis is poor, an effective therapy has not been established. Because Janus kinase 2 has attracted attention as a therapeutic target in several cancers, we investigated the expression of the Janus kinase 2 protein and the relationship between its level of expression and clinical significance in 53 patients with extramammary Paget's disease in our hospital. Immunohistochemistry showed that most extramammary Paget's disease tissues were positive for Janus kinase 2 (50/53, 94.3%), and the immunostaining intensity of Janus kinase 2 was correlated with the degree of invasiveness, lymph node metastasis and distant metastasis. Based on these findings, Janus kinase 2 may be a promising therapeutic target in extramammary Paget's disease.

Existence of Staphylococcus aureus correlates with the progression of extramammary Paget's disease: potential involvement of interleukin-17 and M2-like macrophage polarization.

BACKGROUND: The microbiome plays an important role in the tumour microenvironment (TME). OBJECTIVES: In this study, we investigated the clinical significance of the microbiota in extramammary Paget's disease (EMPD). MATERIALS & METHODS: Patients with EMPD, treated between March 2007 and September 2019 at Kumamoto University Hospital, were investigated retrospectively. Inclusion criteria included: histological diagnosis of EMPD, inspection of the bacterial culture of the cancer lesion using swab sampling, and availability of sufficient tissue in paraffin blocks for immunohistochemistry. For the latter, primary antibodies against IL-17, CD163 and ionized calcium-binding adapter molecule 1 (Iba1) were used. RESULTS: Bacterial cultures of the cancer lesion revealed that Staphylococcus aureus (S. aureus) was highly prevalent in EMPD patients, with dermal invasion or lymph node metastasis, compared to patients without these findings. Furthermore, the number of IL-17-positive cells and CD163-positive M2-like macrophages (pro-tumour macrophages) were increased in EMPD tissues with S. aureus. Moreover, the number of IL-17-producing cells in EMPD tissues positively correlated with the accumulation of CD163-positive M2-like macrophages. In addition, the percentage of CD163-positive cells within Iba-1-positive macrophages (total macrophages) was also significantly elevated in EMPD tissues with S. aureus. CONCLUSION: Based on these findings, S. aureus may exacerbate the pathological condition of EMPD via the accumulation of IL-17 and M2-like macrophages.

Circulating tumor necrosis factor-α DNA are elevated in psoriasis.

In psoriasis, tumor necrosis factor (TNF)-α is a key pro-inflammatory cytokine that activates keratinocytes to produce other inflammatory mediators. In addition, increased serum or plasma TNF-α levels are considered to be biomarkers of psoriasis. Circulating cell-free DNA (cfDNA) originates from apoptotic or necrotic cells and reflects the severity of cellular damage. Although cfDNA has recently attracted attention as a marker in the diagnosis and prognosis of various disorders, there are few reports of its clinical implications in the field of dermatology including psoriasis. The aim of this study was to investigate whether the TNF-α gene is present in the cfDNA, and whether its levels can be utilized as a biomarker for patients with psoriasis. cfDNA was isolated from serum samples of 79 patients with psoriasis vulgaris and 29 with psoriatic arthritis. The levels of TNF-α in the cfDNA were assessed by droplet digital polymerase chain reaction. In this study, we made two novel findings. First, circulating TNF-α DNA levels in the cfDNA were significantly higher in patients with psoriasis than in healthy controls. In addition, the area under the curve was 0.91, suggesting that serum TNF-α DNA levels are effective as a diagnostic biomarker. Second, the levels of TNF-α DNA copies in the cfDNA were positively correlated with the Psoriasis Area and Severity Index (PASI) score in the group of patients with a PASI score higher than 10. Generally, a PASI score of more than 10 is defined as severe psoriasis; therefore, the levels of TNF-α DNA copies in the cfDNA could be a biomarker for severity in patients with severe psoriasis. Further studies are needed to establish serum TNF-α DNA levels as a novel biomarker of psoriasis.

Overexpression of cyclin-dependent kinase 4 protein in extramammary Paget's disease.

Cyclin-dependent kinase 4 and 6 (CDK4/6) plays an important role in cell cycle progression, and the CDK4/6-cyclin D1 complex controls the cell cycle transition from G1 phase to S phase. CDK4 is enhanced in several types of cancers and CDK4/6 inhibitors attenuate the proliferation of several types of cancer in vitro/in vivo. The purpose of our study was to investigate the expression pattern of CDK4 and evaluate its clinical importance in extramammary Paget's disease (EMPD). Almost all EMPD tissues were positive for CDK4, and metastatic lesions had a similar immunostaining intensity to primary lesions. In addition, CDK4 protein levels were positively correlated with those of cyclin D1 protein. Taken together, CDK4 may assume a crucial role in EMPD progression.