Metastatic Extramammary Paget's Disease: Pathogenesis and Novel Therapeutic Approach

NECTIN4-targeted antibody-drug conjugate is a potential therapeutic option for extramammary Paget disease

Extramammary Paget disease (EMPD) is a rare skin cancer mainly found in areas rich in apocrine sweat glands. Since the effective treatments for advanced and/or metastasized EMPD are limited, there is an urgent need to develop novel therapeutic approaches. Nectin cell adhesion molecule 4 (NECTIN4) is highly expressed in cancers and considered to be a promising therapeutic target. NECTIN4 is also expressed in EMPD, but its role and the efficacy of NECTIN4-targeted therapy in EMPD remain unclear. This study investigated the potential of NECTIN4 as a novel therapeutic target for EMPD. NECTIN4 expression was immunohistochemically analysed in EMPD patients' primary (118 samples) and metastatic (21 samples) lesions. Using an EMPD cell line, KS-EMPD-1, the effects of NECTIN4 inhibition on cell proliferation and migration were investigated. NECTIN4 was expressed in primary and metastatic EMPD lesions, and the H-score of NECTIN4 staining was significantly higher in metastatic lesions than in primary ones. Knockdown of NECTIN4 significantly inhibited cell proliferation and affected cell migration. The cytotoxic effects of NECTIN4-targeted antibody-drug conjugate (ADC) were further evaluated, revealing a significant decrease in EMPD cell viability. In conclusion, NECTIN4 is a potential therapeutic target and NECTIN4-targeted ADC is promising as a therapeutic option for EMPD.

Recent treatment and prognosis in 643 patients with extramammary Paget's disease

Information about extramammary Paget's (EMPD) treatment is limited because of the rarity of the disease. The prognosis differs between in situ EMPD and invasive EMPD; therefore, therapy should be planned according to the disease stage. We collected data on 643 EMPD cases treated between 2015 and 2019 in Japan and assessed recent trends in EMPD treatment and prognosis based on the EMPD-oriented TNM staging. Among the 643 patients, 317 had stage 0 (49.3%), 185 had stage I (28.8%), 51 had stage II (7.9%), 18 had stage IIIA (2.8%), 48 had stage IIIB (7.5%) and 24 had stage IV (3.7%) disease. Each stage showed a distinct survival curve, with the exception of stages II and IIIA. Curative surgery was most common in patients with stage 0-III disease. Chemotherapy was the first-line therapy, mainly in patients with stage IIIB and IV disease, most commonly with docetaxel (DTX), followed by DTX + tegafur gimeracil oteracil potassium (TS-1) and TS-1. Patients with local disease exhibited a 4.4% recurrence rate. Univariate analysis revealed no prognostic differences according to age, sex or primary tumour site. SLNB was not related to disease-specific survival. In multivariate analysis, female sex significantly predicted local relapse in stage 0-I (HR 3.09; 95% CI, 1.13-8.43), and initial treatment with curative surgery was significantly protective in terms of disease-specific survival in stage II-IIIA (HR, 0.17; 95% CI, 0.04-0.71) and stage IIIB-IV (HR 0.16; 95% CI, 0.05-0.51). Further clinical studies are needed to improve the prognosis of patients with stage II-IV EMPD.

Targeting tumor-associated macrophages: Novel insights into immunotherapy of skin cancer

BACKGROUND

The incidence of skin cancer is currently increasing, and conventional treatment options inadequately address the demands of disease management. Fortunately, the recent rapid advancement of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has ushered in a new era for numerous cancer patients. However, the efficacy of immunotherapy remains suboptimal due to the impact of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs), a major component of the TME, play crucial roles in tumor invasion, metastasis, angiogenesis, and immune evasion, significantly impacting tumor development. Consequently, TAMs have gained considerable attention in recent years, and their roles have been extensively studied in various tumors. However, the specific roles of TAMs and their regulatory mechanisms in skin cancer remain unclear.

AIM OF REVIEW

This paper aims to elucidate the origin and classification of TAMs, investigate the interactions between TAMs and various immune cells, comprehensively understand the precise mechanisms by which TAMs contribute to the pathogenesis of different types of skin cancer, and finally discuss current strategies for targeting TAMs in the treatment of skin cancer.

KEY SCIENTIFIC CONCEPTS OF OVERVIEW

With a specific emphasis on the interrelationship between TAMs and skin cancer, this paper posits that therapeutic modalities centered on TAMs hold promise in augmenting and harmonizing with prevailing clinical interventions for skin cancer, thereby charting a novel trajectory for advancing the landscape of immunotherapeutic approaches for skin cancer.

KS-EMPD-1: a novel cell line of primary extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a rare skin cancer that mainly occurs in apocrine sweat gland-rich areas in elderly people. The prognosis of metastatic EMPD is unfavorable because of the lack of fully effective systemic therapies. However, the difficulty in establishing a model of EMPD has hampered basic research for exploring its pathogenesis and optimal treatments. Here, we established for the first time an EMPD cell line (named KS-EMPD-1) from a primary tumor on the left inguinal region of an 86-year-old Japanese male. The cells were successfully maintained for more than 1 year, with a doubling time of 31.2 ± 0.471 h. KS-EMPD-1 exhibited constant growth, spheroid formation, and invasiveness, and was confirmed to be identical to the original tumor by short tandem repeat analyses, whole exome sequencing, and immunohistochemistry (CK7+CK20-GCDFP15+). Western blotting of the cells revealed the protein expression of HER2, NECTIN4, and TROP2, which have recently attracted attention as potential therapeutic targets for EMPD. KS-EMPD-1 was highly sensitive to docetaxel and paclitaxel on chemosensitivity test. The KS-EMPD-1 cell line is a promising resource for basic and preclinical research on EMPD to better define the tumor characteristics and treatment strategy of this rare cancer.

Treatment outcomes of advanced/metastatic extramammary Paget's disease in Korean patients: KCSG-RC20-06

BACKGROUND

Extramammary Paget's disease (EMPD) is rare. There are no standard treatments due to its rarity and few clinical trials.

METHODS

The objective of this multicenter study was to investigate treatment outcomes of Korean patients with advanced/metastatic EMPD. Data were collected retrospectively from 14 institutions participating in Korean Cancer Study Group (KCSG) Rare Cancer Committee.

RESULTS

A total of 37 patients were identified. Of these 37 patients, 6 received locoregional therapy as a first-line treatment. In 31 patients who received systemic chemotherapy as a first-line treatment, platinum-based chemotherapy (n = 22) achieved an objective response rate (ORR) of 45.5% and a median progression-free survival (PFS) of 7.89 months. Taxane-based chemotherapy (n = 8) achieved an objective response rate of 62.5% and median PFS of 9.73 months. In second-line chemotherapy, platinum-based chemotherapy (n = 4) had a disease control rate (DCR) of 75.0% and median PFS of 3.45 months. Taxane-based chemotherapy (n = 8) had a DCR of 75.0% and a median PFS of 8.67 months. Six patients received anti-human epidermal growth factor receptor 2 (HER2) antibody during first- and second-line chemotherapy. Overall, systemic chemotherapy combined with anti-HER2 antibody had an ORR of 100% and a median PFS of 13.31 months. The ORR and PFS with systemic chemotherapy combined with trastuzumab was better than platinum- and taxane-based chemotherapy only.

CONCLUSIONS

Due to its rarity, advanced or metastatic EMPD still has no established standard treatment. Results of our study indicate that the combination of trastuzumab with taxane has longer survival than trastuzumab monotherapy or conventional platinum- or taxane-based chemotherapy.

Perianal extramammary Paget's disease with adenocarcinoma of perianal skin area, a case report

Extramammary Paget disease (EMPD) is an uncommon slow-growing skin adenocarcinoma originating in the anogenital region and axilla outside the mammary glands, often in regions with apocrine glands. The most common location is the vulva, followed by perineal, perianal, scrotal and penile skin. Here, we report a case of a 63-year-old male with EMPD in the perianal region. He reported 4 years of pain associated with an increasing region of skin irritation and bleeding on defecation that did not improve with topical agents. A biopsy sample revealed poorly differentiated carcinoma consistent with adenocarcinoma and associated with Paget disease. Workup was done. The patient tolerated local excision of the region well with no complications. A rare disease, EMPT, is challenging to diagnose and manage. Histopathological findings can, however, differentiate it from a wide array of similar skin conditions. Thorough investigations should be undertaken before initiating treatment to ensure the best outcomes.

Vulvar Paget’s Disease: A Systematic Review of the MITO Rare Cancer Group

Vulvar Paget’s disease (VPD) is a rare form of cutaneous adenocarcinoma of the vulva, which accounts for about 1–2% of all vulvar neoplasms and mainly affects post-menopausal women. The clinical presentation is usually non-specific and mimics chronic erythematous skin lesions; therefore, the diagnosis is often difficult and delayed. Although VPD is typically diagnosed at a locally advanced stage and has a high recurrence rate, the prognosis is overall favorable with a 5-year survival of nearly 90%. Due to the limited and poor-quality evidence, there is no global consensus on optimal management. Therefore, we performed a systematic review of the literature through the main electronic databases to deepen the current knowledge of this rare disease and discuss the available treatment strategies. Wide surgical excision is recommended as the standard-of-care treatment and should be tailored to the tumor position/extension and the patient’s performance status. The goal is to completely remove the tumor and achieve clear margins, thus reducing the rate of local recurrences. Non-surgical treatments, such as radiotherapy, chemotherapy, and topical approaches, can be considered, especially in the case of unresectable and recurrent disease. In the absence of clear recommendations, the decision-making process should be individualized, also considering the new emerging molecular targets, such as HER2 and PD-L1, which might pave the way for future targeted therapies. The current review aims to raise awareness of this rare disease and encourage international collaboration to collect larger-scale, high-quality evidence and standardize treatment.

Nomograms for predicting the prognosis of patients with penoscrotal extramammary Paget’s disease: A retrospective study in the SEER database and two medical centers

Background

Extramammary Paget’ s disease (EMPD) is a rare cutaneous malignant tumor, and the prognostic factors associated with penoscrotal EMPD remains unclear. The purpose of this study is to investigate prognostic factors and construct nomograms to predict the outcome of patients with EMPD located in the penis or scrotum.

Methods

From the Surveillance, Epidemiology and End Results (SEER) database, we extracted 95 patients with primary EMPD located in the penis or scrotum as the training cohort. Forty-nine penoscrotal EMPD patients were included from two medical centers as the external validation cohort. Univariate and multivariate Cox regression model were applied to investigating risk factors of cancer-specific survival (CSS) and overall survival (OS). Based on the results of multivariate Cox regression analysis, the nomograms were constructed for predicting CSS and OS of patients with penoscrotal EMPD. The concordance index (C-index), receiver operating characteristic (ROC) curves and calibration curves were applied to evaluate the practicability and accuracy of the nomograms.

Results

In the training cohort, multivariate Cox regression analysis showed that marital status and tumor stage were independent factors of CSS, and marital status, tumor stage and surgery are associated with OS independently in patients with penoscrotal EMPD. Based on these results, we developed nomograms to predict CSS and OS respectively. The C-index values were 0.778 for CSS, and 0.668 for OS in the training set, which displayed the good discriminations. In the external validation set, the C-index values were 0.945 for CSS, and 0.703 for OS. The areas under the curve (AUC) values of nomogram predicting 1-, 3-, and 5-year CSS were 0.815, 0.833, and 0.861 respectively, and 0.839, 0.654, and 0.667 for nomogram predicting 1-, 3-, and 5-year OS respectively. In the validation set, the AUC values of nomogram predicting 1-, 3-, and 5-year CSS were 0.944, 0.896, and 0.896 respectively, and 0.777, 0.762 and 0.692 for nomogram predicting 1-, 3-, and 5-year OS respectively. Additionally, the internal calibration curves also proved that our nomograms have good accuracy.

Conclusions

By incorporating marital status, tumor stage and/or surgery, our nomograms can efficiently predict CSS and OS of patients with penoscrotal EMPD.

Cell origin and genome profile difference of penoscrotum invasive extramammary Paget disease compared with its in situ counterpart

Penoscrotum extramammary Paget disease (pEMPD) is a rare cutaneous carcinoma with an unknown cell origin. pEMPD always presents as a tumor in situ with an indolent process, whereas some progress into invasive forms with more aggressive behavior. The in situ and invasive cases display different morphologies and biological behavior, and thus far, a relationship between these two components has not been demonstrated. Immunohistochemistry was used to disclose the immunotype of pEMPD, and the results revealed that invasive/in situ pEMPD possessed with some identical immunophenotypes such as CK7, P63, and CK10, which inferred the clonal relatedness. The variable expressions of GCDFP-15 and carcino embryonic antigen hinted that tumor cell origin might be an epidermal sweat gland in epiderma. In our cohort, invasive pEMPD presented increased expression of androgen receptor and decreased MUC5CA expression, and these two changes might bring to the shift of invasive phenotype. To better understanding the relationship between these distinct tumor forms, we performed whole exome sequencing testing to evaluate overlapping genomic alterations of six paired invasive/in situ pEMPDs. The results showed that missense mutation was the predominant mutation type, and C>T transition accounted for 65.1% in all SNP mutation. Among the top 20 differential genes obtained from the six paired invasive/in situ pEMPD analysis, MUC4 (one missense, one in frame del, and one multi-hit), AHNAK2 (two missense and one multi-hit), DOT1L (two missense and one multi-hit), and FRG1 (two missense and one-multi hit) mutations were most enriched in invasive pEMPDs, which postulated that these genes may play roles in the disease progression.

Case Report: Prolonged clinical benefit with sequential trastuzumab-containing treatments in a patient with advanced extramammary Paget disease of the groin

Extramammary Paget disease (EMPD) is a rare form of cutaneous, intraepithelial adenocarcinoma, which typically presents itself as an erythematous plaque originating from apocrine-gland rich regions, such as the vulva, the perianal region, the scrotum, the penis, or the axilla. EMPD patients typically have a good prognosis, with expected 5-year survival of 60%–92%, but it is estimated that about one-third of EMPD patients will develop lymph node or distant metastases. Treatment approaches for EMPD include locoregional therapies such as broad surgical resection, radiotherapy, or topical imiquimod, when the disease is localized, and chemotherapy and biological agents for advanced EMPD. We report the case of a 58-year-old man diagnosed with locally advanced, symptomatic HER2-overexpressing, AR-positive EMPD, who achieved long-term tumor control with a sequence of several trastuzumab-based treatments (more than 30 months with second-line carboplatin plus paclitaxel plus trastuzumab followed by trastuzumab maintenance; 9 months for third-line vinorelbine plus trastuzumab). Even if it is reported that AR expression occurs concomitantly with HER2 overexpression in more than half of the cases of EMPD, to the best of our knowledge, this is the first case report describing androgen receptor blockade therapy in combination with an anti-HER2 agent. Our patient did not benefit from androgen receptor blockade in combination with trastuzumab, thus suggesting that AR expression may simply reflect an intrinsic characteristic of the EMPD cell of origin, rather than tumor dependence upon AR signaling. Given the reported sensibility to anti-HER2 therapy, also new antibody drug conjugates targeting HER2 are worth exploring in the management of advanced EMPD.

From Anti-HER-2 to Anti-HER-2-CAR-T Cells: An Evolutionary Immunotherapy Approach for Gastric Cancer

Current Therapeutic modalities provide no survival advantage to gastric cancer (GC) patients. Targeting the human epidermal growth factor receptor-2 (HER-2) is a viable therapeutic strategy against advanced HER-2 positive GC. Antibody-drug conjugates, small-molecule tyrosine kinase inhibitors (TKIs), and bispecific antibodies are emerging as novel drug forms that may abrogate the resistance to HER-2-specific drugs and monoclonal antibodies. Chimeric antigen receptor-modified T cells (CAR-T) targeting HER-2 have shown considerable therapeutic potential in GC and other solid tumors. However, due to the high heterogeneity along with the complex tumor microenvironment (TME) of GC that often leads to immune escape, the immunological treatment of GC still faces many challenges. Here, we reviewed and discussed the current progress in the research of anti-HER-2-CAR-T cell immunotherapy against GC.

HER2-Targeted Antibody–Drug Conjugates Display Potent Antitumor Activities in Preclinical Extramammary Paget’s Disease Models: In Vivo and Immunohistochemical Analyses

Simple Summary

The prognosis for advanced Extramammary Paget’s disease (EMPD) is almost always poor. HER2-targeted antibody–drug conjugates (ADCs) such as trastuzumab emtansine and trastuzumab deruxtecan have proven to be effective against HER2-positive breast cancers; however, no studies have addressed HER2-targeted ADCs as treatments for EMPD. We examine the efficacy of ADCs against an EMPD patient-derived xenograft (PDX) model harboring pathogenic ERBB2 mutations. Treatment with trastuzumab emtansine or trastuzumab deruxtecan was found to significantly regress EMPD-PDX tumors in only seven days, with no recurrence observed for 10 weeks. Our results suggest that HER2-targeted ADCs could be novel and promising treatment options for patients with EMPD, especially in cases with the ERBB2-mutation or ERBB2-overexpression.

Abstract

Extramammary Paget’s disease (EMPD) is an adenocarcinoma that develops mainly in the genital region of older adults. The prognosis for advanced EMPD is almost always poor; thus, novel therapeutic strategies need to be developed. HER2-targeted antibody–drug conjugates (ADCs) such as trastuzumab emtansine and trastuzumab deruxtecan have proven effective against HER2-positive breast cancers; however, no studies have addressed HER2-targeted ADCs as treatments for EMPD. We examine the efficacy of ADCs against an EMPD patient-derived xenograft (PDX) model harboring pathogenic ERBB2 mutations and investigate the expression levels of HER2 using EMPD clinical samples. Trastuzumab emtansine or trastuzumab deruxtecan was administered intravenously to tumor-bearing NOD/Scid mice. Treatment with trastuzumab emtansine or trastuzumab deruxtecan was found to significantly regress EMPD-PDX tumors in only seven days, with no recurrence observed for 10 weeks. EMPD tumors extracted 48 h after drug administration revealed the TUNEL-positive ratio to be significantly higher for the HER2-targeted ADC-treated tumors than for the control tumors. EMPD patients’ clinical samples revealed a significant correlation between HER2 positivity and invasion, suggesting that HER2 status is associated with tumor progression. Our results suggest that HER2-targeted ADCs could be novel and promising treatment options for patients with EMPD, especially in ERBB2-mutant or ERBB2-overexpressed cases.

Phase II Study of Afatinib in Patients With Tumors With Human Epidermal Growth Factor Receptor 2-Activating Mutations: Results From the National Cancer Institute-Molecular Analysis for Therapy Choice ECOG-ACRIN Trial (EAY131) Subprotocol EAY131-B

PURPOSE

National Cancer Institute-Molecular Analysis for Therapy Choice is a multicohort trial that assigns patients with advanced cancers to targeted therapies on the basis of central tumor genomic testing. Arm B evaluated afatinib, an ErbB family tyrosine kinase inhibitor, in patients with ERBB2-activating mutations.

METHODS

Eligible patients had selected ERBB2 single-nucleotide variants or insertions/deletions detected by the National Cancer Institute-Molecular Analysis for Therapy Choice next-generation sequencing assay. Patients had performance status ≤ 1, left ventricular ejection fraction > 50%, grade ≤ 1 diarrhea, and no prior human epidermal growth factor receptor 2 (HER2) therapy. Patients received afatinib 40 mg once daily in 28-day cycles. The primary end point was objective response rate (ORR). Secondary end points were 6-month progression-free survival, overall survival, toxicity, and molecular correlates.

RESULTS

A total of 59 patients were assigned and 40 were enrolled. The median age was 62 years, 78% were female, 68% had performance status = 1, and 58% had received > 3 prior therapies. The confirmed ORR was 2.7% (n = 1 of 37; 90% CI, 0.14 to 12.2), and 6-month progression-free survival was 12.0% (90% CI, 5.6 to 25.8). A confirmed partial response occurred in a patient with adenocarcinoma of extra-mammary Paget disease of skin who progressed after cycle 6. Two unconfirmed partial responses were observed (low-grade serous gynecological tract and estrogen receptor-positive/HER2-negative immunohistochemistry breast ductal carcinoma). Of 12 patients with breast cancer, 1 additional patient with lobular carcinoma (estrogen receptor-positive/HER2 fluorescent in situ hybridization) had a 51% reduction in target lesions but progressed because of a new lesion at cycle 6. The most common (> 20%) treatment-related adverse events were diarrhea (68%), mucositis (43%), fatigue (40%), acneiform rash (30%), dehydration (27%), vomiting (27%), nausea (27%), anemia (27%), and anorexia (22%). Four patients (11%) discontinued because of adverse events.

CONCLUSION

Although afatinib did not meet the prespecified threshold for antitumor activity in this heavily pretreated cohort, the response in a rare tumor type is notable. The safety profile of afatinib was consistent with prior studies.

Treatment of Metastatic Primary Extramammary Paget Disease With Combination Anlotinib and Tislelizumab: A Case Report and Review of the Literature

Extramammary Paget’s disease (EMPD) is a rare cutaneous neoplasm with distant metastases and a poor prognosis. We report the case of a 63-year-old male patient exhibiting stage IV primary EMPD with neuroendocrine differentiation, and harboring a somatic mutation in AMER1. After four cycles of Anlotinib combined with Tislelizumab, the patient achieved partial response for the metastatic lesions according to mRECIST1.1 criteria. Total positron emission tomography and computed tomography (PET-CT) scans revealed a significant reduction in SUV from 18.9 to 5.3, and the serum CEA decreased to normal levels after the treatment regimen. However, the patient developed fractures of the fourth and fifth thoracic vertebrae during the treatment. Therefore, percutaneous vertebroplasty was performed, and the patient experienced severe postoperative pneumonia and died from pulmonary encephalopathy and respiratory failure in June 2021. The overall and progression-free survival of the patient after diagnosis were 9 and 8 months, respectively. During the systemic treatment, the patient suffered grade 1 rash in the back and thigh and grade 1 hypertension. Nevertheless, the combination treatment of anlotinib and tislelizumab had a favorable clinical outcome and provided a survival advantage, and should be considered a therapeutic option for patients with AMER1-mutant metastatic EMPD.

Current Management and Treatment of Extramammary Paget's Disease

OPINION STATEMENT

Extramammary Paget's disease (EMPD) is a rare neoplastic disease affecting areas rich in apocrine glands in the elderly. EMPD clinically resembles a benign inflammatory skin disease, and ill-defined tumor borders can lead to misdiagnosis and incomplete excision. Several prognostic factors have been reported, including nodule formation, tumor thickness, tumor invasion, lymphovascular invasion, and a perianal location, which are characteristic of primary tumors. EMPD typically presents as an in situ tumor spreading horizontally within the epidermis and then invading into the dermis as it transitions to a vertical growth phase. For this reason, tumor thickness, rather than tumor size, is correlated with patient prognosis. The best treatment for resectable EMPD is complete surgical removal of the tumor. EMPD sometimes has unclear tumor borders, and it can unexpectedly spread beyond its clinical boundaries. Surgical resection in such cases is often associated with tumor-positive margins, which can result in recurrence. However, surgical excision with wide margins may deteriorate patients' organ functions and quality of life. Mohs micrographic surgery may be ideal for controlling the surgical margins and minimizing the sacrifice of normal tissue, but this technique is not always feasible because of constraints associated with the medical environment. No standard treatment for unresectable or metastatic EMPD has been established. Although conventional chemotherapy has been used as the first-line treatment, it frequently causes adverse events, and consequently, targeted therapy will become more valuable in the near future.

Nectin-4: a Novel Therapeutic Target for Skin Cancers

OPINION STATEMENT

Nectin-4 is a tumor-associated antigen that is highly expressed on various cancer cells, and it has been further proposed to have roles in tumor development and propagation ranging from cellular proliferation to motility and invasion. Nectin-4 blockade reduces tumor proliferation and induces apoptosis in several malignancies. Nectin-4 has been used as a potential target in antibody-drug conjugate (ADC) development. Enfortumab vedotin, an ADC against Nectin-4, has demonstrated efficacy against solid tumor malignancies. Enfortumab vedotin has received US Food and Drug Administration approval for treating urothelial cancer. Furthermore, the efficacy of ADCs against Nectin-4 against solid tumors other than urothelial cancer has been demonstrated in preclinical studies, and clinical trials examining the effects of enfortumab vedotin are ongoing. Recently, Nectin-4 was reported to be highly expressed in several skin cancers, including malignant melanoma, cutaneous squamous cell carcinoma, and extramammary Paget's disease, and involved in tumor progression and survival in retrospective studies. Nectin-4-targeted therapies and ADCs against Nectin-4 could therefore be novel therapeutic options for skin cancers. This review highlights current knowledge on Nectin-4 in malignant tumors, the efficacy of enfortumab vedotin in clinical trials, and the prospects of Nectin-4-targeted agents against skin cancers.

Value of pseudopod sign on high-frequency ultrasound in predicting the pathological invasion of extramammary Paget's disease lesions

BACKGROUND

Vertical invasion of extramammary Paget's disease (EMPD) is associated with poor prognosis. The usual vertical invasion route is directly downward or along the skin appendages. High-frequency ultrasound (HFUS) can be used to measure the EMPD lesion thickness, and visualize the pseudopod extensions due to skin appendage involvement. It is a non-invasive method for evaluating the extent of vertical invasion in EMPD.

OBJECTIVE

To investigate the value of HFUS in predicting the extent of vertical invasion in EMPD.

METHODS

In this retrospective study, 85 patients with EMPD were divided into two groups based on the pathology: invasive EMPD (iEMPD) group (n = 13) and in situ EMPD group (n = 72). The clinical and HFUS features of both the groups were analyzed. The different types of pseudopodia morphology on HFUS were as follows: no pseudopodia, irregular bottom, small sphere, short strip, long strip, vase shape, and nodular convex. These were further stratified into low-risk and high-risk levels.

RESULTS

The clinical features were comparable between the two groups (P > .05). There were significant differences between the two groups in the HFUS features (lesion thickness, lesion shape, bottom shape, layer involvement, pseudopodia morphology, and color Doppler blood flow signal; all P < .05). The distribution of the pseudopodia morphology types in the in situ EMPD and iEMPD groups, was as follows: no pseudopodia, 30/72 and 0/13; irregular bottom, 5/72 and 0/13; small sphere, 5/72 and 0/13; short strip, 21/72 and 0/13; long strip, 8/72 and 3/13; vase shape, 3/72 and 3/13; and nodular convex, 0/72 and 7/13 (P < .05 for all). The sensitivity and specificity of high-risk pseudopodia in identifying iEMPD were 100% and 84.7%, respectively.

CONCLUSIONS

HFUS provides morphological information regarding EMPD lesions. Risk stratification for pseudopodia can help to distinguish between iEMPD and in situ EMPD lesions.

Extramammary Paget Disease of Peristomal Skin Secondary to Bladder Urothelial Carcinoma

Extramammary Paget disease (EMPD) is a rare, cutaneous condition, which can present secondary to underlying carcinoma as an eczematoid rash that often mimics other conditions. Secondary EMPD should, therefore, be considered in the differential diagnosis where there is potential for malignant extension, particularly in post-operative tissue. This report describes a case of secondary EMPD of the peristomal skin in a patient with a distant history of cystectomy with ileal conduit for urothelial carcinoma, who developed an extensive eczematoid rash over 5 years after attempting several ineffective treatments. Early dermatologic referral for persistent inflammatory cutaneous disorders and appropriate histopathologic testing may reduce delays in the diagnosis of EMPD.

Cyclin-dependent kinase 4/6 inhibitors suppress tumor growth in extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a rare adnexal neoplasm commonly seen in the genital areas among the senior population. The prognosis of advanced EMPD is not favorable; thus, the development of potential treatments has long been sought. Cyclin-dependent kinase (CDK) 4/6 inhibitors such as abemaciclib and palbociclib have been proven effective against metastatic breast cancer; however, no studies have addressed CDK4/6 inhibitors as an EMPD treatment. We herein examine the efficacy of CDK4/6 inhibitors against an EMPD patient-derived xenograft (PDX) model. Abemaciclib (50 mg/kg/day) or palbociclib (120 mg/kg/day) was given orally to tumor-bearing NOD/Scid mice over a 3-week period. We also investigated the protein expression levels of CDK4/6 and cyclin D1 through immunohistochemical staining using EMPD clinical samples. Treatment with abemaciclib or palbociclib as a single agent was found to significantly suppress tumor growth in EMPD-PDX. The Ki-67-positive ratio of the treated EMPD-PDX tumors was significantly lower than that of the nontreated tumors. Clinically, the expression levels of CDK4 and cyclin D1 were significantly higher in the EMPD tumor cells than in the normal epidermis. Our results suggest that CDK4/6 inhibitors could be novel and potent therapeutics for the treatment of EMPD.

Extramammary Paget's Disease: Diagnosis, Pathogenesis, and Treatment with Focus on Recent Developments

Extramammary Paget’s disease (EMPD) is a rare neoplasm that usually develops in apocrine gland-bearing areas, such as the vulva, scrotum, and penis. EMPD may present with a focal, multifocal, or an ectopic lesion. Clinically, EMPD lesions often exhibit infiltrative erythema, which is sometimes similar to other skin disorders such as eczema. While primary EMPD arises as intraepithelial neoplasm of the epidermis, EMPD-like lesions may occur from epidermotropic spread of malignant cells or direct extension from an underlying internal neoplasm, known as secondary EMPD. Because treatment strategies differ for primary EMPD and secondary EMPD, accurate diagnosis based on detailed histopathological evaluation is required. In the early stages, EMPD usually shows indolent growth, and most cases are diagnosed as carcinoma in situ. However, invasive lesions may result in metastases, and deep invasion is associated with high incidence of metastases. Conventional chemotherapies have been used for EMPD treatment in patients with distant metastases, but the efficacy is not satisfactory, and the prognosis for such patients remains poor. Recent studies have provided various insights into the molecular pathogenesis of the development and advancement of EMPD, which may lead to novel treatment approaches for metastatic EMPD. This review addresses the diagnosis, pathogenesis, and treatment of EMPD with focus on recent progress in understanding this disease.

CDK4: A Novel Therapeutic Target for Extramammary Paget's Disease

BACKGROUND

The outcome of extramammary Paget's disease (EMPD) is poor when it progresses to metastasis because of the lack of effective systemic therapies. Recently, CDK4-targeted therapy has attracted attention as a potential therapeutic target for some cancers. The aim of this study was to analyze the impact of CDK4 expression on the survival of patients with EMPD.

METHODS

We retrospectively reviewed 110 patients with EMPD. We conducted immunohistochemical analysis of CDK4 and cyclin D1 expression, and assessed the association between their expression and survival.

RESULTS

Most EMPD lesions (108/110, 98.2%) were positive for CDK4 staining and there was a positive correlation between CDK4 expression and cyclin D1 expression (r = 0.54, p < 0.001). Tumor thickness (p = 0.0003) and the presence of regional lymph node metastasis (p = 0.015) were significantly associated with high CDK4 expression. Regarding invasive EMPD, the multivariate analysis did not show the correlation between the expression of CDK4/cyclin D1 and survival outcomes (HR: 3.14, p = 0.14).

CONCLUSION

The overexpression of CDK4 was identified as a major risk factor for disease progression. CDK4-targeted therapy could thus be a novel treatment option for unresectable EMPD.

Trop2 Expression in Extramammary Paget's Disease and Normal Skin

Extramammary Paget's disease (EMPD) is a rare skin cancer arising in the apocrine gland-rich areas. Most EMPD tumors are dormant, but metastatic lesions are associated with poor outcomes owing to the lack of effective systemic therapies. Trophoblast cell surface antigen 2 (Trop2), a surface glycoprotein, has drawn attention as a potential therapeutic target for solid tumors. Sacituzumab govitecan, an antibody-drug conjugate of Trop2, has recently entered clinical use for the treatment of various solid cancers. However, little is known about the role of Trop2 in EMPD. In this study, we immunohistochemically examined Trop2 expression in 116 EMPD tissue samples and 10 normal skin tissues. In normal skin, Trop2 was expressed in the epidermal keratinocytes, inner root sheaths, and infundibulum/isthmus epithelium of hair follicles, eccrine/apocrine glands, and sebaceous glands. Most EMPD tissues exhibited homogeneous and strong Trop2 expression, and high Trop2 expression was significantly associated with worse disease-free survival (p = 0.0343). These results suggest the potential use of Trop2-targeted therapy for EMPD and improve our understanding of the skin-related adverse effects of current Trop2-targeted therapies such as sacituzumab govitecan.

Update on Molecular Genetic Alterations of Cutaneous Adnexal Neoplasms

Cutaneous adnexal tumors recapitulate follicular, sweat gland, and/or sebaceous epithelia, and range from benign tumors to aggressive carcinomas. Adnexal tumors can be hallmarks for inherited tumor syndromes. Oncogenic drivers of adnexal neoplasms modulate intracellular pathways including mitogen-activated protein kinase, phosphoinositide-3-kinase, Wnt/β-catenin, Hedgehog, nuclear factor κB, and Hippo intracellular signaling pathways, representing potential therapeutic targets. Malignant progression can be associated with tumor suppressor loss, especially TP53. Molecular alterations drive expression of specific diagnostic markers, such as CDX2 and LEF1 in pilomatricomas/pilomatrical carcinomas, and NUT in poromas/porocarcinomas. In these ways, improved understanding of molecular alterations promises to advance diagnostic, prognostic, and therapeutic possibilities for adnexal tumors.

Mucosal Invasion, but Not Incomplete Excision, Has Negative Impact on Long-Term Survival in Patients With Extramammary Paget's Disease

Background

Extramammary Paget’s disease (EMPD) sometimes spreads from the skin to mucosal areas, and curative surgical excision of these areas is challenging. The aim of this study is to analyze the impact of mucosal involvement and surgical treatment on the survival of patients with EMPD.

Methods

We conducted a retrospective review of 217 patients with EMPD. We also assessed the associations between tumor involvement in boundary areas (anal canal, external urethral meatus, vaginal introitus), prognostic factors, and survival in 198 patients treated with curative surgery.

Results

Of 217 patients, 75 (34.6%) had mucosal boundary area involvement. Lesions in these areas were associated with frequent lymphovascular invasion (p = 0.042), lymph node metastasis (p = 0.0002), incomplete excision (p < 0.0001), and locoregional recurrence (p < 0.0001). Boundary area involvement was an independent prognostic factor associated with disease-specific survival, per multivariate analysis (HR: 11.87, p = 0.027). Incomplete excision was not significantly correlated with disease-specific survival (HR: 1.05, p = 0.96).

Conclusion

Boundary area tumor involvement was a major risk factor for incomplete excision, local recurrence, and poor survival outcomes. However, incomplete removal of primary tumors was not significantly associated with poor prognosis. A less invasive surgical approach for preserving anogenital and urinary functions may be acceptable as the first-line treatment for resectable EMPD.

High-Frequency Ultrasound for Evaluation of the Pathological Invasion Level of Extramammary Paget Disease

OBJECTIVES

Pathological invasion level of extramammary Paget disease (EMPD) is strongly related with its risk staging, treatment, and prognosis. However, the current evaluation before treatments fails to evaluate pathological invasion level of EMPD. High-frequency ultrasound (HFUS) may play a key role to solve this problem. The purpose was to explore the performance of HFUS in the evaluation of pathological invasion level of EMPD.

METHODS

Sixty pathologically proven EMPD patients were retrospectively enrolled and divided into 2 groups as follows: in situ in the epidermis (IE) (n = 42) and invasion into the dermis or subcutaneous (ID) (n = 18) groups. Clinical and HFUS features were compared between the 2 groups.

RESULTS

Between the 2 groups, HFUS features (lesion shape, internal echogenicity and echotexture, surface shape, epidermal hyperechoic layer on the surface, the "pseudopod sign", and color Doppler ultrasound features) and clinical features were comparable (all P >.05). Tumor growth pattern significantly differed between the 2 groups (P <.05). Infiltration depth was significantly deeper for the ID group than the IE group (P <.05). With a cutoff value of 1.55 mm for infiltration depth, the area under the receiver operating characteristic curve was 0.833.

CONCLUSIONS

HFUS features of tumor growth pattern and infiltration depth may contribute to the assessment of invasion level of EMPD.

Treatment of Metastatic Extramammary Paget Disease with Combination Ipilimumab and Nivolumab: A Case Report

Metastatic primary cutaneous extramammary Paget disease (EMPD) is a rare clinical entity with a 5-year survival <10% and no standard therapy. We report the first case to our knowledge of metastatic EMPD with treatment response to checkpoint inhibitor immunotherapy. The patient had diffusely metastatic disease and previously progressed on cytotoxic chemotherapy and a molecularly targeted agent. Treatment with four cycles of ipilimumab 1 mg/kg plus nivolumab 3 mg/kg resulted in a durable partial response lasting 7 months. Analysis of metastatic tumor tissue failed to identify known predictors of treatment response to immune checkpoint inhibitors, such as high PD-L1 expression, high tumor mutation burden, or microsatellite instability. These findings support further investigation of immune checkpoint inhibition for the management of metastatic EMPD, which currently has an abysmal prognosis and no standard therapies.

The Outcome of Chemotherapy for Metastatic Extramammary Paget's Disease

The efficacy and survival impact of conventional chemotherapies for metastatic extramammary Paget’s disease (EMPD) have not been fully elucidated. This study examined the long-term outcome of chemotherapy for this indication. We conducted a retrospective review of 21 patients with distant metastatic EMPD (14 patients treated with chemotherapy and 7 patients treated without chemotherapy). The response rate of chemotherapy and patient survival were statistically analyzed. Among the 14 patients treated with chemotherapy, 12, 1, and 1 patient received docetaxel, paclitaxel, and low-dose 5-fluorouracil plus cisplatin, respectively, as the first-line treatment. The response rate was 50.0% (7/14), and the disease control rate was 64.3% (9/14). The median progression-free survival (PFS) and overall survival (OS) were 16.8 and 27.9 months, respectively. Multivariate analyses revealed that chemotherapy was a significant factor for prolonged PFS (hazard ratio (HR) 0.22, p = 0.038) but not for OS (HR = 1.71, p = 0.54). Ten patients (71.4%) had severe (grade 3 or 4) hematological adverse events. Although conventional chemotherapy improved PFS, we failed to show a significantly improved OS. Considering the frequent adverse events of conventional chemotherapy, targeted therapy may become a mainstay for the treatment of metastatic EMPD.

Hypercalcemia Associated with Extramammary Paget's Disease

Hypercalcemia of malignancy occurs in up to one third of patients at some point during the course of their advanced stage. The majority of them is caused by humoral hypercalcemia of malignancy due to systemic secretion of parathyroid hormone–related protein (PTHrP) by tumor cells. Extramammary Paget's disease is a slow-growing cutaneous malignancy commonly limited to the epidermis of the anogenital region, but rarely becomes invasive and metastatic to distant sites. Herein, we report a 70-year-old male patient with metastatic extramammary Paget's disease. He consulted our hospital with altered consciousness and tumor in his genital area. Physical examination revealed erythematous plaque with a tumor on the scrotum and perineum. It was diagnosed as extramammary Paget's disease (multiple liver metastases and multiple lymph node metastases by skin biopsy and image examination). Increases in serum-corrected calcium and PTHrP-intact levels (15.3 mg/dL and 66.1 pg/L, respectively) were confirmed. PTHrP immunohistochemistry showed positive staining in the tumor cells. We diagnosed humoral hypercalcemia of malignancy. We treated hypercalcemia with saline, furosemide, zoledronic acid, and elcatonin. Regarding the local control of the tumor, 30 Gy/10 Fr electron beam therapy was performed. However, treatment with zoledronic acid was only temporally effective to correct hypercalcemia, and an increased serum calcium level developed again. Concurrently, the liver metastases were rapidly enlarged, and his general condition gradually deteriorated. The patient died on day 55. When patients with extramammary Paget's disease show unconsciousness, serum calcium level should be measured and PTHrP-producing tumor distinguished.

Extramammary Paget disease of the vulva

Extramammary Paget disease (EMPD) is a rare neoplasm with uncertain histogenesis, usually presenting in the anogenital area, most commonly in the vulva. The disease is characterized by slow grow and high recurrence rates. This article reviews the epidemiological, clinical, morphological, genetic and treatment features of EMPD of the vulva reported in recent years.

NECTIN4 Expression in Extramammary Paget's Disease: Implication of a New Therapeutic Target

Extramammary Paget's disease (EMPD) is a rare skin cancer arising in the anogenital area. Most EMPD tumors remain dormant as in situ lesions, but the outcomes of patients with metastatic EMPD are poor because of the lack of effective systemic therapies. Nectin cell adhesion molecule 4 (NECTIN4) has attracted attention as a potential therapeutic target for some cancers. Urothelial cancer is one such cancer, and clinical trials of enfortumab vedotin, a drug-conjugated anti-NECTIN4 antibody, are ongoing. However, little is known regarding the role of NECTIN4 in EMPD. In this study, we conducted immunohistochemical analysis of NECTIN4 expression in 110 clinical EMPD samples and normal skin tissue. In normal skin, positive signals were observed in epidermal keratinocytes (particularly in the lower part of the epidermis), eccrine and apocrine sweat glands, inner and outer root sheaths, and matrix of the hair follicles. The most EMPD lesions exhibited strong NECTIN4 expression, and high NECTIN4 expression was significantly associated with increased tumor thickness, advanced TNM stage, and worse disease-specific survival. These results support the potential use of NECTIN4-targeted therapy for EMPD. Our report contributes to the better understanding of the pathobiology of NECTIN4 in the skin and the skin-related adverse effects of NECTIN4-targeted therapy.

Frequent FOXA1-Activating Mutations in Extramammary Paget's Disease

Extramammary Paget’s disease (EMPD) is a neoplastic skin disease of indeterminate origin with an unknown genetic cause. We performed a comprehensive genetic analysis or targeted gene sequencing in 48 patients with EMPD. We identified FOXA1 mutations, a GAS6–FOXA1 fusion gene, and somatic hotspot mutations in the FOXA1 promoter region in 11 of the 48 EMPD patients (11/48, 23%). Additional mutations were identified in PIK3CA (six patients) and in HIST1H2BB, HIST1H2BC, and SMARCB1 (one patient each), but none were found in other frequently mutated genes in cancer. A global gene expression analysis using EMPD clinical samples found the upregulation of PI3 kinase–AKT–mTOR signaling. ABCC11, which is specifically expressed in the apocrine secretory cells and is necessary for their sweat secretion, was upregulated in the EMPD samples. This upregulation suggests that Paget cells originate from apocrine secretory cells. Immunohistochemical staining revealed that FOXA1 expression was prevalent in all of the EMPD samples analyzed and was associated with estrogen receptor expression. Our genetic analysis indicates that EMPD frequently involves FOXA1 mutations. FOXA1 is a transcriptional pioneer factor for the estrogen receptor, and the present results suggest that certain treatments for hormone-dependent cancers could be effective for EMPD.

Comparison of the biomarkers for targeted therapies in primary extra-mammary and mammary Paget's disease

Background

Primary Extra‐mammary Paget's disease (EMPD) is a very rare cutaneous adenocarcinoma affecting anogenital or axillary regions. It is characterized by a prolonged course with recurrences and eventually distant metastatic spread for which no specific therapy is known.

Methods

Eighteen EMPD (13 vulvar and five scrotal) and ten mammary Paget's disease (MPD) cases were comprehensively profiled for gene mutations, fusions and copy number alterations, and for therapy‐relevant protein biomarkers).

Results

Mutations in TP53 and PIK3CA were the most frequent in both cohorts: 7/15 and 5/15 in EMPD; 1/6 and 4/7 in MPD HER2 gene amplification was detected in 4/18 EMPD (3 vulvar and 1 scrotal case) in contrast to MPD where it was detected in the majority (7/8) of cases. TOP2A gene amplification was seen in 2/12 EMPD and 1/6 MPD, respectively. Similarly, no difference in estrogen receptor expression was seen between the EMPD (4/15) and MPD (3/10). Androgen receptor was also expressed in the majority of both cohorts (12/16 EMPD) and (7/8 MPD).Here ARv7 splice variant was detected in 1/7 EMPD and 1/4 MPD cases, respectively. PD‐L1 expression on immune cells was exclusively observed in three vulvar EMPD. In contrast to MPD, six EMPDs harbored a “high” tumor mutation burden (≥10 mutations/Mb). All tested cases from both cohorts were MSI stable.

Conclusions

EMPD shares some targetable biomarkers with its mammary counterpart (steroid receptors, PIK3CA signaling pathways, TOP2A amplification). HER2 positivity is notably lower in EMPD while biomarkers to immune checkpoint inhibitors (high TMB and PD‐L1) were observed in some EMPD. Given that no consistent molecular alteration characterizes EMPD, comprehensive theranostic profiling is required to identify individual patients with targetable molecular alterations.

In vitro effect of Pannexin 1 channel on the invasion and migration of I-10 testicular cancer cells via ERK1/2 signaling pathway

Pannexin (Panx) plays a crucial role in several cellular processes such as immune cell death, cell proliferation, invasion, and migration, apoptosis, and autophagy. However, the role of Panx in regulating cell migration and invasion in testicular cancer remains to be elucidated. In the present study, we determined the correlation between Panx-1 channel function and migration and invasion in I-10 testicular cancer cells. Transwell and wound healing assays showed that inhibition of Panx-1 by carbenoxolone (CBX) and probenecid (PBN) attenuated the migration and invasion of testicular cancer cells in vitro. Moreover, knockdown of Panx-1 with short hairpin RNA (shRNA) remarkably decreased the migration and invasion ability of I-10 cells. In shRNA-transfected cells, extracellular ATP (released through Panx channel) was also found to be decreased. Similarly, overexpression of Panx-1 with mPanx-1 increased the migration and invasion ability of I-10 cells. Moreover, we found that in mPanx-1-transfected cells treated with U0126 (inhibitor of p-ERK1/2), the migration and invasion of I-10 cells were remarkably attenuated. Overall, increased Panx-1 promotes migration and invasion in testicular cancer cells, and the effect is probably be related with ERK1/2 kinase activity. Thus, Panx-1 can serve as a potential therapeutic target for the treatment of testicular cancer.

Expression of PD-1 and PD-L1 in Extramammary Paget Disease: Implications for Immune-Targeted Therapy

Extramammary Paget disease (EMPD) is a locally aggressive cutaneous malignancy that usually arises in anogenital or axillary skin. Immune checkpoint inhibitors targeting programmed cell death receptor (PD-1) and/or its ligand (PD-L1) are approved for the treatment of several types of cancer, and response to these generally correlates with increased PD-L1 expression by tumor cells. The expression of PD-L1 and composition and density of the tumor-associated immune infiltrate in EMPD have been little studied. To determine whether EMPD might be amenable to immune checkpoint blockade, we analyzed the expression of PD-1 and PD-L1 and the composition and density of the tumor-associated immune infiltrate in EMPD and evaluated associations between biomarker expression and clinicopathologic parameters. Twenty-one EMPD tumors were evaluated for tumor cell PD-L1 expression and for relative expression and distribution of CD3, CD8, PD-1, and PD-L1 in the tumor-associated immune infiltrate by using a combination of visual and image analysis (Aperio ImageScope). In addition, PD-L1 expression was assessed in 10 cases of mammary Paget disease (MPD). In EMPD cases, PD-L1 was expressed by tumor cells (3/21; 14%) and the tumor-associated immune infiltrate (15/21; 71%), and PD-1 was expressed by the tumor-associated immune infiltrate in all cases analyzed (18/18). However, PD-L1 expression by EMPD tumor cells did not correlate with the density of CD3-, CD8-, or PD-1-positive cells in the tumor-associated immune infiltrate or other clinicopathologic parameters. Furthermore, the density of CD3, CD8, PD-1, and PD-L1 in the tumor-associated immune infiltrate did not correlate with any clinicopathologic parameters evaluated with the exception that CD3 positive values were significantly higher in patients who were still alive (median, 1310 cells/mm²; range, 543–2115;) than in those who died (median, 611 cells/mm²; range, 481–908; p = 0.049). In all MPD cases, PD-L1 was absent in tumor cells but present in the tumor-associated immune infiltrate, and PD-L1 expression in lymphocytes was lower in patients with HER2/neu-positive than in those with HER2/neu-negative disease (p = 0.07). Our findings raise the possibility of therapeutic targeting of the PD-1/PD-L1 axis in EMPD.

Extramammary Paget Disease

Extramammary Paget disease is an intraepidermal adenocarcinoma, most often limited to the epidermis, with typical cases affecting genital skin. When limited to the epidermis, primary extramammary Paget disease is not life-threatening, but invasive disease may portend a poor prognosis. Surgical excision remains the mainstay of treatment of extramammary Paget disease, and Mohs micrographic surgery is the surgical treatment of choice. Alternative treatments include topical 5-fluorouracil and imiquimod, photodynamic therapy, laser vaporization, chemotherapy, and radiation therapy but data are limited. Implementation of cytokeratin 7 immunostain has increased the ability to detect extramammary Paget disease on frozen section.

Nation-wide survey of advanced non-melanoma skin cancers treated at dermatology departments in Japan

BACKGROUND

There are limited treatment options for advanced non-melanoma skin cancers (NMSCs). To overcome this issue, we need to conduct clinical studies, however, there is a lack of information on how many patients with advanced NMSCs are treated annually in Japan.

OBJECTIVE

To investigate the actual number of advanced NMSC patients in Japan.

METHODS

A questionnaire survey was sent to 668 institutes to educe information on: 1) the numbers of patients with squamous cell carcinoma (SCC), extramammary Paget disease (EMPD), other skin origin carcinomas, and cutaneous angiosarcoma (CAS) admitted in 2016 and 2017; 2) the preferred first- and second-line chemotherapies; and 3) the anticipated for future development.

RESULTS

Questionnaires were returned from 383 (57.3%) institutes. They reported a total of 1765 patients over the 2 years. The annual number patients with SCC, EMPD, other skin carcinomas, and CAS was 323.5, 192.5, 126, and 240.5, respectively. We estimated the annual number of patients for all 668 institutes to be 1255.6. Current first- and second-line treatment for NMSCs were chemotherapy regimens, but immune checkpoint inhibitors were the most anticipated new drugs for SCC and CAS, while chemotherapy was still the most anticipated treatment for EMPD.

CONCLUSION

Considering that during 2017, the number of deaths in Japan due to NMSC was reported to be 948, our estimated annual number of patients with NMSCs, 1255.6 seems to be an accurate estimation. As most of the treatment options for advanced NMSCs are outdated, the results of this study should be used to propose clinical studies.

Boron neutron capture therapy for vulvar melanoma and genital extramammary Paget's disease with curative responses

BACKGROUND

Although the most commonly recommended treatment for melanoma and extramammary Paget's disease (EMPD) of the genital region is wide surgical excision of the lesion, the procedure is highly invasive and can lead to functional and sexual problems. Alternative treatments have been used for local control when wide local excision was not feasible. Here, we describe four patients with genital malignancies who were treated with boron neutron capture therapy (BNCT).

METHODS

The four patients included one patient with vulvar melanoma (VM) and three with genital EMPD. They underwent BNCT at the Kyoto University Research Reactor between 2005 and 2014 using para-boronophenylalanine as the boron delivery agent. They were irradiated with an epithermal neutron beam between the curative tumor dose and the tolerable skin/mucosal doses.

RESULTS

All patients showed similar tumor and normal tissue responses following BNCT and achieved complete responses within 6 months. The most severe normal tissue response was moderate skin erosion during the first 2 months, which diminished gradually thereafter. Dysuria or contact pain persisted for 2 months and resolved completely by 4 months.

CONCLUSIONS

Treating VM and EMPD with BNCT resulted in complete local tumor control. Based on our clinical experience, we conclude that BNCT is a promising treatment for primary VM and EMPD of the genital region. Trial registration numbers UMIN000005124.