Efficacy of S-1 plus docetaxel in the treatment of metastatic extramammary Paget's disease: a multicentre retrospective study

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.

FOXM1: a new therapeutic target of extramammary Paget disease

Extramammary Paget disease (EMPD) is a rare skin cancer that primarily affects older individuals predominantly in areas with apocrine sweat glands. Although most early EMPD lesions are indolent, patients with metastatic EMPD have a poor prognosis due to the lack of effective systemic treatment. In this study, we investigated the role of forkhead box M1 (FOXM1), a potent transcription factor, in EMPD and assessed the potential of FOXM1 as a therapeutic target. Immunohistochemistry of 112 primary and 17 metastatic EMPD samples revealed that FOXM1 expression increased with tumor progression. Patients in whom FOXM1 was expressed in more than 10% of tumor cells had significantly shorter disease-specific survival than the other patients (p = 0.0397). In in vitro studies using our newly established EMPD cell line, KS-EMPD-1, we found high expression of FOXM1. Knockdown of FOXM1 impaired tumor cell viability, migration, and invasion. Inhibition of FOXM1 using thiostrepton also reduced tumor cell viability in a dose-dependent manner. These findings suggest that FOXM1 is a promising therapeutic target for patients with 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.

Eribulin for patients with metastatic extramammary Paget disease: Study protocol for a single-arm phase II trial

Extramammary Paget disease (EMPD) is a rare cutaneous malignancy that predominantly affects the anogenital areas of the elderly. Although the efficacy of docetaxel and other cytotoxic agents for advanced EMPD has been reported in small retrospective case studies, no treatment has been proven effective in prospective clinical trials. We established the world's first in vivo EMPD experimental model (a patient-derived xenograft model). In our treatment experiment, xenograft tumours showed a remarkable response to eribulin. This study evaluates the efficacy of eribulin for patients with advanced EMPD. In October 2022, we started a single-arm phase II trial to evaluate the efficacy of eribulin as a treatment for adult patients with unresectable EMPD with measurable lesions. Enrolment in this clinical trial is open to patients with any prior treatment for EMPD. The primary endpoint is overall response rate; the secondary endpoints include disease control rate, overall survival, progression-free survival and adverse events. The study protocol was approved by the Ethics Committee of Hokkaido University and the other collaborating institutions. If the primary endpoint is met, it is our hope that eribulin will be regarded as a standard medication for patients with advanced EMPD.

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.

Efficacy of chemotherapies for unresectable extramammary Paget disease: a single-centre retrospective study

BACKGROUND

Extramammary Paget disease (EMPD) is a cutaneous neoplasm that can metastasize to the lymph nodes and distant organs, resulting in a poor prognosis. For unresectable distant metastases of EMPD, no consensus has been reached regarding optimal chemotherapy owing to a lack of data.

OBJECTIVES

To evaluate the efficacy of three regimens: docetaxel (DTX) monotherapy; combination therapy with 5-fluorouracil, epirubicin, carboplatin, vincristine and mitomycin C (FECOM); and tegafur (S-1) monotherapy.

METHODS

This single-centre retrospective study included 32 patients diagnosed with unresectable EMPD and treated with chemotherapy between 2002 and 2022 at the National Cancer Center Hospital in Japan. Patient characteristics, responses to treatment and survival data were evaluated for each of the first-line therapies.

RESULTS

Among the 17 patients who received DTX monotherapy, the response rate (RR) and disease control rate (DCR) were 47% and 77%, respectively. The median progression-free survival (PFS) and overall survival (OS) were 12.3 months [95% confidence interval (CI) 6.1-26.6] and 19.2 months (95% CI 8.5-not reached), respectively. Among the 11 patients who received combination FECOM chemotherapy, the RR and DCR were 55% and 64%, respectively. The median PFS and OS were 6.8 months (95% CI 3.5-not reached) and 13.4 months (95% CI 8.6-21.3), respectively. Among the four patients who received S-1 monotherapy, the RR and DCR were 0% and 25%, respectively. The median PFS and OS were 5.4 months (95% CI 2.3-not reached) and 12.5 (95% CI 2.3-not reached) months, respectively.

CONCLUSIONS

Further investigations with prospective analysis are required to confirm these findings.

Neutrophil-to-lymphocyte ratio is a potential prognostic biomarker for extramammary Paget disease: A retrospective study

The neutrophil-to-lymphocyte ratio (NLR) is a useful prognostic biomarker for many cancer types. However, the prognostic value of NLR in patients with extramammary Paget disease (EMPD) remains unclear. This study aimed to determine whether NLR is associated with overall survival (OS) in patients with EMPD. In this single-center retrospective case series, we analyzed data of 109 patients with previously untreated EMPD who presented to our hospital. Data on age, sex, primary tumor site, invasion level, presence of lymph node and distant metastases, baseline NLR, and OS were analyzed. The enrolled patients were classified into the metastatic or non-metastatic EMPD groups. The metastatic EMPD group had higher invasion level and NLR value (p < 0.001 and p = 0.005, respectively) compared with the non-metastatic EMPD group. Cox proportional hazards model analysis showed invasion level (p = 0.0093) and NLR value (p = 0.019) to be independent prognostic factors for OS. Notably, multivariate analysis revealed that invasion level (p = 0.045) and NLR value (p = 0.036) were independent prognostic factors for OS in the metastatic EMPD group. The limitations of this study include the small number of participants and its retrospective nature. In conclusion, since NLR can be routinely assessed with high feasibility, it might be a useful biomarker for predicting prognosis in patients with 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.