Establishment of a trastuzumab-resistant extramammary Paget disease model: loss of PTEN as a potential mechanism.

BACKGROUND/OBJECTIVES: Extramammary Paget disease (EMPD) is a rare, cutaneous intraepithelial adenocarcinoma typically treated with wide local excision. Unfortunately, a number of patients with metastases show poor responses to chemotherapy. While some studies have explored trastuzumab's effectiveness against EMPD positive for human epidermal growth factor receptor 2 (HER2), trastuzumab resistance (TR) may emerge after anti-HER2 therapy. METHODS/SUBJECTS: In this study, we established TR EMPD patient-derived xenografts (PDX) that replicated the histological and HER2 expression traits of naive EMPD tumours. RESULTS: Cancer gene analyses revealed a loss of the PTEN gene in TR tumours, which was further confirmed by immunohistochemical staining and immunoblotting to test for protein expression levels. Reduced PTEN levels correlated with increased protein kinase B (Akt) phosphorylation and p27 downregulation, suggesting a potential mechanism for trastuzumab resistance in EMPD cells. In the trastuzumab-sensitive EMPD-PDX mouse model, PTEN inhibitors partially restored trastuzumab-mediated tumour regression. The TR EMPD-PDX responded favourably to targeted therapy (lapatinib, abemaciclib, palbociclib) and chemotherapy (eribulin, docetaxel, trastuzumab deruxtecan). CONCLUSIONS: This study demonstrates an innovative TR EMPD-PDX model and introduces promising antineoplastic effects with various treatments for TR EMPD tumours.

Phase II clinical trial of docetaxel and trastuzumab for HER2-positive advanced extramammary Paget's disease (EMPD-HER2DOC).

BACKGROUND: No consensus has been reached regarding the optimal chemotherapy for metastatic extramammary Paget's disease (EMPD), a rare cutaneous adenocarcinoma, because of the lack of solid evidence from prospective trials. However, the immunohistochemical profile of EMPD reportedly resembles that of breast cancer, particularly in terms of human epidermal growth factor receptor 2 (HER2) expression, suggesting that HER2 is a promising therapeutic target for advanced HER2-positive EMPD. METHODS: In this phase II single-arm trial, 13 Japanese patients received intravenous trastuzumab (loading dose of 8 mg/kg and maintenance dose of 6 mg/kg) and docetaxel (75 mg/m2) every 3 weeks for up to 2 years. The docetaxel dose was reduced or discontinued according to its toxicity. The primary trial endpoints were objective response rate (ORR) after 3 cycles of treatment and safety throughout the study period. RESULTS: All 13 patients completed 3 cycles of combination therapy. The median follow-up was 27.9 months. The ORR was 76.9% (n = 10/13; 90% CI, 50.5-93.4). Frequently observed adverse events were neutropenia (100%), hypoalbuminemia (84.6%), and mucocutaneous infection (84.6%), all of which were well tolerated. CONCLUSION: The combination of docetaxel and trastuzumab demonstrated a favorable clinical effect and acceptable tolerability, which makes it a good treatment option for HER2-positive metastatic EMPD (ClinicalTrials.gov Identifier: UMIN000021311, jRCTs031180073).

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.

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.

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.

Treatment of extramammary Paget disease with imiquimod in a real-life setting: a multicentre retrospective analysis in Spain.

BACKGROUND: Topical imiquimod has been shown to be an effective treatment for extramammary Paget disease (EMPD), although available evidence supporting its use is based on case reports and small series of patients. OBJECTIVES: To investigate the therapeutic outcomes and analyse potential clinicopathological factors associated with the imiquimod response in a large cohort of patients with EMPD. METHODS: Retrospective chart review of 125 patients with EMPD treated with imiquimod at 20 Spanish tertiary-care hospitals. RESULTS: During the study period, patients received 134 treatment regimens with imiquimod, with 70 (52.2%) treatments achieving a complete response (CR), 41 (30.6%) a partial response and 23 (17.2%) no response. The cumulative CR rates at 24 and 48 weeks of treatment were 46.3% and 71.8%, respectively, without significant differences between first-time and previously treated EMPD. Larger lesions (≥ 6 cm; P = 0.04) and EMPD affecting > 1 anatomical site (P = 0.002) were significantly associated with a worse treatment response. However, the CR rate did not differ significantly by the number of treatment applications (≤ 4 vs. > 4 times per week; P = 0.112). Among patients who achieved CR, 30 of 69 (43%) treatments resulted in local recurrences during a mean follow-up period of 36 months, with an estimated 3- and 5-year recurrence-free survival of 55.7% and 36.4%, respectively. CONCLUSIONS: Imiquimod appears as an effective therapeutic alternative for both first-line and previously treated EMPD lesions. However, a less favourable therapeutic response could be expected in larger lesions and those affecting > 1 anatomical site. Based on our results, a three to four times weekly regimen of imiquimod with a treatment duration of at least 6 months could be considered an appropriate therapeutic strategy for patients with EMPD.

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.

Treatment Outcomes of Adjunct and Stand-alone Photodynamic Therapy in Patients With Extramammary Paget Disease: A Literature Review.

BACKGROUND: Extramammary Paget disease (EMPD) is a rare malignant neoplasm arising from apocrine gland-bearing skin. The surgical management of EMPD is often coupled with noninvasive techniques including cryotherapy, ablative lasers, topical chemotherapies, and photodynamic therapy (PDT). The specificity and preservation of tissue that PDT with photosensitizers 5-aminolevulinic acid or 5-methyl aminolevulinate allows makes it a potential treatment of EMPD. METHODS: The authors present a review of 13 studies, from 2002 to 2019, examining the reported efficacy of PDT alone and adjunctive PDT in EMPD treatment. RESULTS: In the 52 patients with 56 lesions who received stand-alone PDT, 20 lesions (35.7%, n = 20/56) experienced complete resolution, 31 lesions (55.4%, n = 31/56) experienced partial resolution, 5 lesions (8.9%, n = 5/56) failed to demonstrate response to treatment, and 23 lesions (41.1%, n = 23/56) had recurrence. In the 56 patients with 66 lesions that received adjunctive PDT paired with surgery ( n = 55/66), imiquimod ( n = 4/66), holmium laser and surgery ( n = 1/66), Mohs surgery ( n = 2/66), and combined surgery, imiquimod, and 5-fluorouracil ( n = 1/66), 34 lesions (51.5%) experienced complete resolution, 27 lesions (40.9%) experienced partial resolution, 5 lesions (7.6%) failed to demonstrate any response to treatment, and 16 lesions (24.2%) had EMPD recurrence. CONCLUSION: Further studies with larger sample size are needed to consolidate these findings and inform clinical decisions.

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.

Successful treatment of a case of hormone receptor-positive metastatic extramammary Paget disease with tamoxifen.

Extramammary Paget disease (EMPD) is a rare cutaneous adenocarcinoma that usually is of epidermal origin and shows glandular differentiation and that is treated by wide local excision depending on the disease extent. For widely metastatic disease, however, a standard treatment remains to be established. Similar to breast cancer, EMPD has been found to overexpress human epidermal growth factor receptor 2 (HER2) or hormone receptors (HRs). Whereas HER2-directed therapy was recently shown to be effective for HER2-positive EMPD, the potential role of endocrine therapy for HR-positive EMPD has remained unknown. We here report a case of metastatic EMPD with HR positivity that was successfully treated with the selective estrogen receptor modulator tamoxifen. This first-line treatment of systemic metastasis resulted in durable tumor regression for > 20 months without any treatment-related toxicities. This is the first report to reveal the promise of tamoxifen as a safe and effective treatment for HR-positive metastatic EMPD.

The Paget Trial: topical 5% imiquimod cream for noninvasive vulvar Paget disease.

BACKGROUND: Vulvar Paget disease is an extremely rare skin disorder, which is most common in postmenopausal women. Most vulvar Paget disease cases are noninvasive; however, it may be invasive or associated with an underlying vulvar or distant adenocarcinoma. The current treatment of choice for noninvasive vulvar Paget disease is wide local excision, which is challenging because of extensive intraepithelial spread and may cause severe morbidity. Recurrence rates are high, ranging from 15% to 70%, which emphasizes the need for new treatment options. Imiquimod, a topical immune response modifier, has been shown to be effective in a few studies and case reports, and is a promising new treatment modality. OBJECTIVE: To prospectively investigate the efficacy, safety, and effect on quality of life of a standardized treatment schedule with 5% imiquimod cream in patients with noninvasive vulvar Paget disease. STUDY DESIGN: The Paget Trial is a multicenter prospective observational clinical study including 7 tertiary referral hospitals in the Netherlands. A total of 24 patients with noninvasive vulvar Paget disease were treated with topical 5% imiquimod cream 3 times a week for 16 weeks. The primary efficacy outcome was the reduction in lesion size at 12 weeks after the end of treatment. Secondary outcomes were safety, clinical response after 1 year, and quality of life. Safety was assessed by evaluation of adverse events and tolerability of treatment. Quality of life was investigated with 3 questionnaires taken before, during, and after treatment. RESULTS: Data were available for 23 patients, 82.6% of whom responded to therapy. A complete response was reported in 12 patients (52.2%), and 7 patients (30.4%) had a partial response. A histologic complete response was observed in 10 of the 12 patients with a complete response. Patients experienced side effects such as fatigue (66.7%-70.9%) and headaches (16.7%-45.8%), and almost 80% needed painkillers during treatment. Eight patients (34.8%) adjusted the treatment protocol to 2 applications a week, and 3 patients (13.0%) stopped treatment because of side effects after 4 to 11 weeks. Treatment improved quality of life, whereas a slight, temporary negative impact was observed during treatment. Two patients with a complete response developed a recurrence within 1 year after treatment. Follow-up showed 6 patients with a noninvasive recurrence after a median of 31 months (14-46 months) after the end of treatment. CONCLUSION: Topical 5% imiquimod cream can be an effective and safe treatment alternative for noninvasive vulvar Paget disease, particularly when compared with treatment with surgical excision.

Serum Cytokeratin 18 as a Metastatic and Therapeutic Marker for Extramammary Paget's Disease.

Extramammary Paget's disease (EMPD) is a rare cutaneous adenocarcinoma with unfavourable prognosis once it becomes invasive. A tumour marker that reflects disease progression is required for adequate management of EMPD. Cytokeratin 18 is highly expressed in many types of cancer and its soluble forms are detected by M30 (for caspase-cleaved form) and M65 (for both caspase-cleaved and intact forms) assays. We report here that tumour cells of EMPD in both lesional skin and lymph node metastasis are immunohistochemically positive for CK18, and the baseline serum M30 and M65 levels in patients with metastatic EMPD are significantly higher than those in non-metastatic patients. In addition, serial serum M30 and M65 levels might reflect recurrence of EMPD and response to chemotherapy. These results suggest that serum CK18 levels may be a useful tumour marker for advanced 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.

Excision combined with photodynamic therapy for scrotal Paget's disease in patients aged over 60 years.

OBJECTIVE: To investigate the safety and efficacy of wide local excision combined with aminolevulinic acid (ALA) photodynamic therapy (PDT) for the treatment of scrotal Paget's disease in patients of advanced age. METHODS: Data were collected for 16 patients (mean age, 68.44 years) with scrotal Paget's disease treated with wide local excision combined with ALA PDT and followed up from June 2014 to February 2018. Pathological examination after wide local excision confirmed Paget's disease. The patients underwent three courses of ALA PDT postoperatively and were followed up to determine the curative effect and complications in the short and middle term. RESULTS: The disease duration ranged from 4 to 76 months (mean, 36 months). Ten patients underwent simple excision, six underwent skin flap transfer, and two required reoperations due to skin flap necrosis and infection. The patients were followed up for 3 to 42 months after ALA PDT, during which time two patients developed metastasis (recurrence rate, 12.50%). No other serious complications occurred during follow-up except for lower limb movement disorder in one patient (6.25%). CONCLUSIONS: Wide local excision combined with ALA PDT shows good clinical efficacy and a low complication rate in patients of advanced age with scrotal Paget's disease.

Human epidermal growth factor receptor-2 (HER2) is a potential therapeutic target in extramammary Paget's disease of the vulva.

BACKGROUND: Invasive vulvar Paget's disease with over-expression of the human epidermal growth factor receptor 2 (HER2) protein is potentially suitable for targeted therapy, especially in a metastatic setting where no effective treatments are available. METHODS: Four consecutive patients with HER2 positive advanced vulvar Paget's disease, treated with weekly trastuzumab (loading dose 4 mg/kg, then 2 mg/kg) and paclitaxel (80 mg/m2) followed by 3-weekly trastuzumab maintenance (6 mg/kg), are reported. RESULTS: Median age and follow-up of patients were 62.5 years (45-74) and 16 months (6-54), respectively. Complete or partial responses were observed in all patients. Median time to response was 3 months (range 2-4), while median duration of response was 10 months (range 2-34). Case 1 presented with pulmonary and lymph nodes involvement. She experienced a radiological complete response after 24 treatment administrations, and a progression-free survival of 36 months. At disease progression, treatment re-challenge achieved partial response. She is currently receiving treatment with trastuzumab-emtansine. Case 2 was a 74-year-old woman who developed pulmonary metastasis after first-line cisplatin treatment. She had a partial response and a progression-free survival of 10 months. Case 3 had inguinal and para-aortic lymphadenopathy in complete response after 18 treatment administrations. She developed brain metastasis while receiving trastuzumab maintenance. Case 4 was treated for locally advanced disease and experienced a subjective benefit with relief in perineal pain and itching. No unexpected treatment-related side effects were reported. CONCLUSIONS: Advanced vulvar Paget's disease is a rare disorder and no standard treatment is available. In the sub-group of HER2 positive disease, weekly paclitaxel-trastuzumab appears to be active and safe, and may be considered a therapeutic option in these patients.

Is There a Place for Immune Checkpoint Inhibitors in Vulvar Neoplasms? A State of the Art Review.

Vulvar cancer (VC) is a rare neoplasm, usually arising in postmenopausal women, although human papilloma virus (HPV)-associated VC usually develop in younger women. Incidences of VCs are rising in many countries. Surgery is the cornerstone of early-stage VC management, whereas therapies for advanced VC are multimodal and not standardized, combining chemotherapy and radiotherapy to avoid exenterative surgery. Randomized controlled trials (RCTs) are scarce due to the rarity of the disease and prognosis has not improved. Hence, new therapies are needed to improve the outcomes of these patients. In recent years, improved knowledge regarding the crosstalk between neoplastic and tumor cells has allowed researchers to develop a novel therapeutic approach exploiting these molecular interactions. Both the innate and adaptive immune systems play a key role in anti-tumor immunesurveillance. Immune checkpoint inhibitors (ICIs) have demonstrated efficacy in multiple tumor types, improving survival rates and disease outcomes. In some gynecologic cancers (e.g., cervical cancer), many studies are showing promising results and a growing interest is emerging about the potential use of ICIs in VC. The aim of this manuscript is to summarize the latest developments in the field of VC immunoncology, to present the role of state-of-the-art ICIs in VC management and to discuss new potential immunotherapeutic approaches.

Combination Cisplatin-Epirubicin-Paclitaxel Therapy for Metastatic Extramammary Paget's Disease.

Extramammary Paget's disease (EMPD) is a rare cutaneous adenocarcinoma that clinicopathologically resembles breast cancer. The prognosis of metastatic EMPD is poor. Although several chemotherapies have been tried, the effects are temporary; better drugs and combinations are required.In the present study, we retrospectively analyze the efficacy and safety of combination of cisplatin, epirubicin, and paclitaxel in five metastatic EMPD cases. The efficacy was better than that for previously reported regimens: 80% partial responses, including two patients who were refractory to taxane- and/or platinum-based regimens. In terms of safety, four patients who were able to continue treatment exhibited acceptable tolerability.This is the first regimen to combine taxane and anthracycline. When treating breast cancer, anthracycline is regarded as the key cytotoxic agent, and anthracycline in combination with taxane constitutes a key chemotherapeutic regimen. Given our results, we speculate both drugs are critical chemotherapeutic agents for the treatment of metastatic EMPD.

Rare perianal extramammary Paget disease successfully treated using topical Imiquimod therapy.

BACKGROUND: Perianal Paget's disease (PPD) is a rare intraepithelial adenocarcinoma of the anal margin. Primary PPD likely represents intra-epithelial neoplasm from an apocrine source, whereas secondary disease may represent "pagetoid" spread from an anorectal malignancy. CASE PRESENTATION: Histologic CDX-2 and CK20 are hallmark markers for colorectal-derived Paget's cells. Interestingly, our primary PPD patient presented both positive and no internal malignancy was identified. In addition, a negative CK7 marker was observed in our case in contrast with previously reported. Surgical excision is the standard treatment; however, previous studies have demonstrated good response with Imiquimod 5% cream in patients with vulval extramammary Paget disease (EMPD). The efficiency of Imiquimod treatment for PPD has not been well described. Our PPD patient was successfully treated using Imiquimod 5% cream. CONCLUSIONS: This study describes a primary cutaneous PPD patient CDX-2+/CK20+/CK7- without invasion of the dermis and no associated colorectal carcinoma effectively treated using topical Imiquimod therapy, suggesting that Imiquimod might potentially be considered as a first-line treatment for PPD.

Anal canal adenocarcinoma with neuroendocrine features accompanying secondary extramammary Paget disease, successfully treated with modified FOLFOX6: a case report.

BACKGROUND: Anal canal cancer occasionally accompanies extramammary Paget disease. Although most of them are squamous cell carcinoma, anal canal adenocarcinoma with neuroendocrine features accompanying secondary extramammary Paget disease has never been reported. CASE PRESENTATION: Here, we report a 76-year-old man presented with pruritus in the perianal area. Investigation revealed a fist-sized perianal erythema, diffuse liver tumors, and right inguinal lymph node swelling. Pathological examination of biopsies from the erythema suggested secondary extramammary Paget disease with positive cytokeratin-7 and -20 expressions and negative GCDFP-15 expression. The anal canal tumor was confirmed by digital examination and endoscopy. Biopsies from the anal canal tumor, swollen lymph node, and Paget lesion all showed poorly differentiated adenocarcinoma with neuroendocrine features expressing synaptophysin and chromogranin A. Serum CEA and NSE levels were high, 809.4 ng/ml and 85.8 ng/ml, respectively. After chemotherapy with modified FOLFOX6 for 2 months, the Paget lesion disappeared, and the primary anal canal tumor and liver metastases shrunk remarkably. Serum CEA and NSE levels decreased promptly to within normal ranges. CONCLUSIONS: This is a clinically significant case, as it reveals novel pathological features about anal canal cancer with secondary Paget disease and successfully treated with modified FOLFOX6. Careful pathological investigation and appropriate treatment choice are needed for this rare cancer.