HER-2 Gene Amplification in Paget Disease of the Nipple and Extramammary Site: A Chromogenic In Situ Hybridization Study

Whole genome sequencing of HER2-positive metastatic extramammary Paget's disease: a case report

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare cancer that occurs within the epithelium of the skin, arising predominantly in areas with high apocrine gland concentration such as the vulva, scrotum, penis and perianal regions. Here, we aim to integrate clinicopathological data with genomic analysis of aggressive, rapidly-progressing de novo metastatic EMPD responding to HER2-directed treatment in combination with other agents, to attain a more comprehensive understanding of the disease landscape.

METHODS

Immunohistochemical staining on the scrotal wall tumor and bone marrow metastasis demonstrated HER2 overexpression. Whole genome sequencing of the tumor and matched blood was performed.

RESULTS

Notable copy number gains (log2FC > 0.9) on chromosomes 7 and 8 were detected (n = 81), with 92.6% of these unique genes specifically located on chromosome 8. Prominent cancer-associated genes include ZNF703, HOOK3, DDHD2, LSM1, NSD3, ADAM9, BRF2, KAT6A and FGFR1. Interestingly, ERBB2 gene did not exhibit high copy number gain (log2FC = 0.4) although 90% of tumor cells stained HER2-positive. Enrichment in pathways associated with transforming growth factor-beta (TGFβ) (FDR = 0.0376, Enrichment Ratio = 8.12) and fibroblast growth factor receptor (FGFR1) signaling (FDR = 0.0082, Enrichment Ratio = 2.3) was detected. Amplicon structure analysis revealed that this was a simple-linear amplification event.

CONCLUSION

Whole genome sequencing revealed the underlying copy number variation landscape in HER2-positive metastatic EMPD. The presence of alternative signalling pathways and genetic variants suggests potential interactions with HER2 signalling, which possibly contributed to the HER2 overexpression and observed response to HER2-directed therapy combined with other agents in a comprehensive treatment regimen.

Extramammary Paget Disease: a Therapeutic Challenge, for a Rare Entity

PURPOSE OF REVIEW

Extramammary Paget disease (EMPD) is a rare entity which is more frequently localized at the vulva, though it only accounts for 1-2% of vulvar neoplasms. It is a primary cutaneous adenocarcinoma whose cell of origin is still a matter of controversy: it can either arise from apocrine/eccrine glands or from stem cells. The diagnosis demands a biopsy and entails a histopathological analysis by which cells show similar characteristics as breast Paget disease.

RECENT FINDINGS

Treatment approach can entail surgery, radiotherapy, photodynamic therapy, systemic chemotherapy, and topical chemotherapy. For metastatic disease, many different chemotherapy regimens have been explored and even targeted therapy can play an important role in this disease. Since almost 30-40% of patients overexpress HER-2, trastuzumab and anti-HER-2 therapies can be employed in this setting. Due to its low incidence, there is almost no specific evidence on therapeutic interventions for this disease. Thus, there is a neat unmet need for molecular characterization of EMPD and diagnostic tools that allow clinicians to guide treatment both in the early and in the advanced disease settings. In this review, we aim to summarize available evidence about diagnosis and treatment of EMPD, both localized and metastatic, and to provide a comprehensive analysis that may help clinicians for therapeutic decisions.

Hormonal Environment and HER2 Status in Extra-Mammary Paget's Disease (eMPD): A Systematic Literature Review and Meta-Analysis with Clinical Considerations

Background. Extra-mammary Paget’s disease (EMPD) is a rare neoplasm of epithelial origin, whose precise incidence is not clear. Starting from what is already known, we performed a systematic review and meta-analysis to investigate in male and female patients the immunohistochemical expression of biological markers that could serve as potential prognostic/therapeutic factors, including only human epidermal growth factor receptor 2 (HER2/neu), Estrogen Receptor (ER), Progesterone Receptor (PR), and Androgen Receptor (AR). Methods. A literature search was performed of the PubMed, Scopus, and Web of Science databases for English-language studies published from January 2000 to June 2020. Results. A total of 27 studies with 713 patients assessed the role of HER2/neu, AR, ER, and PR expression in male and female with EMPD. The overall rate of HER2/neu expression was 30%, the expression’s rate for ER and AR was 13% and 40%, respectively, and the overall rate for PR was 8%. The subgroup analysis revealed that there is a different expression of molecular markers between male and female patients. Conclusions. This study revealed that AR status and HER2/neu overexpression/amplification have been shown as two fundamental pathogenetic pathways in both female and male patients affected by EMPD.

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.

Molecular subtyping of mammary Paget's disease using immunohistochemistry

Objective:

To evaluate the molecular subtypes of Mammary Paget’s disease (MPD) and the associated breast carcinomas.

Methods:

This retrospective study was carried out at King Khalid University Hospital and King Faisal Specialist Hospital, Riyadh, Saudi Arabia. Data from MPD patient cases from January 2010 to June 2016 were reviewed. The molecular subtypes were determined based on estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) expression with immunohistochemical staining. The relative frequencies of the luminal A and B, HER2-enriched and basal-like molecular subtypes were calculated and compared for MPD and the associated breast carcinomas.

Results:

Among 22 patients with MPD, HER2-enriched was the most frequently occurring molecular subtype and was observed in 11 (50%) patients. Mammary Paget’s disease was classified as basal-like in 5 (22.7%) patients, and luminal A and B were each detected in 3 (13.6%) patients. The molecular subtype of MPD corresponded with the subtype of the associated breast carcinoma in 18 out of 20 patients (90%).

Conclusions:

The HER2-enriched subtype is the most frequently occurring molecular subtype in MPD. The molecular subtype of the associated breast carcinoma is usually similar to that of MPD. The molecular subtypes vary between MPD associated breast carcinoma and overall breast carcinoma. The HER2-enriched subtype is the most frequently occurring subtype of MPD associated breast carcinoma, while luminal subtypes are more common in overall breast carcinoma.

Immunohistochemical study of HER2 and TUBB3 proteins in extramammary Paget disease

Metastatic extramammary Paget disease (EMPD) is a potentially fatal malignancy for which effective chemotherapy and good biomarkers are desirable for management. We investigated the status of human epidermal growth factor receptor (HER2) and neuronal β-tubulin isotype (class III β-tubulin; TUBB3), whose overexpression is a factor involved in resistance of tumor cells to taxane derivatives) in 32 patients with EMPD. HER2 status was evaluated by immunohistochemistry followed by fluorescence in situ hybridization, and TUBB3 status was evaluated by immunohistochemistry. On the basis of the US Food and Drug Administration-approved criteria, 20 (63%) of the 32 EMPD tumors were found to overexpress HER2. Positive immunoreactivity for TUBB3 was observed in 7 (22%) of the 32 patients. Although some clinicopathologic variables (nodule formation, depth of tumor cells, presence of lymph node metastasis, and serum carcinoembryonic antigen level) were significantly associated with disease outcome (P < 0.05), HER2 gain or aberrant TUBB3 expression showed no significant correlation. However, the higher incidence of HER2 gain and the relatively lower incidence of aberrant TUBB3 expression suggested that HER2-targeted immunotherapy combined with taxane derivatives is warranted for metastatic EMPD, and that HER2 and TUBB3 status might be a good biomarker for determining the most appropriate therapeutic modality.

Lesions of anogenital mammary-like glands: an update

Long considered to be ectopic breast tissue representing the caudal remnants of the milk ridges, anogenital mammary-like glands are nowadays thought to represent a normal constituent of the anogenital area. Lesions involving these glands, benign or malignant, epithelial or stromal manifest a striking similarity to their mammary counterparts. This review addresses the recent literature on lesions of anogenital mammary-like glands and our personal experience with various lesions related to these structures. Discussed are the normal anatomy and histology of these glands as well as the clinical presentation, histopathological and immunohistochemical features, molecular biological aspects, and differential diagnosis of various lesions involving anogenital mammary-like glands, including lactating adenoma, hidradenoma papilliferum, hidradenocarcinoma papilliferum, fibroadenomas, phyllodes tumor, pseudoangiomatous stromal hyperplasia, extramammary Paget disease, and other carcinomas. In addition, "nonspecific" epithelial or stromal changes some of which can be likened to similar changes occurring in a range of benign breast disease, including sclerosing adenosis, columnar cell lesions, ductal lesions and various metaplastic changes affecting epithelium and myoepithelium are discussed. Although lesions of anogenital mammary-like glands are often discussed in many dermatopathology textbooks in the context of cutaneous adnexal neoplasms we advocate that the best approach to the diagnosis of these lesions is to relate them to analogous well recognized lesions occurring in the breast, that is, through the eyes of a breast pathologist. This will enable their recognition, precise classification and should introduce greater uniformity in how they are reported in the literature so that more meaningful clinicopathological comparisons and correlations may be made.

Frequent expression of the breast differentiation antigen NY-BR-1 in mammary and extramammary Paget's disease

While mammary Paget's disease (MPD) is clearly linked to breast cancer, the histogenesis of extramammary Paget's disease (EMPD) is controversial. Recently NY-BR-1, a differentiation antigen expressed in the breast and in skin adnexal structures was identified. Its protein expression is restricted to normal and neoplastic breast epithelium and to adnexal tumors of the skin. In this study, we examine NY-BR-1 expression by immunohistochemistry in 24 MPD cases with synchronous ductal carcinoma in situ or invasive breast cancer. Results were compared with 26 cases of EMPD of men (n= 4) and women (n= 22) as well as in apoeccrine glands of the axilla and mammary-like glands of the anogenital region. We found NY-BR-1 positivity in 18 of 24 MPD (75%) and in 21 of 26 EMPD (80.8%). All apoeccrine glands of the axilla and mammary-like glands of the anogenital region were NY-BR-1-positive. NY-BR-1 expression is a common finding in MPD and in EMPD. When considering the diagnosis of Paget's disease, NY-BR-1 is a useful diagnostic marker. Furthermore NY-BR-1 positivity in apoeccrine glands of the axilla and anogenital region suggests a potential histogenetic link between these structures and Paget's disease.

The role of immunohistochemistry in discriminating primary from secondary extramammary Paget disease

BACKGROUND

Extramammary Paget disease (EMPD) is categorized into 2 groups: primary EMPD or EMPD secondary to underlying malignancy. Primary EMPD has a better prognosis, and the ability to distinguish between the 2 subsets has clinical relevance. Recent studies have suggested that immunostains, including cytokeratin (CK) 7, CK20, and BRST-2, distinguish between the 2 groups. We analyzed a large series of EMPD with an expanded immunohistochemical panel to assess its value in distinguishing primary from secondary disease.

DESIGN

Formalin-fixed, paraffin-embedded sections of 98 EMPD specimens from 61 patients (45 primary and 16 secondary) were immunostained with CK7, CK20, HER-2/neu, BRST-2, CDX2, androgen receptor (AR), and cyclin D1. The study included 44 women and 17 men (median age: 73 years). Median follow-up time was 47 months.

RESULTS

All EMPD specimens were vibrantly positive for CK7. The frequency of positivity for all EMPD samples was CK20 (28%), BRST-2 (40%), HER-2/neu (64%), CDX2 (10%), AR (16%), and cyclin D1 (76%). For primary EMPD, the frequency of positivity was CK20 (22%), BRST-2 (48%), HER-2/neu (65%), CDX2 (2%), AR (21%), and cyclin D1 (84%). For secondary EMPD, the frequency of positivity was CK20 (50%), BRST-2 (25%), HER-2/neu (60%), CDX2 (33%), AR (0%), and cyclin D1 (53%). Notably, all 6 of 7 cases of EMPD secondary to an anorectal adenocarcinoma tested were HER-2/neu negative and 5 of those 6 cases (80%) were CDX2 positive.

CONCLUSIONS

The role of CK7, CK20, and BRST-2 in distinguishing primary and secondary EMPD is limited because CK20 and BRST-2 were positive in large subsets of both groups. An expanded immunohistochemical panel, including HER-2/neu and CDX2, may be useful in discriminating primary EMPD from EMPD secondary to anorectal adenocarcinoma but fails to distinguish primary EMPD from EMPD secondary to urothelial or prostatic malignancy. The consistent overexpression of HER-2/neu in primary EMPD suggests a role for trastuzumab therapy in patients with recurrent disease.

Apocrine gland carcinoma of the mammary skin concomitant with pagetoid phenomenon

We reported a 52-year-old woman with an apocrine gland carcinoma of the mammary skin concomitant with pagetoid phenomenon. She had a 23-year history of a small nodular lesion on the lower left part of her right breast with a 1-year history of the pigmented plaque spreading peripherally around the nodule. Our diagnosis revealed that the nodule was an apocrine gland carcinoma and the intraepidermal neoplastic cells with pagetoid spread in the pigmented plaque were derived from the apocrine gland carcinoma. No Paget's cells were detected in the right nipple, and no tumor cells were observed in the sentinel lymph node and underlying mammary gland tissue. We also investigated the immunohistochemical changes in this case. They showed that both intraepidermal neoplastic cells with pagetoid spread and tumor cells of the apocrine gland carcinoma were positive with cytokeratin-7 and human epidermal growth factor receptor-2 (HER-2)/neu overexpression. The results of the present study conclude that the intraepithelial spread of tumor cells in the mammary skin distant from the nipple occurred as a pagetoid phenomenon, and that HER-2 may have a key role in pagetoid phenomenon of an underlying apocrine gland carcinoma, as well as in mammary Paget's disease.

Lesions of the Nipple

Because of the singular anatomic structure of the nipple, some breast lesions only occur at this site. The overlying skin includes normal Toker cells near the duct orifices. These cells are occasionally so numerous as to be called Toker cell hyperplasia. Ductal carcinoma in situ (DCIS) may involve nipple skin by direct extension from the underlying ducts (Paget disease of the nipple). The numerous skin appendages (eg, sebaceous, apocrine, and eccrine glands(1)) in the nipple and areola are the likely origin of syringomatous adenomas. At the duct orifices, the normal squamous epithelium dips into the breast for a short distance and abruptly transitions to glandular luminal and myoepithelial cells. When keratin-producing cells extend deeper into the ducts, the condition of squamous metaplasia of lactiferous ducts (SMOLD) results. With age, the lactiferous sinuses are subject to weakened duct walls, inspissated secretions, and rupture, which result in the inflammatory masses or nipple discharge associated with duct ectasia. Superficial epithelial proliferations within the large lactiferous sinuses form nipple adenomas, and deeper proliferations often result in large-duct papillomas. Below the areola is a supporting smooth muscle layer that can give rise to leiomyomas, although these tumors are extraordinarily rare. The proximity of these lesions to the skin results in the majority of them presenting as palpable masses, skin changes, or nipple discharge. Biopsy specimens from these lesions may be small, superficial, or fragmented because of concern about maintaining the cosmetic appearance of the nipple and areola. Knowledge of the location of the biopsy, and the clinical presentation, is often essential in making the correct diagnosis.