The etiology and epidemiology of merkel cell carcinoma

Complete Spontaneous Regression of Merkel Cell Carcinoma After Biopsy: A Case Report and Review of the Literature

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumor that typically occurs on the head and neck of the elderly and follows an aggressive clinical course. Merkel cell polyomavirus (MCPyV) has been identified in up to 80% of cases and has been shown to participate in MCC tumorigenesis. Complete spontaneous regression of MCC has been rarely reported in the literature. We describe a case of a 79-year-old man that presented with a rapidly growing, 3-cm mass on the left jaw. An incisional biopsy revealed MCC. Additional health issues were discovered in the preoperative workup of this patient which delayed treatment. One month after the biopsy, the lesion showed clinical regression in the absence of treatment. Wide excision of the biopsy site with sentinel lymph node dissection revealed no evidence of MCC 2 months later. The tumor cells in the patient's biopsy specimen were negative for MCPyV by polymerase chain reaction and immunohistochemistry (CM2B4 antibody, Santa Cruz, CA). The exact mechanism for complete spontaneous regression in MCC is unknown. To our knowledge, only 2 previous studies evaluated the presence of MCPyV by polymerase chain reaction in MCC with spontaneous regression. Whether the presence or absence of MCPyV correlates with spontaneous regression warrants further investigation.

Merkel cell carcinoma: Epidemiology, prognosis, therapy and unmet medical needs

Merkel cell carcinoma (MCC) is a rare skin cancer that is associated with Merkel cell polyomavirus infection in most cases. Incidence rates of MCC have increased in past decades. Risk factors for MCC include ultraviolet light exposure, immunosuppression and advanced age. MCC is an aggressive malignancy with frequent recurrences and a high mortality rate, although patient outcomes are generally more favourable if the patient is referred for treatment at an early stage. Although advances have been made recently in the MCC field, large gaps remain with regard to definitive biomarkers and prognostic indicators. Although MCC is chemosensitive, responses in advanced stages are mostly of short duration, and the associated clinical benefit on overall survival is unclear. Recent nonrandomised phase 2 clinical trials with anti-PD-L1/PD-1 antibodies have demonstrated safety and efficacy; however, there are still no approved treatments for patients with metastatic MCC. Patients with advanced disease are encouraged to participate in clinical trials for treatment, indicating the largely unmet need for durable, safe treatment within this population.

Merkel Cell Carcinoma of the Hand: A Case Report and Review of the Literature

Background: Merkel cell carcinoma (MCC) is a relatively rare and aggressive cutaneous neuroendocrine malignancy characterized by high incidence of local recurrence, distant metastases, regional nodal metastases, and high mortality. Clinically, MCC presents as a persistent asymptomatic red/pink shaped nodule, usually smaller than 2 cm with nontender intracutaneous swelling, with rapidly growing localized disease with lymph node metastases preceding distant metastases. Because of its rare nature and the lack of comprehensive understanding of the disease, management of MCC has been controversial. Methods: An 87-year-old retired Caucasian male with a history of tobacco use, chronic sun exposure, and multiple squamous and basal cell carcinomas presented with a 1.8 × 1.3 cm red, nontender nodule on the dorsum of the proximal phalanx of the left long finger first noticed 6 months prior to presentation. Biopsy was consistent with MCC after which he was treated with wide local excision, full-thickness skin grafting, and sentinel lymphadenectomy (1/4 nodes positive) followed by adjuvant radiation therapy. Results: He recovered appropriately and was clinically and radiographically disease free at 2.5-year follow-up. Conclusion: Although it remains rare, MCC has increased in incidence over the last several decades and has a predilection to occur over sun exposed areas. Highly aggressive, it has a high incidence of regional and distant metastasis as well as local recurrence. As a result, it is important that practitioners involved in the care of skin and hand lesions be aware of this condition and the need for a multidisciplinary treatment approach.

Merkel Cell Carcinoma: rising incidence in the East of England

BACKGROUND

Merkel Cell Carcinoma (MCC) is an infrequent but highly aggressive skin cancer. Five-year survival rates are poor, as there are high rates of metastases at primary diagnoses. Recurrences are also common. There is controversy about actual incidence rates which vary considerably between developed countries with majority populations of fair skin types.

OBJECTIVES

We report the age-standardized incidence rates of MCC for both males and females from the East of England, and use linear regression analyses to estimate numbers of cases for 2020 and 2025 to aid healthcare planning and allocation of resources.

METHODS

All cases of MCC diagnosed histopathologically between 1^st January 2004 and 31^st December 2013 were extracted from the databases of the Eastern Office, National Cancer Registration Service, Public Health England, and the Pathology department of the Norfolk and Norwich University Hospital, which serves as the tertiary referral centre for the region. Age-standardization incidence rate calculations (ASIs) and linear regression analyses were performed.

RESULTS

The ASIs for males and females were 0.70 and 1.08 per 100 000 person-years respectively. The total age-adjusted incidence rate was therefore 1.78 per 100 000 person-years. The ratio of female: male disease was 3:2. The total number of cases for this region over the time period studied was 73. There has been a threefold increase over this period. Estimated cases for this region are 17 in 2020, and 22 in 2025. Estimated UK cases for 2020 are 920, and 1134 in 2025.

CONCLUSIONS

MCC is increasing steadily in the East of England, and has risen threefold over the last 10 years and is similar to the highest reported rates from Western Australia. These data are 12-fold higher than previous UK estimates, and suggest that the incidence rate is also rising in other regions of the UK.

Clinicopathological characteristics of head and neck Merkel cell carcinomas

BACKGROUND

There are still controversies about the therapeutic strategies and subsequent outcome in head and neck Merkel cell carcinoma.

METHODS

Clinicopathological data of 23 Merkel cell carcinomas, 93 cutaneous head and neck squamous cell carcinomas (HNSCCs), 126 malignant melanomas, and 91 primary parotid gland carcinomas were comprehensively analyzed. Merkel cell carcinomas were cytokeratin 20 (CK20)/neuron-specific enolase (NSE)/chromogranin A (CgA)/synaptophysin (Syn)/thyroid transcription factor-1 (TTF-1)/MIB1 immunostained.

RESULTS

All Merkel cell carcinomas underwent wide local excision. Parotidectomy/neck dissection was performed in 40%/33% cutaneous Merkel cell carcinoma and 100%/100% in parotid gland Merkel cell carcinoma. Five-year recurrence-free interval (RFI)/overall survival (OS) was significantly higher in malignant melanoma (81/80%) than in cutaneous Merkel cell carcinoma/HNSCC. Interestingly, 5-year RFI/OS was significantly higher in Merkel cell carcinoma (61%/79%) than in HNSCC (33%/65%; p < .0001) despite comparable TNM classifications and treatment regimens. There were neither differences of RFI/OS between parotid gland Merkel cell carcinoma and parotid gland carcinomas, nor in the immunohistochemical profile.

CONCLUSION

Five-year RFI/OS was significantly better in cutaneous Merkel cell carcinoma when compared with TNM classification matched HNSCC. Five-year RFI/OS was comparable in parotid gland Merkel cell carcinoma and other primary parotid gland malignancies. © 2016 Wiley Periodicals, Inc. Head Neck 39: 92-97, 2017.

Assessment of Epstein-Barr virus nucleic acids in gastric but not in breast cancer by next-generation sequencing of pooled Mexican samples

Gastric (GC) and breast (BrC) cancer are two of the most common and deadly tumours. Different lines of evidence suggest a possible causative role of viral infections for both GC and BrC. Wide genome sequencing (WGS) technologies allow searching for viral agents in tissues of patients with cancer. These technologies have already contributed to establish virus-cancer associations as well as to discovery new tumour viruses. The objective of this study was to document possible associations of viral infection with GC and BrC in Mexican patients. In order to gain idea about cost effective conditions of experimental sequencing, we first carried out an in silico simulation of WGS. The next-generation-platform IlluminaGallx was then used to sequence GC and BrC tumour samples. While we did not find viral sequences in tissues from BrC patients, multiple reads matching Epstein-Barr virus (EBV) sequences were found in GC tissues. An end-point polymerase chain reaction confirmed an enrichment of EBV sequences in one of the GC samples sequenced, validating the next-generation sequencing-bioinformatics pipeline.

Merkel Cell Carcinoma: When Does Size Matter for Radiotherapy?

Merkel cell carcinoma is a very aggressive, rare cancer of the skin. It has a high propensity for local, regional, and distant recurrence and has recently been associated with a viral etiology from the recently diagnosed Merkel Cell Polyoma Virus. The optimal management remains controversial. We discuss the case of a man with a 26 cm axillary lymph node metastasis of unknown primary treated with radiotherapy.

Merkel cell carcinoma: Do you know your guidelines?

BACKGROUND

Merkel cell carcinoma (MCC) is a cutaneous neuroendocrine malignancy that exhibits clinically aggressive features and is associated with a poor prognosis. The incidence of MCC seems to be increasing for reasons unknown, and is estimated to be 0.32/100,000 in the United States.

METHODS

This article will review the current literature and National Comprehensive Cancer Network practice guidelines in the treatment of MCC.

RESULTS

Resection of MCC with negative margins remains the mainstay of therapy. Positive nodal disease should be treated with neck dissection and adjuvant radiotherapy. High-risk patients should undergo adjuvant radiotherapy, which improves oncologic outcomes. The role of chemotherapy is less clear and is currently reserved for advanced-stage MCC and palliative therapy.

CONCLUSION

The pathogenesis of MCC has recently been impacted with the discovery of the Merkel cell polyomavirus (MCPyV). Research to establish targeted and immunologic therapeutic options are ongoing.

Dramatic Increase in the Incidence and Mortality from Merkel Cell Carcinoma in the United States

Merkel cell carcinoma is a cutaneous neuroendocrine neoplasm that has been poorly studied in contemporary cohorts. Patients with Merkel cell carcinoma from 1986 to 2011 were identified in the Surveillance Epidemiology and End Results registry. A total of 5211 patients met the inclusion criteria. The mean age was 74.9 years; majority were male (61.4%) and white (94.9%). Patients were divided into two cohorts: Group 1 (1986 and 1999) and Group 2 (1999-2010). Group 2 was more likely to have Stage III disease (14.6 vs 23.3%, P < 0.001) and less likely to have Stage I/II disease (71.8 vs 65.1%, P < 0.0001). The increase in Stage III was likely secondary to increased use of sentinel lymph node biopsy. Disease-specific five-year survival for Stages I/II was 78.1 per cent and Stage III was 54 per cent. Disease-specific five-year survival was unchanged between Groups 1 and 2, 69.9 versus 66.6 per cent, respectively (P = 0.44). Both incidence and mortality significantly increased over the study period with P value for both trends <0.0001. In 1986, incidence and mortality rates per 100,000 were 0.22 and 0.03, respectively, and increased to 0.79 and 0.43 in 2011, respectively. There has been a greater than 333 per cent increase in mortality from Merkel cell carcinoma.

Merkel cell carcinoma of the head and neck: pathogenesis, current and emerging treatment options

Merkel cell carcinoma (MCC) is a relatively uncommon, neuroendocrine, cutaneous malignancy that often exhibits clinically aggressive features and is associated with a poor prognosis. It typically presents as a painless, rapidly enlarging, dome-shaped red or purplish nodule in a sun-exposed area of the head and neck or upper extremities. Our understanding of MCC has increased dramatically over the last several years and the pathogenesis continues to be an area of active research. The etiology is likely multifactorial with immunosuppression, UV-induced skin damage, and viral factors contributing to the development of MCC. The recent discovery of Merkel cell polyomavirus has allowed for at least one aspect of disease development to be much better understood. In most cases, treatment consists of wide local excision with adjuvant radiation therapy. The role of chemotherapeutics is still being defined. The recent advancement of knowledge regarding the pathogenesis of MCC has led to an explosion research into novel therapeutic agents and strategies. This review seeks to summarize the current body of literature regarding the pathogenesis of MCC and potential targets for future therapies.

Incidence of Merkel cell carcinoma in Olmsted County, Minnesota: a population-based study

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive, often cutaneous malignancy. The incidence has been estimated from national registries in the USA and elsewhere, and data indicate variations depending on the region studied. The objective of this study was to determine the incidence of MCC in Olmsted County (MN, USA).

METHODS

Using the Rochester Epidemiology Project, which contains health records for all the residents of Olmsted County, we retrospectively reviewed the records for all cases of MCC from 1976 to 2011.

RESULTS

The overall annual age- and sex-adjusted incidence of MCC in Olmsted County during 1976-2011 was 0.35 per 100,000 person-years (95% CI, 0.14-0.57). The incidence tended to be higher among men than women with 0.69 per 100,000 (95% CI, 0.24-1.14) and 0.10 per 100,000 (95% CI, 0-0.24), respectively.

CONCLUSIONS

These data are within the range of previous MCC incidence reports, and the incidence of MCC in Olmsted County is consistent with rates reported in the remainder of the USA.

Merkel Cell Carcinoma of the Axilla and Adrenal Gland: A Case Report with Imaging and Pathologic Findings

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine carcinoma of the skin. MCC is characterized by a high incidence of locoregional recurrence, and distant metastasis, and often requires short-term follow-up after treatment. In this present paper, we describe a rare case of MCC, which presented as a palpable axillary mass and an incidental adrenal mass, and report on the ultrasonography, computed tomography, and (18)F-fluorodeoxyglucose-positron emission tomography findings. The patient underwent surgery and adjuvant radiation therapy. Seven months after the initial diagnosis, distant metastasis was detected during a follow-up examination.

Merkel Cell Carcinoma Analysis of Outcomes: A 30-Year Experience

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with poor prognosis. Limited data exists to guide treatment decisions. Here we report on our institutional experience and outcomes treating patients with MCC.

METHODS

A database search (1984-2014) of patients treated at the University of Wisconsin Hospital and Clinics was used to identify patients with histologically confirmed MCC. Patient, tumor, and treatment characteristics were examined via review of medical records. Statistical analyses were performed to assess outcomes and associated prognostic factors.

RESULTS

A total of 87 patients with MCC were identified with a median follow-up of 17 months (mean: 38, range: 0-210 months). Two and five-year overall survival rates were 53.9% and 32.8%, respectively. Recurrence was documented in 31.0% of patients (85.2% locoregional, 48.1% distant and 33.3% both). Patients with a history of immunosuppression exhibited significantly worse survival (hazard ratio, 2.01; 95% CI, 1.1-3.7) when compared to immune-competent individuals. The head and neck region was the most common location of primary lesion (N=49) followed by the extremities (N=31). Upper extremity primaries predicted significantly better overall survival (hazard ratio, 0.48; 95% CI, 0.23-0.99) while lower extremity primaries did not have significantly better results (hazard ratio, 0.5; 95% CI, 0.21-1.2) in comparison to head and neck site of primary. Nodal involvement (hazard ratio, 2.95; 95% CI, 1.5-5.79) was also a negative prognostic factor associated with poor overall survival when compared with clinically node negative patients. Primary tumor size > 2 cm (hazard ratio, 1.76; 95% CI, 0.91-3.4) was not associated with survival.

CONCLUSIONS

This study highlights the role of various factors in determining prognosis of Merkel cell carcinoma; history of immunosuppression, nodal involvement, and head/neck primary predicted worse overall survival. These findings suggest that improvements in both distant and locoregionally directed therapies might play an important role in control of MCC and identify areas for future study.

[Merkel cell carcinoma]

Merkel cell carcinoma is a rare aggressive malignant neuroendocrine skin tumor, which can metastasize to lymph nodes early and often shows local recurrence. The prognosis depends on tumor size and disease stage. The majority of recurrences appear during the first 2 years after the primary diagnosis. The 5-year survival rate for primary tumor < 2 cm is 66-75 % and for primary tumors > 2 cm is 50-60 %. With lymph node metastases the 5-year survival rate is 42-52 %, while with distant metastases it drops to 17-12 %. Extensive staging inclusive sentinel lymph node biopsy is essential to assess the risk for distant metastasis and to allow the best recommendations for therapy. After surgical treatment with adequate safety margin, subsequent adjuvant radiation therapy of the tumor region and lymphatic draining basin is recommended to reduce the risk of local recurrence and lymphatic spread.

Joint occurrence of Merkel cell carcinoma and non-Hodgkin lymphomas in four Nordic countries

The objective of this study was to assess the reciprocal association between non-Hodgkin lymphoma (NHL) and Merkel cell carcinoma (MCC) using the data of four Nordic Cancer Registries. Data for this study were drawn from the Danish, Finnish, Norwegian, and Swedish cancer registries. Standardized incidence ratios (SIRs) for MCC among NHL patients, and for NHL among MCC patients, were calculated. There were 109 838 individuals with NHL and 1411 individuals with MCC, of which 28 had joint occurrence of NHL and MCC. In 18 cases, NHL was diagnosed first, and in 10 cases, MCC was diagnosed first. The SIR for MCC after NHL was 4.34 (95% confidence interval 2.57-6.85). The SIR for NHL after MCC was 3.13 (1.50-5.77). Although the absolute frequency of joint occurrence of MCC and NHL is low, individuals suffering from one of the cancer forms have an increased risk of the other.

Malignant cutaneous adnexal tumours of the head and neck: an update on management

Adnexal tumours form a heterogeneous group of relatively rare neoplasms. Many of them have a poor prognosis and treatment can sometimes be difficult and controversial. We summarise the latest publications relating to malignant cutaneous adnexal tumours of the head and neck, and give an update on their management. We discuss Merkel cell carcinoma and other rare malignant adnexal tumours including dermatofibrosarcoma protuberans and atypical fibroxanthoma.

Identification of the neutralizing epitopes of Merkel cell polyomavirus major capsid protein within the BC and EF surface loops

Merkel cell polyomavirus (MCPyV) is the first polyomavirus clearly associated with a human cancer, i.e. the Merkel cell carcinoma (MCC). Polyomaviruses are small naked DNA viruses that induce a robust polyclonal antibody response against the major capsid protein (VP1). However, the polyomavirus VP1 capsid protein epitopes have not been identified to date. The aim of this study was to identify the neutralizing epitopes of the MCPyV capsid. For this goal, four VP1 mutants were generated by insertional mutagenesis in the BC, DE, EF and HI loops between amino acids 88-89, 150-151, 189-190, and 296-297, respectively. The reactivity of these mutants and wild-type VLPs was then investigated with anti-VP1 monoclonal antibodies and anti-MCPyV positive human sera. The findings together suggest that immunodominant conformational neutralizing epitopes are present at the surface of the MCPyV VLPs and are clustered within BC and EF loops.

A systematic review of patients with Merkel cell carcinoma of the head and neck and a negative sentinel lymph node biopsy

Background

A negative sentinel lymph node biopsy (SLNB) from patients with head and neck Merkel cell carcinoma (HNMCC) may allow the patient to avoid further adjunctive therapies. However, there is considerable regional variability of lymphatic drainage from primary sites involving the head and neck, and Merkel cell carcinoma (MCC) has aggressive biologic behavior.

Objective

The primary aim of this systematic review was to document the incidence of regional recurrence and mortality from HNMCC patients after a negative SLNB.

Methods

A systematic search of the English literature was conducted via Ovid Medline and Embase from inception until 2013 and the Cochrane Central Register of Controlled Trials from 1991 to January 2014.

Results

Twenty-three studies, with a total of 81 patients matched the inclusion criteria. The incidence of regional recurrence from the entire cohort was 12.3%, and there was a 5% mortality rate. The mean follow-up time, excluding the 30 patients who did not have individual follow-up times specified, was 32.8 months.

Limitations

This review included studies had variable follow-up durations and treatments for MCC.

Conclusions

Despite negative pathologic staging of the neck using SLNB in HNMCC patients, there is still a high incidence of regional recurrence and mortality, over a short follow-up period.

•

Merkel cell carcinoma is an aggressive neoplasm.

•

Patients with a negative sentinel lymph node biopsy from head and neck Merkel cell carcinoma showed a high incidence of future regional lymph node involvement.

•

In this context, a negative sentinel lymph node biopsy is not necessarily reassuring for the patient or the clinician.

Merkel cell carcinoma in East Yorkshire: A case series and literature review of current management

INTRODUCTION

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumour of the skin. The incidence is rising and it is associated with sun exposure and immunosuppression. Our aim was to perform a 10-year retrospective review of MCC treated in East Yorkshire and to examine disease progression, surgical and adjuvant management, and outcomes.

METHODS

A 10-year retrospective review was undertaken of patients identified through the histopathology database. Case notes and digital patient records were examined for patient demographics, disease characteristics, management and outcome. Disease stage was calculated using the 2010 AJCC TNM classification.

RESULTS

Thirty-seven patients with complete records were included. Twenty-one patients were male and 16 female, with mean age 76.7 years at presentation. Pre-malignant or malignant skin changes were documented in 15 patients, and immunosuppression in 15 patients. Mean duration of lesion was 17.5 weeks. Following diagnosis 22/37 patients underwent further surgery with 11 patients undergoing sentinel lymph node (LN) biopsy. LN disease was palpable at presentation in 8 patients. Three year survival is 40%.

CONCLUSIONS

There is no standardised management of MCC and randomised trials are challenging due to relatively small numbers. There has been little progress made in terms of improving survival. Development of a national database for patients with this condition would allow prospective data collection and more accurate assessment of current treatment protocols and their efficacy.

LEVEL OF EVIDENCE

IV.

Mutational analysis of merkel cell carcinoma

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine malignancy that is associated with a poor prognosis. The pathogenesis of MCC is not well understood, and despite a recent plethora of mutational analyses, we have yet to find a set of signature mutations implicated in the majority of cases. Mutations, including TP53, Retinoblastoma and PIK3CA, have been documented in subsets of patients. Other mechanisms are also likely at play, including infection with the Merkel cell polyomavirus in a subset of patients, dysregulated immune surveillance, epigenetic alterations, aberrant protein expression, posttranslational modifications and microRNAs. In this review, we summarize what is known about MCC genetic mutations and chromosomal abnormalities, and their clinical significance. We also examine aberrant protein function and microRNA expression, and discuss the therapeutic and prognostic implications of these findings. Multiple clinical trials designed to selectively target overexpressed oncogenes in MCC are currently underway, though most are still in early phases. As we accumulate more molecular data on MCC, we will be better able to understand its pathogenic mechanisms, develop libraries of targeted therapies, and define molecular prognostic signatures to enhance our clinicopathologic knowledge.

Primary Merkel Cell Carcinoma of the Submandibular Gland: When CK20 Status Complicates the Diagnosis

Merkel cell carcinoma is a neuroendocrine tumor that occurs predominantly on the sun-exposed skin, with rare cases in the extracutaneous sites. It represents one of the extremely rare malignant neuroendocrine tumors of the salivary glands. We report a case of primary Merkel cell carcinoma of the right submandibular gland. The preoperative diagnosis was doubtful and the definitive histological diagnosis proved to be very difficult considering the extreme rarity of this tumor. The intraoperative evaluation of the macroscopic characteristics of the lesion led to an elective lymph node dissection. The extreme aggressiveness of the disease has resulted in the necessity of a new post-operative staging and in a multimodal treatment. This is the first primary submandibular gland Merkel cell carcinoma described in the literature. Differential diagnosis may be challenging and proper hematoxylin-eosin staining and immunohistochemical studies are mandatory.

Retinoblastoma gene mutations detected by whole exome sequencing of Merkel cell carcinoma

Merkel cell carcinoma is a highly aggressive cutaneous neuroendocrine tumor that has been associated with Merkel cell polyomavirus in up to 80% of cases. Merkel cell polyomavirus is believed to influence pathogenesis, at least in part, through expression of the large T antigen, which includes a retinoblastoma protein-binding domain. However, there appears to be significant clinical and morphological overlap between polyomavirus-positive and polyomavirus-negative Merkel cell carcinoma cases. Although much of the recent focus of Merkel cell carcinoma pathogenesis has been on polyomavirus, the pathogenesis of polyomavirus-negative cases is still poorly understood. We hypothesized that there are underlying human somatic mutations that unify Merkel cell carcinoma pathogenesis across polyomavirus status, and to investigate we performed whole exome sequencing on five polyomavirus-positive cases and three polyomavirus-negative cases. We found that there were no significant differences in the overall number of single-nucleotide variations, copy number variations, insertion/deletions, and chromosomal rearrangements when comparing polyomavirus-positive to polyomavirus-negative cases. However, we did find that the retinoblastoma pathway genes harbored a high number of mutations in Merkel cell carcinoma. Furthermore, the retinoblastoma gene (RB1) was found to have nonsense truncating protein mutations in all three polyomavirus-negative cases; no such mutations were found in the polyomavirus-positive cases. In all eight cases, the retinoblastoma pathway dysregulation was confirmed by immunohistochemistry. Although polyomavirus-positive Merkel cell carcinoma is believed to undergo retinoblastoma dysregulation through viral large T antigen expression, our findings demonstrate that somatic mutations in polyomavirus-negative Merkel cell carcinoma lead to retinoblastoma dysregulation through an alternative pathway. This novel finding suggests that the retinoblastoma pathway dysregulation leads to an overlapping Merkel cell carcinoma phenotype and that oncogenesis occurs through either a polyomavirus-dependent (viral large T antigen expression) or polyomavirus-independent (host somatic mutation) mechanism.

Somatostatin receptor expression in Merkel cell carcinoma as target for molecular imaging

Background

Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment.

Methods

To non-invasively assess SSTR expression in MCC using PET and the radiotracers [⁶⁸Ga]DOTA-D-Phe¹-Tyr³-octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT).

Results

SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%).

Conclusion

SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management.

Melanotic and non-melanotic malignancies of the face and external ear - A review of current treatment concepts and future options

Skin has the highest incidence and variety of tumors of all organs. Its structure is of great complexity, and every component has the potential to originate a skin neoplasm (SN). Because of its exposed nature, skin is vulnerable to carcinogenic stimuli such as UV radiation. Various entities can cause SN. Nonmelanotic skin cancers (NMSC) are the most common of all cancers, with over one million cases diagnosed annually in the US. Basal cell carcinoma (BCC) accounts for approximately 80% of all NMSC, most of the remaining 20% being squamous cell carcinoma (SCC). The skin of the head and neck is the most common site for tumors, accounting for more than 80% of all NMSC. BCC, SCC, and malignant melanomas (MM) represent 85-90% of all SN. Merkel cell tumors (MCC), lymphoepithelioma-like carcinomas of the skin (LELCS), dermato-fibro-sarcomas, leiomyosarkomas, and Kaposi-sarcomas are less frequent in the facial skin region and the external ear. Based on data from the German Federal Cancer Registry (2003/2004), 140,000 people in Germany were affected by SN (100,000 BCC, 22,000 SCC, 22,000 MM). This number increases considerably if malignant precursors, such as actinic keratosis, are included. Each year, the frequency of SN diagnosis rises by 3-7%. Among all known malignant tumors, MM exhibits the highest rate of increase in incidence. In the past, SN was primarily diagnosed in people aged 50 years or older. However, recently, the risk for developing SN has shifted, and younger people are also affected. Early diagnosis is significantly correlated with prognosis. Resection of SN creates defects that must be closed with local or microvascular flaps to avoid functional disturbing scar formation and deflection of the nose, eyelids, or lips. All therapeutic strategies for SN, the current standard for adjuvant and systemic treatment, and the management of the increasing number of patients under permanent blood thinner medication are described with regard to the treatment of SN.

RB1 gene in Merkel cell carcinoma: hypermethylation in all tumors and concurrent heterozygous deletions in the polyomavirus-negative subgroup

Sequestration of the tumor suppressor retinoblastoma protein (RB) by the Merkel cell polyomavirus (MCV) is a crucial step in the pathogenesis of Merkel cell carcinoma (MCC). RB expression is frequently lost, particularly in MCV-negative MCC tumors, through yet unknown mechanisms. We compared the genomic copy number changes of 13 MCV-positive and 13 -negative MCC tumors by array comparative genomic hybridization. The analysis revealed increased genomic instability, amplification of 1p34.3-1p34.2, and losses of 11p in the absence of MCV infection. Deletions of the RB1 locus were also detected at high rates in MCV-negative tumors. None of the tumors with heterozygous RB1 losses expressed RB in immunohistochemistry. RB1 promoter hypermethylation was studied with a methylation-specific multiplex ligation-dependent probe amplification technique. The RB1 promoter was methylated in all tumor specimens at CpG islands located close to the ATG start codon, albeit at low levels. The pattern of hypermethylation was similar in all MCC samples, despite RB expression, survival or MCV status. In conclusion, the frequent heterozygous losses of the RB1 locus could partly explain the decreased RB expression in MCV-negative MCC tumors, although the effects of RB1 mutations, coinciding promoter hypermethylation and, for example, miRNA regulation, cannot be excluded.

The HSP70 modulator MAL3-101 inhibits Merkel cell carcinoma

Merkel Cell Carcinoma (MCC) is a rare and highly aggressive neuroendocrine skin cancer for which no effective treatment is available. MCC represents a human cancer with the best experimental evidence for a causal role of a polyoma virus. Large T antigens (LTA) encoded by polyoma viruses are oncoproteins, which are thought to require support of cellular heat shock protein 70 (HSP70) to exert their transforming activity. Here we evaluated the capability of MAL3-101, a synthetic HSP70 inhibitor, to limit proliferation and survival of various MCC cell lines. Remarkably, MAL3-101 treatment resulted in considerable apoptosis in 5 out of 7 MCC cell lines. While this effect was not associated with the viral status of the MCC cells, quantitative mRNA expression analysis of the known HSP70 isoforms revealed a significant correlation between MAL3-101 sensitivity and HSC70 expression, the most prominent isoform in all cell lines. Moreover, MAL3-101 also exhibited in vivo antitumor activity in an MCC xenograft model suggesting that this substance or related compounds are potential therapeutics for the treatment of MCC in the future.

Shared decision-making in treatment of Merkel cell carcinoma

An 82-year-old woman presented with an asymptomatic mass, rapidly growing on her left cheek for the previous 3 months. Punch biopsy of the tumour was performed, and the pathology was compatible with Merkel cell carcinoma. A resection margin of more than 1 cm would involve left oral commissura, potentially damaging speech, eating and drinking ability. The patient had a strong wish of keeping surgery simple in order to maintain quality of life. Tumour excision was performed with 1 cm resection margin, and postoperatively the patient was referred to adjuvant radiation therapy. Sensibility of upper and lower lip remained unaffected, while motor innervation of left upper lip was impaired. Despite this, the patient's ability to talk and eat was unaffected. Surgery, with adjunctive radiation therapy, is the first-line of treatment for the primary tumour. The option for a more conservative treatment is not first choice, but can be considered upon individual assessment.

Merkel Cell Carcinoma: Epidemiology, Target, and Therapy

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin with a rising incidence. MCC has metastatic potential regardless the size of the primary tumor and a 5-year disease associated mortality rate is 46 %. Surgery and radiation are the mainstays of management for primary MCC. There is no evidence-based effective chemotherapy for recurrent or metastatic diseases to date. In-depth mechanistic studies in MCC have uncovered important cellular events and the association with a polyomavirus, which has provided direct evidence for molecular targeted and immunotherapy. Further perspective studies and clinical trials are warranted to provide reliable evidence of possible pitfalls and effectiveness of molecular targeted immunotherapy alone or in combination with chemotherapy in MCC.

Merkel cell carcinoma of the hand and upper extremity: current trends and outcomes

Merkel cell carcinomas represent an uncommon yet aggressive skin cancer. We sought to identify changes in incidence and predictors of outcomes and survival of patients with Merkel cell carcinomas of the hand and upper extremity. The Surveillance, Epidemiology and End Results database was used to identify all patients with Merkel cell carcinomas of the skin located specifically in the hand and upper extremity. Overall, 5211 cases were identified in the period from 1986 through 2009. The age-adjusted incidence of Merkel cell carcinoma of the hand and upper extremity increased from 0.02 cases per 100,000 in 1986 to 0.14 cases per 100,000 in 2009. The mean age of these patients was 75 years and positive regional lymph nodes were identified in 33%. Rate of metastasis was 4.1%. Overall survival for the study cohort was 49%. Multivariate analysis identified tumor size >5 cm, positive regional lymph nodes and metastasis at diagnosis as independent predictors of mortality. The incidence of Merkel cell carcinomas has increased substantially over the study period. Overall survival for Merkel cell carcinomas of the body and hand and upper extremity is related to tumor size and extent of disease at time of clinical presentation. Merkel cell carcinomas of the hand and upper extremity tend to be diagnosed at an earlier stage with lower rates of regional and systemic spread, and subsequently have a higher overall survival rate.

Immunomics in Skin Cancer - Improvement in Diagnosis, Prognosis and Therapy Monitoring

This review will focus on the elements of the skin’s immune system, immune cells and/or non-immune cells that support immune mechanisms, molecules with immune origin and/or immune functions that are involved in skin carcinogenesis. All these immune elements are compulsory in the development of skin tumors and/or sustainability of the neoplastic process. In this light, recent data gathered in this review will acknowledge all immune elements that contribute to skin tumorigenesis; moreover, they can serve as immune biomarkers. These immune markers can contribute to the diagnostic improvement, prognosis forecast, therapy monitoring, and even personalized therapeutical approach in skin cancer. Immune processes that sustain tumorigenesis in non-melanoma and melanoma skin cancers are described in the framework of recent data.

Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, clinically aggressive cutaneous neuroendocrine neoplasm with a high mortality rate. Though the etiology is not precisely known, Merkel cell polyomavirus DNA has been found recently in a large percentage of MCC tumors. Other suggested risk factors include sun exposure, immunosuppression, and a history of prior malignancy. Work up of patients with MCC most notably includes nodal staging via clinical examination or sentinel lymph node biopsy. The prognosis for most patients with MCC is poor, and the rarity of MCC precludes the prospective, randomized clinical trials necessary to elucidate optimum treatment protocols. Most published data support the use of a multimodality approach centered around surgical excision with negative margins, sentinel lymph node biopsy to establish the presence or absence of nodal metastases, adjuvant radiothearpy to decrease the risk of recurrence, and systemic chemotherapy in the case of widespread disease.

Tumor-specific T cells in human Merkel cell carcinomas: a possible role for Tregs and T-cell exhaustion in reducing T-cell responses

Merkel cell carcinomas (MCCs) are rare but highly malignant skin cancers associated with a recently described polyomavirus. MCC tumors were infiltrated by T cells, including effector, central memory, and regulatory T cells. Infiltrating T cells showed markedly reduced activation as evidenced by reduced expression of CD69 and CD25. Treatment of MCC tumors in vitro with IL-2 and IL-15 led to T-cell activation, proliferation, enhanced cytokine production, and loss of viable tumor cells from cultures. Expanded tumor-infiltrating lymphocytes showed TCR repertoire skewing and upregulation of CD137. MCC tumors implanted into immunodeficient mice failed to grow unless human T cells in the tumor grafts were depleted with denileukin diftitox, suggesting that tumor-specific T cells capable of controlling tumor growth were present in MCC. Both CD4(+) and CD8(+) FOXP3(+) regulatory T cells were frequent in MCC. Fifty percent of nonactivated T cells in MCC-expressed PD-1, a marker of T-cell exhaustion, and PD-L1 and PD-L2 were expressed by a subset of tumor dendritic cells and macrophages. In summary, we observed tumor-specific T cells with suppressed activity in MCC tumors. Agents that stimulate T-cell activity, block regulatory T cell function, or inhibit PD-1 signaling may be effective in the treatment of this highly malignant skin cancer.

Human polyomavirus reactivation: disease pathogenesis and treatment approaches

JC and BK polyomaviruses were discovered over 40 years ago and have become increasingly prevalent causes of morbidity and mortality in a variety of distinct, immunocompromised patient cohorts. The recent discoveries of eight new members of the Polyomaviridae family that are capable of infecting humans suggest that there are more to be discovered and raise the possibility that they may play a more significant role in human disease than previously understood. In spite of this, there remains a dearth of specific therapeutic options for human polyomavirus infections and an incomplete understanding of the relationship between the virus and the host immune system. This review summarises the human polyomaviruses with particular emphasis on pathogenesis in those directly implicated in disease aetiology and the therapeutic options available for treatment in the immunocompromised host.

Merkel cell carcinoma: the past, the present, and the future

Since the first description of the Merkel cell carcinoma by Cyril Toker in 1972, the number of studies has significantly increased over the last 4 decades. In this review, we will illustrate the historical background of the Merkel cell carcinoma beginning with the 19th century, the first description of the Merkel cell to the finding of the CK20 as a highly specific diagnostic marker and finally to the recently detected Merkel cell polyomavirus (MCPyV). Moreover, we will highlight the beginning of adjuvant therapeutic regimens with radiotherapy and chemotherapy and discuss the diagnostic work-up including imaging and histology of patients with Merkel cell carcinoma. Another very rapidly growing and interesting field of research is the development of patients' specific and tailored targeted therapy, in particular in patients with distant metastatic disease.

Clinicopathologic features of primary Merkel cell carcinoma: a detailed descriptive analysis of a large contemporary cohort

BACKGROUND

Little uniformity exists in the clinical and histologic variables reported with primary Merkel cell carcinoma (MCC).

OBJECTIVE

To provide a rigorous descriptive analysis of a contemporary cohort and promote the prospective collection of detailed data on MCC for future outcome studies.

METHODS AND MATERIALS

A detailed descriptive analysis was performed for clinical and histologic features of 147 patients with 150 primary MCC tumors in a prospectively collected database from 2006 to 2010.

RESULTS

The majority (73.5%) of patients were at American Joint Committee on Cancer clinical stage I or II at presentation, 20.4% at stage III, and 6.1% at stage IV. Detailed descriptive clinical and histologic findings are presented.

CONCLUSION

Clinical and histologic profiling of primary MCC in the literature is variable and limited. Systematic prospective collection of MCC data is needed for future outcome studies and the ability to compare and share data from multiple sources for this relatively rare tumor.

Merkel cell carcinoma: chemotherapy and emerging new therapeutic options

Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor that typically occurs in elderly, immunosuppressed patients. Infection with Merkel cell virus (MCV) and immunosuppression play an important role in the development of MCC. Different staging systems make it difficult to compare the existing clinical data. Furthermore, there predominantly exist single case reports and case series, but no randomized controlled trials. However, it is necessary to develop further therapy options because MCC tends to grow rapidly and metastasizes early. In the metastatic disease, therapeutic attempts were made with various chemotherapeutic combination regimens. Because of the high toxicity of these combinations, especially those established in SCLC, and regarding the unsatisfying results, the challenge is to balance the pros and cons of chemotherapy individually and carefully. Up to now, emerging new therapy options as molecular-targeted agents, for example, pazopanib, imatinib, or somatostatin analogues as well as immunologicals, for example, imiquimod and interferons, also showed less success concerning the disease-free response rates. According to the literature, neither chemotherapy nor molecular-targeted agents or immunotherapeutic strategies have shown promising effects in the therapy of the metastatic disease of MCC so far. There is a great demand for randomized controlled studies and a need for an MCC registry and multicenter clinical trials due to the tumors curiosity.

Imaging in patients with merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor of the skin with a mortality rate of approximately 25% (Peloschek et al., 2010). Accurate assessment of nodal involvement in patients with MCC predicts significantly overall outcome (Smith et al., 2012 and Ortin-Perez et al., 2007). Due to the rarity of this highly aggressive disease, only a few imaging reports on MCC were published, and subsequently still to date no accepted imaging algorithm for MCC is available. For primary staging of MCC, general recommendations have included ultrasonography, chest X-ray CT, and MRI, but recent articles show that the use of sentinel node and FDG-PET/PET-CT is gaining more and more importance.

Merkel cell carcinoma: interdisciplinary management of a rare disease

Background. The goal of this paper is to review contemporary multidisciplinary treatment with reference to Merkel cell carcinoma. Management of this rare but highly aggressive skin cancer is a complex undertaking that necessitates an understanding of its etiology, epidemiology, clinical presentation, and the coordinated work of several clinical specializations. Recent Findings. The contemporary literature employs a multidisciplinary approach to achieve the best patient's treatment. Conclusion. This paper presents an algorithm for contemporary management for the rare and aggressive Merkel cell carcinoma. Multidisciplinary approach in a tumor center provides high-quality care for patients with Merkel cell carcinoma.