Transient complete remission of metastasized Merkel cell carcinoma by high-dose polychemotherapy and autologous peripheral blood stem cell transplantation

Stem cell therapy in dermatology

Stem cells are precursor cells present in many tissues with ability to differentiate into various types of cells. This interesting property of plasticity can have therapeutic implications and there has been substantial research in this field in last few decades. As a result, stem cell therapy is now used as a therapeutic modality in many conditions, and has made its way in dermatology too. Stem cells can be classified on the basis of their source and differentiating capacity. In skin, they are present in the inter-follicular epidermis, hair follicle, dermis and adipose tissue, which help in maintaining normal skin homeostasis and repair and regeneration during injury. In view of their unique properties, they have been employed in treatment of several dermatoses including systemic sclerosis, systemic lupus erythematosus, scleromyxedema, alopecia, Merkel cell carcinoma, pemphigus vulgaris, psoriasis, wound healing, epidermolysis bullosa and even aesthetic medicine, with variable success. The advent of stem cell therapy has undoubtedly brought us closer to curative treatment of disorders previously considered untreatable. Nevertheless, there are multiple lacunae which need to be addressed including ideal patient selection, timing of intervention, appropriate conditioning regimens, post-intervention care and cost effectiveness. Further research in these aspects would help optimize the results of stem cell therapy.

Systematic literature review of efficacy, safety and tolerability outcomes of chemotherapy regimens in patients with metastatic Merkel cell carcinoma

AIM

Merkel cell carcinoma (MCC) is a rare neuroendocrine, cutaneous malignancy with poor prognosis once metastasized. The aim of this study was to conduct a systematic literature review to assess clinical outcomes associated with chemotherapy regimens in metastatic MCC.

MATERIALS & METHODS

Embase^®, MEDLINE^®, MEDLINE^®-In-Process and CENTRAL were searched for studies published in January 2016.

RESULTS & CONCLUSION

Overall, the literature on chemotherapy in patients with metastatic MCC is sparse, with most studies being case series/reports. Across all studies, response rates ranged from 20 to 61%, with higher response rates in first-line setting (53-61%) versus second-line setting (23-45%). Among responders, duration of response was short (≤8 months) in both first- and second-line settings. There is a need for novel agents that can induce durable responses in metastatic MCC.

Merkel cell carcinoma in immunosuppressed patients

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous malignancy. The infectivity of Merkel cell polyomavirus (MCPyV), an apparent agent in MCC development, may be exacerbated with impaired immune responses. This paper reviews relevant data regarding the role of immunosuppression in the development of MCC and describes modes of immunodeficient states. Because of the inherently low incidence rate of MCC, several case studies and series are also briefly mentioned to provide a more comprehensive summary of MCC in the setting of immunosuppression. We describe immunosuppressed patients who have experienced excessive UV radiation, organ transplantation, human immunodeficiency virus infection/AIDS, autoimmune diseases, and lymphoproliferative disorders. Iatrogenic forms of immunosuppression are also highlighted. Studies that quantify risks consistently report that individuals with a history of solid organ transplantation, autoimmune diseases, AIDS, and/or lymphoproliferative diseases have a significantly elevated risk of developing MCC. Overall, immunocompromised patients also appear to have an early onset and more aggressive course of MCC, with poorer outcomes. Recommendations for multidisciplinary approaches are proposed to effectively prevent and manage MCC in these patients.

Recent advances in the understanding of the genetics, etiology, and treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a highly aggressive skin malignancy. The growing incidence and recognition of this cancer in elderly or immunosuppressed individuals suggests that it is becoming an increasing clinical challenge. MCC recently has been demonstrated to have a probable viral pathogenesis related to a novel member of the polyomavirus (termed Merkel cell polyomavirus [MCV]). The molecular pathogenesis of viral carcinogenesis is currently being worked out in MCC. Current diagnostic and therapeutic strategies are discussed, with an eye toward the future development of molecularly targeted treatments.

A comprehensive review of the treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an uncommon but malignant cutaneous neuroendocrine carcinoma with a high incidence of local recurrence, regional lymph node metastases, and subsequent distant metastases. The etiology of MCC remains unknown. It usually occurs in sun-exposed areas in elderly people, many of whom have a history of other synchronous or metachronous sun-associated skin lesions. The outcome for most patients with MCC is generally poor. Surgery is the mainstay of treatment. The role of adjuvant therapy has been debated. However, data from recent development support a multimodality approach, including surgical excision of primary tumor with adequate margins and sentinel lymph node dissection followed by postoperative radiotherapy in most cases, as current choice of practice with better locoregional control and disease-free survival. Patients with regional nodal involvement or advanced disease should undergo nodal dissection followed by adjuvant radiotherapy and, perhaps, systemic platinum-based chemotherapy in most cases.

Merkel cell carcinoma

Background

Merkel cell carcinoma (MCC) is an unusual primary neuroendocrine carcinoma of the skin. MCC is a fatal disease, and patients have a poor chance of survival. Moreover, MCC lacks distinguishing clinical features, and thus by the time the diagnosis is made, the tumour usually have metastasized. MCC mainly affects sun-exposed areas of elderly persons. Half of the tumours are located in the head and neck region.

Methods

MCC was first described in 1972. Since then, most of the cases reported, have been in small series of patients. Most of the reports concern single cases or epidemiological studies. The present study reviews the world literature on MCC. The purpose of this article is to shed light on this unknown neuroendocrine carcinoma and provide the latest information on prognostic markers and treatment options.

Results

The epidemiological studies have revealed that large tumour size, male sex, truncal site, nodal/distant disease at presentation, and duration of disease before presentation, are poor prognostic factors. The recommended initial treatment is extensive local excision. Adjuvant radiation therapy has recently been shown to improve survival. Thus far, no chemotherapy protocol have achieved the same objective.

Conclusion

Although rare, the fatality of this malignancy makes is important to understand the etiology and pathophysiology. During the last few years, the research on MCC has produced prognostic markers, which can be translated into clinical patient care.

Merkel cell carcinoma--current therapeutic options

Merkel cell carcinoma (MCC) is a rare, highly malignant skin tumour of neuroendocrine origin that occurs predominantly in elderly people in sun-exposed areas. It exhibits high levels of radiosensitivity and chemosensitivity both in vivo and in vitro. A variety of adverse prognostic factors have been identified which allow more aggressive therapy to be delivered to patients who are at higher risk of recurrence. The most powerful prognostic factor is the presence of nodal secondaries. Local disease should be excised, but there is some controversy over how wide the margins should be. Wide resection margins are not required provided postoperative radiotherapy is used. In the event of inoperable disease, patient refusal of surgery or frailty, radiotherapy can be used as the sole treatment modality, with a high likelihood of achieving local control. Patients with involved nodes have a higher risk of distant disease. Traditionally, involved nodes have been managed with resection but, currently, there are protocols exploring the use of synchronous chemoradiotherapy as definitive treatment. Although adjuvant chemotherapy has been used in this setting to reduce the risk of distant metastases, its role still remains under investigation. The presence of distant disease carries a grave outlook with responses to chemotherapy occurring frequently, albeit of short duration.

Merkel cell carcinoma--a retrospective analysis of 17 cases

OBJECTIVE

To report clinical experience with the rare neuroendocrine Merkel cell carcinoma of the skin.

SUBJECTS AND SETTING

Seventeen patients with Merkel cell carcinoma of the skin treated at the Departments of Dermatology and ENT, Krankenhaus Dresden-Friedrichstadt, Dresden, Germany, during the years 1984-2000 were evaluated.

METHODS

A retrospective analysis was performed. Age and sex distribution, clinical data and therapy were collected. Outcome measures including overall survival, tumour-free survival and relapse-free survival were determined.

RESULTS

Six male and 11 female patients with an age range of 68-90 years (mean age 73.3 years) were identified. The primary tumour localization was head and neck region (n = 8), upper limbs (8), lower limbs (1). Twelve patients presented in tumour stage I, three in stage II and one in stage III. First line therapy was complete surgical excision with wide margins in 16 patients followed by loco-regional radiation in 12 of 16 cases. In 16 patients follow up data were available. After primary treatment complete response was achieved in 14 of 16 patients (87.5%), two patients had a partial response. The median of relapse-free survival was 44 weeks [mean +/- standard deviation: (44 +/- 118) weeks]. The median of overall survival was 102 weeks [mean +/- standard deviation: (137 +/- 94) weeks]. Three patients with a PR after primary treatment had a median overall survival of only 48 weeks [mean +/- standard deviation: (51 +/- 20) weeks].

CONCLUSIONS

Primary surgical treatment with wide excision combined with radiotherapy seems to be a reasonable first-line treatment but prospective controlled multicentre trials are necessary for validation.

Lumbosacral metastatic extradural Merkel cell carcinoma causing nerve root compression--case report

A 63-year-old man presented with a rare metastatic Merkel cell carcinoma (MCC) involving the lumbosacral spine and causing nerve root compression. Magnetic resonance (MR) imaging revealed an extradural soft tissue mass at the L5-S1 levels. The tumor was subtotally removed and chemotherapy was administered, but he died of multiple metastases from the primary epigastric tumor. Lumbosacral metastatic epidural tumor can manifest as lumbar disc disease symptoms, but MR imaging can non-invasively and rapidly reveal the presence of spinal epidural tumor and any extension to the spinal canal. Extradural MCC metastasis in the lumbosacral area should be considered in the differential diagnosis of radicular symptoms caused by disc herniation.

Management of Merkel cell carcinoma

Merkel cell carcinoma is an uncommon cutaneous malignancy. Although it is rare, Merkel cell carcinoma has been described as the most malignant primary skin tumor. It is therefore important that once diagnosed, Merkel cell carcinoma is treated appropriately. The aim of this short review is to provide a summary of the available literature to guide clinicians in the future management of such patients. Inevitably in such a rare disease, there are no randomized trials of therapy. The treatment of individual patients will rely on opinion as much as the 'evidence'.