Merkel cell carcinoma of the head and neck: Potential histopathologic predictors

Survival Outcomes of Mohs Surgery versus Wide Local Excision for Less Common Nonmelanoma Skin Cancers: A Stabilized Inverse Probability of Treatment Weighting Analysis

BACKGROUND

Compared with wide local excision (WLE), Mohs micrographic surgery (MMS) can not only remove the tumor tissue but also ensure a negative margin. However, there is limited evidence on whether there is a difference in prognosis between the two techniques for less common nonmelanoma skin cancers (NMSCs).

OBJECTIVES

The aim of our study was to compare the survival outcomes of MMS and WLE for less common NMSCs.

METHODS

This study retrospectively analyzed data from the Surveillance, Epidemiology, and End Results dataset between 2003 and 2018. The less common NMSCs include Merkel cell carcinoma, skin appendage neoplasm, fibromatous malignancy, and other rare NMSCs. The stabilized inverse probability of treatment weighting (SIPTW) and the Kaplan-Meier methods were adopted to assess the overall survival (OS) and cancer-specific survival (CSS). Furthermore, the Cox proportional hazards, Fine-and-Gray regression analysis, and subgroup analysis models were applied to examine the effects of MMS versus WLE based on all-cause and cancer-specific mortality.

RESULTS

We identified 6,582 individuals with less common NMSCs for survival analysis, among which 1,946 patients (29.5%) had undergone MMS and 4,636 (70.5%) had received WLE. Diseases diagnosed in the most recent year, older age, the White race, married status, eyelid/face site, small tumor size, and localized disease were factors significantly associated with MMS treatment. Compared with the WLE group, the MMS group had comparable OS before and after the SIPTW analysis. Additionally, after adjusting for other confounding covariates, the surgery type (WLE vs. MMS) did not show significant associations with all-cause mortality (hazard ratio [HR]: 1.03, 95% confidence interval [CI]: 0.94-1.14, p = 0.517) and disease-specific mortality (HR: 1.16, 95% CI: 0.95-1.42, p = 0.134). Moreover, the subgroup analysis validated these findings.

CONCLUSION

MMS and WLE have comparable OS and CSS for less common NMSCs.

The Evolving Treatment Landscape of Merkel Cell Carcinoma

OPINION STATEMENT

Merkel cell carcinoma (MCC) has a high risk of recurrence and requires unique treatment relative to other skin cancers. The patient population is generally older, with comorbidities. Multidisciplinary and personalized care is therefore paramount, based on patient preferences regarding risks and benefits. Positron emission tomography and computed tomography (PET-CT) is the most sensitive staging modality and reveals clinically occult disease in ~ 16% of patients. Discovery of occult disease spread markedly alters management. Newly diagnosed, localized disease is often managed with sentinel lymph node biopsy (SLNB), local excision, primary wound closure, and post-operative radiation therapy (PORT). In contrast, metastatic disease is usually treated systemically with an immune checkpoint inhibitor (ICI). However, one or more of these approaches may not be indicated. Criteria for such exceptions and alternative approaches will be discussed. Because MCC recurs in 40% of patients and early detection/treatment of advanced disease is advantageous, close surveillance is recommended. Given that over 90% of initial recurrences arise within 3 years, surveillance frequency can be rapidly decreased after this high-risk period. Patient-specific assessment of risk is important because recurrence risk varies widely (15 to > 80%: Merkelcell.org/recur) depending on baseline patient characteristics and time since treatment. Blood-based surveillance tests are now available (Merkel cell polyomavirus (MCPyV) antibodies and circulating tumor DNA (ctDNA)) with excellent sensitivity that can spare patients from contrast dye, radioactivity, and travel to a cancer imaging facility. If recurrent disease is locoregional, management with surgery and/or RT is typically indicated. ICIs are now the first line for systemic/advanced MCC, with objective response rates (ORRs) exceeding 50%. Cytotoxic chemotherapy is sometimes used for debulking disease or in patients who cannot tolerate ICI. ICI-refractory disease is the major problem faced by this field. Fortunately, numerous promising therapies are on the horizon to address this clinical need.

Best practices in surgical and nonsurgical management of head and neck Merkel cell carcinoma: An update

Merkel cell carcinoma (MCC) is a rare, highly aggressive cutaneous neuroendocrine carcinoma. Controversy exists regarding optimal management of MCC as high-quality randomized studies and clinical trials are limited, and physicians are bound to interpret highly heterogeneous, retrospective literature in their clinical practice. Furthermore, the rising incidence and notably poor prognosis of MCC urges the establishment of best practices for optimal management of the primary tumor and its metastases. Herein, we summarized the relevant evidence and provided an algorithm for decision-making in MCC management based on the latest 2021 National Comprehensive Cancer Network guidelines. Additionally, we report current active MCC clinical trials in the United States. The initial management of MCC is dependent upon the pathology of the primary tumor and presence of metastatic disease. Patients with no clinical evidence of regional lymph node involvement generally require sentinel node biopsy (SLNB) while clinically node-positive patients should undergo fine needle aspiration (FNA) or core biopsy and full imaging workup. If SLNB or FNA/core biopsy are positive, a multidisciplinary team should be assembled to discuss if additional node dissection or adjuvant therapy is necessary. Wide local excision is optimal for primary tumor management and SLNB remains the preferred staging and predictive tool in MCC. The management of MCC has progressively improved in the last decade, particularly due to the establishment of immunotherapy as a new treatment option in advanced MCC. Ongoing trials and prospective studies are needed to further establish the best practices for MCC management.

A SEER analysis of survival and prognostic factors in merkel cell carcinoma of the head and neck region

While Merkel cell carcinoma (MCC) of the head and neck is highly malignant, it remains poorly characterized due to its rarity. The purpose of this study was to examine prognostic factors for overall survival (OS) and disease-specific survival (DSS) in patients with MCC of the head and neck region. The Surveillance, Epidemiology and End Results registry was reviewed for patients diagnosed between 1984 and 2016 with histologically confirmed, primary MCC of the head and neck region. A total of 2818 patients met the inclusion criteria, with a median age at diagnosis of 77 years. At five and 10 years, respectively, the OS was 42.4% and 25.1% and the DSS was 67.9% and 64.1%. Multivariate Cox analysis indicated that predictors of decreased DSS included age at diagnosis ≥75 years, white race, increasing tumor spread, lymph node involvement and either the lip or the scalp/neck as a primary site. When adjusting for the aforementioned factors, tumor depth was not found to be a prognostic factor for DSS. We anticipate these results will help clinicians to counsel patients regarding expectations and potential prognosis.

Mohs Micrographic Surgery for the Treatment of Merkel Cell Carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive malignant neoplasm. Traditionally, wide local excision has been used for local control. However, the tissue-sparing capability of Mohs micrographic surgery (MMS) and the greater certainty of complete tumor removal offer a potential advantage over wide local excision if MMS offers acceptable cure rates.

OBJECTIVE

This study aims to help elucidate management of MCC and includes one of the largest groups of patients from a single institution.

MATERIALS AND METHODS

This study is a retrospective chart review of 22 patients with cutaneous MCC treated with MMS at our practice over 20 years. Clinical characteristics and outcomes were examined. The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in the approval by our institution's human research review committee.

RESULTS

The overall local recurrence rate was 5% (1/22). The overall rate of biopsy-proven metastasis to regional lymph nodes was 14% (3/22). No cases of distant metastases were documented.

CONCLUSION

To our knowledge, this is the largest group of patients with MCC treated with MMS from a single institution and indicates that MMS may be a useful treatment modality for this rare aggressive disease.

Merkel cell carcinoma of the head and neck: poorer prognosis than non-head and neck sites

Background:

Merkel cell carcinoma is a rare, aggressive neurocutaneous malignancy. This study investigated whether patients with Merkel cell carcinoma in the head and neck had poorer outcomes than patients with Merkel cell carcinoma located elsewhere.

Methods:

A retrospective study was performed of patients with Merkel cell carcinoma treated at the Jewish General Hospital in Montréal, Canada, from 1993 to 2013. Associations between clinicopathological characteristics and disease-free and disease-specific survival rates were examined according to the Kaplan–Meier method.

Results:

Twenty-seven patients were identified. Although basic clinicopathological characteristics and treatments were similar between head and neck and non-head and neck Merkel cell carcinoma groups, disease-free and disease-specific survival rates were significantly lower in the head and neck Merkel cell carcinoma group (log-rank test; p = 0.043 and p = 0.001, respectively). Mortality was mainly due to distant metastasis.

Conclusion:

Patients with head and neck Merkel cell carcinoma had poorer survival rates than patients with non-head and neck Merkel cell carcinoma in our study. The tendency to obtain close margins, a less predictable metastatic pattern, and/or intrinsic tumour factors related to the head and neck may explain this discrepancy.

Merkel cell carcinoma: An algorithm for multidisciplinary management and decision-making

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumor of the skin. Therapeutic approach is often unclear, and considerable controversy exists regarding MCC pathogenesis and optimal management. Due to its rising incidence and poor prognosis, it is imperative to establish the optimal therapy for both the tumor and the lymph node basin, and for treatment to include sentinel node biopsy. Sentinel node biopsy is currently the most consistent predictor of survival for MCC patients, although there are conflicting views and a lack of awareness regarding node management. Tumor and node management involve different specialists, and their respective decisions and interventions are interrelated. No effective systemic treatment has been made available to date, and therefore patients continue to experience distant failure, often without local failure. This review aims to improve multidisciplinary decision-making by presenting scientific evidence of the contributions of each team member implicated in MCC management. Following this review of previously published research, the authors conclude that multidisciplinary team management is beneficial for care, and propose a multidisciplinary decision algorithm for managing this tumor.