Survival outcomes and epidemiology of Merkel cell carcinoma of the lower limb and hip: A Surveillance, Epidemiology, and End Results analysis 2000-2018

Avelumab in the Treatment of Advanced Merkel Cell Carcinoma: A Systematic Review

BACKGROUND

Avelumab, a programmed death ligand-1 inhibitor, has shown success in providing durable responses for difficult-to-treat Merkel cell carcinomas (MCCs).

OBJECTIVE

Evaluate the efficacy and safety of avelumab in the treatment of advanced MCC.

METHODS

Studies reporting the use of avelumab as a monotherapy or in combination with other agents in the treatment of stage III or IV (advanced) MCC were included. The primary outcomes were overall response rate, overall survival (OS), and treatment-related adverse events.

RESULTS

A total of 48 studies were included, involving 1,565 patients with advanced MCC. Most patients were male (1,051, 67.3%) with stage IV MCC (517, 97.0%). The overall response rate was 46.1% (partial response-25.4% and complete response-20.7%) after a mean follow-up period of 9.5 months. Kaplan-Meier survival curves for the pooled stage III and IV group demonstrated OS rates of 58% at 1 year, 47% at 2 years, and 28% at 5 years after completion of treatment with avelumab (median OS: 23.1 months). The most common treatment-related adverse events consisted of constitutional (44%), gastrointestinal (19%), and dermatologic (12%) symptoms.

CONCLUSION

Avelumab monotherapy and combination therapy have shown success in the overall response rate and survival for patients with advanced MCC.

Clinicopathological characteristics and prognosis of Merkel cell carcinoma: a single-center retrospective study in Korea

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin with high mortality. However, its clinical characteristics in Asian patients remain uncertain owing to its low incidence.

OBJECTIVE

To analyze the clinicopathological features of MCC and identify factors associated with its prognosis.

METHODS

The medical records of 62 patients with MCC were retrospectively reviewed. Data on clinical features, survival outcomes, prognostic factors, histopathology and immunohistochemical profile of the patients were collected and analyzed. Merkel cell polyomavirus status was evaluated using immunohistochemistry.

RESULTS

The incidence of MCC significantly increased over time. The mean duration of follow-up was 51.2 months, with an overall 5-year survival of 80.6%. More female patients with MCC were identified than male patients (1.3:1). Approximately half of the patients had stage I disease at the time of initial presentation. The primary tumor was frequently located in the lower extremities (40.3%), followed by the head and neck (32.3%), upper extremities (22.6%), and the trunk (4.8%). Male sex was associated with poorer overall survival (p = 0.003). Post-resection adjuvant radiotherapy significantly improved the overall survival (p = 0.023). Sentinel lymph node biopsy during surgery ameliorated the progression-free survival (p = 0.036) in patients with stage I or II cancer. Lymphovascular and perineural invasion were associated with a poor prognosis. Old age, immunohistochemical profiles, and Merkel cell polyomavirus-positivity were not associated with prognosis.

CONCLUSION

Post-surgical adjuvant radiotherapy and sentinel lymph node biopsy significantly improve the course of MCC.

Demographic and Clinicopathological Factors as Predictors of Lymph Node Metastasis in Merkel Cell Carcinoma: A Population-Based Analysis

Merkel cell carcinoma is an aggressive malignant skin tumor with high recurrence and low survival. Lymph nodal metastases are associated with a worse overall prognosis. Our aim was to assess how lymph node procedures and positivity are influenced by demographic, tumor, and treatment characteristics. The Surveillance, Epidemiology and End Results database was searched for all cases of Merkel cell carcinoma of the skin between 2000 and 2019. Univariable analysis was conducted using the chi-squared test with the aim of identifying differences in lymph node procedures and lymph node positivity for each variable. We identified 9182 patients, of which 3139 had sentinel lymph node biopsy/sampling, and 1072 had therapeutic lymph node dissection. Increasing age, increasing tumor size, and truncal location were associated with higher positive lymph node rates.

Epidemiology of Merkel Cell Polyomavirus Infection and Merkel Cell Carcinoma

Merkel cell polyomavirus (MCPyV) is a ubiquitous virus replicating in human dermal fibroblasts. MCPyV DNA can be detected on healthy skin in 67−90% of various body sites, and intact virions are regularly shed from the skin. Infection occurs early in life, and seropositivity increases from 37 to 42% in 1- to 6-year-olds to 92% in adults. Merkel cell carcinoma (MCC) is a rare but very aggressive neuroendocrine tumor of the skin. It develops mainly on sun-exposed areas as a fast-growing, reddish nodule. Two MCC entities exist: about 80% of MCC are MCPyV-associated. Tumorigenesis is driven by viral integration into the host genome and MCPyV oncogene expression. In MCPyV-negative MCC, UV radiation causes extensive DNA damage leading to the deregulation of the cell cycle. In recent decades, MCC incidence rates have increased worldwide, e.g., in the United States, from 0.15 in 1986 to 0.7/100,000 in 2016. Risk factors for the development of MCC include male sex, older age (>75 years), fair skin, intense UV exposure, and immunosuppression. Projections suggest that due to aging populations, an increase in immunosuppressed patients, and enhanced UV exposure, MCC incidence rates will continue to rise. Early diagnosis and prompt treatment are crucial to reducing high MCC morbidity and mortality.

Merkel Cell Carcinoma of the External Ear: Population-Based Analysis and Survival Outcomes

(1) Background: Due to its highly aggressive behavior, the ability to identify and manage Merkel Cell Carcinoma (MCC) with a full understanding of its characteristics is essential. Because the external ear is an exposed area, resection can have dramatic consequences on patient’s self-image, which is why it is fundamental to detect MCC, typically found on UV-exposed regions such as the ears, at an early stage. (2) Methods: The Surveillance, Epidemiology, and End Results (SEER) database was searched for all external ear MCC between 2000 and 2019. A descriptive analysis based on frequencies was made to describe the demography of pathophysiologic features linked to MCC. Overall survival (OS) was studied and compared between variables with a log rank test. A multivariable Cox regression analysis was then computed to identify independent prognostic factors. (3) Results: A total of 210 patients (160 men) were identified with a median age of 80 years. The median OS was 47 months. Factors associated with lower OS included an age of over 80 years, the male gender, a tumor size of >5 cm, and metastatic disease. Gross (<1 cm) and wide (>1 cm) surgery excision margins were the surgery types with the best OS. (4) Conclusions: MCC of the external ear is diagnosed mostly in old men. Among the 182 patients who received a surgical procedure, gross and wide excision without radiotherapy were associated with the best OS.