Incidence, mortality and survival of Merkel cell carcinoma: a systematic review of population-based studies

Abstract

Background Merkel Cell Carcinoma (MCC) is a rare, aggressive skin cancer that most commonly occurs in UV-exposed body sites. Its epidemiology in different geographies and populations is not well characterised. Objective The objective of this systematic review is to summarize evidence on the incidence, mortality, and survival rates of MCC from population-based studies. Methods We searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from database inception to June 6th, 2023. No geographic, age or date exclusions were applied. We included population-based studies of MCC that reported the incidence, survival, or mortality rate, and considered systematic reviews. A data-charting form was created and validated to identify variables to extract. Two reviewers then independently charted the data for each included study with patient characteristics, and estimates of incidence rate, mortality rate, and survival rate and assessed the quality of included studies using the Joanna Briggs Institute Checklist for Prevalence studies, Newcastle-Ottawa Scale and Assessment of Multiple Systematic Reviews. We abstracted age-, sex-, stage- and race-stratified outcomes, and synthesized comparisons between strata narratively and using vote counting. We assessed the certainty of evidence for those comparisons using the Grading of Recommendations, Assessments, Developments and Evaluations framework. Results We identified 11,472 citations, of which 52 studies from 24 countries met our inclusion criteria. Stage 1 and the head and neck were the most frequently reported stage and location at diagnosis. The incidence of MCC is increasing over time (high certainty), with the highest reported incidences reported in Southern hemisphere countries (Australia [2.5 per 100,000], New Zealand [0.96 per 100,000]) (high certainty). Male patients generally had higher incidence rates compared to female patients (high certainty), although there were some variations over time periods. Survival rates varied, with lower survival and/or higher mortality associated with male sex (moderate certainty), higher stage at diagnosis (moderate-to-high certainty), older age (moderate certainty), and immunosuppression (low-to-moderate certainty). Conclusions MCC is increasing in incidence and may increase further given the ageing population of many countries. The prognosis of MCC is poor, particularly for males, those who are immunosuppressed, and patients diagnosed at higher stages or at an older age.

Merkel cell carcinoma overlapping Bowen’s disease: two cases report and literature review

“…The annual incidence rate of MCC is approximately 0.24 cases per 100,000 individuals, showing a trend of exponential increase. This rising incidence can be attributed to a confluence of factors, including demographic shifts towards an aging population, heightened use of immunosuppressive agents, significant improvements in diagnostic technologies facilitating earlier and more accurate detection, and a general enhancement in clinical vigilance and awareness regarding this malignancy (Mistry et al 2023 ; Mohsen et al 2023 ). Our retrospective examination has disclosed that incidences of MCC overlapping BD present a gender distribution, with a male-to-female ratio of 1:1.6.…”

Genetic predisposition to milder forms of COVID-19 may provide some resilience to head and neck cancers

“…The effects of immunosuppression are nonspecific; they do not depend on its etiology. For example, prolonged immunosuppression in inflammatory bowel disease also increases the risk of developing HNC ( 29 , 30 ). In the case of asymptomatic disease, which is expected to be common in adult COVID-19 controls according to recent epidemiological evaluations ( 31 , 32 ), the state of immunosuppression may be present at the time of infection and is due to various genetic or environmental causes.…”

Color Analysis of Merkel Cell Carcinoma: A Comparative Study with Cherry Angiomas, Hemangiomas, Basal Cell Carcinomas, and Squamous Cell Carcinomas

“…Recent epidemiological data indicate that around 2500 new cases of MCC are reported each year within the European Union (EU), and approximately 1000 of these patients will succumb to the disease [5,6]. The high mortality rate can be attributed to the lack of effective standard treatments for metastatic MCC until recently [7][8][9][10].…”