Background: Merkel cell carcinoma (MCC) is a malignant skin cancer with a 5-year survival rate of approximately
50%. Knowledge of MCC has increased in recent years mostly due to improved diagnosis techniques. In Spain
there is lack of information regarding the incidence and tumour characteristics, and the treatment approaches are not standardised. The objective of this study was to provide information of the clinical and epidemiological
characteristics of MCC patients in Spain.
Methods: Retrospective, observational study involving 192 patients from 25 Spanish hospitals. Evaluated vari ables included overall survival and incidence rate of Merkel cell polyomavirus, in patients diagnosed from 2012
to 2016.
Results: The Spanish incidence rate was estimated 0.32/100,000 inhabitants/year, with variations according to
geographical regions, being slightly higher in areas with greater sunlight exposure. In total, 61.5% of tumours
showed expansive growth (progressive growth of the tumour), 78.6% showed localisation in UV-exposed skin.
97.4% of patients were diagnosed by excisional biopsy. Surgery was the first line treatment in 96.6% of patients,
radiotherapy in 24.6%, and chemotherapy in 6.3%. These treatments were not mutually exclusive. Median
overall survival was 38.3 months (78.4% at 12 months and 60% at 24 months). MCPyV was present in 33.8% of
patients.
Conclusion: The incidence of MCC in Spain is one of the highest in Europe, with a slight predominance in men.
The sample has shown that a biopsy is available for diagnosis in most cases. Moreover, the treatment is surgical
when the tumour is localized and is associated with lymphadenectomy, and/or it is radiotherapy if widespread