Clinical stage of Merkel cell carcinoma and survival are not associated with Breslow thickness of biopsied tumor.

Background: Merkel cell carcinoma (MCC) is an aggressive malignancy that often presents on the skin with concurrent metastatic disease.

Objective: To determine whether Breslow thickness of biopsied MCC correlates with clinical disease stage.

Materials And Methods: We performed a retrospective review of clinical data and histopathology specimens from 34 individuals with MCC treated at the Roswell Park Cancer Institute for whom complete clinical information and histopathology specimens were available.

Results: There was no correlation between Breslow thickness of biopsied MCC on the head and neck or body and clinical stage of disease, progression-free survival, or overall survival. Hence, thin MCCs should not be taken to represent lesions with less-aggressive clinical behavior.

Conclusion: Our findings validate the current practice of staging all newly diagnosed MCC, irrespective of size or Breslow thickness.