How common is stage 3 squamous cell carcinoma?

It's difficult to determine the exact number of cases of stage 3 squamous cell carcinoma. This is due in part to the fact that the cancer may be diagnosed and treated before it reaches stage 3, or it may not be diagnosed till it's reached a later stage. The disease usually progresses pretty slowly, so stage 3 may not be as common as earlier stages. In general, squamous cell carcinoma is a pretty common type of skin cancer. It's estimated that there are about 200,000 to 300,000 new cases diagnosed in the United States each year.