How Prevalent is Advanced CSCC?

Michael R. Migden, MD:Squamous cell carcinoma of the skin is also known as cutaneous squamous cell carcinoma. This is distinguished from head and neck squamous cell carcinoma, which is sometimes called oral mucosal squamous cell carcinoma. The latter has a different etiology, whereas the skin squamous cell carcinoma is an ultraviolet damage disease, for the most part. The nonskin head and neck, or mucosal disease, has other etiology, and could be human papilloma virus, so that’s the big difference.

The skin cancers in general are made up of 2 main types. You have melanoma, then you have your nonmelanoma. Your nonmelanoma skin cancers are predominantly basal cell carcinoma—the most common, and squamous cell carcinoma—the second most common; both skin cancers. Approximately, 80% are basal cell carcinoma and approximately 20% are squamous cell carcinoma. It’s hard to know accurate numbers for incidence and prevalence because of the fact that cutaneous cell carcinoma is not found as part of cancer registries.

Although the numbers that we do have, show us that approximately 3.5 million cases per year incidence, based on some data from some years ago; maybe higher than that now. If you use 20%, it gives you 700,000 cases of cutaneous squamous cell carcinoma a year. The vast majority of these—approximately 95%, are curable with surgery alone and can be completely removed. Of course, the others that aren’t removed can become advanced. Advanced is an umbrella term that includes locally advanced contiguous disease, which can be quite extensive and is also potentially life threatening, as well as metastatic disease. The 2 broad categories of metastatic disease include the locoregional, such as neck, lymph nodes, or parotid lymph nodes, or the distant metastasis such as distant organ or bone.

Although the majority of these nonmelanoma skin cancers are cured completely with surgery, either with wide local excision or Mohs surgery—Mohs surgery being a more precise surgical technique with a high cure rate—there are some that can progress and become advanced and can even lead to death. Both basal cell and squamous cell carcinoma can produce death; both locally advanced and metastatic disease, not just metastatic disease. The estimated death from cutaneous squamous cell carcinoma ranges from approximately 3900 to [about] 8700 cases per year, and that’s a lot of deaths.

Transcript edited for clarity.