Squamous Cell Carcinoma

Squamous Cell Carcinoma Overview

Squamous cell carcinoma (SCC) or cutaneous squamous cell carcinoma (CSCC) is the second most common form of skin cancer after basal cell carcinoma. It starts in squamous cells in the outer layer of your skin, the epidermis. Usually, squamous cell carcinomas form on areas of your skin that receive the most sun exposure like your head, arms and legs. Cancer can also form in areas of your body where you have mucous membranes, which are the inner lining of your organs and body cavities like in your mouth, lungs and anus.

There are five stages of squamous cell carcinoma:

Stage 0: Cancer is only in the top layer of your skin (epidermis). This is also called squamous cell carcinoma in situ.
Stage I (1): Cancer is in the top and middle layers of your skin (epidermis and dermis).
Stage II (2): Cancer is in the top and middle layers of your skin and moves to target your nerves or deeper layers of skin (epidermis, dermis and subcutis).
Stage III (3): Cancer has spread beyond your skin to your lymph nodes.
Stage IV (4): Cancer has spread to other parts of your body and your organs like your liver, lungs or brain.

Squamous Cell Carcinoma Symptoms

Symptoms of squamous cell carcinoma include skin changes like:

  • A rough-feeling, bump or growth, which might crust over like a scab and bleed.
  • A growth that’s higher than the skin around it but sinks down (depression) in the middle.
  • A wound or sore that won’t heal, or a sore that heals and then comes back.
  • An area of skin that’s flat, scaly and red that’s larger, about 1 inch (2.5 centimeters).

Squamous Cell Carcinoma Causes

A mutation to the p53 gene causes squamous cell carcinoma. The most common way that your p53 gene mutates is from ultraviolet (UV) exposure from the sun, or from using indoor tanning beds.

The p53 gene provides instructions for your cells to divide and replicate to replace cells when they reach the end of their lifespan. Your p53 gene is a tumor suppressor, which means that the gene controls how much and how often your cells should create new cells. Too many cells create tumors, which can be cancerous.

A mutation to the p53 gene means that your cells don’t have the instructions they need to do their job correctly. As a result, your squamous cells divide and replicate too often, causing tumors (bumps, lumps or lesions) to form in and on your body.

Squamous Cell Carcinoma Diagnostics

After your physical exam, your healthcare provider might offer tests to confirm a diagnosis, which could include:

  • Skin biopsy: Removing a small sample of the affected tissue to examine it under a microscope.
  • Imaging tests (CT scan or MRI): Your healthcare provider will use an imaging test to identify the size of your carcinoma underneath your skin and to see if it spread to other parts of your body, especially your lymph nodes.

Squamous Cell Carcinoma Treatment

Treatment for squamous cell carcinoma focuses on removing cancer from your body. Your treatment options vary based on the size, shape and location of your cancer and could include:

Cryosurgery: Freezing the cancer cells to destroy them.
Photodynamic therapy (PDT): Using blue light and light-sensitive agents to remove cancer from your skin.
Curettage and electrodesiccation: Scratching off the cancerous lump with a spoon-like instrument (curette), then burning the area with an electric needle.
Excision: Cutting the cancer out of your skin and stitching your skin back together.
Mohs surgery: Removing layers of skin affected by cancer, most common for facial cancers.
Systemic chemotherapy: Using powerful medicines to destroy cancer cells in your body.