Squamous cell carcinoma (SCC) can occur in other organs of the body but most commonly occurs on the skin. The cancer usually grows slowly but over time can invade deeper tissues and nerves. When it occurs on the skin, SCC is almost always treatable and is seldom life-threatening, especially when it is treated promptly. Squamous cell cancer of the skin is curable with surgery alone 95% of the time.
Squamous cell carcinoma is more common in people with fair skin and with a history of increased sun exposure and sun-damaged skin. People in this category can develop multiple SCCs. Sometimes, these cancers are preceded by a pre-cancerous growth called Actinic Keratosis (AK).
Diagnosis and Workup: Diagnosis and workup of SCC starts with a skin and lymph node exam. SCCs often have a typical appearance so your doctor may diagnose the cancer by visual exam, but a skin biopsy is usually done to confirm the diagnosis. [link diagnosis of skin cancer]. Most of the time, imaging and lab studies are not needed unless this is a large cancer in a delicate area or there is a concerning finding on physical exam.
Staging: Staging is a process to categorize the cancer by how big it has grown and how far it has spread
- Stage 1: The tumor is smaller or equal to 2cm in greatest dimension and has not spread to lymph nodes or other organs
- Stage 2: The tumor is larger than 2cm, but smaller than or equal to 4cm is greatest dimension. It has not spread to lymph nodes or other organs
- Stage 3: The tumor is larger than 4cm or there is minor bone erosion, involvement of nerves, deep invasion defined as extension beyond the fat underneath the skin or more than 6 millimeters in depth or spread to a single nearby lymph node.
- Stage 4: The tumor invades nearby bone or the skull, many nearby lymph nodes or distant organs such as the brain or lungs
Treatment and Outcomes: Superficial treatments can be used for very superficial or shallow cancers, also called squamous cell carcinoma in situ, or Bowen’s disease.
- Cryotherapy- using a cold liquid or tool to freeze cancer cells
- Photodynamic therapy(PDT)- using light energy to activate a drug that is applied to the area
- Topical medications- Imiquimod and fluorouracil(5-FU)
- Electrodesiccation & Curettage – scraping away the visible tumor with a sharp tool followed by cauterization of the base of the wound with an electric needle.
- If the cancer is more invasive, treatment usually consists of surgery to remove the cancer. This can be done with Mohs micrographic surgery or conventional surgery (WLE). [link to WLE vs MOHS] Radiation may be used rarely as primary therapy or added after surgery [See radiation].
- If your cancer returns after it has been treated, this is considered a high-risk squamous cell skin cancer. Other high-risk situations include fast growth, growing deeply, a weakened immune system, a tumor that forms in skin that has been previously damaged by a burn, surgery or radiation and signs of nerve involvement. High risk situations are more likely to require radiation after surgery.
Surveillance and Survivorship: Once you have developed a SCC, you are at a higher risk of having another one, so please be sure to follow up with your doctor and also with your dermatologist to discuss the need for routine full-body skin exams.