How Serious Is A Squamous Cell Carcinoma?

Squamous cell carcinoma is one of the most common types of skin cancer that occurs in the top layer of skin (the epidermis).

Squamous cell carcinoma is one of the most common types of skin cancer that occurs when cells in the top layer of skin (the epidermis) grow out of control. Squamous cells are flat cells in the upper (outer) part of the epidermis that constantly shed as new ones form. 

About 20% of all skin cancers are squamous cell carcinomas. Though squamous cell cancer is not as serious as melanoma, the deadliest form of skin cancer, it can still be serious in advanced cases.

Squamous cell carcinoma tends to develop on sun-exposed areas of the body such as the face, lips, ears, scalp, neck, shoulders, backs of the hands, and forearms, though it may occur anywhere on the skin. 

Characteristics of squamous cell carcinomas include:

• Raised growths or lumps, which may be depressed in the center
• Rough or scaly red patches, which may crust or bleed
• Open sores that may ooze or crust over, don’t completely heal, or that heal and return
• Wart-like growths
• A flat area only slightly different from normal skin

Most squamous cell carcinomas are caused by repeated unprotected skin exposure to ultraviolet (UV) light from sunlight and tanning beds. 

Risk factors for developing squamous cell carcinoma include: 

• Ultraviolet (UV) light exposure (sunlight and tanning beds)
• Light-colored skin
• Age: being older
• Gender: being male
• Radiation treatment 
• Previous skin cancer
• Exposure to certain chemicals such as arsenic, coal tar, paraffin, and some petroleum products 
• Long-term or severe skin inflammation or injury
• Scars from severe burns, areas of skin over serious bone infections, and skin damaged by severe inflammatory skin diseases 
• Psoriasis treatment with psoralens and ultraviolet light (PUVA) 
• Xeroderma pigmentosum 
• Basal cell nevus syndrome (also called nevoid basal cell carcinoma syndrome or Gorlin syndrome)
• Weakened immune system from certain diseases or medical treatments
• Smoking

Treatment for squamous cell carcinoma may include one or more of the following:

• Surgery 
  • Excision: removes the entire tumor
  • Curettage and electrodesiccation: a long, thin instrument with a sharp looped edge on one end (a curette) scrapes off the cancer and the area is treated with an electric needle (electrode) to destroy any remaining cancer cells
  • Mohs surgery (also called Mohs micrographic surgery, or MMS): removes one layer of skin at a time, samples are checked for cancer, and the process is repeated until there are no cancer cells in the skin sample. Can be a slow process but can leave more tissue intact.
  • Lymph node surgery
    • Biopsy
    • Lymph node dissection: many nodes are removed 
  • Skin grafting and reconstructive surgery
• Local treatments 
  • Cryotherapy: liquid nitrogen is applied to the tumor to freeze and kill cancer cells
  • Photodynamic therapy (PDT): a drug is applied to the skin that makes the cells sensitive to certain types of light, and a special light source is focused on the tumors, to kill the cells
  • Topical chemotherapy: anti-cancer medicine applied directly to the skin, usually as a cream or ointment
    • 5-fluorouracil (5-FU) (Efudex, Carac, and Fluoroplex)
  • Immune response modifiers
    • Interferon 
  • Laser surgery: uses a beam of laser light to vaporize cancer cells
• Radiation therapy
  • Used when a tumor is very large or is on an area of the skin where it is difficult to remove with surgery
  • Also used on some patients who can’t have surgery
  • Can often cure small squamous cell skin carcinomas and can delay the growth of advanced cancers
• Systemic chemotherapy 
  • Cisplatin 
  • 5-fluorouracil (5-FU) 
• Targeted therapy 
  • Hedgehog pathway inhibitors: vismodegib (Erivedge) and sonidegib (Odomzo)
  • EGFR inhibitors: cetuximab (Erbitux)
• Immunotherapy for advanced squamous cell skin cancers
  • Immune checkpoint inhibitors called PD-1 inhibitors: cemiplimab (Libtayo) and pembrolizumab (Keytruda)

The prognosis for squamous cell skin cancers is generally good, and death is rare. When the cancer is detected at an earlier stage, it can often be cured.

When squamous cell carcinoma has spread to nearby lymph nodes, it still may be treated with a combination of surgery and radiation. 

Recurrence of squamous cell carcinoma is possible and it is important to follow-up and see a dermatologist regularly to increase the chances of early detection and treatment.