Here’s What Can Happen If Skin Cancer Goes Untreated?

Written by Peggy Chern, MD, Board Certified Dermatologist on February 22, 2021 No Comments

untreated skin cancer

Like all types of cancer, skin cancer is serious. In the United States, more than 2 people die of skin cancer every hour. Skin cancer is also highly prevalent, with an estimated 1 in 5 people being diagnosed with some form of skin cancer before the age of 70. In fact, there are more skin cancer diagnoses than for all other cancers combined. (Source)

When left untreated, skin cancer can permanently damage surrounding cells, or metastasize throughout the body, becoming fatal. This post discusses the three main types of skin cancer, and the risks in leaving each untreated. Preventing Skin Cancer

The best treatment for skin cancer is prevention. One major modifiable risk factor for skin cancer is UV exposure, so it’s best to be careful with your time in the sun.

  • Never use tanning beds, which damage the skin with UV light.
  • Avoid the sun between 10am-4pm when radiation is strongest
  • If you are in the sun, wear protective clothing and a wide-brimmed hat
  • Use a full-spectrum sunscreen or sunblock that protects from both UVA and UVB rays on all exposed skin

Additional risk factors for skin cancer include exposure to carcinogenic chemicals or other toxins, genetics, and health issues and medications that suppress the immune system.

Why Early Detection Is So Important

Early detection is your best line of defense against the risks posed by skin cancer. What you notice as a small growth or area of discoloration could be just the tip of a much more serious problem underneath the skin’s surface.

Do self-checks monthly and see your dermatologist for a thorough, full-body check once per year. Early detection that leads to early treatment can reduce the need for invasive procedures and will improve your chances for survival.


  • Exposure to ultraviolet (UV) light is a major risk factor for most melanomas
  • Melanoma accounts for just 4-7% of skin cancer cases, but the most skin cancer deaths
  • Those who wait more than 119 days to get treatment have a 41% greater risk of dying
  • With early detection and treatment of an early-stage melanoma, the 5-year survival rate is 99%

Melanoma can be a very dangerous type of skin cancer. There have been many recent advances in melanoma treatment, but the best defense is prevention and early detection. This cancer develops in the body’s melanocytes, a type of skin cell that produces pigment. Melanoma can be a quickly growing cancer and is more likely to metastasize than any other type of skin cancer.

Because it can be quickly growing, it’s very dangerous to leave melanoma untreated. This skin cancer can become life-threatening within 4-6 weeks. The cure rate is high, however, if the melanoma is diagnosed and treated when it is thin or at an early stage.

Basal Cell Carcinoma

  • Basal Cell Carcinoma (BCC) is the most common type of skin cancer
  • 90% of BCC cases are associated with exposure to UV radiation from the sun
  • BCC is the slowest growing type of skin cancer and least likely to metastasize
  • However, BCC can cause permanent tissue damage and disfigurement if left untreated

Basal Cell Carcinoma is a type of skin cancer that can affect both upper and deeper layers of the skin. BCCs most commonly appear on the face. While BCC is the slowest growing skin cancer, it can spread locally to adjacent cells and cause lesions, ulcers, bleeding or infection. In very rare cases, it can metastasize.

When left untreated, these skin lesions present a risk of permanent damage to skin tissue, which can be costly and invasive to repair. Related infections may become systemic, which puts your health at risk.

Squamous Cell Carcinoma

  • Squamous Cell Carcinoma (SCC) is the second most common type of skin cancer
  • Like BCC, 90% of cases are associated with exposure to UV radiation from the sun
  • If you’ve had an organ transplant, you’re 100 times more likely to develop SCC
  • In the United States, more than 15,000 people die from SCC each year

Squamous Cell Carcinoma primarily affects the top layer of the skin, but can go deeper and metastasize if left untreated. The cancer is likely to grow locally before it begins to metastasize to unrelated areas of the body. However, for some people, SCC grows very quickly.

If left untreated, SCC can metastasize, and is more likely to do so if it’s first detected on high-risk sites like the ears and lip, or within scars. While SCC is less likely to metastasize than melanoma, it can be life-threatening if it does.

If you notice any abnormalities on your skin, such as new or changing moles, it’s best to see your doctor as soon as possible.

Peggy Chern, MD

Dr. Chern practices dermatologic surgery and procedural dermatology, including Mohs surgery, laser, vein, and cosmetic procedures. She joined Westlake Dermatology in 2009. Dr. Chern is Board Certified by the American Board of Dermatology and is a member of the American Academy of Dermatology, the American Society for Dermatologic Surgery, the American College of Mohs Surgery, the Texas Medical Association, and the Travis County Medical Association.

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