What Happens if You Let Skin Cancer Go Untreated?

November 17, 2020

Elderly woman has untreated skin cancer

Many patients who are diagnosed with skin cancer, especially in the earliest stages, find themselves wondering whether treatment is really necessary. Skin cancer, like other forms of cancer, is serious and requires proper treatment. According to Dr. Valerie Truong of U.S. Dermatology Partners in Dallas, Plano, Sherman, and Corsicana, Texas, “The visible part of skin cancer can often be like the tip of an iceberg. What you see on the surface is only a small percentage of the actual cancer. Even if the skin cancer appears to be negligible, there is always a risk that it will grow and spread. I recommend that people who suspect they have skin cancer get a skin check for an earlier diagnosis, and therefore, earlier treatment.” In this blog, Dr. Truong talks more about what happens if you let skin cancer go untreated and the potential risks that may arise for skin health as well as overall health and well-being.

Skin Cancer Basics

Skin cancer, like other types of cancer, is caused by damage to the skin on a cellular level. When the skin cells are damaged, they begin to grow and reproduce aberrantly. In some cases, skin cancer will grow slowly and only impact cells locally. Other forms of skin cancer can metastasize, spreading to surrounding tissues and/or to parts of the body that aren’t directly connected. The size, location, and degree of metastasis will determine what stage of skin cancer an individual is diagnosed with. Staging in all forms of cancer is an efficient way to develop a treatment plan.

Not all skin cancer is the same. There are many different types of skin cancer, but the three most common are basal cell carcinoma, squamous cell carcinoma, and melanoma.

  • Basal cell carcinoma can develop both superficially and within the deeper layers of skin. This type of skin cancer is typically low-grade, slow-growing, and unlikely to metastasize.
  • Squamous cell carcinoma develops within the top layers of the skin but can invade deeper layers of skin. The rate of growth is variable. These skin cancers tend to grow locally before spreading. However, there are instances where squamous cell carcinoma can grow rapidly and metastasize.
  • Melanoma is the most serious type of skin cancer. Melanoma develops from the melanocytes, the body’s pigment-producing skin cells. Melanoma often grows quickly, and it’s the most likely form of skin cancer to metastasize.


It is important to note that as these skin cancers arise from different cell lines, they cannot turn into each other (i.e. a basal cell carcinoma will never become a melanoma and vice versa).

Risks Associated with Untreated Basal Cell Carcinoma

Basal cell carcinoma is the most common form of skin cancer. It’s also the slowest growing of the common forms of skin cancer and the least likely to metastasize, meaning it rarely spreads to other parts of the body. However, basal cell carcinoma presents a risk for disfigurement if left untreated. Without proper intervention, basal cell carcinoma can grow and invade local structures.  Additionally, these lesions may present a risk for ulceration (the development of sores), bleeding, and infection. The type of treatment available in the early stages is likely to be more effective, less invasive, and more cost-effective. The longer basal cell carcinoma goes untreated, the procedures necessary to remove it become more advanced, invasive, and costly.

To receive treatment in the earliest stages, patients should let their dermatologist know if they notice small bumps that have a shiny or pearly appearance. Basal cell carcinomas can be completely asymptomatic.  In most cases, basal cell carcinomas are not painful, but these lesions may bleed frequently or create sores and ulcers. Commonly, patients will mistake basal cell carcinomas for pimples or bug bites. If the pimple or bug bite does go away after two weeks, it should be evaluated by a dermatologist. According to Dr. Truong, “I recommend early treatment for cancerous growths. The longer the skin cancer goes untreated, the more complicated the treatment. There is a greater risk for a more invasive surgery with more severe cosmetic complications. If treated early, basal cell carcinomas can typically be treated more quickly and easily, with minimal impact to a patient’s appearance, health, and function.”

Risks Associated with Untreated Squamous Cell Carcinoma

Squamous cell carcinoma is the second most common type of skin cancer. This type of cancer has a variable growth rate. Some squamous cell carcinomas grow slowly, while others can grow rapidly. Smaller squamous cell carcinomas have a lower risk of metastasis, however, if they are large, they are at higher risk for spreading to other organs, including the lymph nodes. In certain locations, such as the ear, lip, and temple, there is a higher risk of spread as well.  As with all skin cancers, treatment in earlier stages is always recommended to prevent cancer from spreading. Squamous cell carcinomas can be life-threatening if left untreated.

According to Dr. Truong, “We recommend patients keep a close eye on any changes to their skin color, texture, or sensation by completing self-exams at home every month or every other month. With squamous cell carcinoma, the first thing patients notice is red, rough, and scaly patches of skin. This type of skin cancer can be asymptomatic, but can also be painful to the touch. Some patients experience abnormal sensations in the areas (numbness, burning, tingling, itchiness). The feelings of pain and numbness may be the first sign that squamous cell carcinoma is spreading and impacting surrounding nerves, therefore it is important to let your dermatologist know if you are experiencing these symptoms.”

Risks Associated with Untreated Melanoma

Melanoma makes up a very small percentage of overall skin cancer cases. However, melanoma is responsible for over half the annual deaths attributed to skin cancer. Dr. Truong says, “Melanomas are an aggressive and quickly evolving form of cancer. It’s the most likely to grow quickly and metastasize. A treatment plan should be formulated as soon as possible. When caught and treated early, melanoma has a high cure rate, but when treated in later stages, cure rates drop drastically, especially if the cancer has metastasized.”

Within six weeks of initial development, melanoma can become life-threatening, therefore, early treatment is extremely important. In order to access treatment in the earliest stages, patients need to know what to look for. Melanoma develops from the melanocytes, cells that create the skin’s pigment. For this reason, patients will need to carefully note any existing or new moles, freckles, or dark spots on the skin, assessing the area for the ABCDEs: Asymmetry, uneven Border, inconsistent or unusual Color, Diameter greater than the size of a pencil eraser, and any areas that are Evolving or changing.

Skin Cancer Treatment in Older Adults

According to Dr. Truong, “Some of my older patients tell me they prefer to leave skin cancer untreated. Every patient has unique attributes and a different picture of overall health, therefore, the pros and cons of leaving cancer untreated must be thoroughly discussed to determine the most appropriate management. Most of the time, I will recommend treatment to avoid further complications in the future, however, in some cases, it is more appropriate to defer treatment.” Each patient situation will be different, but at any age, a serious conversation with your dermatologist is necessary to determine whether or not skin cancer treatment is necessary for your specific situation.

Skin Cancer Diagnosis & Treatment

On skin cancer diagnosis, Dr. Truong says, “To the untrained eye, skin cancer can mimic the appearance of natural irregularities or other common skin conditions. The deadliest form of skin cancer, melanoma, may look like a mole, therefore, it is very important to note new growths or changing lesions, and to bring them to the attention of your dermatologist. A skin biopsy may be needed for a definitive diagnosis.”

Once a patient receives a definitive skin cancer diagnosis, treatment planning begins. The treatment depends on the type of skin cancer, the size, location, and level of aggressiveness. The main methods of treatment include surgery, radiation, and light-based treatments.

Surgery is the most common and effective treatment for most skin cancers. Depending on the size, aggressiveness, and location of the skin cancer, a wide local excision (removal of skin cancer with safety margins) or Mohs micrographic surgery may be recommended. Both surgeries are minimally invasive and usually done under local anesthesia. Mohs Micrographic Surgery is a specialized skin cancer surgery designed to remove skin cancers on sensitive areas such as the head and neck. The surgery removes skin cancer completely while preserving as much healthy skin as possible. The cancerous lesion is removed layer by layer, and the margins of each specimen are examined by your Mohs surgeon while you wait. Due to the on-site 100% margin evaluation, cure rates are superior and more healthy skin can be preserved, minimizing the scar.

Some small and less aggressive basal and squamous cell carcinomas may be treated using a simple scrape and burn procedure (called an electrodessication and curettage), topical creams, or nonsurgical radiotherapy (low levels of targeted radiation to destroy cancerous skin cells).

Photodynamic therapy (PDT) is another nonsurgical treatment that is beneficial when skin cancer is caught early. This treatment combines photosensitizing agents and controlled light exposure to target and destroy damaged skin cells, including cancer cells and areas damaged by other skin conditions.


For melanoma or basal and squamous cell carcinomas that have metastasized, the dermatologist will likely collaborate with a team of cancer doctors (surgical oncologists, medical oncologists, radiation oncologists). These professionals will help dermatologists determine whether or not more advanced cancer treatments like immunotherapy, medication therapy, chemotherapy, or radiation may be necessary to completely remove cancer.

Preventing Skin Cancer

Sun exposure is the most common cause of all forms of skin cancer. Therefore, applying sunscreen every day and limiting sun exposure is the best way to prevent skin cancer. Other causes include chemical and toxin exposure, genetics, and other underlying health problems that may be causing a suppressed immune system.

Taking the time to complete a thorough at-home self-exam for skin cancer every month or every other month makes early diagnosis and prevention of the most serious effects of skin cancer more likely. When caught early, skin cancer is more easily treatable. Visiting a dermatologist once a year for a professional skin exam ensures that you remain knowledgeable about areas that need attention, and gives you a much better chance of receiving early diagnosis and treatment for skin cancer.

Visit U.S. Dermatology Partners

Whether you’re worried a spot you’ve noticed is cancerous or you’re just ready for your annual professional skin exam, the U.S. Dermatology Partners team would love to hear from you. You can get started scheduling your visit by completing our online request form. Once we receive your scheduling request, one of our local team members will be in touch to finalize the details of your office visit.

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