Keratinocyte Skin Cells and Cancer

Table of Contents
View All
Table of Contents

Keratinocytes are the most common type of skin cells. They make keratin, a protein that provides strength to skin, hair, and nails. These cells form in the deep basal-cell layer of the skin, and take about a month to reach the surface.

It is normal for many to die off in the process. But it's also possible for their cell division to go awry, leading to what are sometimes called "keratinocyte cancers." This includes two types of non-melanoma skin cancers: basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC).

Because BCC is at work in most keratinocyte cancer cases, this article focuses primarily on the causes of BCC, as well as symptoms that suggest it may be time to call your healthcare provider. It also discusses the link to sun exposure and why this type of cancer is on the rise as people age.

dermatologist examining patient

Universal Images Group / Getty Images

Basal Cell Carcinoma

Basal cell carcinoma is the far more common of this skin cancer type. BCC accounts for some 80% of these cancers, though they rarely cause death. The other 20% are cSCC. A small percentage of people with cSCC will go on to see the cancer metastasize, or spread, and roughly 70% of that small subset will die, according to one 2019 study.

Symptoms of Basal Cell Carcinoma

BCCs usually develop on sun-exposed parts of your body, especially your head and neck. A much smaller number occur on the torso and legs. Yet BCCs also may occur on parts of your body that are rarely exposed to sunlight.

A more general warning sign of skin cancer comes as a sore that won't heal, or that repeatedly bleeds and scabs over. In people with darker skin, this type of cancer may look brown or black. But BCC may also appear as:

  • A pearly white or waxy bump, often with visible blood vessels, on your face, ears, or neck. It may bleed and develop a crust.
  • A flat, scaly, brown or flesh-colored patch on your back or chest. Over time, these patches can grow quite large.
  • More rarely, a white, waxy scar. This type of BCC is easy to overlook, but it may be a sign of a particularly invasive and disfiguring cancer called morpheaform BCC.

Causes of Basal Cell Carcinoma

BCC occurs when one of the basal cells of the epidermis develops a mutation, or change, in its DNA. The process of creating new skin cells is controlled by a basal cell's DNA. A mutation in the DNA may cause a basal cell to multiply fast and continue growing when it would normally die. Eventually, the abnormal cells add up and may form a cancerous tumor.

Ultraviolet Light and Other Causes

Most BCCs are linked to long-term exposure and damage from ultraviolet (UV) radiation. Avoiding the sun and using sunscreen may help protect against this skin cancer.

This UV radiation also comes from commercial tanning lamps and tanning beds. But sun exposure doesn't explain skin cancers that develop on skin not ordinarily exposed to sunlight. This suggests that other factors may contribute to your risk of skin cancer. They may include exposure to toxic substances, or having another medical condition that weakens your immune system.

Recap

Basal cell carcinoma is at work in some 80% of skin cancers arising from keratinocytes, the most common kind of skin cancer cell. They are linked with exposure to UV light from the sun or tanning lamps, but may have other causes. Most of these cases will not lead to death.

Cutaneous Squamous Cell Carcinoma

After BCC, it's cutaneous squamous cell carcinoma (cSCC) that is the second most common kind of skin cancer. Both are of the keratinocyte type. Though cSCC occurs less often, it may have more serious outcomes, including death.

As with other skin cancers, cases are on the rise in aging populations. It's thought that early exposure to UV light, in childhood and youth, contributes to the development of BCC and cSCC.

Annual screenings are important if you've had a previous diagnosis of either type of skin cancer. Be sure to tell your d because some dietary supplements, like retinoids or selenium, should not be given to people with a history of cSCC. Tell your healthcare provider about any family history of skin cancer too.

Summary

There are two primary types of skin cancer that arise from keratinocytes, the most common type of skin cells. Basal cell carcinoma accounts for the vast majority of them. Cutaneous squamous cell carcinoma accounts for just one of every five cases but it often proves the more fatal of the two.

The single greatest risk known to date is exposure to UV light from the sun or artificial sources. Limiting this UV exposure may reduce the risk of getting one of these "keratinocyte cancers."

A Word From Verywell

If you've noticed skin changes, or symptoms like sores that won't heal, it may be time to find out why. Make an appointment with your healthcare provider if you have any signs or symptoms that worry you.

Was this page helpful?
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Choquet H, Ashrafzadeh S, Kim Y, Asgari MM, Jorgenson E. Genetic and environmental factors underlying keratinocyte carcinoma riskJCI Insight. 2020 May;5(10):e134783. doi:10.1172/jci.insight.134783

  2. Nagarajan P, Asgari MM, Green AC, et al. Keratinocyte carcinomas: current concepts and future research prioritiesClin Cancer Res. 2019;25(8):2379-2391. doi: 10.1158/1078-0432.CCR-18-1122

  3. American Academy of Dermatology Association. Skin cancer types: basal cell carcinoma signs and symptoms.

  4. Cameron MC, Lee E, Hibler BP, et al. Basal cell carcinomaJournal of the American Academy of Dermatology. 2018 May;80(2):303-317. doi:10.1016/j.jaad.2018.03.060

  5. Iannacone MR, Wang W, Stockwell HG, et al. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control studyBMC Cancer. 2012 Sep;12(1):417. doi:10.1186/1471-2407-12-417

  6. Le Clair MZ, Cockburn MG. Tanning bed use and melanoma: Establishing risk and improving prevention interventionsPreventive Medicine Reports. 2016 Jan;3:139-144. doi:10.1016/j.pmedr.2015.11.016

  7. Kim T-H, Seo J-W, Hong Y-S, Song K-H. A case-control study of skin cancer and exposure of toxic heavy metalsAnn Dermatol. 2018 Feb;30(2):238. doi:10.5021/ad.2018.30.2.238

  8. Kim JYS, Kozlow JH, Mittal B, et al. Guidelines of care for the management of cutaneous squamous cell carcinomaJournal of the American Academy of Dermatology. 2018;78(3):560-578. doi: 10.1016/j.jaad.2017.10.007

Additional Reading