Skin Cancer

Skin cancer is common. There are more new cases of skin cancer each year than the number of breast, prostate, lung and colon cancers combined!

About the Skin

Types of skin cancer

Skin & Eye Damage

Risk Factors

In Saskatchewan

Common and preventable

What is Skin Cancer?

Skin cancer is the uncontrolled growth of abnormal cells in the skin.

There are several types of skin cancer – melanoma and non-melanoma skin cancers. Melanoma is the most dangerous form of skin cancer and if left untreated can cause serious illness and death.

The most common risk factor for skin cancer is exposure to ultraviolet radiation (UVR), whether from the sun or from tanning beds.

The biggest risk factor

UVR and skin cancer

Though there are genetic factors that contribute to your risk of skin cancer, the most common cancers are strongly associated with exposure to ultraviolet radiation (UVR).

UVR causes damage to DNA and cell functions. This damage can show itself immediately as a tan or sunburn, though cells can be damaged even if neither of these is observed.

Skin cells have repair mechanisms, but they are not perfect.

Some skin cells die as a consequence of being too damaged to repair, but the biggest problem comes when some of the DNA damage is not repaired and the cells become defective.

An incredible organ

All about the skin

The top layer of the skin is called the epidermis. The epidermis is made up of 3 types of cells:

  • Squamous cells are flat, thin cells on the surface of the skin.
  • Basal cells are round cells that lie under the squamous cells.
  • Melanocytes are found in between the basal cells. They’re the melanin-producing cells (melanin is the pigment primarily responsible for your skin’s colour).

Skin cells

Types of skin cancer

Skin cancer types are named after the skin cell in which the cancer develops: basal cell carcinoma, squamous cell carcinoma (together called non-melanoma skin cancer) and melanoma.

When cancer starts in melanocytes, it is called melanoma. When skin cancer starts in squamous cells or basal cells, it is called non-melanoma skin cancer.

Although one of the less common types of skin cancer, melanoma is considered the most serious type of skin cancer because it is more likely to spread to other parts of the body, especially if not detected early.

Melanoma is considered the most serious type of skin cancer because it is more likely to spread to other parts of the body, such as the lungs, liver, brain and bones, even though it is not as common as non-melanoma skin cancer.

The earlier melanoma is diagnosed, the more successful treatment is likely to be. Left untreated, melanoma may spread deeper into the skin where it can be carried to other parts of the body by lymph vessels or blood vessels.

Worldwide, melanoma accounts for 4% of all skin cancers, but is responsible for 80% of skin cancer deaths.

Not just skin cancer

Skin and Eye Damage

Wrinkles and more

UVR and aging

Photoaging is premature aging of the skin caused by exposure to UVR from the sun or from tanning beds. It’s different from regular chronological aging that we can all expect as we get older – it’s caused by UVR exposure.

Photoaging appears most often on the face, neck, and back of the hands. These areas often receive the most sun exposure.

Premature aging looks like wrinkles, age spots, sagging and leathery skin. Probably not the look you might go for if you’re seeking a tan to look good…

UVR and our eyes

Eye damage

Exposure to the sun and other sources of UVR without sufficient protection is known to cause harm to the eyes.

Chronic exposure to UVR is a risk factor for several eye-related disorders, including cortical cataracts and pterygium.

Acute exposure to UVR can also cause photokeratitis, photoconjunctivitis and retinal burns (e.g., from looking directly at the sun).

Skin cells in trauma

Tans and sunburns

There is a misconception that as long as you don’t get a sunburn, you haven’t done any damage. But a tan itself is a sign of skin damage. There is no such thing as a healthy tan.

A tan is your skin’s physiological response to the stress caused by UVR.

Sunburns can be painful in the short term and can cause long-term damage to your skin. A history of sunburns in childhood and across the lifespan put you at a much higher risk to develop skin cancer.

Are you at risk?

Risk factors for skin cancer

Anyone can develop skin cancer. However, the risk is higher for some.

  • People with fair skin or freckly skin, with blond or red hair, and with light-coloured eyes.
  • People who burn easily.
  • People with a large number of moles on their skin.
  • People who spend a lot of time outdoors (such as outdoor workers).
  • People with a past history of skin cancer.
  • People with a family history of skin cancer.
  • People who take medication that makes them more sensitive to the sun.
  • People who use tanning beds.

While skin cancer is more common in people with fair skin, people with all skin types and colours can develop skin cancer. Skin cancer in people with darker skin is often detected at a more advanced stage and so the outcomes tend to be more serious.

Research shows a 59% increased risk of melanoma when tanning bed use starts before the age of 35.

The most significant preventable risk factor for developing skin cancer is exposure to ultraviolet radiation from the sun or from artificial tanning beds.

By the numbers

Skin cancer in Saskatchewan

In 2014 (the most recent year we have data for), 2,987 cases of non-melanoma skin cancer and 185 cases of melanoma were diagnosed in Saskatchewan. In the same year, 30 people died from melanoma.

In Saskatchewan, there are over 3,000 new cases of skin cancer diagnosed each year!

View sources

International Agency for Research on Cancer. (2012). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans – Volume 100: A Review of Human Carcinogens, Part D: Radiation. World Health Organization,  IARC: Lyon.

Hussein MR. Ultraviolet radiation and skin cancer: molecular mechanisms. J Cutan Pathol. 2005; 32(3):191-205.

IARC. A review of human carcinogens. Part D: Radiation. IARC monographs on the evaluation of carcinogenic risks to humans. 2012 Lyon: France.

Government of Canada. Canadian Cancer Statistics. 2014. Special Topic: Skin Cancers

Hussein MR. Ultraviolet radiation and skin cancer: molecular mechanisms. J Cutan Pathol. 2005; 32(3):191-205.

IARC. A review of human carcinogens. Part D: Radiation. IARC monographs on the evaluation of carcinogenic risks to humans. 2012 Lyon: France.

Boniol M, Autier P, Boyle P, Gandini S. Cutaneous melanoma attributable to sunbed use: systematic review and meta-analysis. BMJ 2012; 345: e4757

Wehner M, Shive M, Chren M, Han J, Qureshi A, Linos E. Indoor tanning and non-melanoma skin cancer: systematic review and meta-analysis. BMJ 2012; 345: e5909.

Gandini S, Sera F, Cattaruzza MS, Pasquini P, Picconi O, Boyle P, Melchi CF. Meta-analysis of risk factors for cutaneous melanoma: II. Sun exposure. Eur J Cancer. 2005 Jan;41(1):45-60.

Agbai O. N., Buster, K., Sanchez, M., Hernandez, C., Kundu, R. V., Chiu, M. et al. (2014). Skin cancer and photoprotection in people of color: a review and recommendations for physicians and the public. J Am Acad Derm 70, 748-62.

Sliney DH. Photoprotection of the eye—UV radiation and sunglasses. J Photochem Photobiol B. 2001 Nov 15;64(2-3):166–75.

Lucas RM. An epidemiological perspective of ultraviolet exposure—public health concerns. Eye Contact Lens. 2011 Jul;37(4):168–75.

Cullen AP. Ozone depletion and solar ultraviolet radiation: ocular effects, a United Nations Environment Programme perspective. Eye Contact Lens. 2011 Jul;37(4):185–90.

Phillips Z, Narasimhan G, Sarker S, Trecker M, Zhu T, Alvi R, & Tonita J. Saskatchewan Cancer Control Report: Profiling Cancer in Regional Health Authorities. Saskatoon: Saskatchewan Cancer Agency; 2017. An online version of the report can be accessed here.