All of the following play a role in determining your risk of developing skin cancer:

  • the total amount of sun exposure over the years
  • the number of sunburns or tans you have had
  • your skin type
  • your family history
  • the environment you live in

Nearly 50% of people over the age of 65 have or have had some form of skin cancer. Almost all skin cancers are preventable. There is some good news, however: 95% of all skin cancers are curable with removal if they are found early enough.

Light-skinned people are most at risk of developing non-melanoma skin cancers such as basal cell carcinoma and squamous cell carcinoma. The lesions usually show up on sun-exposed areas such as the arms, the backs of the legs, the neck, the face, and the scalp.

These cancers are usually not metastatic. This means that, typically, they don't spread to other parts of the body and are cured upon removal of the lesion. Nearly 70% of non-melanoma skin cancers are basal cell carcinomas and 30% are squamous cell carcinomas.

Malignant melanomas are more serious, as they can quickly spread to other organs in the body and can result in death. They account for 2% of all skin cancers.

It takes 10 to 20 years or more for skin cancers to develop, which means that a cancer discovered in your 50s may be due to sun exposure in your early 20s.

Actinic (solar) keratosis

Actinic keratoses are precancerous lesions that arise due to increased production of keratin (a tough, fibrous protein) in sun-exposed areas such as face, hands, neck, and forearms. The lesion is scaly, 2 mm to 2 cm wide, and has an irregular outline. It ranges from red to pink in colour and expands over time. It can be itchy or painful, and the number of lesions often increases with age. Actinic keratosis arises due to repeated sun exposure and usually affects people over the age of 40. Up to 10% of actinic keratoses can change into squamous cell carcinoma.

Squamous cell carcinoma

Squamous cell carcinoma lesions occur on the head, the neck, and the backs of hands. 90% to 95% appear on sun-exposed areas. The lesions have irregular borders, are usually quite thick, range from red to brown in colour, and may ulcerate (form an ulcer). You are more likely to develop squamous cell carcinoma if you are fair-skinned, have blond or red hair, or work outdoors. Surgical removal usually cures the cancer. However, in some case, it can spread to other organs in the body if not removed in time.

Basal cell carcinoma

Basal cell carcinoma lesions form on sun-exposed areas such as the eyelids, the bridge of the nose, the hands, or the forearms. They appear translucent and red, with a rolled border. They usually reach 1 cm to 3 cm in size before they ulcerate and bleed. They often have a central ulceration. They are very slow-growing cancers, taking months to years to grow, and they almost never spread to other parts of the body. They can be cured with topical (surface-applied) chemotherapy, radiation, or surgery. Since they are related to a lifetime of sun exposure, they can recur after initial treatment.

Malignant melanoma

Every year, approximately 5,000 Canadians are afflicted with malignant melanoma, and 900 of these die as a result of it. This cancer can spread rapidly to other organs in the body through the blood and lymph (the almost-clear fluid that bathes body tissues), and this can lead to death. The incidence of malignant melanomas in men is rising faster than any other cancer. The death rate is also increasing for this particular cancer, with more men dying than women.

You should see your doctor if you have a mole, birthmark, beauty mark, spot, or sore that:

  • has an irregularly shaped outline
  • changes colour or is dark black
  • is asymmetrical (uneven)
  • is larger than 6 mm
  • is changing (such as changes in its size or shape)