Could that bump, sore or mole be a sign of something sinister? What you should know about spotting skin cancer.

Only air-brushed magazine models have perfect skin. For the rest of us, bumps, moles, dry patches and scaly skin are usually part of the picture — and so common we might not give them a second thought. They may not be pretty, but there’s more than beauty at stake: These issues could signal skin cancer.

Already one of the most common cancers in the world, the incidence of skin cancer is on the rise. Currently, experts estimate that one in three new cancer cases is skin cancer. Luckily, it’s also one of the most curable forms of cancer — but early detection is key.

Here’s what you need to know to spot trouble:

Skin cancer: The big three

Think skin cancer is all about odd moles? One type is: melanoma. This most dangerous form of skin cancer starts in the melanocytes (the cells that make melanin, the pigment that colours our skin and hair). If left untreated, tumours can grow deep into the skin and metastasize — spreading the cancer to other parts of the body.

Melanoma isn’t as deadly as other types of cancer, but it can still claim lives. This year, doctors will diagnose about 5,500 new cases of melanoma, according to predictions from the Canadian Cancer Society. While 950 people are predicted to die due to melanoma in 2011, the disease still has a high five-year survival rate: 86 per cent for males and 93 per cent for females.

Less risky — but not to be under estimated — are non-melanoma skin cancers. Two of the most common kinds include:

Basal cell carcinoma (BCC) is a slow-growing tumour that starts in the cells at the base of our top layer of skin, the epidermis. BCC is the most common kind of skin cancer and often appears as a bump on the skin. While it doesn’t usually metastasize, it can affect surrounding tissues and cause disfigurement.

Squamous cell carcinoma (SCC) also occurs in the epidermis but often appears as a scaly patch or sore that crusts over or bleeds. It’s the second most common type of skin cancer, and can spread in some cases.

Non-melanoma skin cancers are usually treated by dermatologists, and are often not noted in cancer statistics because they don’t usually involve hospital stays or complications. However, the Canadian Cancer Society forecasts 74,100 cases of non-melanoma skin cancers will be diagnosed in 2011.

Who is most at risk?

We’ve heard it before: experts consider UV ray exposure to be the top cause of most kinds of skin cancer whether it comes from the sun or a tanning bed. The more exposure you get, the higher the risk — especially if you’ve had severe sunburns in the past. Many skin cancers occur on parts of the skin that get regular exposure — like the back, face, arms and lower legs. People who are often outdoors or work outdoors have an increased risk.

What else should you consider?

- Complexion: people with light-coloured skin, hair and eyes are more likely to develop skin cancer. If you burn before you tan, you could be at higher risk.