Signs of Skin Cancer

Written By Ingrid Whitehead

Skin cancer is the most commonly diagnosed cancer in Canada. Tens of thousands of Canadians are diagnosed each year, including melanoma, the most serious form of skin cancer. When melanoma is detected early (stage 1), survival rates are very high—around 98–99%.

Most skin cancers begin as small changes in the skin that can be subtle and easy to miss. Knowing what to look for is important for early detection.

If you notice a concerning mole or skin change, a professional skin cancer screening can help assess it properly.

If you’re unsure whether a mole is concerning, you can also review when to worry about a mole.

There are several types of skin cancer, and each can appear differently:

1. Melanoma (most serious type)

Melanoma develops from melanocytes, the pigment-producing cells in the skin.

Warning signs include:

  • A mole that is changing in size, shape, or colour

  • Irregular borders or uneven edges

  • Multiple colours within one mole (brown, black, red, white, or blue)

  • A mole that looks different from others on your body (“ugly duckling” sign)

  • Itching, bleeding, or crusting

A helpful guide used in clinical practice is the ABCDE rule:

  • Asymmetry

  • Border irregularity

  • Colour variation

  • Diameter change or growth

  • Evolving over time

2. Basal cell carcinoma (most common type)

Basal cell carcinoma often grows slowly and may appear as:

  • A pearly or shiny bump

  • A sore that does not heal

  • A red or irritated patch

  • A spot that bleeds and returns

It is usually found on areas exposed to the sun, such as the face, neck, and arms.

3. Squamous cell carcinoma

Squamous cell carcinoma may appear as:

  • A rough, scaly, or crusted patch

  • A firm, red or skin-coloured bump

  • A sore that does not heal over several weeks

  • A lesion that may bleed or become tender

  • A new sore or raised area on an old scar

It can grow more quickly than basal cell carcinoma and should be assessed promptly.

Other warning signs to watch for

You should consider getting a skin check if you notice:

  • A new mole after age 30

  • A mole that is different from others on your body

  • A spot that continues to change over weeks or months

  • Any lesion that bleeds without injury

  • A sore that does not heal

Most skin changes are not cancer

It’s important to note that many skin changes are benign (non-cancerous).

However, skin cancer can sometimes look very similar to harmless spots in its early stages. This is why changes should always be assessed if you are unsure.

Why early detection matters

When skin cancer is found early:

  • Treatment is usually simpler

  • Outcomes are significantly better

  • In many cases, it can be removed completely

The key is not waiting for symptoms to become obvious.

When to get a skin cancer screening

You should consider booking a screening if you notice:

  • A changing mole

  • A new or unusual skin lesion

  • Anything that looks different from your other moles

  • Or simply uncertainty about a spot

If something doesn’t look or feel right, it is worth having it checked. Mark My Mole provides dedicated skin cancer screening focused on early detection and clinical assessment of moles and skin lesions. Understanding what to expect during a skin cancer screening can help you feel more prepared.

No referral is required, and appointments are available within days.

References:

Ingrid Whitehead
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