Understanding Skin Cancer: Symptoms, Causes, Prevention and Tips

What is skin cancer?

When skin cells are damaged, usually by exposure to the sun or tanning beds, they can begin to multiply uncontrollably and form a tumour. In skin cancer, these tumours typically appear as spots on the skin or changes in the appearance of a mole.

Basal cell carcinoma

Basal cell carcinoma (BCC) is the most prevalent form of skin cancer, accounting for 75% to 80% of all diagnosed cases. The condition affects the basal cells located in the epidermis (the outermost layer of the skin). It typically develops on areas of skin that have been exposed to significant sunlight, such as the face, arms, and hands.

If left untreated, BCC has the potential to invade adjacent tissues. However, it rarely spreads to other organs, making metastasis an extremely rare occurrence. Since it develops gradually, it can typically be identified and treated at an early stage.

Squamous cell carcinoma

Squamous cell carcinoma (SCC) affects the squamous cells located in the outer part of the epidermis. It is estimated that approximately 20% of all skin cancers are attributed to this particular form of cancer.

SCC also develops in areas of skin that are highly exposed to the sun. It develops gradually and doesn't often spread to other organs, making it more likely to respond well to treatment.

Melanoma

Melanoma is less common, accounting for only 5% of all skin cancers. It originates in melanocytes, the skin cells that form moles and are responsible for producing melanin (the dark pigment that causes the skin to change colour when exposed to the sun). Melanoma is most commonly found in these moles, but it can also occur in other areas of the body where melanocytes are found, such as the mucous membranes that line the nasal passages, mouth, or anus.

Melanoma is more serious than BCC and SCC because it develops more rapidly and tends to invade surrounding tissue. It can spread (metastasize) to other organs in the body. Early detection is crucial to increase the chances of successful treatment.

What causes skin cancer?

The main cause of skin cancer is exposure to sunlight or tanning beds. For BCC and SCC, the risk increases with total lifetime exposure, and lesions typically appear later in life, often after age 80. For melanoma, the number and severity of sunburns during childhood increases the risk. Lesions generally appear at a younger age and tend to progress rapidly.

Individuals with fair skin and pale eyes are at an elevated risk of developing skin cancer, as their skin is less resilient to the harmful effects of ultraviolet (UV) radiation. Conversely, individuals with darker skin tones may also be susceptible to skin cancer, particularly in areas of the body not exposed to the sun (e.g., the soles of the feet and the palms of the hands).

Individuals with a high number of moles or those with atypical moles (irregular shape with ill-defined edges, often multicoloured) are at an elevated risk of developing melanoma-type skin cancer.

Additionally, a weakened immune system and a personal or family history of skin cancer are also risk factors for skin cancer. In regard to non-melanoma skin cancers, exposure to arsenic and radiotherapy have also been identified as contributing factors.

What does skin cancer look like?

Skin cancer can take many forms, depending on whether it's BCC, SCC, or melanoma. 

The following changes may indicate the presence of a cancerous lesion and should be evaluated by a healthcare professional.

• A mole that has changed in appearance, that bleeds, oozes, itches, or forms a crust
• A growth that is itchy, irritated or sore
• A sore that does not heal or returns after disappearing
• A sore this is crusty or bleeds easily
• Raised scaly red patches of skin
• Shiny lumps that are small, smooth and have a pearly white, pink or red colour
• Flat areas of skin that are pale white or yellow and resemble scars
• A pink growth that has raised edges and a dent in its centre
• A growth with small blood vessels on its surface
• A growth that resembles a wart

Many skin problems can cause lesions that look like skin cancer. To confirm that it is skin cancer, you need to see a doctor who may decide to perform a biopsy to confirm the presence or absence of cancer cells.

How is skin cancer treated?

Skin cancer treatment varies depending on the type of cancer.

Basal cell carcinoma and squamous cell carcinoma

BCCs and CSCs are usually treated with local surgery, such as

• Excision of the lump: the lesion and a small amount of normal skin around it are removed;
• Curettage with electrodessication: the area is scraped and the cancer cells are destroyed with an electric current;
• Cryosurgery: liquid nitrogen is applied to the lesion to freeze and destroy the cancer cells.

The type of procedure depends on the size of the lesion, its location, and the severity of the cancer. Less commonly, these cancers may be treated with radiation if they are in an area that is difficult to treat otherwise (eye, ear) or cannot be completely removed by excision. Small superficial lesions can be treated with a cream or gel.

In rare cases where these cancers have spread to other organs, chemotherapy may be needed.

Melanoma

Choosing the best treatment for melanoma is based on several factors, including the stage of the cancer (early-stage, locoregional, or metastatic), the risk of recurrence, and the location of the melanoma.

For early-stage melanoma, which is detected when it is only in the skin, surgery to remove the lesion and some surrounding healthy skin is usually the only treatment needed.

If the melanoma has spread to the lymph nodes or other areas of the skin (locoregional), the affected lesions and nodes will be removed surgically. The oncologist may also recommend chemotherapy (such as immunotherapy or targeted therapy) or radiation therapy to reduce the risk of recurrence.

For locoregional melanoma that cannot be removed surgically, or for metastatic melanoma (melanoma that has spread to other organs), chemotherapy (conventional, immunotherapy, targeted therapy) or radiation therapy is required. Surgery may not be possible unless the cancer or metastases are localized.

Regular skin checks are an important habit!

The best way to detect an abnormal lesion early is to examine your skin regularly. Ideally, you should examine your skin every month and see a healthcare professional every year or as soon as you notice a change.

Take the time to look at your skin, paying special attention to moles. Ask a friend or family member to check hard-to-reach areas such as your back and scalp or use a mirror to check yourself.

Use the ABCDE rule to evaluate your moles:

• Asymmetry: Is a mole asymmetrical (one side is shaped differently from the other)?
• Border: Is the edger of a mole irregular (e.g., jagged, notched, blurry)? The mole’s colour may spread into adjacent skin.
• Colour: Is a mole different shades of brown or black instead of a solid colour? Some cancerous lesions may also be red, grey, pink or blue.
• Diameter: Is a mole 6 mm or larger (equivalent to the eraser on the end of a pencil)?

Prevention is always the key!

The best way to reduce your risk of skin cancer is to reduce your exposure to the sun. No matter how old you are, it’s never too late to protect yourself from the sun's damaging rays.

• Whenever you're outdoors, apply a broad-spectrum sunscreen with an SPF of at least 30 to all exposed skin. Don't forget your lips, ears and the tops of your feet!
• Reapply sunscreen every 2 hours or after swimming or sweaty activities.
• During the summer or when travelling south, cover your skin or avoid exposure to the sun between 11 a.m. and 3 p.m. when it is most intense.

Because the risk of melanoma increases with childhood sun exposure, it's important to protect your children's skin by covering up or applying sunscreen whenever they are outdoors.

Your pharmacist is there for you!

Have questions about skin cancer screening or treatment? Need help choosing a sunscreen? Ask your pharmacist for professional advice!