Skin cancer is a highly prevalent condition, affecting people of all skin tones. It arises from the uncontrolled growth of cells in the epidermis, the skin's outermost layer. The epidermis is primarily made up of three cell types—squamous cells, basal cells, and melanocytes—and the specific type of cancer is determined by which cell layer the cancer begins in. Globally, skin cancer is one of the most common malignancies.
The three most common types of skin cancer are:
This is the most common form of skin cancer, originating in the basal layer of the epidermis, where new skin cells are produced. BCCs are typically slow-growing and rarely spread to other parts of the body. However, if left untreated, they can invade and destroy surrounding tissues and bone.
The second most common type, SCC begins in the squamous cells that form the majority of the epidermis. It grows more quickly than BCC and has a higher chance of spreading (metastasising). Like BCC, it can destroy underlying tissue and muscle if not treated, but most cases are not life-threatening.
Starting in the pigment-producing cells (melanocytes), melanoma is less common but significantly more aggressive and potentially fatal. When detected early, the prognosis is excellent, with a near 100% five-year survival rate.
Note: This information focuses on Basal Cell Carcinoma and Squamous Cell Carcinoma, collectively known as non-melanoma skin cancer. When diagnosed at an early stage, most non-melanoma skin cancers are curable. Melanoma, being more aggressive, requires a distinct treatment approach.
A rare cancer characterised by purple, red, or brown lesions on the skin, often linked to a virus and typically affecting individuals with suppressed immune systems.
This presents as red, shiny nodules, usually on the face, hands, and neck.
A rare cancer that originates in the oil or sweat glands of the skin.
Any factor that increases the likelihood of developing skin cancer is considered a risk factor. These include:
Extensive lifelong sun exposure or occasional, intense exposure, especially without sun protection.
Living in a sunny climate or at a high altitude.
A history of previous sunburns.
Risk increases with age due to accumulated sun exposure.
Having a fair complexion, red or blonde hair, freckles, blue eyes, or a tendency to sunburn.
Being immunocompromised, often due to taking immunosuppressive medication.
A family history of skin cancer.
Having numerous moles, particularly large or irregularly shaped (dysplastic nevi) moles.
Having a previous skin cancer diagnosis increases the risk of developing another.
Certain rare genetic conditions, such as xeroderma pigmentosum and basal cell nevus syndrome.
Serious prior skin injuries, like a major burn or scar.
These precancerous lesions appear as rough, red, scaly patches, often found on sun-exposed areas. Approximately 5% of these can progress into a non-melanoma skin cancer.
It is important to remember that not everyone with risk factors will develop skin cancer. If you have any of these factors, it is advisable to discuss them with your healthcare provider.
If you notice any new or changing spots on your skin that persist for two weeks or longer, it is essential to consult your doctor. While skin cancer can often be symptomless in its initial stages, signs can appear at any time.
A new spot appearing on the skin
Changes in the size, shape, or colour of an existing spot or mole
A spot that is painful or itchy
A non-healing sore that bleeds or forms a crust
A red- or skin-coloured, shiny bump
A red, rough, or scaly patch that you can feel
A growth with a raised border and a central crust or bleeding
A growth that looks like a wart
A scar-like patch with indistinct borders
Typically appears on sun-exposed areas like the face, neck, arms, legs, ears, and hands, but can occur elsewhere. Signs include:
Also common in areas with high sun exposure, though it can affect non-sun-exposed skin, particularly in people with darker skin tones. Signs include:
Can develop anywhere on the body, including from existing moles. In darker skin tones, melanoma tends to occur on the palms or soles of the feet. Key signs include:
The ABCDE guide is a helpful tool for identifying the potential warning signs of melanoma:
Asymmetry
One half of the spot does not match the other half in shape
Border
The edges are irregular, ragged, blurred, or notched
Colour
The colour is inconsistent across the spot, possibly including shades of black, brown, red, pink, white, or blue
Diameter
The spot is typically larger than 6 millimetres (the size of a pencil eraser), although smaller melanomas are possible
Evolving
The mole or spot is changing in its size, shape, colour, or behaviour (e.g., bleeding or itching)
A definitive diagnosis of skin cancer requires a tissue sample from the suspicious area to be examined under a microscope. The process of removing this tissue is called a biopsy.
Your doctor will perform a physical examination of the suspected area first. The type of biopsy recommended depends on the size, shape, and location of the growth. Typically, a local anaesthetic is administered before the procedure. Depending on the technique, stitches may be used to close the wound afterwards.
This involves removing the entire suspicious area, or a portion of it, using a scalpel under local anaesthesia. For small growths, this procedure can act as both the diagnostic test and the complete treatment.
A special tool is used to remove a circular core (cylinder) of tissue from the growth. Stitches may be required to close the small, round wound.
The doctor shaves off the top layer of the growth using a scalpel or other surgical tools. This procedure usually does not require stitches.
After the biopsy, the sample is analysed by a pathologist, a medical specialist who diagnoses diseases by examining tissues. Results may indicate benign (non-cancerous) growths, such as moles or warts. If cancer is confirmed, the pathologist identifies the specific type: Basal Cell Carcinoma, Squamous Cell Carcinoma, or Melanoma.
For melanoma or large squamous cell carcinomas, additional tests may be needed to check if the cancer has spread (metastasised). Basal cell cancer rarely spreads. Cancer can invade deeper skin layers, surrounding nerves, or lymph nodes. Your doctor may order medical imaging or a lymph node biopsy if spread is suspected.
The stage of the cancer describes the size of the primary tumour and how far the cancer has spread in the body. Staging is crucial for determining the treatment plan and predicting the patient's prognosis (outlook).
Your skin cancer treatment at SSCHRC is based on a personalised plan tailored to your specific type of cancer. Basal cell and squamous cell skin cancers are typically removed using one of the following treatments.
The diseased area is numbed with local anaesthetic and then completely cut out, along with a small margin of healthy surrounding tissue.
A dermatologic surgeon removes the cancerous tissue in very thin layers, examining each layer immediately under a microscope until no cancer cells are found. This procedure offers a very high cure rate and generally results in minimal scarring. SSCHRC has a dedicated Mohs and Dermasurgery Centre for this procedure.
This less invasive procedure is often used for precancerous conditions (like actinic keratosis) and small, early-stage skin cancers. The doctor uses liquid nitrogen to freeze and destroy the diseased tissue, avoiding the destruction of nearby healthy tissue.
Chemotherapy drugs are applied as a topical ointment directly to the affected skin, killing fast-growing cancer cells. It is used for superficial skin cancers and actinic keratosis, and can cover large sections of skin. Patients may experience redness and crusting, which heals in two to three weeks.
An intense, focused beam of light is used to destroy early, superficial skin cancers and precancerous conditions. The laser can be adjusted to remove the skin in controlled layers based on the cancer's depth.
This procedure uses a scraping instrument (a curette) and electrical currents to destroy and remove small, superficial skin cancers.
When skin cancer has spread or is at a high risk of spreading, the treatment plan is more complex. At SSCHRC, these plans are developed by a multidisciplinary team of doctors from various specialties, including Dermatology, Radiation Oncology, and different Surgical departments. Treatments may include surgery, radiation therapy, chemotherapy, and other modalities.