Skin cancer is a condition characterised by the abnormal growth of skin cells, most often caused by excessive exposure to ultraviolet (UV) radiation from the sun or tanning beds.

It typically develops in areas exposed to the sun, such as the face, neck, hands, and arms, but can occur anywhere on the body. The main types of skin cancer include basal cell carcinoma, squamous cell carcinoma, and melanoma, with melanoma being the most aggressive and potentially deadly if not detected early.

Symptoms may include new or changing moles, sores that don’t heal, or unusual growths on the skin. Early detection and treatment are crucial for successful outcomes, and prevention strategies like using sunscreen, wearing protective clothing, and avoiding excessive sun exposure can significantly reduce the risk.

What Causes Skin Cancer?

These are the causes.

Ultraviolet (UV) Radiation Exposure

The primary cause of skin cancer is prolonged exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. UV rays damage the DNA in skin cells, leading to mutations that can trigger uncontrolled cell growth and cancer.

Genetic Factors

A family history of skin cancer or certain genetic conditions, such as xeroderma pigmentosum, can increase the risk of developing cancer. Inherited traits like fair skin, light hair, and a tendency to burn rather than tan also contribute to higher susceptibility.

Weakened Immune System

Individuals with weakened immune systems, such as organ transplant recipients or those with HIV/AIDS, are at a higher risk of developing skin cancer. The immune system plays a critical role in identifying and destroying abnormal cells, and its impairment can allow cancerous cells to proliferate.

Environmental and Chemical Exposure

Exposure to certain environmental factors, such as arsenic, coal tar, or radiation, can increase the risk of skin cancer. Occupational hazards or living in areas with high levels of these substances may contribute to the development of the disease.

Pre-existing Skin Conditions

Certain skin conditions, such as actinic keratosis or chronic inflammation, can increase the likelihood of developing skin cancer. These conditions often indicate prolonged sun damage or other skin abnormalities that may progress to cancerous growths over time.

Types of Skin Cancer

These are the different types.

Basal Cell Carcinoma (BCC)

Basal cell carcinoma is the most common type of skin cancer, originating in the basal cells of the epidermis. It typically appears as a pearly or waxy bump, or a flat, flesh-colored lesion, and is often caused by long-term sun exposure. While it rarely spreads to other parts of the body, it can cause local tissue damage if left untreated.

Squamous Cell Carcinoma (SCC)

Squamous cell carcinoma arises from the squamous cells in the outer layers of the skin. It often presents as a firm, red nodule or a scaly, crusted lesion. This type of skin cancer is more likely to spread than basal cell carcinoma, particularly if not treated early, and is also strongly linked to UV radiation exposure.

Melanoma

Melanoma is the most aggressive and dangerous form of skin cancer, developing in the melanocytes, the cells responsible for producing skin pigment. It can appear as a new or changing mole with irregular borders, uneven coloring, or an asymmetrical shape. Melanoma can spread rapidly to other organs if not detected and treated early.

Merkel Cell Carcinoma

Merkel cell carcinoma is a rare but highly aggressive type of skin cancer that develops in the Merkel cells, which are located in the top layer of the skin near nerve endings. It often appears as a firm, shiny nodule on sun-exposed areas and tends to grow and spread quickly.

Cutaneous Lymphoma

Cutaneous lymphoma is a type of skin cancer that originates in the lymphocytes, a type of white blood cell. It can manifest as patches, plaques, or tumors on the skin and is part of a broader group of cancers known as lymphomas. This type of skin cancer is rare and requires specialised treatment.

Kaposi Sarcoma

Kaposi sarcoma is a rare skin cancer caused by the human herpesvirus 8 (HHV-8). It typically presents as purple, red, or brown lesions on the skin or mucous membranes and is more common in individuals with weakened immune systems, such as those with HIV/AIDS or organ transplant recipients.

Symptoms of Skin Cancer

These are the symptoms.

Changes in Moles

One of the most common signs of skin cancer, particularly melanoma, is a change in the appearance of an existing mole or the development of a new mole. Look for irregularities in shape, color, size, or texture, such as uneven borders, multiple colors, or a diameter larger than a pencil eraser.

Unusual Growths or Sores

Skin cancer may present as new growths, bumps, or sores that do not heal over time. These can appear pearly, waxy, scaly, or crusted, and may bleed or ooze. Persistent sores that fail to heal after several weeks should be evaluated by a healthcare professional.

Red or Scaly Patches

Squamous cell carcinoma and other types of skin cancer can manifest as red, rough, or scaly patches on the skin. These patches may be tender to the touch and can sometimes resemble eczema or psoriasis.

Dark Spots or Lesions

Melanoma and other aggressive forms of skin cancer may appear as dark spots or lesions on the skin. These spots may have irregular borders, uneven coloring, or a raised surface and can develop anywhere on the body, including areas not exposed to the sun.

Itching or Pain

Skin cancer lesions or growths may cause itching, tenderness, or pain. While these symptoms can be associated with benign skin conditions, persistent discomfort in a specific area should be examined by a doctor.

Spreading Pigmentation

In some cases, skin cancer may cause pigmentation to spread beyond the border of a mole or lesion. This can indicate melanoma or another type of invasive skin cancer and requires immediate medical attention.

Changes in Sensation

Skin cancer may cause changes in sensation, such as numbness, tingling, or a feeling of tightness in the affected area. These symptoms are less common but can occur as the cancer progresses.

How to Treat Skin Cancer

These are typical treatments.

Surgical Excision

Surgical excision is a common treatment for skin cancer, where the cancerous tissue is cut out along with a margin of healthy skin to ensure complete removal. This method is often used for basal cell carcinoma, squamous cell carcinoma, and early-stage melanoma.

Mohs Surgery

Mohs surgery is a specialised technique used for skin cancers in sensitive areas, such as the face, or for cancers with a high risk of recurrence. It involves removing the cancer layer by layer and examining each layer under a microscope until no cancerous cells remain.

Cryotherapy

Cryotherapy involves freezing cancerous cells using liquid nitrogen. This treatment is typically used for precancerous conditions like actinic keratosis or very small, early-stage skin cancers. The frozen tissue eventually falls off as the skin heals.

Radiation Therapy

Radiation therapy uses high-energy beams to target and destroy cancer cells. It is often used for skin cancers that are difficult to treat with surgery, such as those in elderly patients or in areas where surgery could cause significant scarring.

Topical Treatments

For certain types of superficial skin cancers, topical medications such as imiquimod or 5-fluorouracil (5-FU) may be applied directly to the skin. These creams stimulate the immune system or destroy cancer cells over several weeks of treatment.

Photodynamic Therapy (PDT)

Photodynamic therapy involves applying a light-sensitive drug to the skin and then exposing it to a specific wavelength of light to activate the drug and destroy cancer cells. This treatment is often used for precancerous lesions or superficial skin cancers.

Chemotherapy

Chemotherapy for skin cancer may involve topical creams for localised cancers or systemic drugs for advanced cases, such as melanoma that has spread to other parts of the body. It targets rapidly dividing cancer cells but can also affect healthy cells.

Immunotherapy

Immunotherapy boosts the body’s immune system to fight cancer. It is particularly effective for advanced melanoma and can involve drugs like checkpoint inhibitors or interleukin-2. These treatments help the immune system recognise and attack cancer cells.

Targeted Therapy

Targeted therapy uses drugs designed to attack specific genetic mutations or proteins in cancer cells. For example, BRAF inhibitors are used to treat melanomas with BRAF gene mutations. This approach minimises damage to healthy cells.

Lymph Node Surgery

If skin cancer has spread to nearby lymph nodes, surgical removal of the affected nodes may be necessary. This is often followed by additional treatments like radiation or immunotherapy to prevent further spread.

Follow-Up and Monitoring

After treatment, regular follow-up appointments are essential to monitor for recurrence or new skin cancers. Patients are advised to perform regular self-examinations and protect their skin from UV radiation to reduce the risk of future cancers.