Skin Cancer

Skin cancer is a prevalent type of cancer that affects millions of people worldwide. It occurs when abnormal skin cells grow and multiply uncontrollably, forming tumours. While skin cancer can be caused by various factors, the primary cause is exposure to ultraviolet (UV) radiation from the sun or tanning beds. Genetic mutations and environmental factors also play a role in the development of skin cancer.

What is Skin Cancer?

Skin cancer is a malignant growth of skin cells that occurs when DNA mutations cause them to multiply rapidly and form tumours. The three main types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Each type has its own distinct characteristics and stages, which determine the severity and treatment options for the condition. Early detection and treatment are crucial in managing skin cancer effectively.

There are several types of skin cancer, classified based on the type of skin cells affected. The main types include:

• Basal cell carcinoma (BCC): The most common type, developing from basal cells in the lower part of the epidermis. BCCs can appear as flesh-coloured, pearl-like bumps or pinkish patches, commonly found on sun-exposed areas such as the head, neck, and arms.

• Squamous cell carcinoma (SCC): The second most common type, developing from squamous cells in the upper part of the epidermis. SCCs typically appear as red, firm bumps or scaly patches, often forming on skin with frequent sun exposure.

• Melanoma: The most serious type, developing from melanocytes. Melanoma can appear as dark spots or within existing moles and is more aggressive and prone to spreading if left untreated.

The symptoms of skin cancer vary depending on the type and severity. Common symptoms include:

• Changes in skin appearance: One of the most noticeable signs of skin cancer is a change in the appearance of the skin. This can include new growths or sores that do not heal. Skin cancer may present as a new mole or a change in an existing mole, which may become larger, change in colour, or have an irregular border.

• Changes in mole colour or texture: Skin cancers such as melanoma can cause moles to change colour, becoming darker or more varied in hue. The texture of the mole may also become rough, scaly, or develop a raised area. Melanomas often show a mix of colours, such as brown, black, red, or white.

• Bleeding or oozing lesions: A common symptom of skin cancer is a lesion or sore that bleeds, oozes, or crusts over. This is particularly concerning if the bleeding occurs without any obvious cause, such as an injury, or if it persists over time.

• Itching or pain: While not always present, itching, tenderness, or pain in a specific area of the skin can be an indication of skin cancer. This discomfort is often linked to malignant growths that disrupt normal skin tissue.

• Changes in skin texture: Skin cancer can also lead to changes in the texture of the skin. Areas may become rough, scaly, or appear to be forming a crust. These textural changes are often seen in basal cell carcinoma and squamous cell carcinoma.

• Persistent ulcers or sores: Persistent skin ulcers or sores that do not heal can be a sign of skin cancer. Unlike benign sores or wounds, these ulcers can remain unchanged or worsen over time.

• New growths or nodules: New growths or nodules on the skin that are asymmetrical or have uneven edges might be indicative of skin cancer. These growths can vary in size and may feel hard or raised.

The stages of skin cancer are determined by several factors, including the size of the tumour, its depth of invasion, and whether it has spread to nearby lymph nodes or distant organs. The staging system for skin cancer is as follows:

• Stage 0: Stage 0 skin cancer, also known as carcinoma in situ, is the earliest stage of skin cancer. At this stage, the cancer cells are confined to the outermost layer of the skin (epidermis) and have not invaded deeper layers.

• Stage 1: Stage 1 skin cancer is characterised by a localised tumour that has invaded the dermis (the layer beneath the epidermis) but has not spread to nearby lymph nodes or distant organs. For melanoma, the tumour is typically less than 1 mm thick at this stage.

• Stage 2: In stage 2 skin cancer, the tumour has grown thicker and deeper into the skin but has not yet spread to nearby lymph nodes or distant organs. For melanoma, the tumour is typically thicker than 1 mm at this stage and may have one or more high-risk features, such as ulceration.

• Stage 3: Stage 3 skin cancer indicates that the cancer has spread to nearby lymph nodes or has invaded deeper into the skin and surrounding tissues. In the case of melanoma, the tumour may have spread to one or more lymph nodes or caused satellite tumours in the skin near the original tumour.

• Stage 4: Stage 4 skin cancer is the most advanced stage, indicating that the cancer has spread to distant organs or lymph nodes far from the original tumour site. This stage is also known as metastatic skin cancer.

The factors that can contribute to the development of skin cancer include:

• Exposure to ultraviolet (UV) radiation: Prolonged and intense sun exposure, especially during peak sunlight hours, can damage the DNA in skin cells. This damage accumulates over time and increases the risk of developing skin cancer.

• Genetic factors: Individuals with a family history of skin cancer are more likely to develop it themselves. Specific genetic mutations can increase susceptibility to skin cancer, such as those affecting genes responsible for DNA repair or those involved in skin pigmentation.

• Skin type and colour: People with lighter skin, blue or green eyes, and red or blonde hair are at a higher risk for skin cancer. Lighter skin types have less melanin, which provides some protection against UV radiation. Individuals with darker skin have a lower risk, but they are not immune to skin cancer.

• Age: The risk of developing skin cancer increases with age. This is partly due to the cumulative effect of UV exposure over time. Older adults are more likely to have had prolonged sun exposure, which can contribute to the development of skin cancer.

• Immune system suppression: A weakened immune system can increase the risk of skin cancer. This can be due to medical conditions such as HIV/AIDS or as a result of immunosuppressive medications used in the treatment of other diseases, such as organ transplant recipients.

• Exposure to certain chemicals: Exposure to certain chemicals and substances can increase skin cancer risk. For example, arsenic, which can be found in contaminated drinking water or certain industrial processes, has been linked to an increased risk of skin cancer.

• Personal history of skin cancer: Individuals who have previously been diagnosed with skin cancer are at a higher risk of developing new skin cancers.

Several factors can increase your risk of developing skin cancer, including:

• Fair skin that burns easily

• Excessive sun exposure or indoor tanning

• History of sunburns, especially during childhood

• Large number of moles or atypical moles

• Family history of skin cancer

• Weakened immune system

• Exposure to certain chemicals or radiation

Who's at Risk?

While anyone can develop skin cancer, some individuals are at a higher risk:

• People with fair skin, light-coloured eyes, and blonde or red hair

• Individuals with a history of excessive sun exposure or sunburns

• People with a large number of moles or atypical moles

• Those with a family history of skin cancer

• Individuals with weakened immune systems

• Older adults, as the risk increases with age

Skin cancer, if not detected and treated early, can lead to various complications that may have a significant impact on a person's health and quality of life. These include:

• Local tissue damage: Cancer growth can damage surrounding tissues, leading to ulceration, bleeding, and infection. Extensive surgery might be needed, causing cosmetic and functional changes.

• Metastasis: Advanced skin cancer can spread to other body parts, such as lymph nodes, lungs, or liver, complicating treatment and worsening prognosis.

• Lymphoedema: Spreading to or removal of lymph nodes can cause lymphoedema, leading to painful swelling in affected areas that requires ongoing management.

• Psychological impact: The diagnosis and treatment of skin cancer can cause significant psychological stress, including anxiety, depression, and body image issues, especially if visible areas are affected.

• Functional impairment: Skin cancers on areas like the face or hands can impair movement or facial expressions, impacting daily activities.

• Secondary cancers: Those who have had skin cancer are at increased risk of developing new skin cancers, necessitating ongoing monitoring.

• Treatment side effects: Treatment methods such as surgery, radiation, or chemotherapy can cause side effects like fatigue, skin irritation, or systemic issues such as nausea.

Preventing skin cancer is essential to reducing the incidence of this disease and its associated complications. Here are some key measures that can help prevent skin cancer:

• Avoid direct sunlight: Minimise exposure to direct sunlight, especially during peak hours when UV radiation is strongest. Seek shade whenever possible to reduce the risk of skin damage.

• Wear protective clothing: Cover exposed skin with protective clothing, such as long-sleeved shirts, long pants, wide-brimmed hats, and sunglasses. This helps block harmful UV rays and protect the skin from sun damage.

• Use broad-spectrum sunscreens: Apply a broad-spectrum sunscreen with an SPF of at least 30 regularly, even on cloudy days. Reapply every two hours while outdoors, or more frequently if swimming or sweating excessively.

• Perform regular skin checks: Conduct regular self-examinations of the skin and schedule visits to a doctor for professional skin checks. This helps catch any potential skin issues early, when they are most treatable.

Diagnosing skin cancer involves several key steps to accurately identify the presence and type of cancer. This includes:

• Physical examination: During this exam, the doctor inspects any suspicious skin lesions or changes in existing moles. They assess factors such as size, shape, colour, and texture to determine if further investigation is needed.

• Dermatoscopy: To gain a more detailed view of suspicious skin areas, a dermatologist may use a dermatoscope. This handheld device magnifies and illuminates the skin, allowing for a closer examination of the structures and patterns in the skin that may indicate cancer.

• Skin biopsy: If a lesion appears suspicious, a skin biopsy is usually performed. This involves removing a small sample of skin tissue for laboratory analysis.

• Imaging tests: For cases where skin cancer may have spread beyond the skin, imaging tests such as ultrasound, CT scans, or MRI may be used. These tests help to assess the extent of cancer spread and determine the appropriate course of treatment.

• Molecular testing: In some cases, molecular testing of the tumour may be performed to identify specific genetic mutations or markers associated with the cancer. This information can help in tailoring personalised treatment plans and assessing prognosis.

• Staging: Staging involves evaluating the size of the tumour, its depth, and whether it has spread to lymph nodes or other parts of the body.

The management of skin cancer depends on the specific type and stage of the cancer. Treatment options include:

• Surgery: This is the most common treatment for skin cancer. Excisional surgery removes the tumour along with a margin of normal skin, leaving a scar. Mohs micrographic surgery is a specialised surgical technique that minimises damage to normal tissues and helps avoid recurrence. Shave excision is suitable for low-risk basal cell and squamous cell cancers, removing the top layers of the skin.

• Radiation therapy: This treatment uses high-energy rays to kill cancer cells. It is used to treat basal cell carcinoma and squamous cell carcinoma, especially when surgery is not feasible.

• Chemotherapy: Chemotherapy uses medicines to kill cancer cells throughout the body. It is primarily used for advanced stages of skin cancer, such as melanoma.

• Photodynamic therapy: This treatment uses a light-sensitive medication and a special light source to kill cancer cells. It is effective for in situ (stage 0) squamous cell carcinoma.

• Immunotherapy: Immunotherapy helps boost the body's immune system to fight cancer cells. It is helpful in advanced stages of skin cancer, particularly melanoma.

• Targeted therapy: This treatment uses medicines that target specific molecular changes in skin cancer cells, often for melanoma treatment.

• Cryotherapy: This localised treatment freezes and kills cancer cells. It is often used for low-risk pre-cancerous lesions like actinic keratosis.

• Topical chemotherapy: Topical chemotherapy uses medications applied directly to the skin to kill cancer cells. It is commonly used for pre-cancerous conditions.

• Laser surgery: This precise surgical method uses high-intensity light to remove skin cancer.

The choice of treatment depends on factors such as the type and stage of skin cancer, the location and size of the tumour, and the patient's overall health. In some cases, a combination of treatments may be recommended for optimal results.

Medications for Skin Cancer

Several medications are used in the treatment of skin cancer. Dacarbazine (DTIC) is a chemotherapy medicine that has been approved for melanoma treatment since 1975. 5-fluorouracil (5-FU) is commonly used in topical chemotherapy for basal and squamous cell carcinomas. Diclofenac is sometimes used to treat pre-cancerous conditions like actinic keratosis. Imiquimod is used to treat early basal cell carcinomas by boosting the immune response against cancer cells. Cemiplimab and pembrolizumab are immunotherapies used for metastatic or inoperable squamous cell carcinoma.

If you have any concerns or suspicions about skin cancer, it is crucial to consult a doctor promptly. Be on the lookout for unusual moles, changes in skin texture, or unexplained growths on your skin, as these could be early signs of skin cancer. If you have been taking medications that are known to increase the risk of skin cancer, such as hydrochlorothiazide or sildenafil, it is especially important to discuss your concerns with your doctor. They can assess your individual risk factors and recommend appropriate screening, treatment, or alternative medications if necessary.

• Skin cancer is a serious condition that requires prompt medical attention and appropriate treatment.

• The management of skin cancer depends on the type and stage of the cancer, and may include surgery, radiation therapy, chemotherapy, photodynamic therapy, immunotherapy, targeted therapy, cryotherapy, topical chemotherapy, and laser surgery.

• Medications used in the treatment of skin cancer include dacarbazine, 5-fluorouracil, diclofenac, imiquimod, cemiplimab, and pembrolizumab.

• Early detection is crucial for successful treatment, so it is essential to be aware of any changes in your skin and to seek medical attention if you notice any suspicious signs or symptoms.

• Regular skin checks with a dermatologist are recommended for individuals at high risk of developing skin cancer.