Causes of Skin Cancer

Skin cancer occurs as a result of changes or mutations in the genetic material of skin cells, leading to a lack of control over their growth and division. This uncontrolled proliferation can result in the formation of a tumor comprised of cancerous cells within the skin tissues. It is important to note that all body cells replicate through division, despite their varying functions and forms. In normal circumstances, the processes of growth and damage repair are strictly regulated by instructions from the genetic material in the cell’s nucleus, which also directs cellular functions.

The majority of damage to the genetic material of skin cells is attributed to exposure to ultraviolet (UV) rays from the sun and tanning devices. However, skin cancer can also manifest in areas not typically exposed to sunlight, indicating the presence of other risk factors that increase the likelihood of developing skin cancer. These may include exposure to toxic substances or underlying health issues that compromise the immune system. Generally, skin cancer originates in the outer layer of the skin known as the epidermis, which serves to cover and protect the skin cells. The type of cancer is influenced by the specific cells that are affected, and the epidermis consists of several distinct cell types, including:

Squamous Cells: These cells line the skin and lie directly beneath its surface.
Basal Cells: New skin cells are generated from these cells, located beneath squamous cells.
Melanocytes: These cells produce melanin, the pigment that gives skin its natural color. They are situated in the lower part of the epidermis and are stimulated to increase melanin production upon exposure to sunlight, which helps protect the deeper skin layers.

Risk Factors for Skin Cancer

There are several risk factors that may increase the likelihood of developing skin cancer. Having one or more of these factors does not guarantee that an individual will develop the disease, but it may elevate the risk. It is advisable to discuss these risk factors with a healthcare provider. Here are some notable risk factors:

Prolonged Sun Exposure

The risk of skin cancer can rise significantly with prolonged exposure to sunlight, especially if sunscreen is not used or skin-protecting clothing is not worn. Additionally, exposure to the light from tanning devices poses similar risks. It is noteworthy that the tan resulting from these devices is a response from skin cells to damaging UV radiation, leading to heightened melanin production as a defense mechanism against further injury. Repeated exposure to UV radiation over time can result in skin cancer, and the risk of developing ocular melanoma and cataracts also increases with such exposure.

Personal Risk Factors

Several personal risk factors can heighten the risk of skin cancer, including:

Fair Skin: While skin cancer can affect individuals of any skin tone, those with fair skin, light-colored hair, and light-colored eyes are at a significantly increased risk. This heightened susceptibility is due to lower melanin levels, which offer less protection against UV damage.
Previous Sunburns: Individuals who have a history of severe sunburns, particularly those that resulted in blisters during childhood or adolescence, have an elevated risk of developing skin cancer in adulthood.
High Altitudes or Sunny Climates: People residing in high-altitude regions with stronger sunlight or in sunny, warm climates face a higher risk of skin cancer due to increased UV exposure.
Family History: A family history of skin cancer can significantly raise an individual’s risk.
Previous Skin Cancer Diagnosis: Individuals who have previously been diagnosed with skin cancer face a greater risk of recurrence.
Compromised Immune System: A weakened immune system, such as in individuals with HIV or those on immunosuppressive medications, increases the risk of skin cancer.
Radiation Exposure: Prior exposure to radiation treatment for certain skin issues can elevate the risk of skin cancer, particularly basal cell carcinoma.
Pre-cancerous Skin Lesions: Lesions like actinic keratosis can indicate an increased risk for skin cancer and are typically rough, scaly patches appearing on sun-exposed areas.
Exposure to Certain Chemicals: Contact with substances like arsenic, tar, and other chemicals can increase the risk of non-melanoma skin cancers.
Age: The risk of developing skin cancer escalates with age due to cumulative UV exposure, although young individuals can also be at risk.
Gender: Men are generally at a higher risk of skin cancer than women, with a greater likelihood of developing basal and squamous cell carcinomas.
Genetic Disorders: Conditions such as xeroderma pigmentosum, which impair the body’s ability to repair UV damage, significantly increase cancer risk at a young age.
Basal Cell Nevus Syndrome: Also known as Gorlin Syndrome, this genetic condition leads to the development of numerous basal cell carcinomas early in life.
Other Skin Disorders: Conditions characterized by non-healing sores or skin nodules can elevate skin cancer risk.

Types of Moles

The presence of atypical moles, known as dysplastic nevi, can increase the risk of skin cancer. These moles are often larger than typical moles and have irregular shapes, raising the likelihood of malignant transformation. While most moles are harmless, significant changes in size, shape, or color can signal potential melanoma, which warrants monitoring and professional evaluation. Key characteristics of potentially cancerous moles include:

Asymmetry: One half of the mole differs in shape from the other half.
Color Variation: The mole displays multiple colors or shades rather than a uniform hue.
Irregular Borders: The edges of the mole are uneven or jagged.
Diameter: Most regular moles are smaller than 6mm; however, cancerous moles can exceed this size and may vary from 3mm to 6mm in diameter.

Other Risk Factors

Additional risk factors for skin cancer include:

Viral Infections: Certain viral infections, such as those caused by human papillomavirus (HPV), can increase skin cancer risk, particularly in the genital and anal regions.
Smoking: Smoking is associated with an elevated risk of squamous cell carcinoma, particularly on the lips.
Psoriasis Treatments: The combination of certain natural extracts and UV treatments can increase the risk of squamous cell carcinoma and other skin cancers in psoriasis patients.
Genetic Mutations: Specific changes in melanocortin-1 receptors may heighten the risk of skin cancer.

Prevention of Skin Cancer

The primary preventive measure against skin cancer is to avoid prolonged and direct exposure to the sun or tanning lamps and to implement protective measures when outdoors for any duration.

Protection Against UV Exposure

It is crucial to guard against UV exposure year-round, not just during sunny days, as UV rays can penetrate the skin on cloudy or foggy days as well. Here are some strategies to mitigate UV damage:

Avoid direct sun exposure by seeking shade, particularly between the hours of 10 AM and 2 PM, or when the shadow cast is shorter than the person’s height.
Wear protective clothing such as long-sleeved garments, pants, lightweight fabrics, wide-brimmed hats, and sunglasses that block both UVA and UVB rays. Opt for clothing that offers maximum UV protection.
Apply a broad-spectrum, water-resistant sunscreen with a sun protection factor (SPF) of 30 or higher. Such sunscreens protect against both UVA and UVB rays.
Consistently reapply sunscreen every two hours when outdoors, or after sweating or swimming, covering all sun-exposed areas including the neck, ears, scalp, and backs of hands.
Take additional precautions when near reflective surfaces such as snow, water, or sand, as these can intensify UV exposure and increase the risk of sunburn.

Other Preventive Measures

To further reduce the risk of skin cancer, consider the following actions:

Avoid tanning beds due to their harmful UV exposure which accelerates skin aging and raises the risk of skin cancer. Instead, use personal tanning products while also using sunscreen.
Quit smoking; smoking has been linked to increased wrinkle formation and reduced blood flow to the skin.
Moisturize the skin with home humidifiers and moisturizing creams, and limit the use of soap during bathing by opting for moisturizing body washes instead.
Educate children on skin protection and the prevention of skin cancer early in life.
Obtain vitamin D through healthy dietary sources and supplements after consulting a healthcare provider, rather than relying solely on sunlight exposure.
Stay adequately hydrated by drinking enough fluids, particularly water, before feeling thirsty, especially in sunny and humid conditions.
Exercise caution when using medications that increase sensitivity to sunlight and consult a physician before taking any medications.

Protecting Children’s Skin

It is imperative to shield infants and children from prolonged sun exposure from an early age, as they are likely to spend more time outdoors, increasing their risk of sun exposure. Most UV exposure occurs within the first 18 years of life. Strategies for protecting children’s skin include:

Instructing children to avoid lengthy sun exposure.
Ensuring they wear protective clothing, sunglasses, and hats.
Applying a broad-spectrum sunscreen with an SPF of 30 or higher, reapplying every two hours while exposed to sunlight, and after swimming.
Avoiding direct sunlight for infants under 6 months old.

It is noteworthy that the American Academy of Pediatrics endorses the use of sunscreen for children under six months if adequate shade and clothing are not available. Care should be taken to avoid direct sunlight exposure, ensuring lightweight clothing covers as much skin as possible while applying a small amount of sunscreen to the child’s face and the backs of their hands.

Regular Skin Check-ups and Consultation

Regular skin examinations are crucial for detecting new skin growths, changes in existing moles, freckles, and birthmarks. The American Cancer Society recommends annual skin checks for individuals over 40 and every three years for those aged 20 to 40. Self-examination should be conducted in a well-lit area using a full-length mirror, and an additional person’s help may be required for inspecting the back, neck, and scalp. It is essential to monitor sun-exposed areas for those with fair skin, as they are at a higher risk for non-melanoma skin cancers. In contrast, individuals with darker skin tones should be vigilant for squamous cell carcinoma, which often appears in areas less frequently exposed to the sun, such as the lower legs. The steps for self-examination include:

Inspecting the entire body from front to back using a mirror, followed by checking the sides while raising the arms.
Bending the elbows to thoroughly examine the inner and outer forearms, hands, and upper arms, particularly the areas that are often hidden from view.
Checking the legs from all angles, including between toes and heels.
Raising the hair to examine the neck’s back and checking the scalp with a hand-held mirror.
Using a handheld mirror to inspect the buttocks, lower back, and genital areas.

Individuals should consult a healthcare provider if any of the following changes are observed:

Non-healing sores for more than two weeks.
New spots that look different from existing ones on the skin.
Sores that bleed or itch.
Any noticeable changes in the color, texture, shape, or size of an existing skin mark.

Video on Symptoms of Skin Cancer

This disease typically affects skin areas most exposed to sunlight. What are its symptoms?