Skin Cancer: Types, Symptoms, Causes, Treatment

What is skin cancer?

Skin cancer is one of the most common types of cancer in the world and in the United States. Cells in various body organs such as the brain, liver, and gut are in a state of continuous replication, which is finely regulated. Cancer occurs when this normal process of cell turnover goes uncontrolled. A group of abnormal cells can start replicating rapidly, thus giving rise to cancer. The type of cancer is determined by the kind of cells from which the abnormal cells originate. The skin, being the largest organ in the body, is also prone to developing skin cancer similarly.

Within the skin, there are different cells that can give rise to cancer. The skin is divided into two layers - the epidermis and the dermis. The epidermis further consists of five distinct layers of fast-replicating cells. These continually divide, and the epidermis thus gets fully replaced every 28-35 days. This constitutes one skin cycle.

The lowermost layer of the epidermis is the basal layer. The rest of the layers are composed of squamous cells. Between these are a particular type of cells called the melanocytes, which are the pigment-producing cells, wherein melanin is produced. Melanin is distributed from the melanocytes to the other epidermis cells, which gives our skin its natural colour. Skin cancer can arise from any of these three cell types - the basal cells, the squamous cells, or the melanocytes.

What are the risk factors for skin cancer?

Genetics

Some of us are genetically at a higher risk of developing skin cancer. There are certain cancers that run in families due to the presence of cancer-forming genes. Although genetics play an essential role, it does not mean one will inevitably develop skin cancer if they have a family history of the same. Environmental factors play a huge role in the expression of certain genetic predispositions.

A lighter skin

Those belonging to Caucasian and Northern European ethnicities are more prone to developing skin cancer. Individuals with a lighter skin phenotype, characterized by pale skin, red hair, and blue eyes, are more prone to developing skin cancer. The function of melanin is protection of the skin cells. Melanin absorbs UV radiation and thus protects the DNA from getting damaged. Hence, individuals with darker Fitzpatrick skin phototypes (IV-VI) are at a reduced risk of developing sun-induced skin cancers.

Sun exposure

Studies have shown that long-term cumulative exposure to UV radiation significantly increases skin cancer risk. Additionally, short bursts of intense sun exposure not only increase the risk of sunburns but also lead to DNA damage in the skin, which can result in skin cancer. A few countries, based on their latitude, receive more percentage of UV radiation, and this contributes to an increased incidence of skin cancer in those areas. Certain professionals like surfers and other outdoor sportsmen, as well as people with hobbies like gardening who spend a lot of time outdoors during the daytime, are at a cumulatively increased risk of developing skin cancer.

All UV rays are divided into UVA, UVB and UVC types. UVB rays penetrate only up to the dermis and cause direct DNA damage. These are mainly responsible for skin cancer by causing specific mutations in the DNA. DNA damage results in faulty cells that replicate rapidly and disproportionately, then turn into cancerous cells.

UVA, on the other hand, mainly contributes to signs of aging such as wrinkling, sagging of the skin, and uneven, blotchy pigmentation. UVA also penetrates deeper into the skin. It also changes the local immunity of the skin, thus making it more prone to developing cancer.

Tanning

Tanning is a process of exposing the skin to UV rays, either from natural sunlight or from artificial sources such as tanning beds and lamps. However, it is extremely damaging as it leads to direct DNA damage. This creates a conducive environment for mutations, leading to a considerable increase in the overall risk of cancer formation.

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Medications

Certain medications like methotrexate and biologicals can alter the skin's immune system, allowing potentially problematic cells to evade the body's natural defense system. This change in the immune system leads to the profileration of damaged cells going unchecked, which can then turn cancerous.

What are the symptoms of skin cancer?

Different types of skin cancer can have varied signs and symptoms. However, any mole or bump on the skin that has the following characteristics should alert you to visit your dermatologist:

• change in the size or color of the mole
• itching, redness, or soreness
• bleeding or discharge from the mole
• ulceration of the skin overlying the mole
• the borders of the mole looking altered

What are the main types of skin cancer?

Based on the cell of origin of cancer, skin cancer can be of one of these three types:

Squamous cell carcinoma

Originates from the flattened, squamous cells that make up most of the epidermis and occurs when DNA damage from UV exposure triggers abnormal changes in the squamous cells.

Basal cell carcinoma

Occurs when DNA damage from exposure to UV radiation triggers changes in basal cells in the outermost layer of skin (epidermis), resulting in uncontrolled growth.

Melanomas

Comes from skin cells called melanocytes. Most melanomas are black or brown in color, but they can also be pink, red, purple or skin-colored.

How is skin cancer diagnosed?

Skin cancer is diagnosed by undertaking a physical examination of the lesion in question by a qualified dermatologist. Your dermatologist will evaluate any suspicious mole for signs such as variability in color, border, and texture of the mole. A detailed family and lifestyle history are also relevant.

A special dermoscope is used to examine the suspected moles closely. A dermoscope gives an idea of the terrain and the subsurface characteristics of the mole. This helps your dermatologist decide if a mole is suspicious or not and decide the next steps of management.

For confirming the diagnosis, a small sample measuring a few millimeters is excised and sent for laboratory evaluation under a microscope. This is a procedure called a biopsy.

If a cancer is confirmed, other tests such as a lymph node biopsy as well as scans of the chest and abdomen may be needed to gauge the extent of spread of the cancer. This is essential because skin cancer cells can spread to various internal organs via the bloodstream leading to metastases. Knowing the size of the cancer spread can help guide the most appropriate line of treatment.

Is it curable?

Although it can be alarming to receive a skin cancer diagnosis, the overall mortality from skin cancer is pretty low compared to other forms of cancer. As with all cancers, early diagnosis will ensure the best results concerning overall outcomes. So, the earlier a cancer is diagnosed, the higher the chances of it being curable.

What are the treatment options?

There are several treatment options available. Treatments are tailored according to various factors - age, sex, comorbidities, lifestyle and affordability.

For smaller moles that have not spread beyond the skin, the treatment includes surgical excision to remove the mole and a part of the normal skin around it. This is done to ensure that any potentially cancerous cells that have spread beyond the border are removed completely, and no residual cancer cells are left.

A specialized type of surgery called Mohs micrographic surgery achieves excellent results while maintaining the patient's cosmetic appearance. Cryotherapy is another excellent option for smaller, more superficial skin cancers.

Treatment options for advanced skin cancer include chemotherapy, radiation therapy, and advanced treatment such as targeted therapy.

How to prevent skin cancer?

Since a significant risk factor for skin cancer is UV radiation, reducing sun exposure can vastly reduce the chance of developing skin cancer. Practicing sun safety by wearing sunscreen and ensuring sun-safe behavior is the key to preventing skin cancer. The American Academy of Dermatology recommends using water-resistant, broad-spectrum sunscreen with an SPF of at least 30 or higher.

Cultivating a habit of regularly wearing sunscreen is the most important step to reducing your risk of skin cancer. There are two main types: physical or mineral and chemical sunscreens.

Physical sunscreens are based on mineral filters that block the UV radiation from hitting the skin's surface and act as physical barriers. The mineral filters commonly used are titanium dioxide and zinc oxide. Because they work by blocking radiation, they are effective immediately when applied to the skin. This is in contrast to chemical sunscreens that need to be applied around 30 minutes before sun exposure to provide protection.

Physical sunscreens have the advantage of providing greater protection than chemical sunscreens. They are also inert, which means they do not react with the skin, making them safe for all skin types, including sensitive and mature skin. Although earlier physical sunscreens tended to leave a white cast, this is not the case with newer formulation technologies. Products such as our Sunsolve Anti Hyperpigmentation Mineral SPF50 are formulated with non-nano zinc and also include other skin-brightening ingredients, thus providing powerful UV protection and correction of skin tone complexion.

Moreover, non-nano formulations of zinc oxide stay on the surface of the skin without getting absorbed into the bloodstream, thus making them highly safe yet effective. Free radicals are directly responsible for skin inflammation and damage to skin cells. Products such as Sunsolve MD TheSolve ™ harness the ability of zinc oxide to quench free radicals arising from sun damage and pollution to shield your skin.

As explained, UV rays lead to DNA damage in the skin. Our non-nano zinc oxide sunscreen SunsolveMD SolveDNAReverse ™ incorporates a complex repair enzyme that has the ability to reverse DNA photo sun damage. This further minimizes the risk of developing skin cancer.

These will help reduce your risk of skin cancer and prevent premature aging in the form of wrinkles, loss of skin elasticity and age spots. To tackle the appearance of dark spots, the SunsolveMD Mela-Fix™ Technology™ is fortified with clinically-proven melanogenesis-inhibiting technology. The Sunsolve Volume RestoreTM has the advantage of restoring the skin's lipid barrier and eliciting visible plumping and volumizing as it contains fatty acids, in addition to providing excellent sun protection.

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Tips for sun safety

While sunscreen use is essential, a few other habits can be introduced in your lifestyle to further mitigate the risk of skin cancer:

• Avoid being outdoors for long periods, especially between 10 am and 3 pm when the sun's radiation is the highest and cloud cover is low.
• Seek shade whenever possible when outdoors for extended periods.
• Wear long-sleeved clothing to ensure your arms and legs are fully covered.
• Wide-brimmed hats and caps can protect the face and neck from excess sun exposure. This will also help reduce premature signs of aging, such as wrinkling and uneven, blotchy pigmentation.
• Another trick is to wear large, UV-protective sunglasses that cover a wide portion of the skin around the eyes, extending to the cheeks. The eyelids have the thinnest skin in the body and it is a good idea to provide an extra layer of protection to this area. Bonus: this will also reduce dark circles.
• Consider that women get skin cancer often on the legs. There is special UPF clothing available that blocks a majority of the UV rays. Certain fabrics naturally have more UV-blocking capacity based on the weave, thickness, and density of the threads. A UPF rating of over 25 will provide good coverage.
• Avoid tanning beds and sun lamps as these cause significant damage to the skin cells, creating a minefield of potentially cancerous cells.

References

Guerra KC, Zafar N, Crane JS. Skin Cancer Prevention. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519527/

Rosenthal, A., Stoddard, M., Chipps, L., & Herrmann, J. (2019). Skin cancer prevention: a review of current topical options complementary to sunscreens. Journal of the European Academy of Dermatology and Venereology : JEADV, 33(7), 1261–1267. https://doi.org/10.1111/jdv.15522

Zhao, B., & He, Y. Y. (2010). Recent advances in the prevention and treatment of skin cancer using photodynamic therapy. Expert review of anticancer therapy, 10(11), 1797–1809. https://doi.org/10.1586/era.10.154

Sample, A., & He, Y. Y. (2018). Mechanisms and prevention of UV-induced melanoma. Photodermatology, photoimmunology & photomedicine, 34(1), 13–24. https://doi.org/10.1111/phpp.12329