Top Five Risk Factors of Melanoma and Non-melanoma Skin Cancers - An Overview

What Is Melanoma?

Melanoma, also called a black tumor, is the most serious form of skin cancer that develops in the melanin-producing cells called melanocytes. Melanoma proliferates quickly and involves the eyes and, rarely, the nose or throat. The actual cause of melanoma is still unclear, but experts believe exposure to some triggers can increase the risk of melanoma. Knowing the high-risk group for developing melanoma skin cancer is essential because of the fast growth rate of melanomas; a treatment delay sometimes is the difference between life and death. In addition, early identification is important because treatment success is correlated to the depth of cancerous growth.

What Are the Risk Factors of Melanoma?

The following factors can increase the risk of developing melanoma:

• Fair Skin: Melanoma can occur in people of any skin type, but it is more common in white people. Having less melanin pigment in the skin means having less protection from damaging ultraviolet (UV) radiation. In addition, those with blond or red hair, light-colored eyes, and freckles or sunburn are more likely to get melanoma than individuals with a darker complexion. People with darker complexion usually get melanoma on their palms, nails, and soles.

• Prolonged Ultraviolet (UV) Light Exposure: Excessive exposure to ultraviolet radiation from the sun and tanning lights and beds, tanning parlors, or sun lamps can increase the risk of melanoma skin cancers. Frequent extreme sunburns in early childhood can raise melanoma risk but sunburn later in life also contributes to melanoma.

• People Living Nearer to the Equator or at Higher Altitudes: Because the sun's rays are more direct near the earth's equator and higher altitudes, people living closer to these areas get exposed to higher amounts of UV radiation. Thus, these individuals have a greater chance of developing melanoma.

• Moles or Dysplastic Nevi: Having many ordinary or unusual moles called dysplastic nevi on the body indicates an increased risk of melanoma. These moles are larger than normal moles with irregular borders and colors. Healthcare professionals often recommend regular photography of the skin to examine the skin of people with many moles closely.

• Family History of Melanoma: If a person has a family member or close relative diagnosed with melanoma, that person has a two to three times greater risk of developing melanoma. About 10 % of individuals with melanoma skin cancer have a family history of the disease. Therefore, regular skin examination of the close relatives of a person is recommended.

• Individuals With Weakened Immune System: Those with weakened immune systems and those who take medicines to suppress the immune system are more likely to develop melanoma and other skin cancers.

• Previous Skin Cancer: People with melanoma have a greater risk of developing new melanomas. People with basal or squamous cell skin cancer are more prone to melanoma. Therefore, people with previous skin cancer often need ongoing follow-up care to monitor for additional cancers.

• Age: The risk of melanoma is more in young adults (people under 40), especially women than in many other types of cancer.

What Is Non-Melanoma?

Nonmelanoma skin cancer is all the other types of cancers that develop in the skin that are not melanoma. Basal cell carcinoma, Merkel cell carcinoma, cutaneous T-cell lymphoma, Kaposi sarcoma, and squamous cell carcinoma are nonmelanoma skin cancers. Of all, basal cell and squamous cell carcinoma are the most common skin cancers. Some people with several risk factors may raise a person's chance of developing nonmelanoma skin cancer. Knowing the risk factors of skin cancers and discussing them with a health care professional can make people more informed about better lifestyles and health care choices.

What Are the Risk Factors of Non-melanoma Skin Cancer?

The risk factors for developing nonmelanoma skin cancer include:

• Exposure to Ultraviolet Type B (UVB) Radiation: Ultraviolet type B exposure is closely related to skin cancer, but ultraviolet type A (UVA) may also contribute to the development of basal cell carcinoma and squamous cell carcinoma.

• Weakened or Suppressed Immune System: People with weakened immune systems due to immunosuppressive drugs, bone marrow or stem cell transplants, organ transplants, or diseases such as human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS) increase the risk of developing skin cancer, especially squamous cell carcinoma.

• Indoor Tanning: People who frequently use tanning beds and parlors or sun lamps increase the risk of developing skin cancer. In addition, as there is no safe amount of indoor tanning, the use of indoor tanning devices should be discouraged.

• Fair Skin: People with fair skin complexion, blond or red hair, blue eyes, and freckles are at more risk of developing nonmelanoma skin cancer.

• Race or Ethnicity: Merkel cell carcinoma is more common in white people. However, people of Polynesian descent and some black people can also develop the disease.

• Merkel Cell Polyomavirus (MCV): Research suggests an association between the MCV virus and Merkel cell cancer. MCV is present in about 80 % of Merkel cell cancers.

• Gender: Men are at more risk of developing Merkel cell cancer.

• Age: Most basal and squamous cell carcinomas develop after age 50. Younger adults can also develop nonmelanoma skin cancer, especially those with fair skin. Merkel cell cancer is more common in people aged above 70.

• Inherited Syndromes: Certain rare inherited conditions, such as nevoid basal cell carcinoma syndrome, Bazex-Dupré-Christol, and epidermolysis bullosa simplex syndromes, are linked to an increased risk of basal cell carcinoma. Rare syndromes related to an increased risk of squamous cell carcinoma include albinism, xeroderma pigmentosum, epidermolysis bullosa simplex, and dyskeratosis congenita.

• Arsenic Exposure: People exposed to the poison arsenic may increase the risk of Merkel cell carcinoma.

• Previous Treatment With Radiation Therapy: People who receive radiation therapy for cancer treatment have a higher risk of developing basal cell carcinoma. This risk increases with time, particularly after 10 to 20 years. Therefore, children receiving radiation therapy have a six times higher risk of developing basal cell carcinoma.

• Human Papillomavirus (HPV): Research indicates that the HPV virus is one of the risk factors for squamous cell carcinoma, especially if the person's immune system becomes suppressed.

Conclusion

Several types of skin cancers exist, with melanoma being the most serious one. However, others are called nonmelanoma skin cancer. Knowing the warning signs of all skin cancers can help ensure early detection of cancerous changes before cancer has spread. Also, if detected early, these skin cancers can be treated successfully. In addition, knowing the risk factors can help a person be more vigilant in watching changes in their skin and seeking skin examinations.