Skin cancer is closely linked to prolonged sun exposure, one of the main contributors to various types of skin cancer. As the largest organ in the body, the skin performs crucial functions, including protecting against infections and regulating body temperature and fluid balance. Its vital role in shielding us from ultraviolet (UV) radiation highlights the importance of understanding the risks of excessive sun exposure.

While many associate vacations with time spent in the sun, swimming in the sea, or enjoying beach activities, it’s essential to consider the long-term damage sun exposure can cause. Melanin, the pigment produced in the epidermis, plays a critical role in protecting against UV radiation. People with pale skin, often associated with a lower production of melanin, are more susceptible to UV damage and, consequently, skin cancers. However, individuals with darker skin, which is less prone to sun damage, can still develop skin cancer, often years after radiation therapy or exposure to carcinogenic substances.

In the U.S., more than 3.5 million new cases of skin cancer are diagnosed each year, affecting over 2 million people.

Types of Skin Cancer

There are three primary types of skin cancer:

1. Basal Cell Carcinoma (BCC)
2. Squamous Cell Carcinoma (SCC)
3. Melanoma

All three types are at least partially caused by prolonged sun exposure.

Basal Cell Carcinoma (BCC)

BCC is a slow-growing tumor that originates from specific cells in the epidermis. It arises from keratinocytes near the basal layer, known as basaloid keratinocytes. Although metastasis is rare, local growth can cause significant tissue destruction. BCC is typically diagnosed through histological examination. Treatment options vary based on tumor characteristics and include:

• Curettage and Electrocoagulation
• Surgical Excision
• Cryotherapy
• Topical Chemotherapy
• Radiation Therapy

Clinical Presentation and Behavior of BCC

BCC can present in several ways:

• Small, shiny, firm, pink nodules with telangiectasia (visible blood vessels)
• Ulcerated, crusted papules or nodules
• Flat, scar-like, firm plaques that may resemble scleroderma or have indistinct borders
• Red, well-defined papules or plaques that resemble psoriasis or dermatitis

Diagnosis of BCC

A biopsy is necessary for diagnosis, followed by histological examination.

Prognosis

BCC rarely metastasizes, but it can invade healthy tissue. Approximately 25% of patients with a history of BCC develop a new BCC within five years, so annual skin examinations are essential.

Treatment of BCC

Treatment often involves local methods, which vary based on tumor size, location, and histological subtype. These may include:

• Curettage and Electrocoagulation
• Surgical Removal
• Cryotherapy
• Topical Chemotherapy

Melanoma

Melanoma develops from melanocytes in pigment-containing tissues such as the skin, mucous membranes, eyes, or CNS. The risk of metastasis correlates with the depth of penetration into the dermis. For advanced cases, especially with metastasis, the prognosis is often poor. Diagnosis is confirmed through histological examination, and treatment typically involves:

• Wide Surgical Excision for operable tumors
• Immunotherapy and chemotherapy for metastatic or inoperable melanoma

Statistics on Melanoma

In the U.S., about 76,250 new cases of melanoma are diagnosed each year, resulting in around 9,180 deaths. The lifetime risk of developing melanoma is between 1% and 2%. Although melanoma accounts for less than 5% of all skin cancer cases, it is the leading cause of death from skin cancer.

Treatment of Melanoma

• Surgical Excision
• Adjuvant Radiation Therapy
• Imiquimod (not registered in some countries) or Cryotherapy
• Immunotherapy and Radiation Therapy for metastatic melanoma

Why Early Detection is Crucial

Most skin cancers are highly treatable, particularly when detected early. Malignant skin tumors often have no symptoms initially. Therefore, it’s crucial to consult a doctor if any unusual skin growth appears that increases in size or persists for several weeks.

Conclusion

While sunlight has some benefits, excessive exposure can cause significant skin damage and increase the risk of developing skin cancer. Regular skin checks, protection from UV radiation, and early detection are key factors in preventing and successfully treating skin cancer.

Materials Used in This Article: © 2018 Merck & Co., Inc., Kenilworth, New Jersey, USA