Skin Cancer

Question 1

What is the pathophysiology of skin cancer?

Answer 1

Overexposure to sunlight is the major cause of skin cancer, although other factors also are associated. Because sun damage is an age-related skin finding, screening for suspicious lesions is an important part of physical assessment of the older adult. The most common precancerous lesions are actinic (solar) keratosis, and the most common skin cancers are squamous cell carcinoma (SCC), basal cell carcinoma, and melanoma. A biopsy of suspicious lesions is necessary to determine whether a skin lesion is malignant.

Question 2

What are the risk factors associated with skin cancer?

Answer 2

• Genetic predisposition
• Excessive exposure to UV light or certain occupational chemical carcinogens
• The presence of one or more precursor lesions that resemble unusual moles. Melanoma is highly metastatic, and survival depends on early diagnosis and treatment.

Question 3

What are the different types of skin cancer?

Answer 3

• Actinic (solar) keratoses are premalignant lesions of the cells of the epidermis. These lesions are common in adults with chronically sun-damaged skin. Progression to squamous cell carcinoma may occur if lesions are untreated. These appear as pink, reddish, or reddish-brown scaly macules or papules.
• Squamous cell carcinoma (SCC) is a cancer of the epidermis. These cancers can invade locally and are potentially metastatic. SCC is the most common cause of lip cancer, often seen in older Caucasian men. Chronic skin damage from repeated injury or irritation increases risk for this malignancy. Chronic wounds that remain open for long periods are also at increased risk for malignant transformation to cancer.
• Basal cell carcinoma arises from the basal cell layer of the epidermis and is the most common skin cancer worldwide. Early lesions often go unnoticed, and although metastasis is rare, underlying tissue destruction can occur. Genetic predisposition and chronic irritation are risk factors; however, UV exposure is the most common cause.
• Melanomas are pigmented cancers arising in the melanin-producing epidermal cells. Most often they start as the benign growth of a nevus (mole). Normal nevi have regular, well-defined borders and are uniform in color, ranging from light colors to dark brown. The lesion’s surface may be rough or smooth; those with irregular or spreading borders, and/or multiple colors, are abnormal. Other suspicious features include sudden changes in lesion size and reports of itching or bleeding.

Question 4

What are some health promotion and maintenance tips to consider?

Answer 4

• The most effective prevention strategy for skin cancer is avoiding or reducing skin exposure to sunlight (or tanning beds). Teach common prevention practices as listed in the Patient and Family Education: Preparing for Self-Management: Prevention of Skin Cancer box.
• Teach everyone to evaluate all skin lesions using the ABCDE guide for melanoma and to consult his or her health care provider to examine any lesion having unusual features. When lesions such as moles are present, they should be monitored annually by a dermatologist or other health care professional.

Question 5

What are some prevention tips to teach the patient about?

Answer 5

• Avoid sun exposure between 11 a.m. and 3 p.m.
• Avoid all tanning beds.
• Use sunscreens with the appropriate skin protection factor for your skin type.
• Wear a hat, opaque clothing, and sunglasses when you are in the sun.
• Examine your body monthly for possibly cancerous or precancerous lesions.
• Taking pictures of lesions and comparing them month by month can demonstrate changes.
• Keep a “body map” of your skin spots, scars, and lesions to detect when changes have occurred.
• Contact your primary health care provider if you note any of these:
• A change in the color of a lesion, especially if it darkens or shows evidence of spreading
• A change in the size of a lesion, especially rapid growth
• A change in the shape of a lesion, such as a sharp border becoming irregular or a flat lesion becoming raised
• Redness or swelling of the skin around a lesion
• A change in sensation, especially itching or increased tenderness of a lesion
• A change in the character of a lesion, such as oozing, crusting, bleeding, or scaling

Question 6

Explain how to assess for skin cancer?

Answer 6

• In addition to age and race, ask the patient about any family history of skin cancer and any past surgery for removal of skin growths. Recent changes in the size, color, or sensation of any mole, birthmark, wart, or scar are also significant.
• Ask in which geographic regions the patient has lived and where he or she currently resides.
• Obtain information about occupational and recreational activities in relation to sun exposure and any occupational history of exposure to chemical carcinogens (e.g., arsenic, coal tar, pitch, radioactive waste, radium). Ask whether any skin lesions are repeatedly irritated by the rubbing of clothing.
• Skin that has been injured previously is at greater risk for cancer development. Ask if the patient has ever experienced a severe skin injury that resulted in a scar. Examine all scarred skin areas for the presence of potentially cancerous lesions. A biopsy may be required to rule out cancer in a chronic open wound that fails to close with proper treatment.
• Although most skin cancers appear in sun-exposed areas of the body, inspect the entire skin surface and any unusual lesions, particularly moles, warts, birthmarks, and scars. Also examine hair-bearing areas of the body, such as the scalp and genitalia. Palpate lesions with gloves to determine surface texture. Document the location, size, color, and features of all lesions and any reports of tenderness or itching. Use the ABCDE method of evaluating all lesions for possible melanoma.

Question 7

What are some interventions for skin cancer?

Answer 7

Surgical and nonsurgical interventions are combined for the effective management of skin cancer. Treatment is determined by the size and severity of the malignancy, the location of the lesion, and the age and general health of the patient.

Surgical intervention can range from local removal of small lesions to a massive excision of large areas of the skin and underlying tissue. Surgical types for skin cancer include:
- Cryosurgery—Cell destruction by the local application of liquid nitrogen (−200°C) to isolated lesions, causing cell death and tissue destruction
- Curettage and electrodesiccation—Removal of cancerous cells with the use of a dermal curette to scrape away cancerous tissue, followed by the application of an electric probe to destroy remaining tumor tissue
- Excision—Surgical removal of small lesions, often done as first-line treatment for squamous cell carcinomas
- Mohs surgery—A specialized form of excision usually for basal and squamous cell carcinomas
- Wide excision—Deep skin resection often involves the removal of full-thickness skin in the area of the lesion. Depending on tumor depth, subcutaneous tissues and lymph nodes may also be removed.

Actinic keratoses can be treated by excision, cryotherapy, dermabrasion, photodynamic therapy, topical medications, or field ablations (e.g., chemical peels, laser treatment). Determination of the best treatment is influenced by the number and distribution of lesions, the characteristics of the lesions, potential side effects, and availability and cost of methods. Often cryosurgery or excision is chosen owing to their ease and low cost. Topical therapies such as imiquimod and fluorouracil are effective as long as the patient is adherent to the treatment regimen. These medications can cause skin irritation, so some patients prefer to avoid drug therapy.

Squamous cell carcinoma and basal cell carcinoma are usually treated by surgical excision in an outpatient setting with local anesthesia. Curettage and electrodesiccation, in which a dermal curette is used to scrape away cancerous tissue, followed by the application of an electric probe to destroy the remaining tumor tissue, is also effective. Mohs micrographic surgery, in which tissue is sectioned horizontally in layers and examined histologically, layer by layer, to assess for cancer cells, can also be performed. Radiation therapy can be used for older patients with low-risk basal cell carcinoma or squamous cell carcinoma who are not candidates for surgery. It can also be used for very large tumors or in areas where surgical excision is challenging. Targeted therapy is often used for advanced basal cell cancers, and immunotherapy is often used for squamous cell carcinomas.

Melanoma is usually treated by excision or Mohs micrographic surgery. Lymph node dissection may be necessary if lesions are found to be abnormally hard or large, or if melanoma is found in a node. Immunotherapy and targeted therapy (e.g., BRAF and MEK inhibitors) are often used early in the treatment of melanoma. Chemotherapy can be used if other treatments have not worked, but it is not as effective in treating melanoma as immunotherapy and targeted therapy agents. Radiation is not usually used to treat melanoma unless surgery cannot be done; it is given following lymph node removal or is offered as palliative therapy.