In the United States, skin cancer is the most common form of cancer. A 2005 study published in the "Journal of the American Medical Association" showed that 1 in 5 Americans will develop skin cancer during their lifetimes. Ultraviolet radiation from the sun or tanning booths is a known carcinogen that damages the DNA of skin cells. People with increased risk of skin cancer include those who have fair skin or freckles, spend a lot of time in the sun, have a history of sunburn or family history of skin cancer, are immune suppressed, have a large number of moles and have a history of exposure to some chemicals.
Basal Cell Carcinoma
Basal cell carcinomas are the most common skin cancer in the United States. Long-term and intermittent repeated exposure to ultraviolet radiation, either through sun bathing or tanning booths, is a risk factor for developing basal cell carcinomas. This form of skin cancer rarely spreads to other organs, but if left untreated can be disfiguring because it destroys adjacent tissues. Basal cell carcinomas often appear as a nonhealing wound, a red, scaly patch, a pink or white translucent nodule or an area that appears like a scar. Doctors usually treat small basal cell carcinomas with local excision, or surgical removal. Larger lesions, however, often destroy surrounding tissue and may require reconstructive surgery.
Squamous Cell Carcinoma
A 1992 study published in the "Journal of American Academy of Dermatology" showed that squamous cell carcinomas accounted for 20 percent of all skin cancers. The incidence of squamous cell carcinoma is increasing owing both to the advancing age of the population and to an increase in ultraviolet radiation exposure. Squamous cell carcinomas are more commonly found on sun-exposed skin and are correlated with certain risk factors: fair coloring, skin that burns easily, history of nonmelanoma skin cancer, suppressed immunity, age greater than 50, accumulated exposure to ultraviolet radiation over a lifetime and some viruses. Squamous cell carcinomas are usually preceded by a premalignant lesion; the development of symptoms, a change in size or bleeding indicate that the lesion has become cancerous.
A 2005 study in "Laryngoscope" showed that even when squamous cell carcinomas had spread to other distant organs, the survival rate at 5 years was as high as 73 percent. Treatment can involve surgery, chemotherapy, radiotherapy, topical immune modulators and others.
Melanoma
Melanoma is not the most common skin cancer, but it does cause the most fatalities. Caught early, however, it is completely curable. Melanoma is linked to intermittent ultraviolet radiation exposure, especially exposure that result in burning. Some people are more susceptible to melanoma, especially those with a family member with a history of melanoma. Melanomas can develop in moles but can also occur in skin with no previous lesions. People who notice any change in a mole or a new lesion should consult a doctor. Treatment depends on the advancement and spread of the melanoma and can involve surgery, chemotherapy, radiation and immunotherapy.
Merkel Cell Carcinoma
A 2005 study in the "Journal of Surgical Oncology" estimated that 1,200 cases of Merkel cell cancer are diagnosed in the United states annually. The exact cause is unknown but extensive ultraviolet radiation exposure is a risk factor. Merkel cell carcinoma has also been linked to other diseases such as other cancers and HIV. These cancers often appear on sun-exposed skin as a firm, painless lumps.
References
- "Journal of the American Medical Association;" Sun Exposure, Sun Protection, and Vitamin D; Robinson JK; September 2005
- "Journal of the American Academy of Dermatology;" Squamous Cell Carcinoma of the Skin (Excluding Lip and Oral Mucosa); T. M. Johnson, et al; March 1992
- "Laryngoscope"; Surgery and Adjuvant Radiotherapy in Patients with Cutaneous Head and Neck Squamous Cell Carcinoma Metastatic to Lymph Nodes: Combined Treatment Should Be Considered Best Oractice; M. J. Veness, et al; May 2005
- "Journal of Surgical Oncology"; Merkel Cell Carcinoma: Changing Incidence Trends; N. C. Hodgson; January 2005
- "Cancer Epidemiology, Biomarkers and Prevention"; Merkel Cell Carcinoma and Melanoma: Etiological Similarities and Differences; R. W. Miller, et al; February 1999
