The two most common forms of nonmelanoma skin cancer (basal cell carcinoma and squamous cell carcinoma) develop from the actual epidermal cells. Together they account for about 80% of cases of nonmelanoma skin cancer 1.
How Common Is Nonmelanoma Skin Cancer Or Is It A Rare Disease?
Skin cancers (all types including nonmelanoma and melanoma) are becoming more common in recent years. In 2016 (figures from the Cancer Registry), skin cancers (all types combined) were close to 38,000 new cases. These numbers include 3069 cases of melanoma and nearly 7480 cases of squamous cell carcinoma, to which about 28,000 new basal cell carcinomas are added. The latter is not listed in the Cancer Registry which only includes invasive tumors (those that invade the tissues surrounding the tumor itself). (5)
Basal Cell Carcinoma
About 75% of cases of nonmelanoma skin cancer are of this type. It occurs mostly in people aged 45 and over, but younger people may also be affected. It grows slowly and almost never gives rise to metastases (invasion of other organs, away from the starting tumor). Therefore, it consists of tumors with local malignancy. It is the least dangerous form of skin cancer, yet it requires prompt and appropriate treatment. Without adequate treatment, it can extend deep and reach the tissues under the skin making recovery and treatment much more difficult. (2)
Squamous Cell Carcinoma
Ten percent of nonmelanoma skin cancer cases are of this type. It appears especially in people aged 60 and over. Its growth is faster than that of basal cell carcinoma. In the absence of treatment, it eventually gives rise to metastases, usually via the lymph nodes located near the tumor. Compared to the basal cell carcinoma this type is more aggressive. In the case of early treatment, however, the outlook is very favorable. (3)
Precancerous Lesions Of The Skin
There are various abnormalities that are not yet skin cancers, but that can become so in the future if not taken care of. One of the most prominent of this type is the actinic keratosis. This precancerous lesion is mainly found in the elderly. A precancerous lesion can develop into squamous cell carcinoma over time. This transformation is not frequent, but it is better to consult a dermatologist if you have such lesions. Just like the different forms of nonmelanoma skin cancers, precancerous skin lesions also usually appear under the influence of an excess of ultraviolet rays. (4)
Causes And Symptoms Of Nonmelanoma Skin Cancer
In the vast majority of cases, nonmelanoma skin cancer appears as a result of excessive exposure to natural (sun) or artificial (solariums, sunbeds, ultraviolet lamps) ultraviolet radiation. Smokers develop more keratoses (thickenings of the stratum corneum of the skin), which can evolve into skin cancers. Like all other types of cancer, skin cancer is not transmissible.
Basal cell carcinoma occurs mainly in the face. Most often, the patient notices a small glossy, translucent button that grows very slowly. Sometimes you can see dilated blood vessels.
Over time, a small ulcer appears around the center of the lesion and around it, a shiny border. This painless ulcer is often moist and has a crust that comes off easily.
Sometimes it falls spontaneously and a new crust is then formed. Basal cell carcinoma in the trunk often presents as an eczema plaque. (5) (6)
Treatment Options For Nonmelanoma Skin Cancer
Treatment will depend on the type of cancer, the location, and size of the tumor, and the age of the patient. In the first place, the treatment must give the best possible results with regard to healing.
If left untreated, the lesions may continue to grow and cause damage to surrounding tissue. This damage can spread the lesion to other parts of the body. Treatment options for squamous cell carcinoma include surgical extraction or radiotherapy.
Treatment is more complicated for large recurrent tumors or tumors located near important structures, such as the nose or eyes. In this case, it is necessary to make a micrographic surgery, a specialized surgery that isolates and removes the tumor and keeps the surrounding normal tissue intact. This form of surgery has the highest success rate for squamous cell carcinoma. (5)
- Batz S, Wahrlich C, Alawi A, Ulrich M, Lademann J. Differentiation of different nonmelanoma skin cancer types using oct. Skin pharmacology and physiology. 2018;31(6):238-245.
- Rubin AI, Chen EH, Ratner D. Basal-cell carcinoma. New England Journal of Medicine. 2005;353(21):2262-2269.
- Stransky N, Egloff AM, Tward AD, et al. The mutational landscape of head and neck squamous cell carcinoma. Science. 2011;333(6046):1157-1160.
- Aksoy B, Tatlıparmak A, Tamer F, Ergin C, Koç E. The Incidence of Precancerous and Cancerous Skin Lesions: A Retrospective Multicenter Study. Southern Clinics of Istanbul Eurasia. 2017;28(3).
- Queen L. Skin Cancer: Causes, Prevention, and Treatment. 2017.
- Apalla Z, Lallas A, Sotiriou E, Lazaridou E, Ioannides D. Epidemiological trends in skin cancer. Dermatology practical & conceptual. 2017;7(2):1.