Introduction
Non-melanoma skin cancer is the commonest cancer in the UK. It is usually caused by ultraviolet radiation from chronic sun exposure in a fair-skinned population. Basal cell carcinoma is the most frequent variety (74%), and presents as a superficial tumour that very rarely metastasises. Squamous cell carcinoma (23%) can spread to regional lymph nodes.
Surgical excision is the treatment of choice for the majority of tumours. Non-surgical treatment options include radiotherapy, curettage, imiquimod cream, photodynamic therapy and topical 5-FU therapy. Radiotherapy is an important treatment option for older patients and is preferred to surgery for large superficial tumours, multiple tumours, and in areas around the eye, nose and ear where the cosmetic results may be better and function can be preserved. The radiotherapy technique involves treatment with either superficial X-rays (SXR) or electron therapy. Cure rates are about 95% at 5 years.
The National Institute for Health and Clinical Excellence has published service guidance on the care of these patients (NICE, 2006).
Range of tumours
In the differential diagnosis, the tumour could be benign or malignant, and a malignant tumour could be either primary or secondary.
Premalignant conditions
Premalignant conditions include the following (Soutar and Robertson, 2001):
• actinic keratosis;
• Bowen's disease;
• erythroplasia of Queyrat;
• Paget's disease.
Benign tumours
Benign tumours include the following:
• benign naevus;
• sebaceous cyst;
• epidermal cyst;
• basal cell papilloma (seborrhoeic keratosis);
• vascular angioma;
• keratoacanthoma;
• dermatofi broma .
Malignant tumours
Primary malignant tumours include:
• basal cell carcinoma;
• squamous cell carcinoma;
• Merkel cell carcinoma;
• malignant eccrine porocarcinoma;
• amelanotic melanoma;
• cutaneous T-cell lymphoma;
• primary cutaneous B-cell lymphoma;
• Kaposi's sarcoma;
• angiosarcoma;
• lymphangiosarcoma;
• atypical fi broxanthoma.
Secondary malignant tumours can arise from any primary site, but occur most commonly from breast cancer, lung cancer, colon cancer and melanoma.
Incidence and epidemiology
There were about 100,000 cases of non-melanoma skin cancer in the UK in 2010. This comprises about 20% of all new cancers and there are about 500 deaths annually. More than 5% of the population over age 60 will develop a non-melanoma skin cancer (American Cancer Society, 2003).