Basal cell carcinoma is the most common type of skin cancer in the United States and Australia and was first described by Arthur Jacob in 1827. The condition was first referred to as a histopathological entity in 1903, by Edmund Krompecher who believed that the cancer arose from basal cells in the epidermis.
Also called Jacob's ulcer and ulcus rodens, basal cell cancer is localized and rarely spreads. However, because it can still invade and destroy surrounding tissue, it is termed malignant.
Basal cell carcinoma is more common among fair skinned, fair haired individuals. The incidence of basal cell carcinoma is highest in Australia, where there are 726 cases per 100,000 people per year. Both genetics and sun exposure are thought to contribute to this high incidence.
In England, the incidence of basal cell carcinoma has increased from 173.5 to 265.4 per 100,000 inhabitants every year over the last 10 years.
In Germany, there are 96 new cases per 100,000 men per year and 95 cases per 100,000 women per year. For men an women in Canada, Switzerland, the Netherlands, and Finland the respective annual rates of new cases per 100,000 individuals are 87 and 68, 52 and 38, 53 and 38 and 49 and 45.
There is notable variation in the geographic location of basal cell carcinoma incidence. Generally, the incidence of basal cell carcinoma increases as a region's latitude decreases because the closer an area is to the equator, the greater the UV radiation.
In Australia, the incidence in regions of lower latitude is as high as 1,600 per 100,000 inhabitants per year while in areas of higher latitude in Northern Europe, for example, incidence is significantly lower, ranging from 40 to 80 per 100,000 inhabitants per year.
Over the last few decades, the number of people affected by basal cell carcinoma has been on the increase. Among white individuals, the annual incidence has increased by an average of 3.7% in the U.S., Canada and Australia and in the U.S., the incidence is twice that of 20 years ago. In Brazil, the rate of skin cancer increased by around 113% between 2001 and 2006.
Estimates suggest that nearly half of fair-skinned individuals over 60 years old will develop some type of skin cancer. Due to a yearly growth rate of 10% in many countries, basal cell cancer will soon surpass the incidence of all other cancers combined.
The rise in the number of newly diagnosed cases may be attributed to a greater awareness and understanding of the condition, with healthcare professionals making greater efforts to diagnose and refer patients. A greater cumulative exposure to UV rays, a rise in the popularity of tanned skin, increased longevity and ozone depletion are among other factors suggested.
Previous data has shown that men are more commonly affected by basal cell cancer than women. However, recent studies suggest a rise in the amount of females being diagnosed, possibly due to an increase in the use of sun beds and to an increased tendency to seek dermatological care and early medical attention.
Basal cell carcinomas excised in women tend to have smaller diameters than those excised in men, suggesting they do indeed seek early medical attention.
Reviewed by Sally Robertson, BSc