Basal-cell carcinoma
In the United States approximately 3 out of 10 caucasians develop a basal-cell carcinoma during their lifetime. This tumor accounts for approximately 70% of non-melanoma skin cancers. In 80 percent of all cases, basal-cell carcinoma affects the skin of head and neck. Furthermore, there appears to be an increase in the incidence of basal-cell cancer of the trunk in recent years.
Pre- and post-test probability
For example, the incidence of breast cancer in a woman in the United Kingdom at age 55 to 59 is estimated at approximately 280 cases per 100.000 per year, and the risk factor of having been exposed to high-dose ionizing radiation to the chest (for example, as treatments for other cancers) confers a relative risk of breast cancer between 2.1 and 4.0, compared to unexposed. Because a low fraction of the population is exposed, the prevalence in the unexposed population can be assumed equal to the prevalence in the general population. Subsequently, it can be estimated that a woman in the United Kingdom that is aged between 55 and 59 and that has been exposed to high-dose ionizing radiation should have a risk of developing breast cancer over a period of one year of between 588 and 1.120 in 100.000 (that is, between 0,6% and 1.1%).