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.
Giant-cell tumor of bone
Giant-cell tumor of the bone accounts for 4-5% of primary bone tumors and about 20% of benign bone tumors. However, significantly higher incidence rates are observed in Asia, where it constitutes about 20% of all primary bone tumors in China. It is slightly more common in females, has a predilection for the epiphyseal/metaphyseal region of long bones, and generally occurs in the third to fourth decade. Although classified as a benign tumor, GCTOB has been observed to metastesize to the lungs in up to 5% of cases, and in rare instances (1-3%) can transform to the malignant sarcoma phenotype with equal disease outcome.