Figure 1 Estimated incidence and total mortality from cancer in the United States 2001 (16).

In general, the most common cancers are classified as epithelial cancers, as they are initiated from the epithelium of the lung, colon, breast, and prostate (33,34). Carcinogenesis results from the accumulation of multiple sequential mutations and alterations in nuclear and cytoplasmic molecules, which ultimately culminates in invasive neoplasms (35). There are two types of neoplasms or tumors-benign and malignantand the common name for the malignancy is cancer (36).