ABSTRACT
Malignant Tumors, Invasion, and Metastasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 13.3 The Human Cancer Burden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 13.4 Factors Causing Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
13.4.1 Factors Outside the Body — Exogenous Carcinogens . . . . . . . . . . . . . . . . . . . . . . . . . . 296 13.4.2 Factors Inside the Body (Endogenous Factors) that Causes Human Cancer . . . 298
13.5 Interaction of Environmental Factors and Genes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 13.6 The Carcinogenic Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 13.7 Strategies for the Prevention of Human Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
The purpose of this chapter is to give the reader an overview of human cancer induction and the proportional causes of human cancer. Cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells, and can result in death [1-4]. It is estimated that approximately 30% of human cancer is caused by exposure to tobacco smoking and tobacco products (Figure 13.1; reviewed in Reference 3). The cancers induced by tobacco smoking include lung cancer, esophageal cancer, laryngeal cancer, pancreatic cancer, bladder cancer, and cancer of the oral cavity (reviewed in References 3 and 5).
