Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 7

What are the general causes of cancer? What are the relative contributions of these causes in the United States?

Step 1 of 3

Cancer can be caused by a variety of factors. Generally, it is caused by carcinogenic agents that induce and promote unchecked, uncontrollable growth of the cells.

Carcinogens are chemical substances that are potential causes of cancers. They destroy the normal functioning of the cells such as eliminating the metastasis ability of normal cells which induces uncontrollable proliferation of the cells that gives rise to cancerous tumors.

Carcinogens disrupt the metabolic processes of the cell and cause damage to the genome. Mutations in the DNA are the root causes of cancers and results in an altered gene product which can be either non-functional or functions abnormally. Apart from chemical mutagens, gene mutations can be caused by smoking, radiation, viruses, obesity, hormones, chronic inflammation and lack of exercise.