Saturday, July 2, 2016
Lung Cancer: Smoking and Family History
What is the possibilities of getting lung cancer if you are a smoker and have had both parents die from cancer at an early age?
The following information is adapted from "Cancer: Principles and Practice of Oncology" by DeVita, Hellman and Rosenberg.
A 35-year-old man who smokes 25 cigarettes or more per day has a 13% risk of dying from lung cancer before the age of 75, a 10% change of dying from coronary heart disease, and a 28% chance of dying from smoking-related disease (other cancers, emphysema, obstructive pulmonary disease, etc.)
There is evidence for a dose-response relation for smoking and lung cancer. The risk for lung cancer increases with the number of cigarettes smoked, the duration of smoking, earlier age at onset of smoking, degree of inhalation, the tar and nicotine content, and the use of unfiltered cigarettes. It decreases in proportion to the number of years after smoking cessation. [In other words, stopping will cut your risk but not overnight.]
Passive smoking increases the lung cancer risk. Some of the constituents of cigarette smoke that have caused cancer in laboratory animals include: benzo[a]pyrene, dibenz[a]anthracene, nitrosamines, nickel, cadmium, polonium, hydrazine, and vinyl chloride.
There is increasing evidence that genetic factors [such as your family history] can contribute to lung cancer risk. The cancer causing chemicals in your cells, including your lung cells, are produced by biochemical processes. These processes are determined by genes. Some genes may allow more of the cancer causing chemicals to be produced; other genes may allow less. A family whose genes allow more of the chemicals to be produced may be more susceptible to the effects of cigarette smoke and other things in the environment.
The molecular and genetic events underlying the origin of lung cancer are being actively investigated. At this time there is no conclusive genetic cause increasing the risk for lung cancer which has been identified.
Judith A Westman, MD
Associate Professor, Clinical Internal Medicine, Pediatrics and Medical Biochemistry
College of Medicine
The Ohio State University