Never Smoke Chapter 9

Smoking _ The Cancer Connection

Cancer-causing chemicals in cigarette smoke trigger the growth of many kinds of cancer cells


Cells Gone Wild

Cigarette smoke is one complex concoction. It contains thousands of ingredients, hundreds of them known to be toxic and at least 60 deemed carcinogenic, or cancer-causing. How do the carcinogens in cigarette smoke cause cancer? By triggering genetic changes in cells that cause them to start dividing uncontrollably. READ MORE

Some carcinogens directly damage genes. Others interfere with DNA's ability to repair and maintain genes. For example, one cigarette carcinogen called benzo (a) pyrene, or BP, is known to damage a gene called p53. Normally, that gene regulates the rate of cell division, and shuts down growth of cells that have detectable abnormalities. Studies have connected BP with increased lung cancer risk because of its inhibiting effects on p53. The end result is that when a gene whose job is to control cell division and growth is damaged, cells can grow out of control. LESS


Cause and Effect

The first Surgeon General’s Report on smoking in 1964 reported that researchers had found a clear connection between cigarette smoking and lung cancer. Since then, cigarettes have been found to directly cause many other kinds of cancer as well. Cancers of the throat, mouth, larynx, esophagus, and bladder are all directly caused by smoking. Why? READ MORE

Any organ or structure that comes in direct contact with cigarette smoke is susceptible to the genetic damage that results in cancer. The sites a greatest risk for smoking-related cancer are all along the path that smoke travels—mouth, throat, larynx, airways, lungs. Esophageal cancer is also directly related to smoking, and smokers do swallow carcinogens when they drag on a cigarette. And bladder cancer is also considered a primary smoking-related cancer. Smokers are two to three times more likely to get bladder cancer than nonsmokers. Certainly, other environmental factors could contribute to any of these cancers. Nonsmokers account for about 13% of all lung cancer victims, and about half of all cases of bladder cancer. The combination of smoking along with exposure to environmental conditions that affect everyone raises your risk even higher. LESS


Close Links to other Cancers

Smoking is also associated with higher risk of many more kinds of cancer. Cancers of the stomach, kidney, pancreas, cervix, breast, and certain varieties of blood cancer affect smokers disproportionately. Once cigarette-smoke carcinogens are in your bloodstream, they circulate throughout your body. It stands to reason that the toxins bring the threat of harm wherever they pass. READ MORE

The cause-and-effect relationship between smoking and some associated cancers is less clear than the cancers of organs and structures that are directly exposed to smoke. But the statistical patterns of increased cancer diagnoses among smokers is clear. A 2010 study of more than 111,000 women, who were tracked over 30 years, found that any history of smoking raised a woman's risk of developing breast cancer by 6%.. Smoking before bearing children raised the risk by 18%. Other studies have found that as many as 11% of all stomach cancers are smoking-related. At Duke University Medical Center, a study of 845 kidney cancer patients found that heavy smokers were one-and-a-half times more likely to have advanced, harder-to-treat cases of kidney cancer. Researchers will continue to investigate the sequence of events that leads from smoking to cancers of organs that do not come into direct contact with inhaled smoke. For now, we have the statistics to tell the story, and it is very clear that smoking amplifies the risk for many potentially deadly kinds of cancer. LESS

theVisualMD Wishes to Thank our Scientific Collaborators:
