Most everyone understands that smoking cigarettes greatly increases the risk of lung cancer. Unfortunately, not nearly as many people understand the connection between smoking and risk of other cancers. Now we can definitively add colon and rectum (colorectal) cancers to the list of diseases caused by smoking.
In one of the most comprehensive studies on this topic to date, researchers discovered that a long-term history of smoking increases risk of colorectal cancer by 30-50%. In particular, colorectal cancer risk was highest in those who did not quit smoking before age 40 or who smoked cigarettes for 40 or more years.
If you smoke, quitting smoking is the single best thing you can do to improve your health and reduce your risk of cancer. Along with the new study showing that smoking significantly increases the risk of colon cancer, previous research indicates that smoking increases the risk of 16 other cancers as well.
In summary, smoking significantly increases the risk of cancers of the oral cavity, pharynx, nasopharynx, nasal cavity and paranasal sinuses, larynx, lung, esophagus, stomach, colorectum, liver, pancreas, kidney, bladder and lower urinary tract, uterus, cervix, and myeloid leukemia.
Kicking the Habit to Lower Cancer Risk
If you smoke, quitting is the single most important thing you can do to improve your health. But don't go it alone. Numerous studies prove that using quitting aids, ranging from the nicotine patch and chewing gum, to medications that blunt the urge to smoke, to support groups, greatly increases your chances of success. Cold turkey is just plain hard, and more importantly, harder than it needs to be.
Knowing that a smoking habit has many reinforcing aspects to it - the physical addiction, the "ritual" of lighting up, social pressure from fellow smokers - should convince anyone that it's wise to take all the help you can get when you're ready to quit. Along with using quitting aids and support groups, keep in mind that for most people, it takes many attempts to quit to be successful.
Think of each attempt to quit as a fact-finding mission. For example, you can learn what things trigger a relapse, so you can avoid them the next time around. When you put enough of these "self-awareness" facts together, you will increase your odds of successfully quitting.
It also may help to remember that you're quitting as a gift to yourself and your loved ones. While it may feel like punishment to quit smoking, it will feel better and better, like the gift it is, over time.

I understand that smoking has many bad effects besides lung, what about these : http://electroniccigaretteinformation.org/smokestik/
I’ve been using it for the past 4 months, if you can collect evidenct that those have evne close to bad effects a smoking.. i will be DONe with smoking these:
http://electroniccigaretteinformation.org/smokestik/
When it comes to electronic cigarettes (e-cigarettes), it is a question of “harm reduction”. In other words, smoking e-cigarettes may be less harmful than smoking regular cigarettes, but it is still harmful. And it is more harmful than quitting smoking altogether. A recent commentary published in the Journal of the American Medical Association concluded,
“Results of a US Food and Drug Administration (FDA) analysis of 2 widely marketed electronic cigarette products suggest these devices may contain some of the same toxic or carcinogenic compounds as traditional cigarettes.
Electronic cigarettes, or e-cigarettes, are battery-powered devices that vaporize nicotine, flavoring, and/or other chemicals into an inhalable vapor. Chemical analyses of several samples of products by FDA scientists detected tobacco-associated chemicals that may be harmful to humans, including known human carcinogens. One cartridge also contained 1% ethylene glycol, a toxic chemical.”
Kuehn BM. FDA: Electronic Cigarettes May Be Risky JAMA. 2009;302(9):937.
The bottom line is that there is no safe cigarette. E-cigarettes still have health risks for people who use them.
I hope this information is helpful. Colon Cancer Guide (Suzanne Dixon)