Quitting smoking greatly reduces a person's risk of developing lung cancer, and the risk keeps decreasing the longer a person refrains from smoking.
Smoking is the most important risk factor for lung cancer.
Smoking is also a risk factor for other cancers. The risk of developing cancers of the mouth, throat, and esophagus decreases significantly 5 years after quitting. The risk of developing bladder cancer and cancer of the cervix also decreases after just a few years of being smoke-free. Besides lowering the risk of cancer, quitting smoking has many more health benefits. The smoker's heart rate and blood pressure, which are usually high while smoking, begin to return to normal.