Smoking is the number one primary cause of premature death in the US (did you know that the obesity-sedentary lifestyle is number two?)
Many pulmonary physicians, including myself, argued for many years that periodic x-rays of the lungs in heavy smokers could save lives. Several years ago a study showed that doing chest CT scans in heavy smokers leads to early detection and possibly a better cure rate. All this was met with harsh criticism from many professional organizations (I wonder why).
But what the pulmonary specialists knew for quite a few years was finally shown to be true in the June 29 edition of the New England Journal of Medicine. The use of low radiation, periodic CT scans of the lungs in heavy smokers led to early cancer detection, and thereby saved many lives. This is not the total answer to lung cancer, but it certainly helps.
So, if you are a heavy smoker and have not discussed the cancer risk issue with your physician, do it now. If your insurance company doesn't cover this screening test, I know several radiology practices that will do it for $300, and it's well worth it.