Understanding your risk for getting cancer is a critical piece of information that can help you stay healthy. Modifying behaviors to reduce your risk of developing a specific type of cancer makes perfect sense. Many people do this by getting exercise, watching what and how much they eat and drink, and by not smoking.

It was recently disclosed that a new test has been developed that identifies those smokers who have higher risk of developing lung cancer (the test measures metabolites of tobacco carcinogens called NNAL). Lung cancer is the leading cause of cancer-related death for both men and women in the United States. And the leading cause of lung cancer is cigarette smoking.

One advantage of knowing your risk factor for a particular cancer is that you can screen for that cancer more frequently if your risk is high. For example, if you have a family history of colon cancer it is very important to have regular colonoscopies. But this new test raises some interesting questions related to smoking and lung cancer.

Does this mean that smokers who, according to the test, have a low risk for lung cancer can continue to smoke with little risk of getting cancer? Does it mean that those who have higher risk can simply get frequent lung exams to catch the disease early in the event that they get lung cancer? The answers to these questions are no, and definitely no.

First of all, the risk of lung cancer is dramatically higher in smokers than nonsmokers. So even those who have low NNAL still have dramatically higher risk due to their smoking. And the limitations of frequent testing is that it is very difficult to detect lung cancer in its early stages.

So given the fact that fewer than 14% of those who develop smoking-related lung cancer survive for more than 5 years after being diagnosed, it is not at all clear that catching the disease early is any great reassurance. But even if you put this grim fact aside, lung cancer is only one of the deadly risks of smoking. Heart attacks, stroke and emphysema are just a few of the far more common causes of death among smokers. And this test only gives information about lung cancer. Smoking is a major risk factor in nearly every other type of cancer, including breast, liver, mouth, and bladder cancer.

The sad fact is that smokers die at least 10 years earlier than nonsmokers. And, the earlier you quit in life, the more years you add to your life. Even if longevity is not a major goal for you, smokers suffer horrible disabilities as a result of their smoking making their quality of life lower than those who quit or never start.

So while this new test should definitely not give anyone scoring in the lower risk category permission to smoke, those who do score medium to high on the risk scale should have additional motivation to quit smoking. Quitting smoking remains the single best thing a person can do for their health -- bar none!