Should I be screened for lung cancer with a CT scan?

Photo Credit: Phil Boorman/Cultura.

Up until recently, experts did not recommend routine screening for lung cancer, even for patients with COPD. This was in part because studies did not show that chest x-rays did not pick up many smaller lung cancers.  However, since lung cancer is the third most common cause of cancer in the US, researchers investigated whether there were other, better methods for screening patients since early detection of lung cancer is critical for successful therapy.


As a result of research in this area, the US Preventive Services Task Force (USPSTF) released guidelines in March 2014’s edition of the Annals of Internal Medicine, which is a leading journal for cutting edge research and guidelines.  The report recommends routine screening for lung cancer using “low dose” CT scans for patients who are at high risk for lung cancer.  In other words, not everyone needs to be screened for lung cancer, but for those who are at risk, a low dose CT scan is a better screening test than a chest x-ray.

Who should be screened for lung cancer?

Patients who should be screened for lung cancer include those who are:

1) 55-80 years old


2) Have smoked 30 “pack years” or more (pack-year = number of packs per day smoked x the number of years smoking) AND are current smokers or have quit in last 15 years

  • Screening should be done every year until the patient has not been smoking for 15 years.
  • Patients who meet criteria with screening should have a “low-dose” CT scan (not a chest-xray)

Why don’t we just screen everyone?

Although it may seem like a good idea on face value, routine screening for diseases such as lung cancer in patients who are not at high risk of the disease may actually cause more harm than good.

  CT scans commonly detect “incidental findings”– or in other words, an abnormality that is irrelevant to one’s health.  Just as lumps, bumps or scars are commonly found on your skin, CT scans can detect these types of abnormalities inside your body.  The result is that when something like this is found and its significance isn’t known, and the only way to find out is to take a biopsy, or repeat imaging in a few months or years.  For patients, this means repeated exposure to radiation and/or having a potentially risky biopsy procedure, for a finding that has little to no clinical relevance.   In the grand scheme of things, the risks of having complications from the procedures (which are uncommon but potentially disastrous) far outweigh the risk of the lesion being malignant, in a patient who is not at risk for cancer anyway.  This is why the recommendations are that only people AT RISK for cancer get screened.

How is a ‘low-dose’ CT scan different from a regular CT Scan?

Low dose CT scans have less radiation exposure than ‘regular’ CT scans.

 The dose of radiation is extremely low, and in fact, is lower than ‘background radiation exposure’ in the United States. 

Where can I get more information about lung cancer and cancer screening?

The best way to prevent lung cancer is to quit smoking.  85% of lung cancers are caused by smoking. For more information about lung cancer screening, here are some additional resources:

American Thoracic Society: Lung Cancer Prevention patient resource

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