Tiny 2 mm nodule (probably non-calcified) on the lung

[Brandycat]

My wife recently had an abdominal cat scan to confirm liver cysts found on a sonogram were non-woriesome (they were fine), and a 'tiny 2 mm pulmonary nodule in the left lower lobe, no pleral or pericardial effusion' was found.  The recommendation was this: 'follow-up chest CT recommended in 12 months if the patient has a history of smoking.'  These are direct quotes from the radiologist's report.  My fiancee is 53, has never smoked.  My question is as follows.  Shouldn't she have a follow-up CT scan as well, since at least 10% of lung cancers occur in non-smokers?   Or does the risk of actually causing cancer with repeated CT scans (a spiral CT is available at our hospital) outweigh the possibility this nodule is cancerous?  I read on the net that the vast majority (>99%) of non-calcified nodules of this size are non-cancerous, but this does not reassure me, as if this nodule was old (such as from a childhood disease), wouldn't it tend to be calcified?  And if it's recent, what else besides cancer could it be?  She has never been exposed to second-hand smoke, and has not had any illnesses for the fifteen years I've known her. Also, her only sister has breast cancer.  What are the real odds, to the best of your understanding, about this nodule being cancerous?  Would you recommend CT follow up?  Does 12 months make sense?   What if nodules are growing in her upper lobes, which were not scanned?  Thanks in advance for your answer.

[National Jewish]

You are correct in your excellent search and results of the key issues here.

Small nodules of the size you note in a non-smoker are very rarely cancerous.  Thus from a cost-effectiveness perspective the official recommendation would be not to repeat the CT scan.  However, if you are concerned, you could ask the doctor to perform another examination at some future point - 6 to 12 months would be reasonable.

Although radiation can cause cancer, the two or three CT scans in an older individual would not be expected to do so.

Old nodules from old infections are NOT always calcified.

In terms of the possibility of other nodules or some cancer elsewhere in the body with spread to the lungs, a careful history and physical examination including a PAP smear and mammogram would be reasonable.  There is no medical evidence that complete CT scans of the lungs or whole body on a regular basis can improve survival.