Screening test's value depends on individual risk

Dear Doctor: There is an X-ray test ($99) to see if a past smoker is developing lung cancer. We both quit in 1996. Our doctor says we don’t qualify because of how long it’s been since we quit smoking. Is he trying to say that since we quit in 1996, we won’t get lung cancer? — B. and G.

A The test, a low-dose CT scan, can find lung cancers, but the real cost is the possibility of a false-positive test: something that looks like cancer but turns out to be a benign tumour. The higher a risk someone has, the more likely any abnormality is cancer and not a false positive result, which is why the test is recommended only for those at high risk. In a study, about 25 per cent of all participants had a positive test, 95 per cent of them false-positives.

Your doctor can’t say that you won’t ever get lung cancer. He seems to agree, as do I, with the current recommendations that a person needs to have smoked at least one pack a day for 30 years (or equivalent, such as 1 1/2 packs a day for 20 years) and either still be smoking or have quit within the past 15 years to benefit from screening. Doing the low-dose CT scan on people at lower risk makes the risk of false-positives much, much higher than the risk of finding a case of lung cancer. A false-positive means you would need a lung biopsy, and these can have major complications.

Dear Doctor: I am very stressed. My friend recommended the herb rhodiola to reduce my stress hormones and provide better mood and energy. However, I have high blood pressure (well-controlled on lisinopril), and the bottle says not to take it if you are at risk of or being treated for hypertension. — S.F.

A Rhodiola supplements, taken as an extract of the root Rhodiola rosea, have been shown in several studies to have benefits, especially in reducing fatigue in people with stress. It was also found to have some benefit in people with anxiety and depression.

Like any medication, this has potential side effects. It can be dangerous to take in combination with an antidepressant, and with a long list of medicines that are metabolized by a common system (called the CYP3A4) — your doctor can help you. As far as blood pressure goes, some blood pressure medicines (not lisinopril) are affected by this medicine.