DEAR DR. ROACH: I’m a 74-year-old woman who has been a pack-a-day smoker for 40-plus years, having quit about 18 years ago. As a precaution, I asked my primary care physician to order a CT scan, knowing that I am a candidate for lung cancer. The results showed a 3mm nodule in one lung and I was advised not to worry and that my doctor would order another CT scan in six months. I can’t help but wonder if this is cancer and if an oncologist will, in six months, ask me why I waited so long to see him. — TW
ANSWER: Medical professionals have been trying to control lung cancer for decades. Chest X-rays proved insensitive: By the time the cancer could be seen on an X-ray, it was usually too late to do anything about it. CT scans are much more sensitive (perhaps too sensitive; see below), and studies have shown that some lives will be saved with a screening program. However, the number of people who would benefit is relatively small. 256 moderate to heavy smokers will need annual screening for three years to prevent one lung cancer death.
There are two other important concerns about lung cancer screening. The first is the issue you have now: an abnormal result and what to do about it. It is extremely common. Almost 25% of scans will be abnormal and 96% of abnormal results will be false positives. But it will require multiple scans, and sometimes an invasive procedure, to prove it. This means a lot of anxiety among people who get the kind of result you did.
The small size of your nodule means that the risk of this nodule being cancerous is much lower than 1%. A follow-up scan is the usual recommendation and if the nodule is the same size or smaller, the chance that it is cancerous is very close to zero. You should have had a careful explanation of the possibility of false positives before doing the scan. You should also be warned about the possible need for a biopsy and the possible financial costs associated with subsequent testing.
The second concern is that current smokers considering screening should receive intensive counseling and help to quit smoking. A negative CT scan is not a “clean bill of health” for a smoker, and quitting remains the single most important thing most smokers can do for their overall health.
DEAR DR. ROACH: I’m 90 years old. My husband and I donate blood as often as we should — over 100 times — but last week, my doctor said I tested positive for syphilis. I almost fell off the chair. I haven’t slept for four nights. Have you ever heard of this? — E.
ANSWER: The screening test for syphilis, called the VDRL or RPR test, is not particularly accurate. About 1-2% of people will have a false positive, meaning the test is positive but they do not have syphilis. There are many possible causes, such as infection and autoimmune diseases like lupus, but some people, especially the elderly, will have a positive test for no identifiable reason.
In your case, I’m sure it’s a false positive, but your doctor can do a more specific test, like an FTA-ABS, to be 100% sure. You shouldn’t let it keep you up at night.
