Q: I just turned 50 and I’m pleased to report that I’ve been a good girl the past decade — I quit smoking! That said, I’m still worried about getting cancer. Should I get a CT scan of my lungs, just in case? I’ve heard it’s the only way to pick up early lung cancer.
A: You’re right — simple chest X-rays are just not sufficiently sensitive to screen for lung cancer which, unfortunately, has become the number one cause of cancer deaths in women. (In fact, there has been a 600 percent increase in the incidence of lung cancer in women over the past 80 years. We’ve come a long way, baby … we became addicted to smoking!)
Doctors have tried to screen for this disease for years, but there have been no significant reductions in deaths from lung cancer with chest X-rays, even when combined with an analysis of coughed-up material (sputum) to check for cancerous cells.
If doctors are able to identify and treat lung cancer in patients at an early stage (Stage 1), the five-year survival rate is greater than 60 percent. But if this cancer is picked up once it has spread, or metastasized (which is the case in three out of four patients), the five-year survival rate is only 15 percent.
So, what can we do about this?
First of all, the fact that you stopped smoking is perhaps the most phenomenal thing you’ve done for your health in the last decade, and will indeed cause a decrease in your risk of a host of health problems.
However, women who smoke are more likely to develop lung cancer than male smokers. And although quitting smoking causes a very rapid drop in your risk of coronary artery disease and heart attack, its effect on lung cancer is slower, and residual damage from smoking can double your risk of lung cancer even 15 years after you’ve quit smoking! (This is still better than the much higher risk, estimated at 20-fold, if you continue to smoke.)
A recent article in The New England Journal of Medicine looked at current information on lung CT scanning, and I feel their recommendations are not biased by anything but the known facts.
Overall, they stated that “55 to 80 percent of cancers are detected in baseline CT scans, and 60 to 100 percent of cancers that are detected in follow-up scans are Stage 1. In contrast, only 16 percent of cancers diagnosed in the course of routine clinical care in the U.S. are Stage 1.”
The authors also looked at studies from Japan that showed a reduction in deaths for patients whose lung cancer was detected by CT scanning. The overall five-year survival rate among these individuals was 84 percent, versus 49 percent among those whose cancers were detected by chest X-ray.
Obviously, we’d like to look at well-controlled American studies as well, and one is currently being conducted through the National Cancer Institute. In this study, 50,000 individuals were assigned to undergo either CT scans or chest X-rays annually for three years. The participants’ mortality rates will be checked through the year 2009, when, hopefully, we’ll ascertain the results.
So far, the findings available would seem to make it a no-brainer: if you’ve smoked, go get a chest CT scan. But there are negative aspects you should be aware of and which have been reviewed by the American Cancer Society and the U.S. Preventive Services Task Force:
- There is still a need for more data from randomized trials.
- There is a concern that CT scans can pick up a lot of changes in the lungs, only a few of which will actually be lung cancer (many abnormalities may be due to previous infection or scarring).
- In order to determine if a CT discovered nodule or mass is cancer, patients often undergo additional procedures, some of which are invasive (like a lung biopsy) and may entail serious risks.
- The scans are expensive.
Most experts today feel that if a nodule is found and is small, it should be followed with another scan three months later to see if it has enlarged or changed significantly.
So, currently, the American Cancer Society recommends that CT scanning not be performed in individuals who may be at risk for lung cancer but who have no symptoms. Those who have a history of heavy smoking and choose to be screened should discuss it with their physician. Testing should only be done in well-established testing centers that are linked to specialty groups who can diagnose and treat lung cancer.
One other note: Most insurance companies will not pay for a screening CT scan, and the cost can be significant if you plan to get scanned on a regular basis. The authors of the New England Journal of Medicine study (who come from the National Cancer Institute) felt that a woman who does not have the equivalent of a 20-pack year history (one pack a day for 20 years) does not need to get a CT scan, but that a longer or heavier smoking history might make such a scan reasonable.
They and I agree on one thing: if you’re going to get a CT screening, participate in one of the ongoing trials so the results can help us all decide what to advise our higher risk patients now and in the future.
Dr. Reichman’s Bottom Line: If you have smoked heavily for more than two decades, CT scanning is a viable choice for the early pickup of lung cancer. But know that it can be costly both in initial out-of-pocket expenses and in subsequent procedures that may be necessary to ensure that a positive finding is not cancer.
Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," which is now available in paperback. It is published by William Morrow, a division of .