For those of you who may not be aware, ABC News is running a one month series on World News Tonight called Quit to Live.
As part of this series, they are producing several topical stories each week, as well as advertising and a website devoted to this effort to help people quit or not start smoking in the first place.
Born out of their grief over the death of Peter Jennings, who was highly regarded and respected by his colleagues, the staff at ABC set out to do something in his memory that would have an impact on smoking and health. It is apparent from what I have seen so far that they deserve commendations for their efforts and their commitment. In this day and age, nothing can influence behavior more effectively than the media, and their willingness to do this is invaluable.
I had the opportunity to appear on this series last evening to discuss the position of the American Cancer Society regarding screening for lung cancer. The question I was asked, and one which we are asked frequently, is “Why not screen for this disease?”
After all, lung cancer is a killer. Although not always caused by cigarettes (estimates of non-smoking related lung cancers usually range around 10 to 15 percent of cases, and many of these are thought due to passive smoking and radon exposure), the reality is that about 172,000 cases will be diagnosed in 2005, and almost all of these folks will die of their disease.
The reason so many people die from lung cancer is simple: it is silent, and usually found at a later stage. That means the disease is more extensive, and difficult to treat.
We have been successful in the past with other screening programs, especially in breast, cervical, colorectal, and possibly prostate cancer. We became successful in each of these by having a test or tests that could find the disease early. When that happens, the stage (or extent) of the cancer is less, and there is a proven direct correlation between screening and improved survival.
Why should lung cancer be any different?
The reality is that it just may be. At least that is what the evidence showed about 30 years ago.
Several studies were done at that time which included either chest x-ray, a sputum sample to look for cancer cells, or both procedures. These research projects, which included thousands of people, did not show any improvement in survival even when the cancer was caught at the very earliest of stages.
I can still remember sitting in a lecture listening to one of the lead investigators in the study, who happened to be one of the best bronchoscopists of that era (bronchoscopy is a test where a tube is put through the mouth into the lungs to look for abnormalities. It used to be done with a rigid steel tube. Now, fortunately, we have flexible tubes that are much better tolerated by patients).
The lecturer was discussing the study performed at his institution, and pointed out that they had patients who had a positive cytology, but where they could not find evidence of a primary cancer in the lung on chest x-ray or bronchoscopy. As part of their procedure in these situations, they did random, blind biopsies of the lining of the lung which would occasionally show them where the cancer came from.
What was chilling about the presentation was the lecturer’s comment that even in these earliest of cases, the patients still would die from their cancer despite surgery, which was the best available treatment.
The result of this research was the conclusion that even with the use of x-rays and/or sputum cytology done regularly, there was no evidence that early detection could save lives. The American Cancer Society created quite a stir back in 1980 when, as a result of the evidence from these studies, it recommended that doctors no longer do routine chest x-rays as part of the annual physical examination.
Fast forward to the present. We have 90 million people in the United States who are either former or present smokers (in fact, according to my colleagues, there are now more former smokers in this country than current smokers). Many of those people are at risk of getting lung cancer, which is far and away the leading cause of cancer death in men and women, not to mention the leading contributor to deaths from many causes, especially heart attack, stroke and emphysema.
New technology, in this case the spiral CT scan, allows us to quickly get detailed pictures of the structures in the lung at a degree of detail never before possible.
It isn’t a long leap to ask the obvious question: if we scanned these folks, we would expect to find lung cancer much earlier than ever before possible even with the best chest x-ray equipment available.
A study was done recently, led by a team of highly regarded radiologists at Cornell University in New York, that demonstrated they could in fact find these early cancers. However, because of the damage caused to lungs by cigarette smoke and other factors, they also found a lot of other things that weren’t cancer. Even so, they have reported that they have found early Stage I cancers and that the survival of these patients is much better than had been possible before the spiral CT scan had been available.
In addition to those findings, other doctors have reexamined the data from the earlier trials and have published their findings suggesting that, in contrast to the prior conclusions, there was in fact a survival advantage for those people who had been screened in the old chest x-ray/cytology studies discussed above.
But some problems remain. There are other very competent doctors who don’t agree that the final answer is in regarding screening for lung cancer.
The ELCAP trial, as the spiral CT studies are known in the medical world, was not a randomized trial. That means the findings have no comparison to a more standard technique to find lung cancer.
Second, many patients in this trial have had other abnormalities that are not lung cancer. The ELCAP investigators indicate they have, through their experience, developed protocols that are effective in determining which spots found on the CT are likely to be cancer, and which are less likely. However, past experience suggests that it is one thing to do a study in a center or centers where the doctors are highly committed to the research and do everything “by the book.” It is quite something different when the programs and the technologies go out into the community. The results may not be as good in those settings.
For example, when mammography was taking hold in this country, many private doctors’ offices provided mammograms, and they were also available in vans that traveled around communities. No matter how well intentioned these doctors were, the reality was the quality of the studies was not good for a variety of reasons. As a result, the government (in cooperation with the radiologists and other experts) put programs into place requiring standardization of mammography. A lot of these “stand alone” mammography machines went away, and the quality of mammography increased significantly.
There is no reason to believe the situation would be any different with lung cancer screening, unless clearly demonstrated in a trial that included more physicians in the community.
Another issue that must be addressed when screening for lung cancer is that inevitably there will be people who have an abnormality found on their CT scan, who undergo diagnostic procedures, and die as a result of those procedures. And, some of those people will be found not to have lung cancer or any other significant illness.
The people who are at high risk for lung cancer (which, in fact, has to be better defined by age and smoking history) are the same people who have bad lung disease and heart disease. They don’t necessarily tolerate diagnostic and therapeutic procedures well, and they can suffer significantly in the best of circumstances.
In this population, recommending diagnostic surgery (and even therapeutic surgery to remove the lung cancer) is a decision that is not necessarily taken lightly.
And then there is the inevitable situation, which we see particularly in breast and prostate cancer, of what I call “biologically indolent disease.”
This is a difficult concept for many people to grasp. Our usual thought is that if you have a cancer, it will grow. Consequently, when we find a cancer we take it out if possible. But what many people don’t understand is that in some circumstances, a cancer does not grow quickly and may not cause a person harm.
There is the possibility that some of the cancers we are now able to find with the spiral CT are ones that we would not have found previously and would have fallen into this “biologically indolent” category. Hard to believe, yes—but still something that is possible and needs to be considered.
So what do we do?
There is a trial currently underway called the National Lung Screening trial, or NLST. Undertaken primarily by the National Cancer Institute and the American College of Radiology, with the cooperation of the American Cancer Society and others, this trial is randomizing 50,000 high risk smokers and former smokers to observation with a spiral CT scan or a chest x-ray on an annual basis.
Our hope is that by 2009 we will have information to show whether or not spiral CT scan saves more lives and decreases the death rates from lung cancer for this population.
Should you have a spiral CT scan now? Why not?
Recent medical history suggests that many initial observations that seemed promising did not turn out to be so and in fact may have caused harm to significant numbers of patients. However, until the right studies were done, we didn’t know these treatments were not effective. The lesson we learned from these experiences is that just because it appears so doesn’t make it so.
So, our recommendation is that until we have the evidence we can’t say in good faith that the case has been proven for spiral CT scans reducing deaths from lung cancer. We may find out that they do, but right now the evidence isn’t in. And, if the procedure is as effective as the proponents say it is, it shouldn’t take us that long to find out. If that’s the case, we will be first in line to join in recommending this procedure.
However, we also need to be realists and understand that with all of the publicity (including Dr. Tim Johnson’s comments last night at the conclusion of the ABC News story on the topic), there will be people who want the scan and are willing to pay for it.
For those folks, we strongly recommend they speak to their doctors first, understand completely the risks and benefits of the test, and realize that they may go through rounds of testing and anxiety only to find out they don’t have cancer. And, yes, unfortunately there will be those patients who do have lung cancer and will die or become severely disabled from the diagnostic and therapeutic procedures.
This is a complicated situation, with no right answer at this time. There are excellent physicians who are proponents of the scans, and there are excellent physicians who are not convinced the evidence is in.
If you are a smoker or former smoker, what you need to know is what we are doing to find the answer, and what choices you have—along with accurate, personalized information from your physician.
Hopefully, as time goes on, this will become less of an issue as the number of smokers continues to decrease. But for those who are or have been smokers, stay tuned as the discussion continues. We need clarity to answer your questions, and we all hope to have that clarity sooner rather than later.
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