Lung Cancer Screening – Do Chest X-Rays Help?
There is one indisputable fact about lung cancer — the earlier the disease is detected, the better the chances of curing it. This is why lung cancer screening is of prime importance.
Doctors point out that although the overall survival rate for lung cancer at the five-year mark is only 15%, the survival rate for those whose cancer was detected early and could be surgically treated is as high as 80%. For this reason, some doctors recommend periodic lung cancer screening with chest x-rays.
Once this disease has progressed somewhat, it will spread rapidly to other areas of the lung and to critical organs all over the body. At that stage, surgery is no longer a viable treatment method.
Unfortunately, the early stages of lung cancer do not give rise to any alarming symptoms. Common symptoms include a persistent cough, a tendency to get respiratory illnesses, etc. These symptoms are not linked to lung cancer alone. This is why lung cancer is rarely diagnosed till it is too late.
In this context, regular screening for lung cancer — at least for those who are most at risk of developing it, like smokers — seems like a sensible choice. However, unlike in the case of many other diseases (including other cancers), there is no truly effective screening test available for lung cancer.
In most cases, lung cancer is detected when doing tests like chest x-rays for other health problems. Because of the risks involved, most doctors do not recommend chest x-rays as a routine screening procedure. Many believed (till recently) that chest x-rays can be fairly misleading when it comes to detecting cancer.
This conclusion was based on studies conducted during the 1970s. Those studies showed that chest x-rays were not effective at detecting dangerous, fast-spreading tumors at the earliest stages. Further, those who were detected with relatively slow-growing tumors had to undergo surgery and other treatments that were not really needed.
However, many things have changed since the time those studies were done. Today, x-rays are far more sensitive than they were back then. In addition, there is a battery of refined tests available that can be used to follow up on any problems detected with the x-ray.
A new study is being conducted by the National Cancer Institute on a group of 150,000 healthy adults. This study, sponsored by the American government, divides these 150,000 people into two equal groups — one group is screened annually with x-rays, while the other (forming the control group) does not receive such screening.
The preliminary results show that about doctors found something abnormal in almost 6,000 people. They were followed upon with CAT scans, more x-rays and other diagnostic tests. From among these people, 206 had biopsies done. Eventually, 126 people were diagnosed with cancer. This is only 2.1% of the original group of 6,000 with abnormalities in their x-rays.
The bad news is that the 6,000 represent a large number of false positives. It resulted in unnecessary follow up x-rays, CAT scans, etc. The good news is that out of those detected with cancer, fully 44% were at the earliest stages of the disease — when the cancer is most treatable and the chances of survival highest.
The final results from this ongoing study will only be available some years from now. But based on the preliminary results, it appears that regular lung cancer screening with chest x-rays may help at early detection and a better cure-rate for this disease.
Linda Day is a researcher who has written articles about what is lung cancer, provides access to lung cancer pictures and more. For more information about this disease, check out the previous links.