Lung Cancer Screening With Chest X-rays

The medical establishment is in total agreement about one thing when it comes to lung cancer – the earlier the detection, the greater the chances of survival. While the overall five year survival rate for those diagnosed with lung cancer is about 15%, the five year survival rate for those diagnosed with early stage lung cancer approaches 80% if that cancer is treatable with surgery.

In addition, once the lung cancer has begun to spread, within or without the lungs, surgery – which offers the best chance for survival in early stage lung cancer – is often no longer possible as a treatment option. Because the earliest symptoms of lung cancer are often masked by ‘normal’ symptoms – a persistent cough, a tendency to respiratory infections, general fatigue – most people who have lung cancer aren’t diagnosed until it’s too late to use the most effective treatments for lung cancer.

It only makes sense that regular screening of those most likely to develop lung cancer would be prudent and in the best interests of health care in general. The problem is that there is no efficient screening test for lung cancer as there is for many other illnesses – including many other types of cancer. Instead, diagnoses are often made in the course of testing for other problems – usually through chest x-rays. Generally, though, doctors don’t recommend routine screening x-rays for patients to look for lung cancer. Until recently, most doctors believed that screening for lung cancer with chest x-rays was inefficient and misleading.

A new study that is still in its early stages may change that. Until recently, doctors used studies that were done in the 1970s to justify not recommending regular screening with chest x-rays. Those studies concluded that regular x-rays did not save lives. They did not catch the deadliest tumors at early stages, said researchers. And they put those with slow-growing tumors through needless surgery and other treatments. A lot has changed since the 1970s – x-rays are more sensitive, and there are further, more refined tests that can follow up on those x-rays.

In the new study, sponsored by the U.S. government, 75,000 healthy adults between the ages of fifty-five and seventy-four were given annual screening x-rays. Another 75,000 in a control group received no screening. The preliminary results were released in early December 2005. Of those x-rayed regularly, doctors found ‘something suspicious’ in nearly 6,000 people. Those people were sent back to the doctors for follow-up x-rays, CAT scans and other diagnostic tests. Of the 6,000 abnormal chest x-rays, 206 eventually had biopsies, and 126 were diagnosed with chest cancer – just 2% of the original ‘suspicious’ results.

That’s an awful lot of initial false positives, cautions a doctor at the National Cancer Institute, which sponsored the study. Those false positives can cause anxiety, and needless x-rays, CAT scans and biopsies. On the other hand, says the lead researcher for the project, 44% of the cancers diagnosed were in the earliest, most treatable stages of the disease. It will be years before the study is finished – and tells us whether those early diagnoses actually save lives. Until then, regular chest x-rays for high-risk patients may be the best way to find early lung cancer while it’s still treatable.