Iflung canceris present, chest X-rays can sometimes detect larger tumors.
More often than not, though, they fail to diagnose the disease.
Chest X-rays also fall short as a tool forlung cancer screening.
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This article looks at chest X-ray and its use for the diagnosis of lung cancer.
It also discusses some of the other diagnostic tools a doctor may use if lung cancer is suspected.
It is not uncommon to hear stories of lung cancer that was discovered on an X-ray.
When this happens, though, the disease usually is in an advanced stage.
The cancer was only seen because the tumor was large and hard to miss.
The problem with this is thatadvanced lung cancerfound instage 3borstage 4is more difficult to treat.
Low Resolution Images
X-ray images appear in shades of gray.
They need to be interpreted by a radiologist who is trained to spot abnormalities.
Even so, the images are not high-resolution, and it is easy to miss subtle details.
The growth might be cancer, but it could also be any number ofbenignor noncancerous conditions.
This is especially true if they are small.
Disease processes can also make cancerous growths hard to see.Pneumonia, for example, commonly occurs withsymptomatic lung cancer.
If you have pneumonia, the pus and mucus that clog the airways can easily hide a tumor.
On an X-ray,tuberculosis (TB)also looks similar to certain lung cancers.
These conditions often occur together.
When this happens, TB may be diagnosed while the cancer is missed.
Even after the TB infection clears up, doctors may assume remaining spots are scars and leave them uninvestigated.
In these cases, the cancer may come to light after advanced symptoms appear.
These may include:
This may seem like negligence, but chest X-rays have fundamental limitations.
This is especially true when it comes to detecting certain types and sizes of lung cancer.
Your medical team can’t diagnose what they can’t see.
Lungadenocarcinomais the most common form of lung cancer.
It usually occurs on the outer edges of the lungs, where it can be hard to spot.
Lung adenocarcinomas often have a diffuse “ground glass” appearance.
These kinds of tumors may also be hard to see on an X-ray.
Small tumors and those with a diffuse appearance are also easily missed.
Risk Factors
Sometimes lung cancers are missed simply because no one was looking for them.
Former smokers are often assumed to be of lesser risk even if their past use was high.
It should be noted, though, thatlung cancer diagnoses are increasing in never-smokers.
As a result:
Doctors may miss lung cancer if a patient’s risk factors are unknown.
The research that has been done, though, is sobering.
Stage 1,stage 2, andstage 3alung cancers are considered treatable with surgery.
If the disease is allowed to progress, it can quickly move from treatable to inoperable.
This not only makes it more difficult to manage, it also significantly reduces the patient’ssurvival time.
This process helps doctors understand how far the cancer has progressed so they can decide on the right treatment.
Positron emission tomography (PET)scans are not usually used for diagnosing lung cancer.
They are considered more useful for staging the disease.
PET scans don’t take snapshots of the body.
On X-rays, lung cancer is missed in 20% to 23% of cases.
This is why CT is considered a much more reliable tool for diagnosing this disease.
Lung Cancer Screening
Chest X-rays are also notsensitive or specificenough to screen for lung cancer.
A 2011 study followed 150,000 people at high risk of lung cancer.
Researchers found that four years of annual chest X-rays did not change the death rate in the group.
Instead of chest X-rays, annual low-dose CT scans are recommended for people at high-risk for lung cancer.
In this population of adults, screening can significantly reduce the risk of advanced cancer and premature death.
Most health officials feel the risks of annual CT screening in other groups outweigh the benefits.
CT scans are generally better at diagnosing lung cancer.
They may also be helpful for lung cancer screening in high-risk patients.
If you think you have symptoms of lung cancer, ask your doctor about a CT scan.
Don’t depend on a chest X-ray for a diagnosis.
2016;10(3):267-71. doi:10.1111/crj.12217
Yang P.Lung cancer in never smokers.Semin Respir Crit Care Med.
2019;14(3):436-444. doi:10.1016/j.jtho.2018.11.002
