Lung Cancer Screening


(relaxing music) – Hi, my name’s David Affleck. I’m a cardiothoracic surgeon
at St. Mark’s Hospital in Salt Lake City. I’ve been asked to talk to you today about screening for lung cancer. A low-dose CT scan is a CAT scan that’s done with a low dose of radiation and it basically takes thin
slices through the chest in order to detect small
nodules in the lung that might be early cancers. It’s a very small radiation exposure, about equivalent to
what a woman might have with a mammogram. It allows us to get a
good picture of the lungs to detect those early cancers. To date, lung cancer screening
with low-dose CT scanning, is the only screening tool that we have that’s been shown to reduce, well increase the risk of, increase the detection of lung cancer and thereby decrease the risk
of death from lung cancer. Patients that are appropriate
for low-dose CT scanning are those that have an
extensive smoking history and they’re divided primarily
into two categories. Age 55 to 74 with a 30
pack year smoking history, so they’ve smoked a pack of
cigarettes a day for 30 years, and even if they’ve quit
smoking in the last 15 years, they still fall in that criteria. The second criteria is someone
that has similar age range but 50 to 74 and they have a
20 pack year smoking history, but they also have a
secondary risk factor. Those risk factors can be
personal history of cancer, exposure to a heavy metals, silica, those sort of things. The two categories are
extensive smoking history of 30 pack years or 20 pack years plus an additional risk factor. If they’re appropriate to be screened with a low-dose CT scan then they have an annual low-dose CT scan. There’s a lot of discussion
about negative CT scans after five years and then stopping that. Usually we find some small
nodules that are benign and we follow those for
some period of time. The next step would be a follow-up CT scan at an earlier interval if
there’s something suspicious. If it’s a very small nodule, say 5 millimeters, then we might just repeat
the scan in one year to make sure that it
hasn’t increased in size. The results of the National
Lung Screening Trial showed that over 90% of the nodules we find actually turn out to be benign. So, greater than 90% of the time, even when we find a nodule, those ultimately are benign. Now, if we find something
that’s suspicious. For example, it’s a little bit hazy or what we call ground glass appearance our suspicions raised a little bit and we follow those more closely. There is a great deal
of evidence that nodules that are between 5 millimeters
and 10 millimeters, or half a centimeter to a centimeter, can be followed safely
for a period of time provided they don’t have those
worrisome characteristics. Some of the incidental findings, that means things that
we weren’t searching for that we find on the CAT scan, are calcification in the heart arteries, or the coronary arteries, occasionally we find a thyroid nodule. We can even see little cysts in the liver, sometimes in the kidneys
or the adrenal glands. Again, mostly these are all
benign things that we find and so they’re incidental findings. Depending on the finding, then we may refer the
patient for follow-up to a specialist in that area. For example, someone that deals with thyroid, we have them meet with that doctor. Most of these findings can
be characterized quite easily on CT scan and are known to
occur with a certain percentage in the general population. (upbeat music)