There are definitely risks, and one of the things that I think it's important to understand is that lung cancers to a radiologist start off as a nodule in the lung. They're an abnormal area of density in the lung which is otherwise not very dense.
But there are a lot of other things that start off as nodules as well, including lots of infections. And depending on where you live in the country you have a very high chance of having been exposed to some of those infections. They're typically fungal infections. One of them being histoplasmosis, another being blastomycosis, and a third being coccidiomycosis, and these can all appear as small nodules, or they can heal leaving small nodules behind.
And the problem for me as a radiologist is when a nodule is very, very small is doesn't have any specific characteristics that I can see to try to distinguish is this an infection or the result of an infection or is this going to be a lung cancer. And so we can't really just rush in because we might be performing a procedure or might be performing a surgery that turns out to have been medically unindicated. We need to have a better idea that something is going to be lung cancer before we take those steps.
And when we say intervention like that, there are risks that go with any interventional procedure, right? So you don't go into it lightly.
No. I mean, the risk that I was talking about just now of the scans themselves is called the false positive. There are lots of little nodules that generally don't turn out to be lung cancer, so just from the screening test itself, the images that we get will have these false positives. There is also then if we find something that looks suspicious there's the risk of any additional imaging or intervention, such as a lung biopsy either done through a bronchoscope or using a needle and going through the skin into the lung, or a surgical biopsy or even ultimately surgery or chemotherapy or radiation for treatment, so all of these things add additional potential risk making us stop and consider what we're doing so that we don't injure patients.
I have another question. So when you look at a nodule, and let's say that you're pretty confident that it's a malignancy, I understand not all malignancies in the lung are alike, that some may be not benign but not aggressive, and others would be more aggressive. Is that always clear? Like this is one that's not going to really go anywhere, we can watch it, or should this is something where, boom, we've got to rush this person to surgery.
It's not always clear, but we're definitely gaining a better understanding of it, both as a result of this trial and actually as a result of the fact that the number of CT scans of the chest being routinely used for other indications has gone up, so we just have much more experience now than we did five or 10 years ago. Certain nodules do have an appearance that suggests to us that they may be relatively nonaggressive. Those have been called minimally invasive adenocarcinoma most recently, and they've had other names in the past. We tend to??they tend to have a characteristic appearance, and we generally then suggest that they be followed up unless there are other reasons for more intervention.
The ones that are going to be aggressive don't have any specific features that say ‘I'm going to be an aggressive tumor,’ but they tend to be more solid in appearance to us. And some of the solid ones will be slightly less aggressive, some will be more aggressive, but anything that looks like it is relatively solid and has other characteristics that suggest to me that it's a lung cancer, those are the patients who then get referred on quickly for additional diagnosis and intervention and hopefully quick therapy.
So, Dr. Hart, let's talk about this. During the trial the CT scans, I believe three, were paid for by the government, but until we have all the results and new guidelines out, which we don't as we're producing this program, it's still a question as to if a heavy smoker went to the local doctor, wanted to get a CT or a series of CT as were done in the study, whether it would be paid for by even Medicare or other insurance. Right?
Correct. The Centers for Medicare and Medicaid are definitely interested in the results of the trial, and they will be starting their considerations of what they think is appropriate once the formal results are published in the upcoming few weeks, so we're looking forward to that. But at this point there are no insurance carrier decisions to pay for this that I'm aware of. And so if someone wants to be screened it's a decision that they certainly should discuss with their physician, and, you know, then having had that discussion and I think probably just more full information of what the potential upside and downside of screening is they can decide if they're willing to pay for it on their own at this point.