WCLC 2021 | Lung cancer screening in the UK

So thanks for having me. My name’s Haval Balata. I’m a consultant chest physician in Manchester. I’ve been quite heavily involved with some of the UK screening work over the past few years. Where we are with lung cancer screening is that it exists in certain parts of the world, America, China, some of the far East, but in Europe we’re sort of in the process of thinking about implementing cancer screening. We don’t quite have a national program as yet in a lot of the countries. In the UK, there’s been quite a bit of work in this last few years in smaller projects or particular teams, either research or aligned with the NHS, commissioned services, trying to look at implementing cancer screening. I think in the cancer screening world, we’re probably in a place where we now know it does work. It can save lives. The question really is, how do you implement it in a effective and safe manner?

So this particular work that we’re presenting at World Lung I’m quite excited to show, because it’s the first time a lot of these UK programs have collaborated and shared data. So we’ve all, individually over recent years published papers, been up presenting it at such conferences, but it’s nice to actually put some of that data together and show some cumulative results to demonstrate what we’ve individually been showing. So this particular work really was looking at a specific element of cancer screening. That’s obviously looking at some of the bigger headlines in terms of, did we find cancers and what are some of the outcomes were from the screening results. But also one of the concerns about cancer screening, lung cancer screening specifically, is false positive results.

So we know scans will pick up cancers, but also some other benign nodules. When we look at some of the older data from the big trials, some of them have reported high numbers, let’s say, of false positive results, which will obviously cause harm, stress people out. You bring them in, you might do more invasive tests, cause some more potential complications. So these are obviously screening harms that we want to avoid. So what this particular work was about was really trying to get an up-to-date sort of modern real-world figure between several different programs of these false positives, as well as cancer detection and so on, and compare it to some of the older extrapolated randomized control trial data that we often use.

So just briefly, what this was, this is five particular programs. So they involve the UKLS, which is a UK’s biggest lung cancer screening RCT. Well-publicized, well-published, well-known. Then we have the lung screen optic trial from London, which again was an RCT, primarily looking at invitation material, but it did involve implementing screening and screening a lot of real-world participants. Then we have a Manchester Lung Health Check pilot, which I was involved with, The Liverpool Healthy Lung Project and the Nottingham Lung Health MOT. Again, the talk isn’t about going through them individually, they’re all well-publicized, published, and presented, but those are the projects that were involved. What we did is we took the baseline figures data from all these programs, put them together and just saw what some of the headlines were.

So in terms of the results, what we had here was when you put all these five programs together, baseline round, we did just over 11,000 screening CT scans. That’s a big number. If you look at a lot of the RCTs, for example, NELSON, which is very well publicized, the intervention group in NELSON was about 6500 men and a much smaller number of women. So 11,000 real-world, real-life participants lung cancer screening data is big and useful. One of the first things we looked at here was just outcomes. Are we getting a lot of positives? Are we getting negatives, et cetera? The encouraging thing here was the majority of the scans, I think it was just over 84%, were negative and that’s good. You don’t want too many positive results in screening. So these are people that come in, get a scan, reassuring results, and then move on to the next round or discharged depending on the protocol. About 1 in 10 needed another scan in three months, but that was it. So they were never called to come into clinic or frightened about needing more tests, et cetera. Just another scan, make sure everything’s clear and then back to the next round.

The positive rate was just over 4%, 4.2%. So it’s good. It’s not very high, lower than a lot of the published RCTs. So that’s a good starting point to show that we’re not bringing too many people into clinic, scaring them and putting them through tests. Then within those positives, obviously you want a good cancer rate. When you put all the results together, we had, I think, an excellent cancer detection rate at 2.2%. So again, much higher than a lot of the big randomized trials. So just to put it in perspective, based on around the NELSON and NLST, the two biggest published or most prominent screening published RCTs, were around 0.91%.

So we’re almost doubled that one in 50 participants, so that’s good. That means essentially when you have a positive scan in this modern work in the UK, essentially just over one in two chance that you do have cancer. So that already tells you that we’re being fairly effective at picking out the cancer results that require more work for a possible… Sorry, screening results for possible cancer. Then I guess just the last bit of the results, which was important was looking at the false positive. As I said at the start, a lot of the cancer discussions of all these false positives and some of the older data there shows that we had high false positive rates and doing a lot of investigations and treatments for a negative or benign non-cancer results. What we showed here is actually the false positive rate was very low in the UK.

Five different programs ran separately, with slightly different methods, but actually the results were consistent. So the false positive rate was 2%, much lower than what’s out there published. Then we looked at bit further, invasive investigations for benign disease. People who have bronchoscopies or biopsies for what’s not cancer was very low, less than 1%. Looking at surgery for benign disease. So some participants will end up having an operation for something that we think could be cancer that is too small, too difficult to biopsy for example, but then they go through the operation and it was never cancer. Of course that’s a harm, because you don’t want to be doing that. Again, variable rates in the data but we showed this was very low, less than 0.1% of the screened population and just under 5% of the surgeries. So again, much lower than what’s out there.

Then when we looked a major complications and these are defined by the big RCTs, so in line with the published literature. We look at the major complications or even deaths from investigations for benign disease. A serious harm if you’re putting somebody through this and causing a complication or worst case death from what was never cancer. We actually had no cases. So across all five programs, over 11,000 scans, we didn’t have a single case. So that’s really encouraging and certainly much lower and much better than a lot of the older data that’s out there that’s extrapolated from these big RCTs. So the point really we’re making is that, as we’ve been doing in the UK over the recent years, looking at implementing cancer screening and with that getting some real important, real life, modern data to show people that what does happen when you actually start trying to screen, as opposed to what’s the theory from the big research studies.

I think this is useful data to show that actually certainly the harms from false positives and investigations of benign disease and surgery for benign disease are very low, if not for certain categories zero. I think that’s really important to know going forward with screening. What that means is really what we’ve concluded with, is that we talk about informed decision-making. So if a participant comes and you should discuss with them about the pros and cons of lung cancer screening, but to do that well, you need some good data or modern data to be able to say like what’s the chances of your scan being positive or negative. What’s the chances of you having a test for benign finding? What’s the chances of you having surgery for benign disease? These are things that are difficult to be exact on.

But I think having this modern data in a large cohort, from different programs in the UK, it means you can update some of these infographics that we’re meant to use in this informed decision process. So if somebody comes to a screening program soon and they want to really think about whether they want to go ahead or not. This kind of data will be useful to say, “Well, listen, based on this real-world modern UK data, we think the chances of this or that or the chances of whatever is this.” So that’s really the point of this particular study. It was really looking at cumulative data from five different UK based screening implementation work over the recent years. It’s good to see that even when put together, results are consistent with what the individual programs have been reporting for recent years, and it gives us a nice update on some of the harms from lung cancer screening, compared with the extrapolated RCT data.