Interview: Zvi Livneh
Ninety per cent of all lung cancer cases are attributable to smoking
Zvi Livneh has spent years researching lung cancer. However, despite all of his work, he is not particularly interested in finding a cure for this killer disease. Rather, the Israeli scientist wants to stop people getting it at all.
Despite a substantial drop in smoking levels in the western world, lung cancer is still responsible for 30 per cent of all cancer deaths.
The good news is that Livneh feels that he and his team at the Weizmann Institute in Rehovot already have the capability to reduce levels substantially. Of course, the most efficient way to achieve this is to persuade everyone to stop smoking - this would reduce worldwide cases of lung cancer by a staggering 90 per cent. However, he is realistic enough to know that this will not happen, so he has another strategy.
Speaking in London during a recent visit, Livneh explains that he has developed a way of detecting who is at higher risk of developing the disease.
He says: "We know that cancer is caused by mutations in our DNA which cause the cell to get out of control. We also know that our bodies are usually very good at repairing damaged DNA. However, smoking not only affects our ability to repair DNA but also overloads the lungs with DNA damage."
Zvi Livneh: developed blood test
However, not all smokers succumb to lung cancer. As Livneh points out, everybody knows of a grandparent or family friend who happily lived to 90 despite being a chain-smoker. They survive because their bodies have the ability to repair their DNA efficiently, thus impeding the growth of cancers. So Livneh has developed tests which can accurately tell you how efficient you are at repairing DNA. "We now have four different blood tests which measure ability to repair DNA. And we performed an study which confirmed that those who have a lower rate of DNA repair have a higher risk of developing cancer."
If you know that you are at high risk of developing cancer, you are probably more likely to stop smoking. And there are also further investigations which can be performed.
Livneh explains: "A spiral CT scan can detect early lung cancer. At this stage, the cancer can be cured through surgery. There was a study of 30,000 people who had this scan and they discovered 500 cases of early lung cancer.
All but 11 people agreed to be operated on. Around 90 per cent of those who were operated on were still alive five years later. Of the 11 who refused, all were dead within two years."
However, there are problems with the spiral CT. It is expensive, it needs to be done every year and it involves some exposure to radiation, so it is not suitable for the entire smoking population. This is where the blood test comes in. If it is possible to find who is at high risk and then give them the scan, early detection and cure of lung cancer is a real possibility.
However, frustratingly, the blood test is currently not commercially available. Says Livneh: "The pharmaceutical companies want to sell drugs - if we prevent disease it will drive them out of business. I was quite shocked when I discovered this. The companies should have an interest in people's wellbeing too. I'm optimistic that eventually these tests will be available commercially."
He adds that the drug companies might well have more of an interest in a compound which could be used to stimulate DNA repair. "That is a thing which certainly in principle is possible to do. It is a project that we are embarking on now. "
Until then, the only sure way to reduce your risk of cancer is by adopting a healthy lifestyle. Livneh observes: "First you need to stop smoking. Second, there is evidence that a diet high in fruit and vegetables reduces cancer."
His best advice is to live like an Israeli. "I eat vegetables three times a day. That is quite typical in my country. In fact, when researchers read about the amount of fruit and vegetables consumed in Israel, they find it hard to believe."
Livneh adds that, despite marginally higher levels of smoking in Israel, lung cancer levels are half of what they are in the US and the UK. This is, he feels, unlikely to be a coincidence.