June 2009 podcast transcript

00:00

Kat: In this month's podcast we find out how quitting smoking could leave you happier as well as healthier and how researchers in Cambridge are tackling the challenging problem of treating pancreatic cancer, and hear about an alarming trend in skin cancer rates.

Coming up later, we discover how a flashy new technique could help to diagnose oesophageal cancer earlier. But first, here's the news with Josephine Querido.

00:59

Josephine: Not only could quitting smoking leave you healthier and wealthier, it could also make you happier, according to a recent Cancer Research UK study.

Researchers at the University College London Health Behaviour Research Centre studied nearly 900 people who had stopped smoking. More than two thirds said they feel happier now they have quit than when they were smoking, and only one in thirty said they felt less happy. The rest felt the same.

The length of time since quitting also affected the level of happiness felt. Ex-smokers who had stopped more than a year ago said they felt happier than people who had quit within the last year. And younger ex-smokers were also more likely to feel happier than older quitters.

Here's lead researcher Dr Lion Shahab to explain more about the findings.

"I think the main message is that a lot of smokers are quite worried when they consider giving up smoking that they're going to be miserable, because they won't be able to cope with stress etc. But what our research shows is that in fact it's likelier that they're going to be happier giving up smoking.

As a smoker, on the whole you're going to be more stressed throughout the day because you're always going to look for the next ‘fix'. So when you smoke a cigarette and you have a feeling of relief, you actually restore the level of stress that any non-smoker would have.

Giving up smoking is not only going to improve your physical health, and you're going to be richer and save money, but you're also likely to be happier."

New figures released by Cancer Research UK show that the number of people diagnosed with malignant melanoma -the deadliest form of skin cancer – has risen alarmingly.

More than 10,400 people a year are diagnosed with the disease, and rates have more than quadrupled over the past thirty years. If current trends continue, statisticians predict that this could rise to over 15,000 cases by the year 2024.

The major cause of skin cancer is ultraviolet light from the sun and sunbeds. People getting sunburnt, whether at home or abroad, and using sunbeds are thought to be behind the dramatic increase in cancer rates.

Here's Katy Scammell, Cancer Research UK's SunSmart Campaign Manager to explain how people can enjoy the sun safely and cut their risk of melanoma.

"It's important to remember to enjoy the sun safely this summer and take care not to burn.

The kind of things you can do in order to prevent yourself burning are to seek shade between 11am and 3pm, wear at least factor 15 sunscreen and apply it regularly and generously, and think about what clothing you can use to protect yourself. So things like a hat and long-sleeved cotton T-shirts might be a good thing to think about."

SAnd finally, Cancer Research UK scientists have discovered that the pattern of genetic faults in tumours could help doctors to tell whether ovarian cancer will respond to chemotherapy.

Currently, all women with ovarian cancer are treated with the drug carboplatin, but those with aggressive cancers are treated with paclitaxel as well. But at the moment, there is no way to tell which patients will benefit from the extra drug, and which won't. This is important, because paclitaxel can have unpleasant side effects.

The scientists discovered that cancers with high levels of abnormal chromosomes, known as CIN, were more likely to be resistant to paclitaxel. And when they looked at tumour samples from ovarian cancer patients, they found that patients with high levels of CIN responded well to carboplatin, but not to paclitaxel. And women whose tumours had low levels of CIN responded to paclitaxel, but not to carboplatin.

The researchers think that a test for CIN may be available within five years, saving patients from ineffective chemotherapy and leading to personalised treatment. And the technique is also being tested in a clinical trial of a paclitaxel-like drug for bowel cancer.

Kat: You can get the latest news from our award-winning Science Update blog, at Scienceblog.cancerresearchuk.org And if you want find out more about these stories, or get the latest from the charity's scientists, and researchers around the world, then have a look at our News & Resources website.

05:03

Kat: The chances of surviving many types of cancer are improved if you can catch it early – and a brilliant way of doing this is to take part in regular screening programmes.

But less well-known is the work being done to help monitor and prevent oesophageal cancer, or cancer of the food pipe. People are at an increased risk of the disease if they have something called Barrett's oesophagus – which affects around half a million people in the UK alone.

Our roving reporter Anna Lacey went to meet Dr Laurence Lovat at St Mark's Hospital to find out more.

"Barrett's oesophagus is a change in the lining of the oesophagus or the gullet which occurs in about a tenth of patients who have acid reflux. It's thought to be a response of the body to minimise the pain of acid reflux, although no-one's absolutely certain of that.

Most people who are diagnosed with Barrett's have gone to the doctor because of acid reflux symptoms and are sent for endoscopy. And it's at the endoscopy it's discovered that they have Barrett's. Barrett's itself doesn't cause any symptoms, but people with Barrett's usually have very bad acid reflux.

It's really important to say that for most people it's not a problem, but for a very small number of people, it can go on to become cancer, and that's where we're concerned. If you can pick up a patient with Barrett's, in theory you should be able to prevent them from getting cancer if you can detect the pre-cancerous changes early enough."

In order to spot any pre-cancerous changes, people diagnosed with Barrett's are asked to go for an endoscopy every two to three years. This involves putting a thin, flexible tube with a camera on the end down the throat and into the food pipe. Doctors then take biopsies – or small pieces of tissue - from the affected area and send them off to be examined.

This process can often make people anxious - and it takes around 6 weeks to get their results. So Cancer Research UK is funding a new trial that compares this current method of monitoring with a new one that involves small flashes of light.

"So the standard approach is taking physical biopsies. Our approach is to shine a flash of light – this is called elastic scattering spectroscopy, or optical biopsy. What we're doing is by shining the light into the tissue, light is scattered by the tissue, and some of that light is scattered back into the probe. We get a signature or ‘fingerprint' which tell us whether this tissue is normal or abnormal."

I went with Laurence to see an optical biopsy in action.

"We have a patient here who's undergoing surveillance for his Barrett's oesophagus. The normal oesophagus is pink, but Barrett's oesophagus is red, much more like the lining of the stomach. So when we're looking at the screen, as we're going down the oesophagus it's all pink, but then it turns red. You think you're in the stomach, but because there are no folds from the stomach visible, the that is Barrett's oesophagus."

Once the consultant and nurses were ready, they started taking their first readings.

"We've got this little probe which you can see is blue with a silver end which we're pushing out of the end of the endoscope. And we're putting that in direct contact with the tissue, like you would with biopsy forceps.

The sound that you hear, the high-pitched squeak, is the optical biopsy being taken... (noises) ... that's the optical measurements, and that was a very brief pulse of white light. That's picked up again through the probe and fed into our computer which interprets the spectrum of light.

The spectrum has a ‘signature'. There's a normal signature for normal tissue, and when the tissue becomes cancerous, the spectrum of light you get starts to change. It changes in very characteristic ways. If you can see on the computer screen in the corner, we're actually getting real-time feedback.

So we can see on the computer screen each time we take the optical biopsy we get a colour on the screen. If it's blue, it means that this is normal Barrett's oesophagus, with no pre-cancerous changes. If it's pink or red, there's a chance that it may actually be cancerous or pre-cancerous changes, and then what we would do is go back and take a proper biopsy.

We know that if it's blue, the likelihood of there being anything abnormal is less than 0.5 per cent. It's exceptionally unlikely that there's anything wrong. When it's red, the chance of there being something wrong is maybe 20 per cent, but that makes it worth taking the biopsy.

So we're reducing the number of physical biopsies we're taking - pieces of tissue we send off to the laboratory - hugely, and we make the procedure much quicker for the patient."

Laurence's trial is now getting underway – and should show whether light biopsies are as good at spotting the early signs of oesophageal cancer as standard biopsies. If they are, then he can see a number of other possible benefits for people with Barrett's oesophagus.

"In the short term the plan is to be able to roll this out so that people have instantaneous results. So instead of waiting six weeks, they get an immediate result. And that I think is very important, because one of the things we know about all cancer screening is that there's an awful lot of anxiety involved. And if you can allay anxiety, it makes the whole screening/surveillance process much more acceptable to patients.

In the longer term, we are using this optical biopsy to look at new markers of cancer risk, and we believe we will be able to give more precise definition as to what a person's future cancer risk is. And if we can do that, we could say to an individual person that we can delay your next endoscopy by not two or three years but by five years, and that is the long-term aim of our work."

11.16

Kat: Pancreatic cancer is notoriously difficult to treat and the disease claims the lives of more than 7,700 people in the UK every year. As part of our new five-year strategy, Cancer Research UK is aiming to increase our investment in pancreatic cancer research, with the aim of improving survival from this disease.

At our Cambridge Research Institute, Dr David Tuveson and his team are working hard to understand the biology that underpins pancreatic cancer, and develop more effective treatments.

Their latest results may help to explain why pancreatic cancers often fail to respond to a commonly used chemotherapy drug, called gemcitabine, and could pave the way for better treatments in the future.

Here's Dr Tuveson to explain more about his work.

"We were able to determine one of the reasons why a common therapy that we give to patients fails in the clinic. And the reason is that the therapy, called gemcitabine, doesn't reach the tumour tissue at high enough levels to kill the cancer cells.

By studying the reasons behind this defect in the delivery of gemcitabine, the scientists in my laboratory and our collaborators internationally determined that the root of the problem was that there weren't enough blood vessels feeding the tumour. These are the blood vessels that would carry the drug therapy to the tumour.

When we looked at human samples we saw the same problem – there were very few blood vessels in the pancreas cancer tumour specimens. Given this information, we thought that if we could increase the number of blood vessels in the pancreas tumour, that would be another way to deliver the therapies to the tumour.

While working on a chemical compound that could change the structure of the tumour, we unexpectedly observed that this compound caused the number of blood vessels to go up inside the pancreas tumour. When the number of blood vessels went up, we could then deliver higher levels of the therapies, and we could measure gemcitabine much higher in the tumours that were treated with this compound.

Fortunately there are several compounds of the class related to the one we used in our studies that are currently in clinical testing. The compounds we use are a class of agents known as hedgehog pathway inhibitors. These compounds are in clinical testing internationally in patients with different types of cancer, including pancreas cancer.

So we think that it will be a very short time before a trial assesses whether combining the hedgehog inhibitor with gemcitabine chemotherapy will provide a big clinical benefit to patients, so we are cautiously optimistic."

14:15

Kat: We've reached the end once more so we hope you've enjoyed this month's podcast. You can keep up to date with all the latest progress in research from our Science Update blog.

And please let us know what you think of this podcast by leaving feedback on the blog, or emailing your comments to podcast@cancer.org.uk.

We'll be back next month with all the latest news from Cancer Research UK, so until then, goodbye!

 

• Credits:
• Presented and produced by Kat Arney
• News by Josephine Querido and Kat Arney
• Oesophageal cancer package produced and presented by Anna Lacey
• Original music written and performed by Kat Arney and Henry Scowcroft
• With special thanks to all the participants