Oesophageal cancer and the prediction of risk

Monday 4 February 2013 5:45PM (view full episode)

The most rapidly rising cancer in wealthy countries such as Australia is a potentially dreadful tumour of the oesophagus - the tube that takes food to your stomach.

Researchers, including Dr Aaron Thrift, from the Cancer Control Group at the Queensland Institute of Medical Research, have developed a tool to help predict your risk of the condition.

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Norman Swan: The most rapidly rising cancer in rich countries like Australia is a potentially dreadful tumour of the oesophagus—the tube that takes food to your stomach. The technical descriptor is adenocarcinoma of the oesophagus, and researchers at the Queensland Institute of Medical Research have developed a tool to help you predict your risk of the condition.

Here's Dr Aaron Thrift from QIMR.

Aaron Thrift: What we've found is that the incidence of this cancer has increased dramatically and survival is quite poor, so most people diagnosed with this cancer will actually die from their disease. In comparison to other cancers, the rate of increase far exceeds anything seen for, say, colon cancer, breast cancer for example. So incidence has increased about six-fold since the 1970s in many Western populations.

Norman Swan: Including Australia.

Aaron Thrift: What we've done here is collect nationwide data to identify the number of men and women diagnosed with oesophageal cancer each year in Australia between 1984 and 2008. Between 1984 and 1994 incidence increased by about 7.7% per year. And since that period it's increasing by around 2% to 3% per year in men and women.

Norman Swan: Do we know why?

Aaron Thrift: A lot of our research has been able to identify the main risk factors, and that being acid reflux, obesity, smoking. So if you consider the trends in obesity, for example, we know that the prevalence of obesity has been increasing in Western populations over the last 30 or 40 years and this coincides with the increase that we're seeing in the incidence of this cancer.

Norman Swan: Smoking has gone down, so what is it so toxic about obesity to the lower end of the gullet?

Aaron Thrift: I think the main driver is that abdominal obesity precisely is actually putting pressure on the lower oesophageal sphincter and that exposes the lower oesophagus to more acid from the stomach and that's driving this increase in incidence.

Norman Swan: So essentially it's a physical phenomenon of erosion from the acid and eventually it turns malignant.

Aaron Thrift: That's correct.

Norman Swan: Now you've developed a risk tool to assess whether or not you're at risk of oesophageal adenocarcinoma, which is the kind of official title for this tumour.

Aaron Thrift: Yes, that's right. Our aim really is to identify people at the highest risk for this cancer in the hope that we can offer therapies and strategies to prevent the cancer. So what we wanted to do was pull together all the known risk factors into a tool to be able to firstly predict someone's future risk of developing the cancer and then secondly classify them into risk categories. So those people identified in the higher risk categories can therefore be triaged for further investigation. These investigations are costly. They're quite invasive as well. So we want to identify the most relevant groups to send through.

Norman Swan: Now on the Health Report in the past we've spoken about risk tools for heart disease and they include various things, depending on which risk tool you're actually doing, but you've got to know your cholesterol, your blood pressure, whether or not you smoke and a few other variables, some have family history, some have exercise. And we've done one for prostate cancer from New York which has the nature of the tumour, how far it might have spread and your PSA level. What are the variables that you need to plug into your tool to be able to assess your risk, what do you need to know to plug in?

Aaron Thrift: You've got someone's body mass index…

Norman Swan: How fat you are, basically.

Aaron Thrift: That's right, yes. How fat you are, whether you currently smoke, your history of reflux symptoms and use of acid suppressant medications…

Norman Swan: So this is usually acid indigestion where you get burning sensations in your lower chest and acid often coming back into the back of your throat.

Aaron Thrift: Yes, so we want to consider someone's frequency of exposure to this acid into the oesophagus. And we also consider terms such as whether or not someone's used aspirin or non-aspirin NSAIDS. And also we have a term for their education status. And that really represents a proxy variable for other socioeconomic factors that we're unable to measure in our study.

Norman Swan: So what, the lower the higher your chances of oesophageal cancer?

Aaron Thrift: That's correct.

Norman Swan: And what's aspirin got to do with this?

Aaron Thrift: What we've seen is that those people who have used aspirin actually have lower risk of oesophageal adenocarcinoma.

Norman Swan: What about alcohol, because you've done some studies of alcohol and oesophageal cancer.

Aaron Thrift: There are two main histological subtypes of oesophageal cancer and…

Norman Swan: So by 'histological subtypes' you mean, when you look down the microscope, which kind of cell in the oesophagus has turned malignant.

Aaron Thrift: Yes, that's right. So we have squamous cell carcinomas which are arising in the squamous cells in the middle and the upper oesophagus, and then these adenocarcinomas arising in the lower oesophagus. So for oesophageal adenocarcinoma we actually don't see an effect from alcohol, in contrast to squamous cell carcinomas, where alcohol is one of the main causal factors for this cancer.

Norman Swan: And what's the proportion in terms of the burden of these two different types of cancer of the gullet?

Aaron Thrift: Adenocarcinoma is the most common subtype, so around 55% to 60% of new cases are adenocarcinomas.

Norman Swan: And can you quantify the link between alcohol and the squamous cell carcinoma, the one that's slightly higher in the gullet?

Aaron Thrift: Those people consuming high amounts of alcohol have greater than tenfold risk compared to those people who don't drink alcohol or drink modest amounts of alcohol. And we've actually seen also that that risk carries then on to survival as well. So not only are people that are consuming high amounts of alcohol more likely to get the cancer in the first place, but they're actually more likely to die from the cancer in comparison to other people who have the disease.

Norman Swan: So let's go back to oesophageal adenocarcinoma, the one at the bottom end, which is still a pretty dreadful cancer to get, and you come up high on the risk assessment, what can you do about it, because, well, you can obviously stop smoking and lose a bit of weight, but my understanding of the literature is that there is no evidence that controlling acid reflux, taking acid suppressant medications, or indeed having an operation to tighten the sphincter, the valve at the lower end of your oesophagus where it goes into the stomach, tightening that, that either of these drugs or surgical procedures makes any difference at all to the incidence of oesophageal cancer. So what's someone to do?

Aaron Thrift: That's a good question. In terms of this particular tool we're looking to identify those people that should go on to this investigation, so we want to establish those people who may have the precursor condition like Barrett's Oesophagus and who can be…

Norman Swan: So the first step is that if you're at high enough risk you need to have an endoscopy, you need to have somebody to look down.

Aaron Thrift: Yes. So we want to avoid the onset of cancer, so removing these segments of your oesophagus, these Barrett's segments…

Norman Swan: And to explain here, Barrett's is when they look down there and take a biopsy, this has more of the appearance of the stomach than the oesophagus, and it's considered a precancerous condition where you need higher levels of surveillance just in case it turns nasty.

Aaron Thrift: Yes that's right. So around 95% or more of adenocarcinomas actually arise from these areas of Barrett's Oesophagus. So the idea is to prevent that going on to cancer, and then also using this tool to get those people who actually have early cancers in and through these endoscopy procedures so that we can get them early and improve their survival chances.

Norman Swan: If people want to get access to this risk tool for themselves, how could they do that?

Aaron Thrift: We've actually published this in the Clinical Gastroenterology and Hepatology Journal, so that's available online, and we're also looking to perhaps make this available electronically.

Norman Swan: But in crude terms, if you're suffering a lot of reflux, you're a bit overweight and you've got a history of smoking and if you're over age 45 you might well be a candidate anyway for getting your GP to refer you to a gastroenterologist for a look-down.

Aaron Thrift: Based on our research, yes, definitely.

Norman Swan: Aaron Thrift is in the Centre for Research Excellence in Oesophageal Cancer at the Queensland Institute of Medical Research in Brisbane.


Dr Aaron Thrift
Researcher at QIMR's Cancer Control Group


Dr Norman Swan
Nick Ridout

Comments (4)

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  • John :

    05 Feb 2013 1:36:01am

    Thanks for this story and the information, though it is a bit depressing. I am a fit 30 year old with eosinophilic oesophagitis with about a five year history of reflux and dysphagia or sticking in the oesophagus. I had an endoscopy a few years ago which reveal my condition and have been on Nexium ever since to control my symptoms, which has work really well. So it is a bit concerning to hear that, despite the treatment and alleviation of my symptoms, this does not reduce my higher risk to cancer of the oesophagus. It would seem that the only option is to undergo regular endoscopies, though being a quite invasive procedure, this is not ideal!

    I have heard that reflux might be caused by or related to allergies and that some people use food avoidance to address their condition. I would be interested to know if anyone has any evidence of this and the types of food that were or could be avoided? Is there any chance that allergic reactions to food could be causing the reflux and higher risk to cancer of the oesophagus considering the reflux itself may not be the cause?

      • Sarah-Jane Matthews :

        07 Feb 2013 2:53:37pm

        I'm not a doctor, but I think that reducing your reflux will reduce your risk. However, because you have chronic symptoms, your risk will be higher than the average joe who doesn't get reflux.

        I'm not sure about the evidence for the link between allergies and reflux, but I have heard the same thing. If you want to, you can try to exclude things from your diet and see if it makes a difference (ie the usual allergic foods: dairy, onion/garlic, gluten).

        Generally, I'd say to stay away from spicy or acidic foods, as they can irritate your stomach and oesophagus.

        I think a dietician or your GP would be the best person to seek concrete advice.

      • Michael :

        09 Feb 2013 12:10:07pm

        The other thing to check for is Obstructive Sleep Apnoea, OSA and night reflux can both have a cause & effect on each other.

  • gardengranny :

    10 Feb 2013 1:49:45pm

    As a first aid officer in a school I often saw girls with eating disorders, many complaining of chest pain and some of whom were later diagnosed with inflammation of their oesophagus. I now wonder if these girls face the same increased risk of cancer.