Lung Cancer Radiation Therapy Increases Heart Disease Mortality

Audio Journal of Oncology

Reporting from ESTRO 2016, Turin

August 26th, 2016

Lung Cancer Radiation Therapy Increases Heart Disease Mortality

Transcript of podcast as broadcast

PETER GOODWIN:

A warning now about the collateral damage that curative radiotherapy can inflict. The Turin conference heard from another Netherlands team about an increase in mortality from heart disease among patients whose stage I—and therefore curable—non-small cell lung cancers—were treated with stereotactic radiation therapy. There were significant associations between non-cancer death and the maximum dose on the left atrium, and to the superior vena cava. The team concluded that heart-sparing radiotherapy should potentially improve outcome.

At the ESTRO meeting Barbara Stam gave me the details:

BARBARA STAM

Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, Department of Radiation Oncology, Amsterdam, The Netherlands

Lung Cancer Radiation Therapy Increases Heart Disease Mortality

ABSTRACT: E35-1427


“Dose to heart substructures is associated with non-cancer death after SBRT in stage I NSCLC patients”

“The rationale for our work is that we know that on the very long-term, patients that received irradiation for breast cancer or for Hodgkins tumors are at risk for dying early because of heart disease. So we were wondering if on the short-term also such a relation occurs. And we cannot look into heart disease exactly. But we can look at the relation between doses that these patients receive, and the risk of non-cancer death.”

PETER:

So from what you’re saying, it was already known that radiation brings danger to the heart. So what did you do that’s new, in this study?

BARBARA STAM:

“We have looked at a new group of patients which are early-stage lung cancer patients that are generally, have a relatively short life expectancy. And therefore, the radiation dose to the heart that are known to have an effect on long-term might not have been taken into account all that much. Of course there is always the intent to give as low dose as possible. But then you have to choose between giving a low dose, either on the lungs or a low dose on the heart. Possibly in the future it will be possible to push the dose in the heart even further.”

PETER:

So what did you do with your patients, and what did you find?

BARBARA STAM:

“We looked retrospectively to a very large group of lung cancer, early-stage lung cancer patients, where I looked at the doses to the heart, and all the different regions in the heart, all the different structures. And I found that the doses to mainly the upper regions of the heart are significantly associated with a higher chance of non-cancer death.”

PETER:

You have conducted a very elegant study in which you were very careful to document where the radiation was going and what it was doing. What should doctors take note of from these results that you now have?

BARBARA STAM:

“Ah, so the interesting bit from our study is that we didn’t look at the dose to the heart as a whole, but also to the dose of all the different sub-structures. And we found that mainly, the dose to the upper region of the heart was significantly associated with non-cancer death. Meaning that if you could, don’t necessarily have to push as low as possible the dose to the heart as a whole structure, but mostly push to the upper regions of the heart.”

2:19”

PETER:

Barbara Stam, from the Netherlands Cancer Institute and the Antoni van Leeuwenhoek Hospital, in Amsterdam.

COMMENT INTERVIEWS: Heike Peulen, Ursula Nestle, Fiona McDonald:

PETER:

I asked Fiona McDonald from London what she made of these data indicating cardio-toxicity from curative radiation for lung cancer?

FIONA McDONALD

Lung Cancer Radiation Therapy Increases Heart Disease Mortality

“I think it’s always very important with any treatment we give patients that we know how safe it is. Because we have to weigh that up against the benefits that we think the patients are going to get. And any new data we can get, particularly with these new techniques, like stereotactic radiotherapy, even if it’s hypothesis-generating, allows us then to do further research to look at this more closely.”

PETER:

Now we have been under the impression that stereotactic radiation is probably about as safe as it can get. What do you make of these data that we’ve been hearing here?

FIONA McDONALD:

“Well no treatment for cancer is completely safe, whether that’s systemic therapy or surgery or radiotherapy. But it is true to say that stereotactic radiotherapy, because it is so precise and so conformal, and we can deliver it so accurately now with new technology, that it has been associated with low toxicity rates. However, we’re always learning about where it can be harmful. Because in the future we want to better be able to select patients, maybe those with underlying cardiac disease, for which we need to adjust our risk benefits, and we’re offering such treatments to patients.”

PETER:

Now what do you learn from this data that Dr. Stam has been presenting here in ESTRO, in Turin?

FIONA McDONALD:

“I think the most important thing is it’s hypothesis-generating. So across the board with non-small cell lung cancer, whether it’s in the stereotactic population, or the patients with the locally advanced disease, we are starting to get more concerned about toxicity to the heart, where maybe previously we focused on more toxicity to the lungs and the esophagus. And really, taking large data sets, like they’ve done, and starting to go down to the sub-structures of the heart is really important as a starting point to then try to build the next trial, looking at the question. We need to generate the hypotheses to then develop the next research question.”

PETER:

And what do you read into this evidence we hear about the superior vena cava and the left atrium being the bits in the heart that seem to make the most difference right now? Can we avoid them with our radiation therapy?

FIONA McDONALD:

“Oh, in theory we can. But I don’t think we’ve got enough data to start changing treatment on this at the moment. It’s certainly very interesting, but we need to look at it more. Look at, you know, how this relates to maybe the electrical effects in the heart because of the structure that was considered concerning. But I don’t think it’s going to change what we do at the moment. But it is again highlighting, whether it’s in this setting or locally advanced disease, we all need to take cardiac doses more seriously.”

2:20”

PETER:

Fiona McDonald Consultant Thoracic Clinical Oncologist at the Royal Marsden Hospital, and the Institute of Cancer Research in London

For another point of view I asked Ursula Nestle, Professor of Radiation Oncology from Freiburg in Germany and specialist in stereotactic radiotherapy of lung cancer?

URSULA NESTLE

Lung Cancer Radiation Therapy Increases Heart Disease Mortality

“I’m very happy about these data because it’s so good to have a large database to assess the risk of toxicity to normal tissue in curative treatments. And it’s very nice to see that most patients in this series have been cured, so that’s why they could make this analysis. And until now we were more scared about the lung, and now we know it’s safe for the lung. And then we then go to the next organs to check how we can improve radiotherapy planning.”

Duration: 0:30

PETER:

Ursula Nestle Professor of Radiation Oncology at the University of Freiburg, Germany.