SIOG 2015

Treatment patterns and relative survival for older patients

Dr Marloes Derks - Leiden University Medical Center, Leiden, Netherlands

Treating patients who are older and have breast cancer is not altogether straightforward and there seems to be a lack of guidelines. What were you doing in the study that you’ve just been talking about here?

What we have been doing is we collected data from cancer registries, that could be either regional registries or national registries, and we looked at data on the one hand for treatment, so we looked at differences in surgical treatment and adjuvant treatment, and then on the other hand we also looked at survival outcomes of those participating countries or regions.

It’s quite a big study, isn’t it?

It is, yes. We were able to include almost 120,000 patients with breast cancer, with non-metastatic breast cancer I have to say.

And six different countries?

Six different countries, yes.

What did you find?

It was interesting because on the one hand we looked at treatment, the number of patients who received a particular kind of treatment, and we looked at local regional treatment, so surgery, axillary surgery and also radiotherapy. We also looked at adjuvant treatment, so the percentage of patients that received adjuvant endocrine treatment or adjuvant chemotherapy. When we looked at local regional treatment the major differences were found in the patients receiving no surgery because there is a part of older patients that does not receive any surgery and it differs across stages and across different countries.

So with no surgery or a reluctance to use surgery or a late diagnosis or whatever, what was the effect of that?

It’s hard to say because breast cancer treatment and outcomes are dependent on many types of treatment so not only surgery does say something about the outcomes and not only chemotherapy does say anything about the outcome. But what we did find was that there are major differences, on the one hand, in local regional and adjuvant therapy. We also found that there are major differences in breast cancer survival across different countries. We looked for patterns so it’s hard to say there’s a direct association but we looked for patterns across the different countries and different survival outcomes and we found that, especially for stage 2 and 3 disease, more adjuvant therapy was linked with a better outcome.

That’s one thing that seems to be floating to the top. It’s always difficult to make a league table of countries, which one is doing better, but tell me which one was doing better?

The country that was absolutely doing better at all stages of disease, because we looked at stages of disease separately, was Belgium. The one that was performing worst was the UK. We already knew that the UK was doing better overall in cancer treatment but we also find it in older patients with breast cancer now again.

Now, I know that yours was a population-based study and you can’t say anything about causality. You have got strong information about associations, what do you think might be the factors giving Belgium this great performance and giving the UK this awful performance?

It’s a very hard question because outcomes are depending not only on treatment but also on access to healthcare, also on time of diagnosis, patient preferences, doctors’ preferences. So I think it’s very hard but, of course, treatment is a major part of breast cancer outcomes because otherwise we shouldn’t treat patients at all. It’s a hard question to answer but I feel that more adjuvant therapy leads to better survival.

So in a nutshell the Belgians are doing well with organisation and delivery, are they, and also giving more systemic therapies or adjuvant therapies?

Yes, Belgium was giving definitely more systemic therapy compared to the Netherlands and they were doing much better than the Netherlands. So Belgium was less conservative in treating older patients. So that could be a reason that they performed better.

And what could be the logistical barriers to treatment that might be holding back the success of outcomes in other countries, then?

The major problem in treating older patients is that there is a lack of evidence for treating them, for how to treat them. In the Netherlands we are quite conservative and we are very anxious that when we give older patients chemotherapy they will experience lots of toxicities and adverse events and we are withholding that treatment from patients while there probably is a specific population or older group of patients that is benefitting from adjuvant therapy.

If you were to sum up the kind of guidelines that you might make, provisionally, of course, because it’s not your job to have the last word on it, for non-metastatic breast cancer in older patients, what might those provisionally be, just briefly?

The major thing is that you should not treat patients according to their biological or chronological age but you have to get a better idea about the physical functioning and the fitness of the patients and treat them accordingly to that. So if you have a very healthy older patient you should treat them according to the normal guidelines. When you have a very frail patient you might be doing a better job withholding certain types of treatment. So that would be my general advice.

And how big are the gains that you can make from this in terms of overall survival? Is it a big difference or are we talking about details here?

Especially when you’re looking at stage 3 breast cancer disease you see that the differences in breast cancer specific survival across the countries is over 10% so there is at least an increase for 10% to make when we use the therapy we already have, like the current therapies, in a better way for older patients. I think there would definitely be room to improve survival outcomes in older patients. For us the reason to do observational research instead of randomised controlled trials is because we…

Shall I ask you? Shall I ask you that, I’ll put that question to you?

Yes, sure.

And your reasons for doing observational research rather than randomised controlled trials?

We have several reasons for that. First of all we know that in the current randomised controlled trials not many older patients are included and we also know that the older patients that are included in the randomised controlled trials are much healthier and have a better prognosis compared to the general older population. So the good thing about observational research is that we include all patients which makes it more representative for the general older population and by doing that we have a better overview of how to treat older patients.