Interrupting breast cancer treatment for young women who desire pregnancy

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Published: 16 Dec 2015
Views: 2867
Dr Olivia Pagani and Dr Ann Partridge

Dr Pagani (POSITIVE co-chair for International Breast Cancer Study Group, Bern, Switzerland) and Dr Partridge (POSITIVE co-chair for US through ALLIANCE, Rochester, Minnesota) talk to ecancertv at SABCS 2015 about the POSITIVE study

The study evaluates the pregnancy outcomes and safety of interrupting endocrine therapy for young women with endocrine responsive breast cancer who desire pregnancy.

ecancer's filming at SABCS 2015 has been kindly supported by Novartis through the ECMS Foundation. ecancer is editorially independent and there is no influence over content.


It’s a very challenging situation because young women with hormone receptor positive cancer, oestrogen receptor positive cancer, can benefit from the hormone therapy but supposing they want to have a baby. You’re doing a study, could you tell me about this study, what exactly are you actually trying to do?

OP: The study is addressing young women who have breast cancer, early breast cancer, before age 40 who are going into adjuvant endocrine therapy and they want to have a baby. So the study is addressing to interrupt treatment for a couple of years to allow them to try to get pregnant and then resume treatment after they succeeded to get pregnant or did not succeed.

So what’s the nuts and bolts of what you’re doing, then?

AP: The goal is to allow women to try and have that break and have a baby and at the same time optimise their breast cancer outcomes because you can’t generally get pregnant on the adjuvant endocrine therapy because it’s contraindicated, it can cause birth defects and all kinds of problems, or you just can’t because it suppresses.

And you’ve begun already, haven’t you? You’ve got some patients.

AP: We’ve started the study, yes.

OP: Yes, we started last year and now we have 25 patients enrolled in eight countries and in 25 centres enrolling patients. We are planning to widen our including centres to accrue more patients because we have to go for 500 patients overall.

Now, here at the San Antonio Breast Cancer meeting we’re hearing about wonderful advances in breast cancer but how often do you, as doctors, encounter women who actually want to consider their fertility? Do they regard that as a high priority, do you find?

AP: We actually have some good data on this. Our group has looked at this and it ranges from about 40-50 some percent of women who are diagnosed with breast cancer under the age of 40 were not done with their families or childbearing at the time they were diagnosed. So this is a concern for that large group of women who are diagnosed at a young age. Whether or not they actually decide to pursue a pregnancy after diagnosis depends on a lot of factors.

What kind of advice do they normally get at the moment?

OP: It depends.

AP: Not always good.

OP: It happens that they are discouraged to have babies because they are endocrine responsive and so they should not get pregnant because hormones are contraindicated and all this quite old stuff. The additional problem these days is that the induction endocrine therapy is going on for longer periods, five to ten years, and so many of these women won’t have the chance to have a baby after they’ve finished treatment. So that’s why we decided to study to interrupt treatment to allow them to get pregnant because otherwise they will be 45 or something like that and the chances to get pregnant afterwards are very low.

AP: And there are lots of data that actually look at is it safe to have a baby after breast cancer. They are all flawed in that nobody has done a randomised trial or even a prospective study looking at that so it’s looking back and saying who got pregnant and who didn’t get pregnant. But even in those studies that are flawed and confounded potentially, the women who get pregnant actually seem to do as well, if not better, even early on. So that’s some of the compelling data that said we think it’s probably safe, we don’t know for sure. We need to test it because it’s such a critical issue for these young women.

And current practice is what? Is it vague and not thought out?

OP:  Usually you should advise women to have at least two years. The data we have is that to encourage women to have at least two years of endocrine therapy and then maybe stop and try. But there is no prospective data, as Dr Partridge says, so we have to go and look for this data and produce this data.

AP: I would say the practice varies widely based on the doctor and their understanding and their comfort level, based on the patient and their understanding and their comfort level and their desire to have a pregnancy. Some people want the pregnancy, they were diagnosed, they’re at the OB’s office trying to get pregnant and some want to put it off and are comfortable with that. So this is not the right study for everyone. But the critical issue here is can we get them some therapy, interrupt it, get them back on. And in breast cancer it’s such a long-term disease with ER positive disease and most women will be cured, can we allow them to safely have a baby and still get great breast cancer care.

OP: And this is the kind of study for women who decide even not to get endocrine therapy because they so much want to have a baby that they decide not even to start. So this is the study for these women who do not dare to stop on their own, they really wish to have a baby but they want to have this within a safe environment which is a study.

What are your feelings about how safe it is? You say there’s some positive data from what we have already that women do just as well but what are the potential problems of stopping?

AP: I would just start with women who have had early breast cancer, it’s all invasive disease, are at risk of hearing from breast cancer again, period. And they’re living with that risk whether they get pregnant or not and whether or not… we don’t think a pregnancy impacts on that risk, based on the retrospective data but we’re going to look at that. But either way, they’re living with risk so that’s one huge concern. Moving forward, becoming pregnant and then having a recurrence during that time.

OK, briefly, when are we going to get the results, do you think?

OP: Well it will take a while. The first analysis will be done in six years from now, more or less, and then the final data. We are following these women for ten years so it will be quite a long time to go.

All the best studies need a long time, without a doubt.

OP: Time, yes.

And you’re doing something called crowdfunding, what are your objectives in that?

OP: This, of course, is not a funded trial because no drug company is interested, there are no drugs involved. So we are looking for funding for co-ordinating the trial to try to involve many more patients and clinics all over the world. So this, of course, needs money.

AP: And we want to be able to accrue so that we can meet our goal so we can really answer this question for folks and it can be generalizable to patients all over the world, not just patients where we get enough funding to accrue.

OP: And to follow these women. And we have a lot of additional questions, psychological survey, and then the health of the baby and all this stuff. We chart the characteristics of women who do not get pregnant. So there are lots of research questions and we think that we will have lots of data for future women to be safe.

You have something called Big Time for Baby, what is that?

OP: This is an instrument, a tool, which was developed by the BIG because the trial is supported by the Breast International Group to try to address these issues to patients, to funders and to try to make the trial available as much as possible and to raise money for this important trial.

So what would you like clinicians to take home from your efforts? Clearly a big message is to get over to women all over the world to support this very important project but what should doctors take home from this?

AP: I would say the first thing is open the study, put your patients on who are interested in having a pregnancy after early hormone sensitive breast cancer. Obviously this is not for the patient who doesn’t want a pregnancy, that goes without saying but you’ve got to say it. And also we need to support our patients in their overall survivorship concerns. This is so important and we need to study things like this. So get people on the study, let’s understand this issue.

OP: Or refer people, or refer patients to other centres because, of course, you cannot open the trial in every centre.

AP: Or refer people.

OP: But refer people, even if you are sceptical as a doctor. This is the opportunity, you refer your patients to a trial so they are followed so they are safe within a trial.

AP: The only thing I would add to that, the sceptical point, is this is the place where we have to remove our own paternalism and maternalism and recognise that for an individual patient their values about having a baby may be different than we think they should feel at that moment. That’s kind of hard but we can do it.

OP: And some of them will stop the treatment anyway because their desire is so, so, so strong.

AP: Right.

Which shows what a powerful and important decision this is.

OP: Yes, absolutely.