Medicine Matters oncology

Here at the San Antonio 2020 Conference we are presenting the results of a large international meta-analysis aiming to assess three important goals. First, chances of post-treatment pregnancies in young breast cancer survivors. So the incidence, the probability, for breast cancer survivor to have a pregnancy following treatment completion.

The second one is the safety of pregnancy after breast cancer from the baby's side, meaning risk of potential complications during pregnancy and the time of delivery.

And the third important objective is the safety on the maternal side. So the potential detrimental prognostic effect of pregnancy after breast cancer in young women.

So in this meta-analysis we included 39 studies for more than 8 million women included in the study. Out of these 8 million women, 115,000 were breast cancer patients. And among them, around 7,500 had a pregnancy following breast cancer. The main message is that pregnancy after breast cancer is safe overall.

So for a patient that completed adequate treatment and period of follow up, pregnancy after breast cancer should not be contraindicated, as was actually done in the past based on safety concern of the baby side and the maternal side.

I think that pulling together all the results from all these studies provide now quite solid evidence to say that pregnancy is safe, again, from both a baby as well as the maternal side.

So another important message for patient and also for physicians is to discuss fertility preservation at the time of diagnosis. So what we call oncofertility counseling should be done. And it is nowadays mandatory as per guidelines at the time of diagnosis. But it's also important to discuss these issues also during treatment, during the follow up of these patients to make sure that the patient had an adequate period of follow up before trying to obtain pregnancy.

The next step is to wait for the results of the positive trial, which is a very important international study that is complete accrual at the end of 2019 led by the International Breast Cancer Study Group. This is a prospective study that is addressing one question that is still unmet so far, which is the safety of a temporary interruption of endocrine therapy during the first five years of treatment to allow women to try to have a pregnancy.

As I've mentioned, the safety data that we have are for a patient that completed adequate treatment. That means also five years of endocrine therapy for a patient with hormone receptor positive disease. If it is safe to stop endocrine treatment in the first five years, it is unknown right now. And the positive trial is actually answering this question.

The study has completed accrual last year at the San Antonio Breast Cancer Symposium. The authors are reporting the baseline patient characteristics for the studies for the more than 500 patients that were included in this study. And we hope in the next few to have the first results of this study and to conclude that this approach is safe to have more opportunities for women with hormone receptor positive disease to have a pregnancy even before the completion of the five years of treatment.

Importantly, during endocrine treatment, pregnancy is contraindicated, especially tamoxifen is teratogenic. So we should wait at least three months following endocrine completion before allowing women to try to have a pregnancy in this setting.