Cancer and Pregnancy 2012
Impact of treatment on pregnancy
Dr Hatem Azim – Institute Jules Bordet, Brussels, Belgium
This is a very relevant topic nowadays because more patients are cured from cancer and then we should focus on certain quality of life issues, top of the list is the possibility and feasibility of getting subsequently pregnant. We have discussed actually that these patients appear to have a significantly lower chance of getting pregnant compared to the general population of the same age. This is perhaps influenced by several factors, whether treatment, whether the risk of relapse, whether fears that pregnancy perhaps could stimulate breast cancer in general to come back is particularly relevant for breast cancer patients. Actually what I would try to highlight in the presentation, that getting pregnant following cancer or in cancer survivors is feasible and is safe in terms of risk of recurrence, this particularly in the case of breast cancer. We don’t have this concern in other tumours but in breast cancer this concern has been raised a lot for the fear that the hormonal changes during pregnancy could have an impact on breast cancer that was previously diagnosed. Well, there is no evidence to support that and, on the contrary, we have decent evidence to favour that these patients do well.
Another concern is whether those who the outcome of pregnancy, is there an impact on previous treatments on the foetal health or the pregnancy raises complications. Actually, what as well has been shown in different tumours where the chemotherapy, for example, that has been previously received does not appear at all to impact the risk of developing something like congenital anomalies or to significantly impact the course of the pregnancy, so the risk of pre-term delivery and so on.
Breast feeding as well was discussed, although more limited information is available on breast feeding compared to pregnancy, however, patients should not be advised not to breastfeed because there is no evidence that breastfeeding has a detrimental effect on outcome. In certain situations, particularly in breast cancer patients, there are some issues related to feasibility of breast feeding because these patients, by definition, were subjected to surgery in the breast and received radiotherapy to the breast as well. So these local therapies pretty much create some changes in the breast which compromise the quality of milk and of milk production. But with the help of breast feeding counsellors, which could play an integral role here, this can in one way or another be addressed and help these women to successfully breast feed.
Do women with ER breast cancer find more difficulties?
It has a certain difficulty in the sense that physicians are more concerned that this is perhaps not a perfect idea. As well as another feasibility aspect which is that patients with ER breast cancer require prolonged treatment with hormonal therapy, classically for five years, which indeed reduces the chance of becoming pregnant afterwards because this could compromise over time and indeed Tamoxifen, for example, compromises in one way or another the ovarian function. So given these two aspects, of course, getting pregnant following ER breast cancer has always been an issue. We recently conducted a large trial in several centres in Europe to address this concern, so the safety of pregnancy following ER breast cancer. In this study we did not show at all that getting pregnant following ER breast cancer has a detrimental effect on outcome. Although we had a lot of data on the apparent safety of pregnancy following breast cancer, we did not have any information on the outcome according to ER and that was a main limiting factor in these studies.
Are there any additional considerations for HER2 cases?
Currently patients who are HER2 new positive are usually advised to… actually just the current standard of care, to receive one year of trastuzumab. These patients should be advised to receive active contraception before starting trastuzumab because trastuzumab does not affect at all the ovarian function, so pregnancy is possible to happen on trastuzumab. Actually in those patients that got accidentally pregnant on trastuzumab, they don’t appear to be at an increased risk of developing malformations but they do appear to be at a slightly increased risk of developing spontaneous abortions. This is pretty much the case with a large variety of agents, when they are given early during the pregnancy. The early pregnancy period is pretty much critical in which you can get considerably larger percentages of congenital anomalies and risk of spontaneous abortions. We did not observe any congenital anomalies which is pretty much supported by pre-clinical work suggesting than monoclonal antibodies like trastuzumab do not cross to the foetus early in the pregnancy so if this was the case, a patient on trastuzumab and then accidentally found to be pregnant, early in the pregnancy, if the drug is stopped this brief exposure doesn’t appear to increase the risk on the foetus but of course it can compromise the whole pregnancy in the sense of a higher incidence of spontaneous abortions. This should be taken in mind but in general patients that are about to start trastuzumab should be advised to use active contraception.