Breast cancer in pregnant women is as common as in non-pregnant women of the same age, with no evidence to suggest pregnancy increases the risk of such cancer. In the majority of cases, pregnant women can have their breast cancer treated with surgery or chemotherapy or both, and the aim in most cases should be a normal length pregnancy to avoid the harm to the unborn child that can be caused by premature birth. Termination of the pregnancy does not improve the outcome for the mother. The issues around this delicate subject are discussed in the second paper in The Lancet Series on cancer in pregnancy, written by Dr Frédéric Amant, Multidisciplinary Breast Cancer Center, Leuven Cancer Institute, Katholieke Universiteit Leuven, Belgium, and colleagues.
Normal physiological changes in pregnancy, such as breasts increasing in size and nipple discharge, can obscure symptoms of breast cancer for both the woman and her doctor. Thus breast cancer in pregnancy is usually diagnosed later than in non-pregnant women, and with worse outcomes.
Radiation therapy is not generally advised during pregnancy, especially later in pregnancy where it becomes more difficult to shield the fetus. However chemotherapy can be given as per standard guidelines for non-pregnant women in the second and third trimesters. In most cases, radiotherapy only becomes necessary after the woman has given birth (but should not be used as a reason to deliver the baby prematurely). There is no evidence to suggest chemotherapy given correctly harms the unborn child (see linked paper in The Lancet Oncology) The authors also advise that the placenta be examined after birth to check for evidence of the spread of cancer (metastases), and that breastfeeding in the first weeks after chemotherapy cannot be recommended.
"The situation remains challenging since in some situations an advanced cancer can be fatal for mother and fetus," says Dr Amant.* "In other situations we were able to save the child though we lost the mother immediately after the delivery, for example by keeping her alive with a terminal brain tumour. Sometimes the woman's partner declares that they feel unable to raise the child in case the mother would not survive her cancer and termination of pregnancy is opted for."
But he adds*: "Importantly, the new insights we gained during our research facilitate cancer treatment and provide hope for mother and child in most cases. Most mothers feel stronger and are even more motivated to undergo the cancer treatment and its side effects, since she is fighting for her child as well."
The authors say*: "Whether the patient already has children, her desire to continue the present pregnancy, the opinion of the partner and the predicted outcome determine her choices and reactions when breast cancer is diagnosed during pregnancy. The patient and her partner should be informed about the different treatment options and the physician should explain that termination of pregnancy does not seem to improve maternal outcome, but the decision to continue or end the pregnancy is a personal one."
They add: "Breast cancer during pregnancy is not an emergency and the time needed to consult an expert team does not worsen the prognosis. The first multidisciplinary discussion should consider a diagnostic strategy aiming to reduce the burden of fetal radiation exposure. Non-ionising examinations are preferred to those needing ionising agents, and staging examinations that are likely to alter breast cancer treatment during pregnancy are done."
They conclude: "Breast cancer staging and treatment are possible during pregnancy, and should be defined in a multidisciplinary setting Cancer treatment during pregnancy will decrease the need for early delivery and thus prematurity, which is a major concern in management of breast cancer in pregnancy."