Breast cancer and Pregnancy
Breast Cancer
risk factor | genetic | malignant | stats | staging | metastic | unusual cancer
inflammatory | paget's disease | pregnancy

Breast Cancer and Pregnancy

Approximately 1 in 4 000 pregnancies are complicated by breast cancer. The breasts of pregnant and lactating women tend to be enlarged and tender hindering early detection of cancer.

Prior to falling pregnant it is a good idea to have a breast examination by a doctors and if a women is having her first pregnancy late after 30 to have a breast ultrasound, and if over 35 to have a mammogram.

Any pregnant woman who feels a lump in her breast should undergo a triple assessment including a breast examination by a doctor, a breast ultrasound by a radiologist with a special interest in breast problems and a needle biopsy of the mass. The biggest problem with breast cancer in pregnancy is delay in diagnosis, any women presenting with a mass in pregnancy should have a breast ultrasound and if the mass is concerning a needle biopsy. As part of a pre-pregnancy planning women who are thinking of falling pregnant should see their physician for a breast examination and if they are over 35 years they should have a mammogram before falling pregnant. . Mammography in pregnancy is inaccurate due to the density of the breast.

We do not delay treatment of the cancer because the woman is pregnant.

Treatment depends on the stage of the pregnancy. Surgery and chemotherapy are the preferred modality of treatment and presents minimal risk to the foetus. Cancer excisional surgery takes place as usual. If the cancer occurs after 24 weeks then breast conserving surgery can still be done. This is followed by radiation once the baby is induced at 32/33 weeks. DXT is delayed until after childbirth, if possible radiation therapy should be avoided until after the birth of the baby as it is harmful at all stages of pregnancy. Chemotherapy can be administered during the second and third trimesters. There is a very small chance of foetal malformation but the most common complication is low birth weight.

Tamoxifen should not be used in pregnancy because it can cause foetal abnormalities. The pregnancy may be terminated in the first trimester (first three months of pregnancy). It is important to realise that termination of the pregnancy does not affect survival and the previous thought that it might is incorrect. Therapeutic abortion has not been shown to improve survival in pregnant women with breast cancer. It is important that women who develop a cancer during pregnancy are treated in a specialised centre and undergo counselling.

Chemotherapy is mandatory for the mother, as these are usually young women. Chemotherapy can be given during pregnancy but just not in the first trimester.

Radiation therapy is not possible during pregnancy because of the side effects to the foetus.

Contrary to previous teaching, inflammatory breast cancer is not more common in pregnancy.

The Future
As we learn more about the genes that cause cancer (proto-oncogenes, oncogenes, suppressor genes, etc) we may be able to replace the defective genes and so prevent and possibly cure the cancer. These genes (“initiators”) are either inherited (BRCA) or sporadic (mutation). The environmental factors (“promoters”) also contribute ego estrogens, fatty diet, etc. We must be more active in combating the promoters right.