Other tests

If breast cancer has been diagnosed, other tests may be needed to find out if cancer cells have spread within the breast or to other parts of the body. This process is called staging. Staging tests are very important for pregnant women with breast cancer because their cancers tend to be diagnosed at a more advanced stage. Which staging tests may be needed depends on the situation.

The fetus is not exposed to radiation with certain tests, such as ultrasound and magnetic resonance imaging (MRI) scans. Overall, these tests are thought to be safe and can be used if they are important to your care. But, the contrast material or dye sometimes used in MRI crosses the placenta (the organ that connects the mother to the fetus). It has been linked with fetal abnormalities in lab animals. For this reason, an MRI that uses contrast dye is not recommended during pregnancy.

Chest x-rays, sometimes needed to help make treatment decisions, use a small amount of radiation. They are thought to be safe for pregnant women when the abdomen is shielded.

Other tests, such as bone scans or computed tomography (CT) scans of the chest, abdomen, or pelvis, are more likely to expose the fetus to radiation. These tests are not often needed, especially if the cancer is thought to be just in the breast. In rare cases when these scans are needed, doctors can adjust the way the test is done to limit the fetus's exposure to radiation as much as possible.

 There are no reported cases of breast cancer being transferred from the mother to the fetus. In very few cases, the cancer has reached the placenta (the organ that connects the mother to the fetus). This could affect the amount of nutrition the fetus gets from the mother.

Breast cancer treatment during pregnancy

If breast cancer is found during pregnancy, the type and timing of treatment depends on many things, such as the size of the tumor, where the tumor is, how far along the pregnancy is, and what the patient prefers. Treating a pregnant woman with breast cancer has the same goals as treating a non-pregnant woman: control the local disease and keep the cancer from spreading.

If the cancer is still in the early stages (Stage I or II), the doctor will most likely recommend that you have surgery to remove either the suspicious lump (lumpectomy) or the affected breast (mastectomy). During the operation, the surgeon will examine the lymph nodes to see whether any are affected and will (usually) remove the lymph nodes where the cancer is most likely to have spread. If it is necessary to give chemotherapy, your doctor will usually wait until after the first trimester to reduce the chances that it will harm the baby.

If the cancer is more advanced (Stage III or IV), the situation can become very complicated. If radiation is needed to treat the cancer, it can be very hard to protect the baby. Additionally, these cancers usually require both surgery and chemotherapy, so the risk of harming the baby is much higher. There have been instances where the cancer is advanced to the point where any treatment is not likely to add more than a year or two to the woman's life. In these cases, whether or not to undergo the treatment and risk harming the baby can be an agonizing decision for both the woman and her family.

It is easier to treat a woman who is not pregnant because there is no fear of harming the fetus. But no studies have proven that ending a pregnancy in order to have cancer treatment improves the woman’s prognosis (outlook for survival).

Surgery

When possible, surgery is the first line of treatment for any woman with breast cancer, including those who are pregnant. Lumpectomy (removal of the tumor), mastectomy (removal of the entire breast), and/or axillary lymph node removal carry little risk to the fetus. But there are certain times in pregnancy when anesthesia (the drugs used to make you sleep for surgery) may be riskier for the fetus. Many doctors, such as the obstetrician, surgeon, and the anesthesiologist will need to work together to decide the best time during pregnancy to do the surgery. They can also decide which medicines and techniques are the safest for both the mother and the baby.

Mastectomy can often be used as the first treatment for early stage cancers. Women who have breast-saving surgery, like lumpectomy, often need radiation therapy afterward to reduce the chance that the cancer will come back. The need for radiation is an important issue for pregnant women when choosing between surgical options. Radiation could affect the fetus if given during the pregnancy, so it cannot be used until after the birth. Doctors don’t know how this delay may affect a woman’s risk of the cancer coming back (recurrence).

Depending on the stage of the disease, a woman may get more treatment such as chemotherapy, radiation therapy, and/or hormone therapy after surgery (this is called adjuvant treatment) to help lower the risk of the cancer coming back.

Chemotherapy

Chemotherapy, which is also called chemo, may be used as an additional (adjuvant) treatment after surgery for some earlier stages of breast cancer. It also may be used by itself for more advanced cancers.

Chemo usually is not given during the first trimester (the first 3 months of pregnancy). This is because most of the fetus's internal organs develop during the first trimester. The risk of miscarriage is also the greatest during the first trimester. The safety of chemo during this time has not been studied because of concerns about damage to the fetus.

Until recently, it was thought that all chemo drugs would harm the fetus. But studies have shown that certain chemo drugs used during the 2nd and 3rd trimesters (the 4th to 9th months of pregnancy) do not raise the risk of birth defects or stillbirths. But we still do not know whether these children have any long-term effects.

When a pregnant woman with early breast cancer needs adjuvant chemo after surgery it is usually delayed until at least the 2nd trimester. For a woman already in her 3rd trimester when the cancer is found, adjuvant chemo may be delayed until after birth. The birth may be induced (brought on) a few weeks early in these cases. Depending on the extent of the cancer, these same treatment plans may also be used for women whose disease is more advanced.

Chemo should not be given 3 to 4 weeks before delivery. This is because one side effect of chemo is that it lowers the mother's blood counts. This could cause bleeding and increase the chances of infection during birth. Holding off on chemo for the last few weeks before delivery allows the mother's blood counts to return to normal levels before childbirth.