Is it True Breast Cancer Affects Your Ability to Get Pregnant?

A breast cancer diagnosis brings with it a flood of questions and concerns, particularly for women of child-bearing age. Will cancer treatment affect my ability to conceive later? Are there any risks if I do become pregnant? Will I be able to breastfeed my baby? What if I’m already pregnant? According to an expert with Baptist Health Miami Cancer Institute, the answer to these questions is, “It depends.”

According to the American Cancer Society (ACS), many women are able to become pregnant after being treated for breast cancer. However, some treatments can make it harder to get pregnant.

Fertility must always be part of the conversation when someone has a newly diagnosed cancer, says breast surgical oncologist Jane Mendez, M.D., chief of breast surgery at Baptist Health Miami Cancer Institute.

Breast surgical oncologist Jane Mendez, M.D., chief of breast surgery at Baptist Health Miami Cancer Institute

“For anyone of child-bearing age – from their teens through their early 40s, depending on if they have had any children or not – it needs to be addressed at the very beginning of the patient’s journey,” Dr. Mendez says. “It should never be an afterthought, because in some cases cancer treatment might impact a woman’s ability to have children.”

Even male cancer patients can encounter fertility issues, adds Dr. Mendez, who notes that penile, scrotal and prostate cancer treatments affect men’s ability to father children.

How long do I have to wait to get pregnant?

For women, a number of factors need to be considered, Dr. Mendez says, including the breast cancer’s sub-type and stage, the type of treatment indicated, the patient’s age and, of course, their personal preference.

One very common issue, she says, is that it is recommended breast cancer patients who have completed their treatment avoid pregnancy for at least five years. “We don’t want the body going through any extreme hormonal changes during that time,” Dr. Mendez explains.

That’s where the patient’s preference comes into play. “But that conversation is a very different one for a woman in her 20s than it is for a woman in her late 30s or early 40s,” she says. “An older patient may decide it’s not worth the risk and better to close the door on having children. It can be an extremely challenging decision.”

What if I’m already pregnant?

For women who are already pregnant when they learn they have breast cancer, it all depends on what trimester they are when diagnosed, Dr. Mendez says. “During the first trimester is when organogenesis occurs, which is when the fetus has the highest chance of developing anomalies, so chemotherapy during that time is to be avoided.”

In the second trimester, she says it’s safe for the patient to receive chemotherapy or to undergo a lumpectomy, if indicated, without affecting the fetus. Dr. Mendez recalls one 40-year-old patient who didn’t even know she was pregnant. “I had to tell her – at the same time – that she not only had cancer but was also pregnant,” she says. “But she wanted to keep her baby. So once she was safely in her second trimester, she underwent chemotherapy and ended up giving birth to a healthy baby boy.”

In the third trimester, Dr. Mendez says it depends on the size and stage of the tumor. “As oncologists, we work very closely with the patient’s obstetrician and gynecologist to make sure the embryo or fetus is safe,” she assures. Only after pregnancy can patients start receiving radiation therapy – if that is indicated as part of their treatment, she adds.

What about Tamoxifen – can I take that?

Tamoxifen is an estrogen receptor modulator that blocks estrogen in the breast tissue so that the cancer can’t recur locally through the same mechanism. Taking it during pregnancy is to be avoided, according to Dr. Mendez.

“Tamoxifen is an estrogen antagonist in the breast, so that’s why it is used to help prevent recurrence of breast cancer. It can also help reduce the likelihood of cancer developing in the other breast, as it works on the entire ductal system,” she explains.

However, Dr. Mendez adds, Tamoxifen also acts as an estrogen agonist in other parts of the body, actually boosting estrogen production in the uterus, for example, which Dr. Mendez says can lead to uterine cancer. In addition, 25 percent of women don’t even have estrogen receptors in their cancer so Tamoxifen wouldn’t help them anyway. Plus, she adds, the drug is expensive and comes with a lot of side effects. “For those reasons, many women decide they don’t want to take it,” she says.

For women facing a breast cancer diagnosis who are concerned about their future fertility, Dr. Mendez says science has advanced “by leaps and bounds” in recent years, with an improved ability to harvest and freeze eggs, perform in-vitro fertilizations and minimize the risk to reproductive organs. She says the process of harvesting eggs for in-vitro fertilization can be expensive, however, and one that isn’t covered by many health insurance plans.

“But if you’re considering becoming pregnant, these are issues that should be discussed early on, as these things take time and coordination,” Dr. Mendez points out. “You definitely don’t want to delay your cancer treatment, so timing becomes an important factor in your decision-making.”

Is it safe for me to breastfeed?

According to the ACS, patients who have had breast surgery and/or radiation might experience problems breastfeeding from the affected breast. “This might include reduced milk production in that breast as well as structural changes that can make breastfeeding painful or make it harder for the baby to latch onto the breast,” the ACS states. Even so, it says, many women are able to breastfeed following their treatment.

The ACS adds that women who are still taking any medications to treat their breast cancer, including hormone therapy, should talk with their doctor before trying to breastfeed. “Some drugs can enter the breast milk and might affect the baby,” it says.

In the meantime, Dr. Mendez recommends that all women keep up with their monthly self-exams and annual mammograms and other screenings. Visit BaptistHealth.net/Mammogram to schedule your screening mammogram. You can also schedule your screening mammogram through PineApp.