Discovering you are pregnant may be a blessing, but the seemingly endless check-ups and health concerns can transform the condition into a stressful chore. This challenge is greatly magnified by a cancer diagnosis while you’re pregnant. Besides the parade of medical professionals, the difficult choices made by all cancer patients are doubled when the risk to the fetus is included. So what should you know about pregnancy and cancer?
An Uncommon Dilemma
Not only does pregnancy not cause cancer, but it may actually reduce a woman’s risk. Breast cancer has been linked to hormones produced by the ovaries. Because pregnancy and breastfeeding reduce the number of menstrual cycles a woman has during her lifetime, they also reduce exposure to endogenous hormones. Women who have their first child after the age of 30 have twice the risk of developing breast cancer as women who give birth while still teenagers. Risk also declines for women who have given birth to more than five children. Since the trend in many places is to have fewer children later in life, it makes sense that the risk of breast cancer will be similarly elevated.
The good news is that a cancer diagnosis in pregnant women is very rare –– around one out of 1,000. The bad news is the rate is rising. This isn’t connected to increased cancer rates. Rather, it’s because the risk of developing cancer increases as we age. Worse, one of the more common cancers, melanoma, is one of the few capable of spreading to the fetus. Although skin cancer rates are rising, it is usually easily treatable. Leukemia has a less optimistic prognosis, and, while rare, it is another form of cancer that can spread to the fetus.
The danger is that the symptoms for certain cancers are identical to the ones for pregnancy. For example, while changes in breast tissue are a normal part of pregnancy, they can also indicate malignancy. Vaginal bleeding can sometimes occur with pregnancy, but it is also a symptom of cervical cancer. Communication is vital, and so is testing––especially if you have a family history of breast, skin, or other cancers. Diagnosis may be made from a biopsy or using ultrasound or MRIs, all of which are safe and pose a very low risk to the fetus. Sometimes an X-ray is required. This is relatively low risk, although you should wear a lead covering across your abdomen to protect the fetus. Delivering up to 300 times the radiation of an X-ray, the CT scan should only be used if the cancer is potentially life threatening as it poses the greatest risk to the fetus. High levels of radiation exposure before the eighth week of pregnancy have the greatest risk of producing malformation of the fetus.
Treatment options vary and are sometimes complicated by pregnancy. Past the first trimester, surgery is considered low risk. Radiation treatment and chemotherapy, which kills cancer cells with toxic chemicals, pose a danger to the fetus and have an elevated risk for pregnant women. Again, the fetal risk is reduced in the second or third trimester.
Because of their low molecular weight, chemotherapeutic agents can cross the placenta. In animal studies, they were connected with fetal abnormalities (there’s little data on pregnant women since the treatment is so risky and cancer so rare in pregnancy). Dangers from radiation and chemotherapy don’t abate once a mother has given birth––if she opts for this course of treatment, she should avoid breastfeeding.
Still, just as the general prognosis for cancer survival has improved, treatment for pregnant women battling the disease has improved as well. In some cases, treatment can be delayed until you give birth. In others, labor may be induced early. Either way, many cancer patients have survived treatment and given birth to a healthy baby. Work with your healthcare team to find a course of treatment that’s best for you and your baby.
Written by John Bankston