Because cancer tends to be life threatening and because delays in treatment may reduce the likelihood of successful treatment, cancer is usually treated the same way whether the woman is pregnant or not. Some of the usual treatments (surgery, chemotherapy drugs, and radiation therapy) may harm the fetus. Thus, some women may consider abortion. However, treatments can sometimes be timed so that risk to the fetus is reduced.
In some cancers (such as rectal and gynecologic cancers), treatment may be modified during pregnancy.
Rectal cancer may require removal of the uterus (hysterectomy) to be sure that all the cancer is removed. In such cases, cesarean delivery may be done as early as 28 weeks of pregnancy so that hysterectomy can be done and aggressive cancer treatment can be started.
Pregnancy does not appear to worsen cervical cancer.
If pregnant women have an abnormal Papanicolaou (Pap) test, doctors examine the cervix with a binocular magnifying lens (colposcopy). Colposcopy does not harm the fetus or affect the pregnancy. Doctors usually consult an expert when doing the colposcopy to help them determine whether they should take a sample of any abnormal tissue to be examined under a microscope (biopsy). A cervical biopsy is not routinely done in pregnant women because bleeding and preterm labor are risks.
If cervical cancer is in a very early stage, treatment is usually postponed until after delivery.
If more advanced cervical cancer is detected early in pregnancy, it is usually treated immediately as needed.
If it is diagnosed late in pregnancy, doctors explain the risk of postponing treatment so that women can decide whether to postpone treatment until after the fetus is mature enough to be delivered. However, if cancer is advanced, cesarean delivery is done, followed by hysterectomy.
Other gynecologic cancers
Cancer of the ovaries is hard to detect during pregnancy. It may require immediate treatment (removal of both ovaries).
Breast cancer is hard to detect during pregnancy because the breasts enlarge. If any lump is detected, doctors evaluate it.
Usually, breast cancer should be treated immediately.
Leukemia and Hodgkin lymphoma
Leukemia and Hodgkin lymphoma are uncommon during pregnancy. The anticancer drugs typically used to treat these cancers increase the risk of miscarriage and birth defects.
Because leukemias can become fatal rapidly, women are treated as soon as possible, without waiting to allow the fetus to mature.
If Hodgkin lymphoma is present only in areas above the diaphragm (the muscle that separates the chest from the abdomen), radiation therapy may be used, and the abdomen is shielded to protect the fetus from radiation. If lymphoma is present in areas below the diaphragm, doctors may recommend abortion.