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, treatment may be modified during pregnancy.

• Rectal cancer: Removal of the uterus (hysterectomy) may be required. In such cases, cesarean delivery may be done as early as 28 weeks of pregnancy to save the baby.
• Cervical cancer: If the 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. Cesarean delivery is usually done, but sometimes vaginal delivery is possible.
• Other gynecologic cancers: Cancer of the ovaries is hard to detect during pregnancy. It may require immediate treatment (removal of both ovaries). Cancer of the uterus (endometrial cancer) or fallopian tubes rarely occurs during pregnancy.
• Breast cancer: 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.

Last full review/revision December 2008 by Sean C. Blackwell, MD