Breast cancer and pregnancy.

Breast cancer occurring during pregnancy is a relatively rare clinical situation that may present many difficult medical and psychosocial problems. Its diagnosis is commonly delayed, largely related to breast changes which normally occur during pregnancy. When matched for age and stage of disease, patients with breast cancer during pregnancy have the same prognosis as nonpregnant patients; the disease stage at diagnosis is the most important predictor of survival. Breast cancer diagnosed during pregnancy should be treated according to the same principles applied in nonpregnant patients. Termination of pregnancy does not appear to improve survival and thus, decisions regarding termination of pregnancy should be based on the desires of the patient, along with the urgency for radiation or chemotherapy that could potentially be harmful to the fetus. Subsequent pregnancy following the diagnosis of breast cancer does not have a known detrimental effect on survival, although it is usually wise to discourage pregnancy for the first few years following the diagnosis of breast cancer.