How subsequent pregnancy affects outcome in women with a prior breast cancer

Of all women who develop breast cancer, approximately 25% will do so in their premenopausal years and may still wish to bear children. The effect of a subsequent pregnancy, with its profound hormonal changes, on the outcome of the breast cancer (which itself may be hormonally responsive) is an important question. The prognosis of the original tumor also may influence the decision regarding pregnancy. Many studies have addressed these issues and have concluded that a pregnancy after a successfully treated breast cancer does not alter the outcome of that tumor, whether analyzed according to overall survival for all breast cancer patients or according to stage or axillary lymph node status. Nevertheless, it is recommended that pregnancy be delayed until 2 to 3 years after completion of treatment, especially if axillary nodes were positive for tumor--not because of any influence of the pregnancy on the malignancy, but rather to defer childbearing until after the period of greatest risk of recurrence of the tumor.