Data are insufficient to determine whether interruption of pregnancy improves the prognosis of patients who are discovered during pregnancy to have potentially curable breast cancer and who receive definitive treatment. Theoretically, the increasingly high levels of estrogen produced by the placenta as the pregnancy progresses could be detrimental to the patient with occult metastases of hormone-sensitive breast cancer. Moreover, occult metastases are present in most patients with positive axillary nodes, and treatment by adjuvant chemotherapy could be potentially harmful to the fetus, although chemotherapy may be given to pregnant women. Under these circumstances, interruption of early pregnancy seems reasonable, with progressively less rationale for the procedure as term approaches. The decision is affected by many factors, including the patient’s desire to have the baby and the generally poor prognosis when axillary nodes are involved.

Equally important is the advice regarding future pregnancy (or abortion in case of pregnancy) to be given to women of child-bearing age who have had definitive treatment for breast cancer. Under these circumstances, it must be assumed that pregnancy will be harmful if occult metastases are present, though this has not been demonstrated. Patients whose tumors are ER negative (most younger women) probably would not be affected by pregnancy. To date, no adverse effect of pregnancy on the survival of pregnant women who have had breast cancer has been demonstrated, though most oncologists advise against it.

In patients with inoperable or metastatic cancer (stage IV disease), induced abortion is usually advisable because of the possible adverse effects of hormonal treatment, radiotherapy, or chemotherapy upon the fetus.

_{Cocquyt VF et al: Better cosmetic results and comparable quality of life after skin-sparing mastectomy and immediate autologous breast reconstruction compared to breast conservative treatment. Br J Plast Surg 2003;56:462. Pubmed: 12890459}

Langer S et al: Lymphatic mapping improves staging and reduces morbidity in women undergoing total mastectomy for breast carcinoma. Am Surg 2004;70:881. Pubmed: 15529842

van der Veen P et al: Lymphedema development following breast cancer surgery with full axillary resection. Lymphology 2004;37:206.