Traditionally, cancers diagnosed during the first or second trimester of pregnancy were treated with modified radical mastectomy. Sentinel node biopsy remains a controversial procedure in pregnancy; the use of blue dye is contraindicated as it is classified as a pregnancy category C drug, and there are serious concerns about the risk of fetal irradiation with the use of radiocolloid despite some literature supporting its safety (133). Most centers do not offer breast conservation therapy based on the theory that radiation therapy should not be given to the gravid patient. In a patient diagnosed before the third trimester, waiting until after delivery may result in an unacceptable delay in the initiation of therapy and should not be encouraged. Adjuvant chemotherapy can be given after the first trimester, although many oncologists prefer not to give it to pregnant women outside of clinical trials. A classic study reported the risk of fetal malformations to be 20% during the first trimester, a rate that dropped to 1.5% during the second and third trimesters (134). Tamoxifen, however, is a class D drug and should not be given to pregnant or lactating patients with breast cancer.
2.
Localized tumors found during the third trimester of pregnancy can be managed with breast conservation therapy, with radiation delayed until after delivery, or with modified radical mastectomy. Tumors should be excised early in the third trimester using local anesthesia. If delivery is imminent, standard therapy can be performed immediately postpartum. In the patient with a viable fetus, it may be preferable to induce early labor to avoid delaying definitive cancer therapy.
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If the breast cancer is diagnosed during lactation, lactation should be suppressed and the cancer should be treated definitively.
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Advanced, incurable cancer should be treated with palliative therapy. Decisions regarding continuation of the pregnancy should be based on the therapy necessary and the desires of the mother.
Counseling regarding future childbearing is important for women who have had carcinoma of the breast. It was assumed that subsequent pregnancies would be detrimental because of the high levels of circulating estrogens, but there is no clear difference in survival for women who become pregnant after the diagnosis of breast cancer. One study evaluated the effect of subsequent pregnancy on overall survival after the diagnosis of early-stage breast cancer. Approximately 40% of the women in the study had node-positive disease. The 5-and 10-year survival rates were better in women who became pregnant than in matched pair controls who did not. This study suggests that subsequent pregnancy does not adversely affect the prognosis of early-stage breast cancer (135). A subsequent investigation demonstrated no increase in the relative risk of death for patients who gave birth more than 10 months after their initial diagnosis of cancer (136). Theoretically, it may be that only women with estrogen receptor–positive or progesterone-positive tumors would be affected deleteriously by subsequent pregnancy, but this possibility has not been studied. Because recurrences are most frequent within the first 2 to 3 years after diagnosis, patients with receptor-positive tumors and advanced-stage disease probably should wait until after that time before becoming pregnant again.
1.
Siegel R, Ward E, Brawley O, et al. Cancer statistics, 2011. CA Cancer J Clin 2011;61:212–236. http://cacancerjournal.org 2.
Anderson WF, Chu KC, Devesa SS. Distinct incidence patterns among in situ and invasive breast carcinomas, with possible etiologic implications. Breast Cancer Res Treat 2004;88:149– 159.
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American Cancer Society. Breast cancer facts and figures 2010. Atlanta: American Cancer Society.
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Greene MH. Genetics of breast cancer. Mayo Clin Proc 1997;72:54– 65.
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