Breast cancer in pregnancy: a literature review.

Hypothesis: Breast cancer in pregnancy will increase as more women postpone childbearing until later in life.

Objective: To review the literature on diagnosis, staging, treatment, and prognosis.

Design And Methods: Articles were obtained from MEDLINE (1966-present) using the keywords breast, cancer, carcinoma, and pregnancy. Additional articles were sought using the references of those obtained. A total of 171 articles were found, 125 in English. More than 100 were reviewed, including 7 prospective and 40 retrospective studies, 6 case reports, and at least 47 review articles on various aspects of pregnancy and cancer. Data extraction was performed by 1 reviewer.

Results: Diagnostic delays are shorter than in the past but remain common. Mammography has a high false-negative rate during pregnancy. Biopsy or needle aspiration are needed for diagnosis and cannot be postponed until after delivery. Pregnancy-associated cancers tend to occur at a later stage and be estrogen receptor-negative. However, they carry a similar prognosis to other breast cancers when matched for stage and age. Although modified radical mastectomy is the traditional treatment, breast-conserving therapy is increasingly common. Therapeutic radiation is contraindicated, but chemotherapy is relatively safe after the first trimester. Tamoxifen should be avoided in the first trimester and possibly beyond.

Conclusions: Physicians should perform a thorough breast examination at the first prenatal visit and maintain a high index of suspicion for cancer. Patients who wish to continue their pregnancies have a growing array of treatment options.