Pregnancy-associated breast cancer.

The incidence of pregnancy-associated (PA) breast cancer is rising, as childbirth is being delayed to the women's 30s and early 40s, when breast cancer is more frequent. Most reports consider "PA breast cancer" as that being diagnosed during pregnancy, or within one year after. The delay of diagnosis often seen in PA breast cancer may be due to physician oversight or reluctance to perform a biopsy during pregnancy. Two-stage procedures are favored in this setting, with biopsy under local anesthesia, then extent-of-disease work-up and definitive treatment, usually mastectomy. The use of scans for staging, and irradiation for treatment, is avoided, where possible, due to fetal risk. Likewise, chemotherapy is carefully gauged to avoid fetal damage. With these precautions, the prognosis for women with PA breast cancer, stage for stage, is similar to that of women of the same age treated at the same time period at MSKCC.