BREAST CANCER DURING PREGNANCY
Pregnancy-associated breast cancer (PABC) or gestational breast cancer is defined as breast cancer that is diagnosed during pregnancy and the 12 months following delivery. Breast cancer is one of the most common cancers diagnosed during pregnancy. Given that many women are delaying childbearing (1), and age is a risk factor for breast cancer, the incidence of PABC appears to be on the rise. A study from the Swedish National Health Registry showed that the incidence of PABC increased from 16 to 37.4 per 100,000 deliveries between 1963 and 2002 (2). Factors associated with a diagnosis of breast cancer included age 35 years or older, women with private insurance, and women who delivered in an urban teaching hospital (3).
The most common clinical presentation of PABC is a painless mass that is either self-detected or noted on clinical exam. The duration of symptoms was significantly longer in patients with PABC compared to their nonpregnant counterparts in a study from Japan. Physiologic changes in a pregnant woman’s breast, especially in women younger than 30 years; physician familiarity with PABC; as well as socioeconomic and cultural factors may contribute to delays in diagnosis (4).
Although the majority of breast masses during pregnancy are benign, a breast mass that does not resolve within 2 weeks requires further investigation (2). Any clinically suspicious breast mass should be biopsied for a definitive diagnosis whether a patient is pregnant or not. Even though a number of small studies have shown the accuracy of fine-needle aspiration (FNA) in the diagnosis of PABC, a core or excisional biopsy of the breast lesion is necessary to make a diagnosis of invasion (5) (Fig. 30-1).
Algorithm for the evaluation and treatment of a suspicious breast mass during pregnancy. CXR, chest x-ray; US, ultrasound.
Two large surgical series of pregnant patients who had general anesthesia for a variety of underlying medical problems failed to demonstrate an increase in the risk of congenital malformations as compared with pregnant women who did not undergo surgery (6,7). Ultimately, the least-invasive and most technically accurate method(s) available should be utilized to determine the nature of a breast mass in a pregnant woman.
Mammography and Ultrasound
Mammography can be safely ordered during pregnancy with abdominal shielding. The estimated fetal radiation exposure was 0.4 mrad, well below the 5-rad threshold for fetal malformations (2). Ultrasound imaging is a preferred choice due to lack of radiation exposure and the better sensitivity for detecting breast masses in young patients. Ultrasound is also a valuable tool ...