CANCER OF THE BREAST IN PREGNANCY

Each year carcinoma of the breast affects more than 175,000 women in the United States. The majority of these cases are stage I or II breast cancer. Local therapy combined with systemic adjuvant therapy frees these patients of disease and provides many with long-term survival. Approximately 25% of all breast cancer patients develop their malignancy while premenopausal-during their childbearing years.(2) Breast cancer is the second most common malignancy during pregnancy, occurring in 10 to 30 patients per 100,000 pregnancies. The current trend in the United States of delaying pregnancy until a later age may increase the proportion of women who develop breast cancer during pregnancy. An individual clinician's experience with gestational breast cancer is usually limited to a handful of cases. Unfortunately, the management strategy is often rooted in obsolete teachings and philosophies. In 1880, Samuel Gross stated that the growth of gestational breast cancer was rapid and its course excessively malignant. Haagensen and Stout(5) declared in 1943 that no patient with breast cancer diagnosed during pregnancy should undergo surgery because these cases were incurable. A survey by Saunders and Baum(8) revealed that general practitioners and general surgeons thought pregnancy conferred a worse prognosis. The reasons included excess inflammatory breast carcinoma, hormonal changes of pregnancies, inherent aggressiveness of these tumors, and relative youth of the patients. None thought diagnostic delay contributed to the poor prognosis of these patients. In contrast, obstetricians did not believe these patients did worse, and they did not believe therapeutic abortion was mandatory. Opinions varied concerning subsequent preg- nancy, the effect of chemotherapy on fertility, and abortion. Thus, the idea appears widespread that breast cancer in a pregnant woman is in some way a different disease from breast cancer in a nonpregnant woman. This attitude has abated, and it has been shown that the outcome in patients with concurrent breast cancer and pregnancy is the same as in their nonpregnant counterparts when matched for age and stage of disease.(9) Yet a woman diagnosed with breast cancer during pregnancy or lactation is more Likely to fare worse than a woman of a similar age who is not pregnant. Why should this be so?