Chapter 32: Neoplasia During Pregnancy

INTRODUCTION

Cancer complicates ~1 in every 1000 pregnancies. Of all the cancers that occur in women, less than 1% complicate pregnancies. The four cancers that most commonly complicate pregnancies are cervical cancer, breast cancer, melanoma, and lymphomas (particularly Hodgkin’s lymphoma); however, virtually every form of cancer has been reported in pregnant women (Table 32-1). In addition to cancers developing in other organs of the mother, gestational trophoblastic tumors can arise from the placenta. The problem of cancer in a pregnant woman is complex. One must take into account (1) the possible influence of the pregnancy on the natural history of the cancer, (2) effects on the mother and fetus of complications from the malignancy (e.g., anorexia, nausea, vomiting, malnutrition), (3) potential effects of diagnostic and staging procedures, and (4) potential effects of cancer treatments on both the mother and the developing fetus. Generally, the management that optimizes maternal physiology is also best for the fetus. However, the dilemma occasionally arises that what is best for the mother may be harmful to the fetus, and what is best for the fetus may compromise the ultimate prognosis for the mother. The best way to approach management of a pregnant woman with cancer is to ask, “What would we do for this woman in this clinical situation if she was not pregnant? Now, which, if any, of those plans need to be modified because she is pregnant?”

Pregnancy is associated with a number of physiologic changes that frequently result in symptoms that may make it difficult to recognize symptoms or physical findings suggestive of a neoplasm. Increased sensitivity of central chemoreceptors to Pco₂ drives an increase in minute ventilation that many women perceive as dyspnea at rest or with minimal exertion. The combination of increased total body water, decreased colloid oncotic pressure, and some obstruction of venous return from the lower extremities causes demonstrable dependent edema in more than 50% of pregnant women. Decreased gastrointestinal motility due to high serum progesterone levels and mechanical compression from an enlarging uterus cause early satiety, gastroesophageal reflux, nausea, vomiting, and constipation. Hemorrhoids develop and often bleed. Breasts enlarge and increase in density and “lumpiness.” These changes may result in delayed recognition and more advanced disease at diagnosis.