Malignancies diagnosed in pregnancy

Abstract

The diagnosis of cancer is estimated to be associated with one in 1,000 pregnancies. Conversely, 0.8% of cancers are diagnosed in pregnant women. The lesions are more likely to present with advanced disease possibly as a result of greater difficulty in establishing diagnosis due to physiologic changes and symptoms of pregnancy, a hormonal milieu supportive of malignancy or immunosuppression. When compared stage for stage, the malignancies diagnosed in pregnancy are associated with the same prognosis as those identified in matched controls. The most common site diagnosed is cervix, followed by breast, skin (melanoma), lymph, ovary, colo/rectum, and thyroid. Presenting symptoms and evaluation are discussed. Treatment of these lesions has to be individualized based on the extent of the patient's disease, the gestational age of the fetus, and a consensus regarding the desire and advisability of continuing the gestation. Administration of chemotherapy during the first trimester may result in an increased risk of congenital anomalies depending on the type of agent and the timing in relationship to organogenesis. Chemotherapy is relatively safe following the completion of the process; more common side-effects have included growth retardation, postnatal developmental delay, and bone marrow suppression, with no detection of untoward effects in the majority of children. Fertility preservation following chemotherapy is related to the overall toxicity of the selected regimen and the age of the patient, with younger women experiencing a lower rate of ovarian failure. Radiation therapy is teratogenic, and its effect increases exponentially with doses above 0.1 Gy (=10 rads). Tumoricidal doses delivered to the pelvis will result in a spontaneous abortion. Other sites may be irradiated if the fetus can be effectively protected with shielding, which becomes more difficult as the pregnancy advances. Fertility should be unaffected if the ovaries are not in the irradiated field; fractionated doses in excess of 1,500 cGy or a single dose greater than 700 cGy will lead to ovarian failure. In conclusion, malignancies are rarely diagnosed in pregnancy, but present in more advanced stages of disease. The survival is comparable to matched controls. Treatment is highly individualized but can often be delivered safely during pregnancy. Awareness of the more common types of cancers presenting in pregnancy, their symptoms and diagnositic evaluation, as well as familiarity with possible treatments will allow the clinician caring for pregnant women to aid in earlier diagnosis and expedite referral for counseling and treatment.