Cancer of unknown primary during pregnancy: An exceptionally rare coexistence

Abstract

Background: Cancer in pregnancy is a rare disease with breast cancer, cervical cancer, melanoma and Hodgkin's disease to be the most commonly diagnosed malignancies during gestation. Cancer of unknown primary (CUP) is a wellrecognized clinical disorder where the primary site can not be identified after a standard diagnostic approach. CUP in pregnancy has rarely been described. Materials and Methods: We searched MEDLINE and contacted cancer Centers in Europe, United States and Australia where patients with CUP or pregnant patients with cancer were diagnosed and treated. Results: Since 1976 we identified 18 pregnant women with CUP in a median gestational age of 34 weeks. Most of these patients were diagnosed with poorly-differentiated histology, had poor response to systemic treatment and a median maternal survival of 8 months. Seventy-two percent of mothers have died, while 80% of the newborns were alive and healthy. Almost one fourth of placentas examined showed metastatic disease. Conclusion: CUP during pregnancy is a very rare coexistence, usually has an aggressive disease with poor response to chemotherapy and a dismal prognosis. Both obstetricians and oncologists should be aware of this rare condition.