Is chemotherapy always required for cancer in pregnancy? An observational study

Cancer in pregnancy is relatively rare, but the incidence is increasing. Several studies show that cytotoxic agents are safe to use in pregnancy from the second trimester onwards.

This study assesses the maternal and foetal outcomes of cancers diagnosed during pregnancy. In particular, it focuses on a subset of women who elected to defer systemic chemotherapy until after delivery. This study examines if all cancers need to be treated during pregnancy or if, in certain cases, treatment can be safely deferred until after full-term delivery.

This is a retrospective observational study of women diagnosed with cancer during pregnancy in an Irish cancer centre over a 27-year period. All women diagnosed with cancer during pregnancy who were referred to the medical oncology department for consideration of chemotherapy were included in this study. Medical and pharmacy records were extensively reviewed.

Twenty-five women were diagnosed with cancer in pregnancy and referred to medical oncology for consideration of systemic chemotherapy. Sixteen women (64%) commenced chemotherapy during pregnancy, seven women (28%) did not receive chemotherapy while pregnant, but commenced treatment immediately after delivery, and two (8%) did not receive any systemic chemotherapy at all. Of the seven women who commenced chemotherapy after delivery, six (85.7%) were diagnosed before 30/40 gestation. There were three cases of Hodgkin's lymphoma, two breast cancers and one ovarian cancer. After a median follow-up of 12 years, all six mothers remain disease-free.

This study identified a select cohort of patients that did not receive chemotherapy during pregnancy. There were no adverse outcomes to mothers due to delayed treatment.