Pregnancy after cancer: Timing is everything

Abstract

Cancer is a relatively infrequent diagnosis in young adults and yet, when it occurs, the medical and psychosocial impact can be profound. Beyond individual mortality, cancer and cancer treatment may threaten or thwart the ability of young survivors to have children. As the field of cancer survivorship has grown, there has been increasing awareness of the risk of infertility after cancer, and research programs and policy initiatives have focused on addressing fertility at diagnosis and developing fertility preservation opportunities for this population. 1 Studies of birth outcomes of pregnancies among childhood cancer survivors have suggested an increased risk of low-birth-weight and preterm births. 2,3 However, relatively little prior work has focused on pregnancy outcomes in adult cancer survivor populations.In this issue of Cancer, Hartnett and colleagues seek to address this gap and build on the existing literature by evaluating fetal outcomes in a large population-based sample of women with a history of cancer. 4 They present an analysis of first subsequent pregnancy outcomes among women who were diagnosed with cancer between ages 20 and 45 years in 3 US states using cancer registry data linked to birth registries. The investigators compare this large group of survivors' pregnancy outcomes with those of matched controls without cancer history. Their main findings suggest that timing of pregnancy in cancer survivors may be critical to the early health of the subsequent progeny. First, early pregnancy after cancer treatment was associated with nearly 2 and 3 times the risk of preterm birth after starting chemotherapy without or with radiation, respectively. However, women who had later conception, with the exception of those with a history of cervical cancer, did not appear to be at greater risk than controls. The risk of low birth weight was similarly associated with conception closer to treatment in the survivor population.Hampering clear understanding of the potential contributors and mechanisms to account for these findings is a lack of information in the report by Hartnett regarding stage of cancer and whether women were receiving ongoing therapy (eg, continued chemotherapy for leukemia or hormone therapy for breast cancer during early or later pregnancy) or continued to have physiologic stressors from early complications of treatment, or had progressive cancer or early recurrence. Similar to other population-based reports of nonpregnant women of reproductive age in the United States, the most common cancers observed in this study were breast, melanoma, thyroid, Hodgkin lymphoma, and cervical, the majority of which would be treated for cure. 5 In addition, whereas most therapies for early stage or curable disease would be completed within a few months of diagnosis, certainly some pregnancies considered in the analysis by Hartnett and colleagues would have been among women who were receiving antineoplastic therapy at conception and/or in the peripartum period, including those living with advanced cancer or ...