312Long-term survival of women diagnosed with cancer during pregnancy or postpartum

Abstract

Abstract Background Cancer is the second leading cause of death in reproductive-aged women, and the incidence of pregnancy-associated cancer is rising. We assessed long-term survival of women diagnosed with cancer during pregnancy or postpartum. Methods A population-based retrospective cohort study included all reproductive-aged women (18-50 years) with a cancer diagnosis in Alberta, Canada, 2004 to 2016. Hazard ratios (HR) were calculated for all-cause and cancer-specific mortality, comparing 244 women who were diagnosed with cancer during pregnancy and 670 women diagnosed with cancer within one year postpartum, with 3,680 women diagnosed with cancer outside of these periods as the referent. Cox regression adjusted for age at cancer diagnosis, parity, cancer stage, and type of cancer. Results Rates of cancer in pregnancy and postpartum did not increase across the study period (trend p-value=0.49). Women diagnosed with cancer in pregnancy had an adjusted HR of 1.61 (95% CI 1.07-2.41) for all-cause mortality, 1.67 (95% CI 1.09-2.57) for cancer-specific mortality, relative to the referent. Those diagnosed with cancer postpartum did not have a greater risk of all-cause (HR = 1.10, 95% CI 0.80-1.50) or cancer-specific (HR = 1.15, 95% CI 0.82-1.60) mortality. Conclusions The risk of all-cause and cancer-specific mortality is increased in women diagnosed with cancer during pregnancy. Key messages Women diagnosed with cancer during pregnancy experience poorer survival than those diagnosed in postpartum or remote from a pregnancy. These findings should be used by physicians to guide care of women diagnosed with pregnancy-associated cancers.